DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT Water Quality Control Commission PRIMARY DRINKING WATER REGULATIONS 5 CCR 1003-1 [Editor’s Notes follow the text of the rules at the end of this CCR Document.] Article 1 General Requirements [Eff. 09/30/2007]

1.1 Authority

Sections 24-4-104, 24-4-105, 25-1.5-101, 25-1.5 Part 2, 25-1-108, 25-1-109, 25-1-114, and 25-1-114.1, Colorado Revised Statutes

1.1.1 Purpose

The purpose of the Colorado Primary Drinking Water Regulations is to assure the safety of public drinking water supplies, and to enable the State of Colorado to assume responsibility for enforcing the standards established by the federal Safe Drinking Water Act (*Public Law 93-523), as amended. The Water Quality Control Commission, pursuant to Part 2, Article 1.5 of Title 25, Colorado Revised Statutes, has promulgated the Colorado Primary Drinking Water Regulations.

1.2 Applicability

The Colorado Primary Drinking Water Regulations shall apply to each public water system, unless the public water system meets all of the following conditions:

(a) Consists only of distribution and storage facilities (and does not have any collection and treatment facilities)

(b) Obtains all of its water from, but is not owned or operated by, a public water system to which such regulations apply (c) Does not sell water to any person, and (d) Is not a carrier which conveys passengers in interstate commerce.

1.3 Reserved

1.4 Effective Date

The Colorado Primary Drinking Water Regulations shall take effect twenty days after the date of publication thereof in the Colorado Register as finally adopted by the Water Quality Control Commission.

1.5 Definitions of General Applicability

1.5.1 Introduction

Definitions of general applicability to the Colorado Primary Drinking Water Regulations promulgated by the Department pursuant to sections 25-1.5-201 through 25-1.5-208, 25-1-108 through 25-1-109, 25-1- 114, and 25-1-114.1, Colorado Revised Statutes, are set forth in section 1.5.2 of the Colorado Primary Drinking Water Regulations, and shall be liberally construed to protect the quality of drinking water supplied to the public and the public health.

1.5.2 Definitions

As used in the Colorado Primary Drinking Water Regulations :

(1) 4-Log Treatment of Viruses is achieved by using inactivation and removal, or a Department- approved combination of 4-log virus inactivation and removal.

(2) Act means the federal public health service act, as amended by the Safe Drinking Water Act, Public Law 93-523.

(3) Action level is the concentration of lead or copper in water specified in section 2.7, which determines, in some cases, the treatment requirements contained in Article 8 that a water system is required to complete.

(4) Assessment Source Water Monitoring can be required by the Department and may compliment triggered source water monitoring and targets higher risk groundwater systems (GWS)s by requiring that the GWS take up to 12 monthly source water samples and analyze for one or more of the GWR fecal indicators (E. coli, enterococci, or coliphage).

(5) Average residence time is a point in the distribution system where treated water has been in the system for approximately half of its longest or maximum time in the system, as measured by water transport time. With respect to section 7.6, sample locations between 25 and 75 percent of the maximum are considered to be representative of average residence time, provided that in total, the average of the selected locations approximate 50 percent of the maximum residence time and take into account population densities and their locations.

(6) Bag filters are pressure –driven separation devices that remove particulate matter larger than 1 micrometer using an engineered porous filtration media. They are typically constructed of a non- rigid, fabric filtration media housed in a pressure vessel in which the direction of flow is from the inside of the bag to outside.

(7) Bank filtration is a water treatment process that uses a well to recover surface water that has naturally infiltrated into groundwater through a river bed or bank(s). Infiltration is typically enhanced by the hydraulic gradient imposed by a nearby pumping water supply or other well(s).

(8) Best available technology or BAT means the best technology, treatment techniques, or other means, which the EPA Administrator finds, after examination for efficacy under field conditions and not solely under laboratory conditions, are available (taking cost into consideration). For the purposes of setting maximum contaminant levels (MCLs) for synthetic organic chemical contaminants, any BAT must be at least as effective as granular activated carbon.

(9) Cartridge filters are pressure-driven separation devices that remove particulate matter larger than 1 micrometer using an engineered porous filtration media. They are typically constructed as rigid or semi-rigid, self-supporting filter elements housed in pressure vessels in which flow is from the outside of the cartridge to the inside.

(10) Certified cross-connection control technician means a person who has responsibility for the testing, operation and maintenance of cross-connection control devices and is certified in accordance with the provisions of Article 12.

(11) Certified laboratory means a laboratory certified by the State of Colorado for analysis of drinking water.

(12) Coagulation means a process using coagulant chemicals and mixing by which colloidal and suspended materials are destabilized and agglomerated into flocs.

(13) Combined distribution system is the interconnected distribution system consisting of the distribution systems of wholesale systems and of the consecutive systems that receive finished water.

(14) Commencement of construction means commencement of the physical effort to construct a project, excluding engineering, architectural, legal, fiscal and economic investigations, studies, and completion of plans and specifications, and surveys. Included in such effort, but not by way of limitation, are site clearance, excavation, construction, and the establishment of an office or construction building on site.

(15) Community water system means a public water system that serves at least 15 service connections used by year-round residents or that regularly serves at least 25 year-round residents.

(16) Compliance cycle means the nine-year calendar year cycle during which public water systems must monitor. Each compliance cycle consists of three three-year compliance periods. The first calendar year cycle begins January 1, 1993 and ends December 31, 2001; the second begins January 1, 2002 and ends December 31, 2010; the third begins January 1, 2011 and ends December 31, 2019.

(17) Compliance gross alpha means the analytical gross alpha minus radon and uranium, but including radium-226. This value is compared to the gross alpha maximum contaminant level (MCL) to determine compliance.

(18) Compliance Monitoring as referenced in Article 13 is required by all groundwater systems (GWSs) that provide at least 4-log treatment of viruses using chemical disinfection, membrane filtration, or a State-approved alternate treatment technology. Disinfectant residual and TCR monitoring is required to demonstrate treatment effectiveness.

(19) Compliance period means a three-year calendar year period within a compliance cycle. Each compliance cycle has three three-year compliance periods. Within the first compliance cycle, the first compliance period ran from January 1, 1993 to December 31, 1995; the second from January 1, 1996 to December 31, 1998; the third from January 1, 1999 to December 31, 2001.

(20) Comprehensive performance evaluation (CPE) is a thorough review and analysis of a treatment plant's performance capabilities and associated administrative, operation and maintenance practices. It is conducted to identify factors that may be adversely impacting a plant's capability to achieve compliance and emphasizes approaches that can be implemented without significant capital improvements. For purposes of compliance with Article 7, the comprehensive performance evaluation must consist of at least the following components: Assessment of plant performance; evaluation of major unit processes; identification and prioritization of performance limiting factors; assessment of the applicability of comprehensive technical assistance; and preparation of a CPE report.

(21) Comprehensive technical assistance (CTA) means the performance improvement phase that is implemented if the Comprehensive Performance Evaluation (CPE) results indicate improved performance potential. The CTA is a combination of utilizing CPE results as a basis for follow-up, implementing process control priority-setting techniques and maintaining long-term involvement to systematically train staff and administrators.

(22) Confluent growth , in the context of bacterial testing, means a continuous bacterial growth covering the entire filtration area of a membrane filter, or a portion thereof, in which bacterial colonies are not discrete.

(23) Consecutive system is a public water system that receives some or all of its finished water from one or more wholesale systems. Delivery may be through a direct connection or through the distribution system of one or more consecutive systems.

(24) Construction means the erection, building, modification, reconstruction, improvement or expansion of waterworks.

(25) Contaminant means any physical, chemical, biological, or radiological substance or matter in water.

(26) Control device means any Department-approved cross-connection control device or method installed on service connections to a premises or auxiliary system.

(27) Conventional filtration treatment means a series of processes including coagulation, flocculation, sedimentation, and filtration resulting in substantial particulate removal.

(28) Corrosion inhibitor means a substance capable of reducing the corrosivity of water toward metal plumbing materials, especially lead and copper, by forming a protective film on the interior surface of those materials.

(29) Cross-connection means any unprotected actual or potential connection or structural arrangement between a public or a consumer's potable water system and any other source or system through which it is possible to introduce into any part of the potable system any used water, industrial fluid, gas, or substance not meeting drinking water requirements in these regulations. By-pass arrangements, jumper connections, removable sections, swivel or changeover devices and other temporary or permanent devices through which or because of which "backflow" can or may occur are considered to be cross-connections.

(30) Cross-connection-controlled means having an accepted cross-connection control device properly installed and maintained. This device shall continuously provide cross-connection protection commensurate with the degree of hazard.

(31) CT or CTcalc is the product of "residual disinfectant concentration" (C) in milligrams per liter (mg/L) determined before or at the first customer, and the corresponding "disinfectant contact time" (T) in minutes, i.e., "C" x "T".

(32) Customer means, for the purpose of section 9.1, billing units or service connections to which water is delivered by a community water system.

(33) Department as used in the Colorado Primary Drinking Water Regulations , means the Colorado Department of Public Health and Environment as created by section 25-1-102(1), Colorado Revised Statutes.

(34) Detected means, for the purpose of section 9.1, at or above the levels prescribed by Article 10 for inorganic chemical contaminants, volatile organic chemical contaminants, synthetic organic chemical contaminants, disinfection byproducts and for radioactive contaminants.

(35) Diatomaceous earth filtration means a process resulting in substantial particulate removal in which (1) a precoat cake of diatomaceous earth filter media is deposited on a support membrane (septum), and (2) while the water is filtered by passing through the cake on the septum, additional filter media known as body feed is continuously added to the feed water to maintain the permeability of the filter cake.

(36) Direct filtration means a series of processes including coagulation and filtration but excluding sedimentation resulting in substantial particulate removal.

(37) Disinfectant means any oxidant, including but not limited to chlorine, chlorine dioxide, chloramines, ozone, and ultraviolet light, added to water in any part of the treatment or distribution process, that is intended to kill or inactivate pathogenic microorganisms.

(38) Disinfectant contact time ("T" in CT calculations) means the time in minutes that it takes for water to move from the point of disinfectant application or the previous point of disinfectant residual measurement to a point before or at the point where residual disinfectant concentration ("C") is measured. Where only one "C" is measured, "T" is the time in minutes that it takes for water to move from the point of disinfectant application to a point before or at where residual disinfectant concentration ("C") is measured. Where more than one "C" is measured, "T" is (a) for the first measurement of "C", the time in minutes that it takes for water to move from the first or only point of disinfectant application to a point before or at the point where the first "C" is measured and (b) for subsequent measurements of "C", the time in minutes that it takes for water to move from the previous "C" measurement point to the "C" measurement point for which the particular "T" is being calculated.

(39) Disinfection means a process that inactivates pathogenic organisms in water by chemical oxidants, ultraviolet light, or equivalent agents.

(40) Disinfection profile is a summary of daily Giardia lamblia inactivation through the treatment plant. For systems that use chloramines, ozone, or chlorine dioxide for primary disinfection this also includes a summary of daily virus inactivation through the treatment plant.

(41) Domestic or other non-distribution system plumbing problem means a coliform contamination problem in a public water system with more than one service connection that is limited to the specific service connection from which the coliform-positive sample was taken.

(42) Dose equivalent means the product of the absorbed dose from ionizing radiation and such factors as account for differences in biological effectiveness due to the type of radiation and its distribution in the body as specified by the International Commission on Radiological Units and Measurements (ICRU).

(43) Dual sample set is a set of two samples collected at the same time and same location, with one sample analyzed for TTHM and the other sample analyzed for HAA5. Dual sample sets are collected for the purposes of conducting an Initial Distribution System Evaluation (IDSE) under section 7.7 and determining compliance with the TTHM and HAA5 MCLs under Section 7.8.

(44) EPA means the United States Environmental Protection Agency.

(45) EPA administrator means the administrator of the United States Environmental Protection Agency.

(46) Effective corrosion inhibitor residual , for the purpose of Article 8 only, means a concentration sufficient to form a passivating film on the interior walls of a pipe.

(47) Emergency source/connection means a water facility that is only used as the result of extreme circumstances, and is otherwise kept offline. These facilities may be either connected or disconnected from a treatment plant/distribution system.

(48) Enhanced coagulation means the addition of sufficient coagulant for improved removal of disinfection byproduct precursors by conventional filtration treatment.

(49) Enhanced softening means the improved removal of disinfection byproduct precursors by precipitative softening.

(50) Enforcement order means an order issued for the purpose of notifying a public water system that it is in violation of the Colorado Primary Drinking Water Regulations , or for the purpose of requiring a public water system to cease such violations. Enforcement orders may prescribe corrective measures necessary to achieve compliance with the Colorado Primary Drinking Water Regulations .

(51) Exemption means a form of temporary relief from a maximum contaminant level in finished potable water granted to a public water system pending installation and operation of treatment facilities, acquisition of an alternate source, or completion of improvements in treatment processes to bring the system into compliance with the Colorado Primary Drinking Water Regulations .

(52) Filter profile is a graphical representation of individual filter performance, based on continuous turbidity measurements or total particle counts versus time for an entire filter run, from startup to backwash inclusively, that includes an assessment of filter performance while another filter is being backwashed.

(53) Filtration means a process for removing particulate matter from water by passage through porous media.

(54) Finished water is water that is introduced into the distribution system of a public water system and is intended for distribution and consumption without further treatment, except as treatment necessary to maintain water quality in the distribution system (e.g., booster disinfection, addition of corrosion control chemicals).

(55) First customer means the first potable water service connection downstream of the point where complete water treatment, including disinfection contact time, has occurred. Typically, the first customer is the water treatment plant’s domestic water system.

(56) First draw sample , as it applies to section 8.7, means a one-liter sample of tap water that has been standing in plumbing pipes for at least six hours and is collected without flushing the tap.

(57) Flocculation means a process to enhance agglomeration or collection of smaller floc particles into larger, more easily settled particles through gentle stirring by hydraulic or mechanical means.

(58) Flowing stream is a course of running water flowing in a definite channel.

(59) GAC10 means granular activated carbon filter beds with an empty-bed contact time of ten minutes based on average daily flow and a carbon reactivation frequency of every 180 days, except that the reactivation frequency for GAC10 used as a best available technology for compliance with Section 7.8 MCLs under Section 2.4 shall be 120 days.

(60) GAC20 means granular activated carbon filter beds with an empty-bed contact time of 20 minutes based on average daily flow and a carbon reactivation frequency of every 240 days.

(61) Gross alpha particle activity means the total radioactivity due to alpha particle emission as inferred from measurements on a dry sample.

(62) Gross beta particle activity means the total radioactivity due to beta particle emission as inferred from measurements on a dry sample.

(63) Groundwater means any water under the surface of the ground being neither "surface water" nor "groundwater under the direct influence of surface water".

(64) Groundwater System (GWS) means a public water system (PWS) that uses groundwater not under the direct influence of surface water as its sole source of water and does not include PWSs that combine all of their groundwater with surface water or groundwater under the direct influence of surface water prior to treatment.

(65) Groundwater under the direct influence of surface water (GWUDI) means any water beneath the surface of the ground with:

(i) Significant occurrence of insects or other macro-organisms, algae, or large-diameter pathogens such as Giardia lamblia or Cryptosporidium ; or (ii) Significant and relatively rapid shifts in water characteristics such as turbidity, temperature, conductivity, or pH, which closely correlate to climatological or surface water conditions.

(66) Haloacetic acids (HAA5) means the sum of the concentrations in milligrams per liter of the haloacetic acid compounds (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid), rounded to two significant figures after addition.

(67) Halogen means one of the chemical elements chlorine, bromine or iodine.

(68) Hydrogeologic Sensitivity Assessment (HSA) is a determination of whether groundwater systems obtain water from hydrogeologically sensitive settings. Sensitive settings are described as: (1) aquifers that exists in an area with high population densities combined with onsite wastewater treatment systems; (2) aquifers in which viruses may travel faster and further than bacteria (e.g. alluvial or sand aquifers), (3) shallow, unconfined aquifers; (4) aquifers with thin or absent soil cover; (5) areas where wells have previously been identified as having fecal contamination; and (6) sensitive aquifers.

(69) Inactivation of pathogens using a chemical disinfectant (for example chorine, chloramine, ozone) is based on the CT concept where C is the measured concentration of the chemical disinfectant residual and T is the contact time between the point of application of the disinfectant and the point where the disinfectant residual is measured. The point where the residual is measured must be before or at the first service connection or customer.

(70) Initial distribution system evaluation (IDSE) means a study and analysis of data to determine locations with representative high TTHM and HAA5 concentrations throughout a system’s distribution system.

(71) Initial compliance period means the first full three-year compliance period which begins at least 18 months after promulgation; except for inorganic, volatile organic and synthetic organic contaminants, initial compliance period means the first full three-year compliance period after promulgation; or the first full three-year compliance period after the effective date of the regulation as stipulated by the rule.

(72) Integrated system means two or more public water systems, one of which is a wholesale system, whose distribution systems are physically connected and who have agreed to operate using a common set of standards that the wholesale system establishes for the purposes of maintaining and protecting drinking water quality.

(73) Lake/reservoir refers to a natural or man made basin or hollow on the Earth's surface in which water collects or is stored that may or may not have a current or single direction of flow.

(74) Lead free , for purposes of Article 8, means:

(i) When used with respect to solders and flux, refers to solders and flux containing not more than 0.2 percent lead (ii) When used with respect to pipes and pipe fittings, refers to pipes and pipe fittings containing not more than 8.0 percent lead, or (iii) When used with respect to plumbing fittings and fixtures intended by the manufacturer to dispense water for human ingestion, refers to fittings and fixtures that are in compliance with standards established in accordance with 42 U.S.C. 300g-6(e).

(75) Lead service line means a service line made of lead, which connects the water main to the building inlet and any lead pigtail, gooseneck or other fitting, which is connected to such lead line.

(76) Legionella means a genus of bacteria, some species of which have caused a type of pneumonia called legionnaires disease.

(77) Liquids from dewatering processes means a stream of liquids generated from a unit used to concentrate solids for disposal. Processes may consist of centrifuges, filter presses, belt presses, vacuum filters, monofills, or other sludge concentrating equipment. Such equipment may be used to dewater sludge from treatment units used in recycling processes or sludge from units found in the primary processes.

(78) Locational running annual average (LRAA) is the average of sample analytical results for samples taken at a particular monitoring location during the previous four calendar quarters.

(79) Man-made beta particle and photon emitters means all radionuclides emitting beta particles and/or photons listed in Maximum Permissible Body Burdens and Maximum Permissible Concentration of Radionuclides in Air or Water for Occupational Exposure , NBS Handbook 69, except the daughter products of thorium-232, uranium-235 and uranium-238.

(80) Maximum contaminant level (MCL) means the maximum permissible level of a contaminant in water, which is delivered to any user of a public water system.

(81) Maximum contaminant level goal or MCLG means the maximum level of a contaminant in drinking water at which no known or anticipated adverse effect on the health of persons would occur, and which allows an adequate margin of safety. Maximum contaminant level goals are non- enforceable health goals.

(82) Maximum residence time is a point in the distribution system where the treated water has been in the system for the longest or maximum time, as measured by water transport time. For purposes of section 7.6, sample locations between 90 and 100 percent of the maximum are considered to be representative of maximum residence time.

(83) Maximum residual disinfectant level (MRDL) means a level of a disinfectant added for water treatment that may not be exceeded at the consumer's tap without an unacceptable possibility of adverse health effects.

(84) Maximum residual disinfectant level goal (MRDLG) means the maximum level of a disinfectant added for water treatment at which no known or anticipated adverse effect on the health of persons would occur, and which allows an adequate margin of safety. MRDLGs are non- enforceable health goals and do not reflect the benefit of the addition of the chemical for control of waterborne microbial contaminants.

(85) Maximum total trihalomethane potential (MTP) means the maximum concentration of total trihalomethanes produced in water containing a disinfectant residual after seven days at a temperature of 25°C or above.

(86) Membrane Filtration is a pressure or vacuum driven separation process in which particulate matter larger than 1 micrometer is rejected by an engineered barrier, primarily through a size-exclusion mechanism, and which has a measurable removal efficiency of a target organism that can be verified through the application of a direct integrity test. This definition includes the common membrane technologies of microfiltration, ultrafiltration, nanofiltration, and reverse osmosis.

(87) Membrane module means the smallest component of a membrane unit in which a specific membrane surface area is housed in a device with a filtrate outlet structure.

(88) Minimum general sanitary standards means the minimum standards for the construction and operation of public water systems reasonably consistent with protection of the public health.

(89) Monitoring plan as it applies to section 1.12 means the written description of the system detailing all sources capable of being used by the system; a summary of the system’s operating characteristics, treatment processes and their associated temporal utilization (e.g., use of peaking facilities, alternative water sources, maintenance schedules that take facilities off line, etc.); a schematic of the facilities and distribution system identifying the location of all sources (including latitude and longitude), treatment processes, entry points to the distribution system, post entry point treatment facilities, storage facilities, treatment and distribution system monitoring points; and a detailed sampling plan to monitor each parameter for which a compliance determination is required. The monitoring plan consists of PART I – FACILITY INVENTORY and PART II - INDIVIDUAL RULE SAMPLING PLANS.

(90) Near the first service connection means at one of the 20 percent of all service connections in the entire system that are nearest the water supply treatment facility, as measured by water transport time within the distribution system.

(91) New source means a source not previously utilized by the public water system.

(92) New waterworks means:

(i) Any newly constructed public water system, or (ii) An existing system that becomes, by definition, a public water system by extending its infrastructure through physical expansion by virtue of increasing the number of connections, the number of individuals served, or by extending the number of days of service.

(93) Non-community water system means a public water system that is not a community water system. A non-community water system is either a "transient, non-community water system" or a "non- transient, non-community water system."

(94) Non-transient, non-community water system means a public water system that is not a community water system and that regularly serves at least 25 of the same persons over six months per year.

(95) Non-transient population means the average number of individuals served per day during the year or normal operating period(s), who do not reside at the place served by the water system, but have a regular opportunity to consume water produced by the system. Regular opportunity is defined as four or more hours per day, for four or more days per week, for six months or more per year.

(96) Optimal corrosion control treatment , for the purpose of lead and copper tap monitoring only, means the corrosion control treatment that minimizes the lead and copper concentrations at users' taps while ensuring that the treatment does not cause the water system to violate any provision of the CPDWR.

(97) Performance evaluation sample, also referred to as laboratory proficiency test samples (PTs) means a reference sample provided to a laboratory for the purpose of demonstrating that the laboratory can successfully analyze the sample within specified limits of performance specified by the agency. The true value of the concentration of the reference material is unknown to the laboratory at the time of the analysis.

(98) Person means an individual, corporation, company, association, partnership, municipality, or State, Federal, or tribal agency.

(99) picoCurie (pCi) means the quantity of radioactive material producing 2.22 nuclear transformations per minute.

(100) Plans and Specifications means the technical design drawings and specifications for waterworks. For new waterworks, this also includes technical, financial and managerial plans.

(101) Plant intake refers to the works or structures at the head of a conduit through which water is diverted from a source (e.g., river or lake) into the treatment plant.

(102) Point of disinfectant application is the point where the disinfectant is applied and water downstream of that point is not subject to recontamination.

(103) Point-of-entry treatment device (POE) is a treatment device applied to the drinking water entering a house or building for the purpose of reducing contaminants in the drinking water distributed throughout the house or building.

(104) Point-of-use treatment device (POU) is a treatment device used for the purpose of reducing contaminants in drinking water applied to a single faucet or other point of use (i.e., drinking fountain, ice maker, etc.).

(105) Population-served means the average daily population that occurs during the busiest month of the year or regular operating period(s). Population-served is further defined as the sum of resident, non-transient, and transient populations.

(106) Presedimentation is a preliminary treatment process used to remove gravel, sand and other particulate material from the source water through settling before the water enters the primary clarification and filtration processes in a treatment plant.

(107) Public water system (PWS) means a system for the provision to the public of water for human consumption through pipes or other constructed conveyances, if such system has at least fifteen service connections or regularly serves an average of at least twenty-five individuals daily at least 60 days out of the year. Such term includes:

(i) Any collection, treatment, storage, and distribution facilities under control of the operator of such system and used primarily in connection with such system.

(ii) Any collection or pretreatment storage facilities not under such control, which are used primarily in connection with such system.

Such term does not include any "special irrigation district." A public water system is either a "community water system" or a "non-community water system." (108) Recycle means the act of returning recycle streams to a plant’s primary treatment process.

(109) Recycle flows means any water, solid or semi-solid, generated by a plant’s treatment processes, operational processes, and residual treatment processes, that is returned to the plant’s primary treatment process. Also referred to as recycle streams.

(110) Rem means the unit of dose equivalent from ionizing radiation to the total body or any internal organ or organ system. A "millirem (mrem)" is 1/1000 of a rem.

(111) Repeat compliance period means any subsequent three-year monitoring period following the initial compliance period.

(112) Resident population means the average number of persons whose primary residence is served by the system. The individual need not live at the residence for 365 days per year for it to be considered his/her primary residence.

(113) Residual disinfectant concentration ("C" in CT calculations) means the concentration of disinfectant measured in mg/L in a representative sample of water.

(114) Sanitary survey means an onsite review of the water source, facilities, equipment, operation and maintenance of a public water system for the purpose of evaluating the adequacy of such source, facilities, equipment, operation and maintenance for producing and distributing safe drinking water.

(115) Secondary Maximum Contaminant Levels (SMCLs) apply to public water systems and which, in the judgment of the EPA Administrator, are requisite to protect the public health. The SMCL means the maximum permissible level of a contaminant in water which is delivered to the ultimate user of a public water system. Contaminants added to the water under circumstances controlled by the user, except those resulting from corrosion of piping and plumbing caused by water quality, are excluded from this definition. The SMCLs are not enforceable, but are intended as guidelines.

(116) Sedimentation means a process for removal of solids before filtration by gravity or separation.

(117) Service connection means a connection to a system that delivers water by constructed conveyance. The definition does not include connections that deliver water by a constructed conveyance other than a pipe if:

(i) The water is used exclusively for purposes other than residential uses (consisting of drinking, bathing, and cooking, or other similar uses)

(ii) The Department determines that an alternative water source to achieve the equivalent level of public health protection provided by the applicable Colorado primary drinking water regulation is provided for residential or similar uses for drinking and cooking, or (iii) The Department determines that the water provided for residential or similar uses for drinking, cooking, and bathing is centrally treated or treated at the point of entry by the provider, a pass-through entity, or the user to achieve the equivalent level of protection provided by the applicable Colorado Primary Drinking Water Regulations .

(118) Service line sample , as it applies to section 8.7, means a one-liter sample of water that has been standing for at least 6 hours in a service line.

(119) Significant deficiency means any situation, practice, or condition in a public water system with respect to design, operation, maintenance, or administration, that the state determines may result in or have the potential to result in production of finished drinking water that poses an unacceptable risk to health and welfare of the public served by the water system. Significant deficiencies include, but are not limited to, defects in design, operation, or maintenance, or a failure or malfunction of the sources, treatment, storage, or distribution system that the Department determines to be causing, or have potential for causing, the introduction of contamination into the water delivered to consumers.

(120) Single-family structure , for the purpose of lead and copper tap monitoring only, means a building constructed as a single-family residence that is currently used as either a residence or a place of business.

(121) Slow sand filtration means a process involving passage of raw water through a bed of sand at low velocity (generally less than 0.4 meters per hour (m/h)) resulting in substantial particulate removal by physical and biological mechanisms.

(122) Small system variance means variance from the requirement to comply with a maximum contaminant level or treatment technique to systems serving a total population of fewer than 10,000 that qualify under all provisions of section 4.3.

(123) Source means the point at which a public water system diverts water from its natural or man- made origin.

(124) Special irrigation district means an irrigation district in existence prior to May 18, 1994 that provides primarily agricultural service through a piped water system with only incidental residential or similar use where the system or the residential or similar users of the system comply with the exclusion provisions outlined in the definition of service connections (section 1.5.2(117)(ii)-(iii)).

(125) Spent filter backwash water means a stream containing particles that are dislodged from filter media when water is forced back through a filter (backwashed) to clean the filter. Spent filter backwash water contains particles including coagulants, metals, and microbes such as Cryptosporidium .

(126) Standard sample means the aliquot of finished drinking water that is examined for the presence of coliform bacteria.

(127) State means the State of Colorado.

(128) Supplier of water means any person who owns or operates a public water system.

(129) Surface water means any water source that is open to the atmosphere and subject to surface runoff. Groundwaters found to be under the direct influence of surface water will be classified as surface water.

(130) SUVA means specific ultraviolet absorption at 254 nanometers (nm), an indicator of the humic content of water. It is a calculated parameter obtained by dividing a sample's ultraviolet absorption at a wavelength of 254 nm (UV254) (in m -1 ) by its concentration of dissolved organic carbon (DOC) (in mg/L).

(131) System with a single service connection means a system that supplies drinking water to consumers via a single service line.

(132) Tamper , as defined in section 25-1-114.1(6), Colorado Revised Statutes, means to introduce a contaminant into a public water system or into drinking water or to otherwise interfere with drinking water or the operation of a public water system with the intention of harming persons or public water systems. It does not include the standardized accepted treatment procedures performed by a supplier of water in preparing water for human consumption.

(133) Thickener supernatant means a stream containing the decant from a sedimentation basin, clarifier or other unit that is used to treat water, solids, or semi-solids from the primary treatment processes. The “clear water” that exits the units after particles have been allowed to settle out is thickener supernatant (or sludge thickener supernatant).

(134) Too numerous to count (TNTC) means that the total number of bacterial colonies exceeds 200 on a 47-millimeter (mm) diameter membrane filter used for coliform detection.

(135) Total organic carbon (TOC) means a parameter measuring the total amount of carbon in water, present as organic molecules. It is used as a surrogate for disinfection byproduct precursors.

(136) Total trihalomethanes (TTHM) means the sum of the concentration in milligrams per liter (mg/L) of the trihalomethane compounds (trichloromethane [chloroform], dibromochloromethane, bromodichloromethane and tribromomethane [bromoform]), rounded to two significant figures.

(137) Transient, non-community water system means a non-community water system that does not regularly serve at least twenty-five of the same persons over six months per year.

(138) Transient population means the average number of individuals served per day during the year or annual operating period(s), who have an opportunity to consume water from the system, but who do not meet the definition of either residents or non-transient customers.

(139) Treatment technique requirement means a requirement of the Colorado Primary Drinking Water Regulations that specifies, for a contaminant, a specific treatment technique(s) known to EPA, which leads to a sufficient reduction in the level of such contaminant to comply with the requirements of the Colorado Primary Drinking Water Regulations .

(140) Trihalomethane (THM) means one of the family of organic compounds, named as derivatives of methane, wherein three of the four hydrogen atoms in methane are each substituted by a halogen atom in the molecular structure.

(141) Triggered Source Water Monitoring means the monitoring requirements for a groundwater system (GWS) when a distribution system Total Coliform Rule (TCR) sample tests positive for total coliform.

(142) Triggered Source Water Monitoring Plan means a plan that specifies the applicable well(s) for collecting source water samples in the event a groundwater system (GWS) with multiple sources is required to collect a triggered source water sample(s).

(143) Two-stage lime softening is a process in which chemical addition and hardness precipitation occur in each of two distinct unit clarification processes in series prior to filtration.

(144) Uncovered finished water storage facility means a tank, reservoir, or other facility used to store water that will undergo no further treatment except residual disinfection and that is open to the atmosphere without properly screened vents, screened overflow pipe, or cover.

(145) Variance means a form of relief from a maximum contaminant level granted to a public water system. Variances may be granted where characteristics of the system's raw water source preclude compliance by the system with the maximum contaminant levels prescribed by the Colorado Primary Drinking Water Regulations , despite application of best available technology, treatment techniques, or other means generally available to said system. In deliberations regarding variance requests, costs shall be taken into consideration.

(146) Violation means failure to comply with any provision of the Colorado Primary Drinking Water Regulations .

(147) Virus means a virus of fecal origin, which is infectious to humans by waterborne transmission.

(148) Vulnerability-use-waiver means a waiver issued by the Department to reduce the monitoring requirements for a specific contaminant pursuant to the Department’s Monitoring Waiver Program, when the Department has determined that the contaminant was not used (including transport, storage or disposal) in the area of a public water system.

(149) Waiver means reduction of a monitoring requirement. A waiver may either eliminate the requirement to monitor for a particular contaminant during a compliance period or reduce the frequency at which the contaminant must be analyzed. There are two types of waivers: (1) a waiver-by-rule and (2) a vulnerability-use-waiver.

(150) Waiver-by-rule means a waiver that is issued by the Department pursuant to the Department’s Monitoring Waiver Program following a determination that a public water system meets the specific criteria for a reduction of a monitoring requirement contained in the Colorado Primary Drinking Water Regulations .

(151) Waterborne disease outbreak means the significant occurrence of acute infectious illness, epidemiologically associated with the ingestion of water from a public water system which is deficient in treatment, as determined by the appropriate local or State agency.

(152) Waterworks means the facilities that are directly involved in the production, treatment, or distribution of water for public water systems.

(153) Water Quality Control Commission means the commission that has been created within the Colorado Department of Public Health and Environment pursuant to section 25-8-201, Colorado Revised Statutes.

(154) Water Vending and Dispensing Machines means any device which, upon payment by insertion of a coin, coins, token, or by other means, dispenses water into a container.

(155) Wholesale system is a public water system that treats source water as necessary to produce finished water and then delivers some or all of that finished water to another public water system. Delivery may be through a direct connection or through the distribution system of one or more consecutive systems.

1.6 Common Provisions

1.6.1 Monitoring Requirements

The Department may require public water systems to install, maintain, and use instrumentation to monitor and record data. Periodic reports are required to demonstrate compliance with applicable regulations on a continuing basis.

1.6.2 Performance Testing

To establish compliance with the Colorado Primary Drinking Water Regulations, the Department may require public water systems to conduct performance tests and monitoring, as the Department deems necessary to protect the public health. These tests shall be conducted in accordance with methods approved by the Department to demonstrate compliance with the Colorado Primary Drinking Water Regulations or terms and conditions of enforcement orders.

1.6.3 Recordkeeping

Each public water system shall retain on the system’s premises or at a convenient location near such premises the following records:

(a) Records of microbiological analyses and turbidity analyses made pursuant to Articles 5 and 7 of the Colorado Primary Drinking Water Regulations for not less than five years, and records of chemical analyses for not less than ten years. The actual laboratory reports may be kept, or data may be transferred to tabular summaries, provided that the following information is included:

(1) The date, place, and time of sampling, and the name of the person who collected the sample;

(2) Identification of the sample as to whether it was a routine distribution system sample, routine entry-point-to-the-distribution-system sample (EPTDS), confirmation sample, raw or processed water sample or a special purpose sample;

(3) Date of analysis;

(4) Laboratory and person responsible for performing analysis;

(5) The analytical technique/method used, and (6) The results of the analyses.

(b) For each violation of the Colorado Primary Drinking Water Regulations, the records of action taken by the public water system to correct the violation shall be kept for not less than three years after the date on which the last action was taken with respect to the particular violation involved.

(c) Copies of any written reports, summaries or communications relating to sanitary surveys of the system conducted by the system itself, a private consultant, or a local, state or federal agency shall be kept for not less than ten years after completion of the sanitary survey.

(d) Records concerning a variance or exemption granted to the system shall be kept for not less than five years following the expiration of such variance or exemption.

(e) Copies of public notices and consumer confidence reports issued pursuant to Article 9 and certifications made to the Department must be kept for not less than three years after issuance.

(f) Copies of monitoring plans developed pursuant to this section shall be kept for the same period of time as the records of analyses taken under the plan are required to be kept under paragraph (a) of the section, except as specified elsewhere in this section.

(g) All records pertaining to the operation and water quality of a public water system are public information and shall be made available to the public by the Department, at request, during normal working hours.

(h) Upon request of the Department the public water system shall submit copies of any records required to be maintained for public notification or copies of any documents in existence, which the Department is entitled to inspect pursuant to the authority of the Colorado Primary Drinking Water Regulations.

(i) In addition to other recordkeeping requirements, systems subject to any of the requirements shown in the first column of the table below, must maintain records as described. Corresponding Description of necessary Duration of time records requirement records must be kept (1) Individual Filter Results of individual At least 3 years. Turbidity Requirements filter monitoring (section 7.3.5)

(2) Disinfection Profiling Results of Profile Indefinitely. (section 7.3.2) (including raw data and analysis)

(3) Disinfection Benchmark (including Indefinitely.

Benchmarking (section raw data and analysis)

7.3.3)

(j) The system must collect and retain on file recycle flow information specified in sections 1.6.3(j)(1) through (6) for review and evaluation by the Department beginning June 8, 2004.

(1) Copy of the recycle notification and information submitted to the Department under section 7.5.2.

(2) List of all recycle flows and the frequency with which they are returned.

(3) Average and maximum backwash flow rate through the filters and the average and maximum duration of the filter backwash process in minutes.

(4) Typical filter run length and a written summary of how filter run length is determined.

(5) The type of treatment provided for the recycle flow.

(6) Data on the physical dimensions of the equalization and/or treatment units, typical and maximum hydraulic loading rates, type of treatment chemicals used and average dose and frequency of use, and frequency at which solids are removed, if applicable.

(k) Systems must keep results from the initial round of source water monitoring under section 7.4.2(a) and the second round of source water monitoring under section 7.4.2(b) until 3 years after bin classification under section 7.4.9 for filtered systems.

(l) Systems must keep any notification to the Department that they will not conduct source water monitoring due to meeting the criteria of section 7.4.2(d) for 3 years.

(m) Systems must keep the results of treatment monitoring associated with microbial toolbox options under sections 7.4.14 through 7.4.18, as applicable, for 3 years.

(n) Systems must retain a complete copy of the IDSE report submitted under section 7.7 for 10 years after the date that the report was submitted. If the Department modifies the section 7.8 monitoring requirements as recommended in the IDSE report or if the Department approves alternative monitoring locations, the system must keep a copy of the Department's notification on file for 10 years after the date of the Department's notification. The system must make the IDSE report and any Department notification available for review by the Department or the public.

(o) In addition to the requirements of section 1.6.3(a) – (n), a groundwater system regulated under Article 13 must maintain the following information in its records:

(1) Documentation of corrective actions. Documentation shall be kept for a period of not less than ten years.

(2) Documentation of notice to the public as required under section 9.1.3(h)(6). Documentation shall be kept for a period of not less than three years.

(3) Records of decisions under section 13.3(a)(5)(ii) and records of invalidation of fecal indicator- positive groundwater source samples under section 13.3(d). Documentation shall be kept for a period of not less than five years.

(4) For consecutive systems, documentation of notification to the wholesale system(s) of total- coliform positive samples that are not invalidated under section 5.3. Documentation shall be kept for a period of not less than five years.

(5) For systems, including wholesale systems, that are required to perform compliance monitoring under section 13.4(b):

1. (i) Records of the Department-specified minimum disinfectant residual. Documentation shall be kept for a period of not less than ten years.
   1. (ii) Records of the lowest daily residual disinfectant concentration and records of the date and duration of any failure to maintain the Department-prescribed minimum residual disinfectant concentration for a period of more than four hours. Documentation shall be kept for a period of not less than five years.
      1. (iii) Records of Department-specified compliance requirements for membrane filtration and of parameters specified by the Department for Department-approved alternative treatment and records of the date and duration of any failure to meet the membrane operating, membrane integrity, or alternative treatment operating requirements for more than four hours. Documentation shall be kept for a period of not less than five years.

1.6.4 Reporting Requirements

(a) Except where a shorter period is specified, the public water system shall report to the state the results of any test measurement or analysis required by the Colorado Primary Drinking Water Regulations within (1) the first ten calendar days following the month in which the result is received, or (2) the first ten calendar days following the end of the required monitoring period, as stipulated by the Department, whichever of these is shorter.

(b) Except where a different reporting period is specified, the public water system must report to the Department within 48 hours the failure to comply with any requirement (including failure to comply with monitoring requirements) set forth in the Colorado Primary Drinking Water Regulations.

(c) The public water system is not required to report analytical results to the Department in cases where the state laboratory performs the analysis and reports the results to the Department, except in instances that relate to monitoring required under sections 7.6 and 13.2.

(d) The public water system, within ten calendar days of completing the public notification requirements under Article 9 for the initial public notice and for any repeat notices, must submit to the Department a certification that it has fully complied with the public notification regulations. The public water system must include with this certification a representative copy of each notice distributed, published, posted, and/or made available to the persons served by the system and to the media.

(e) All reports, notices, summaries, and certifications required to be submitted to the Department by the public water system must bear the original signature of the owner or the owner’s authorized representative.

(f) In addition to the requirements of section 1.6.4(a) – (e), a groundwater system regulated under Article 13 must provide the following information to the Department:

(1) A groundwater system conducting compliance monitoring under section 13.4(b) must notify the Department any time the system fails to meet any Department-specified requirements including, but not limited to, minimum residual disinfectant concentration, membrane operating criteria or membrane integrity, and alternative treatment operating criteria, if operation in accordance with the criteria or requirements is not restored within four hours. The groundwater system must notify the Department as soon as possible, but in no case later than the end of the next business day.

(2) After completing any corrective action under section 13.4(a)(3) or 11.4, a groundwater system must notify the Department within 30 days of completion of the corrective action.

(3) If a groundwater system subject to the requirements of section 13.3(a) does not conduct source water monitoring under section 13.3(a)(5)(ii), the system must provide documentation to the Department within 30 days of the total coliform positive sample that it met the Department criteria for distribution system conditions that will cause total coliform-positive samples.

1.6.5 Severability Clause

If any regulation, section, subsection, paragraph, or other portion of the Colorado Primary Drinking Water Regulations shall for any reason be held inoperative, unconstitutional, void or invalid, the validity of the remaining portions thereof shall not be affected.

1.6.6 Federal Facilities

The Department, notwithstanding any other provisions of the Colorado Primary Drinking Water Regulations, shall enforce the Colorado Primary Drinking Water Regulations against federal facilities, on federally owned lands within the State, excluding Native American Lands.

1.6.7 Enforcement Provisions

(a) Where a public water system has violated any provision of any article of the Colorado Primary Drinking Water Regulations, the Department may issue an enforcement order requiring the public water system to take actions necessary to correct the violation(s). Such orders may require the public water system to design, redesign, install, modify, construct or reconstruct facilities or to take other such corrective action or to demonstrate adequacy of control measures and employ such operational techniques and practices as will eliminate any violations.

(b) The Department may issue an enforcement order on finding significant deviation from plans and specifications or significant inaccuracies in data submitted to the Department on which basis the Department had approved proposed construction or modification of any public water system.

(c) The Department may issue an enforcement order due to the incidence of disease, the source of which is reasonably identified by the Department as originating from consumption of drinking water from a specified public water system.

(d) When the Department determines that contaminants are present in a public water supply and that the presence of these contaminants presents an unreasonable risk to the public health, the utilization of treatment techniques or acquisition of an alternate source may be required by an enforcement order.

(e) When the Department determines that a physical condition, or an operation or maintenance practice poses an unreasonable risk to the public health, the Department may issue an enforcement order.

(f) Violators of the Colorado Primary Drinking Water Regulations or of enforcement orders may be subject to civil or criminal actions pursuant to the provisions of Sections 25-1-114 and 25-1-114.1, Colorado Revised Statutes.

(g) A public water system contesting an enforcement order may request a hearing. Requests for such a hearing shall be filed in writing with the Department within 30 days after service of the order. Such requests shall state the grounds upon which the order is contested and state the amount of time the public water system estimates will be required for the hearing. Hearings on enforcement orders shall be held in accordance with applicable provisions of Article 4 of Title 24, Colorado Revised Statutes.

1.6.8 Tampering

The public water system shall notify the Department as soon as possible, but no later than 10 a.m. of the next calendar day following any tampering, suspected tampering or receipt of tampering threat by the system. Written notice must be provided within five calendar days to the Department explaining the circumstances of the occurrence and setting forth the action(s) taken to ensure the ability of the system to provide a safe and reliable supply of drinking water and to prevent any reoccurrence.

1.6.9 Special Monitoring for Construction Materials

(a) A community water system shall identify whether the following construction materials are present in its distribution system and report to the Department the existence of:

(1) Lead from piping, solder, caulking, interior lining of distribution mains, alloys and home plumbing;

(2) Copper from piping and alloys, service lines, and home plumbing;

(3) Galvanized piping, service lines, and home plumbing;

(4) Ferrous piping materials such as cast iron and steel, and/or (5) Asbestos cement pipe.

(b) In addition, the Department may require identification and reporting of other materials of construction present in distribution systems that may contribute contaminants to the drinking water, such as:

(1) Vinyl-lined asbestos cement pipe; or (2) Coal tar-lined pipes and tanks.

1.6.10 Use of Point-of-Entry Devices

(a) Public water systems may use point-of-entry devices to comply with maximum contaminant levels only if all the requirements of section 1.6.10 are met.

(b) It is the responsibility of the public water system to operate and maintain the point-of-entry treatment system.

(c) The public water system must develop and obtain Department approval for a monitoring plan before point-of-entry devices are installed. Under the plan approved by the Department, point-of-entry devices must provide health protection equivalent to central water treatment. "Equivalent" means that the water will meet all Colorado Primary Drinking Water Regulations and will be of acceptable quality, similar to water distributed by a well-operated central treatment plant. In addition to the VOCs, monitoring must include physical measurements and observations such as total flow treated and mechanical condition of the treatment equipment.

(d) Effective technology must be applied properly, under a plan approved by the Department, and the microbiological safety of the water must be maintained.

(1) The Department requires adequate certification of performance, field testing, and, if not included in the certification process, a rigorous engineering design review of the point-of- entry devices.

(2) The design and application of the point-of-entry devices must consider the tendency for increase in heterotrophic bacteria concentrations in water treated with activated carbon. It may be necessary to use frequent backwashing, post-contactor disinfection, and Heterotrophic Plate Count monitoring to ensure that the microbiological safety of the water is not compromised.

(e) Every building connected to the system must have a point-of-entry device installed, maintained, and adequately monitored to ensure all consumers are protected. The Department must be assured that every building is subject to treatment and monitoring, and that the rights and responsibilities of the public water system customer convey with title upon sale of property.

1.6.11 Use of Bottled Water

Public water systems shall not use bottled water to achieve compliance with an MCL. Bottled water may be used on a temporary basis to avoid unreasonable risk to health.

1.7 Entry and Inspection of Public Water Systems

(a) Upon presentation of proper credentials, authorized representatives of the Department may enter and inspect, at any reasonable time and in a reasonable manner, any establishment, facility, or any other property, premises, or place owned, operated or under the control of a public water system or other person for the purpose of investigating any actual, suspected, or potential violations of any minimum general sanitary standards required by section 25-1.5-202, Colorado Revised Statutes.

(1) Said authorized representatives may obtain samples of drinking water, and (2) Any sample collected may be used as evidence in an enforcement action; a split or duplicate sample shall be offered to the owner, operator, or person in charge of the premises.

(b) A copy of the results of any analysis of such sample shall be furnished promptly to the owner, operator, or person in charge.

(c) If such entry or inspection is denied or not consented to, the Department is empowered to and shall obtain from the district or county court for the judicial district or county in which such property, premises, or place is located, a warrant to enter and inspect said property, premises, or place. The said district and county courts of the state are empowered to issue such warrants upon a proper showing of the need for such entry and inspection, and a copy of any inspection report shall be provided to the court within a reasonable time after making the inspection.

1.8 Wholesale Systems

Wholesale systems are responsible for meeting all of the applicable provisions of these regulations up to the point where treated drinking water from the wholesale system enters a consecutive system. The wholesale system may, under the provisions of section 1.10, accept responsibility for compliance with regulatory provisions that would otherwise apply to a consecutive system.

1.9 Consecutive Systems

1.9.1 Monitoring and Reporting Requirements

(a) Consecutive systems are subject to the monitoring and reporting provisions of the Colorado Primary Drinking Water Regulations unless such consecutive system is a part of an integrated system where the wholesale system has assumed responsibility for compliance with the applicable requirements in accordance with the provisions of section 1.10.

(b) Consecutive public water systems that sell water as a secondary aspect of their business only to recover costs, such as apartment buildings and commercial establishments, are exempt from the requirements of this Section 1.9. If an entity that meets the above criteria is found to be selling water for profit any such entity shall, after notification from the Water Quality Control Division, meet all monitoring requirements as defined in this Section 1.9.

1.9.2 Applicable Maximum Contaminant Levels and Other Requirements

(a) Consecutive systems, unless exempted from the monitoring requirements of section 1.9.1, must meet the maximum contaminant levels (MCLs) and other requirements of the Colorado Primary Drinking Water Regulations unless such consecutive system is part of an integrated system where the wholesale system has assumed responsibility for compliance with the MCL or other applicable requirements in accordance with the provisions of section 1.10.

(b) While not a requirement of these regulations, consecutive systems are also subject to the applicable requirements of Regulation 100, the Water and Wastewater Facility Operators Certification Requirements. Where a wholesale system has assumed responsibility for the operation and maintenance of a distribution system for a consecutive system, in accordance with the requirements for an integrated system, the wholesale system becomes the operator in responsible charge of such distribution system and is responsible to meet the applicable requirements of Regulation 100 in lieu of the consecutive system.

1.10 Integrated Systems

(a) Applicability: Only a public water system that receives, through purchase or other means, treated water from one or more wholesale systems and distributes only that water through a distribution system that it owns may be considered for integrated system status. An integrated system may or may not provide additional disinfection; however, it cannot be considered an integrated system if it provides any treatment other than disinfection. If such a public water system is required to meet additional or more stringent monitoring requirements or maximum contaminant levels than its supplier, it cannot be considered an integrated system. A system may be included in an integrated system, as that term is defined at 1.5.2(72), for the purpose of complying with one or more of the regulatory requirements applicable to the system.

(b) An integrated system may be established by the wholesale system in cooperation with the participating consecutive systems, as restricted by 1.10(a), with the approval of the Department. The wholesale system shall establish requirements for consecutive systems that have been accepted into the integrated system and these requirements shall be included in a contract, memorandum of agreement, or other enforceable mechanism. The decision to accept a consecutive system in the integrated system is solely at the discretion of the wholesale system, except where required under Colorado law, and cannot be appealed.

1.10.1 Requirements for Application for Integrated System Approval

Integrated systems may be established for one or more of the requirements listed in section 1.9.1 or 1.9.2 of these regulations. In order to establish an integrated system, an application that includes the following information must be submitted to the Department and approved:

(a) For qualifying consecutive systems and the wholesale system that intend to participate in at least one of the integrated systems: a contact person, address, and phone number for each participating system, and each regulatory requirement for which an integrated system is being created;

(b) The number of persons served by the wholesale system and each qualifying consecutive system and whether the consecutive system is providing further disinfection;

(c) A map showing the wholesale system and each consecutive system including the relevant elements of the distribution system such as meters, lines 16 inches in diameter or larger, pump stations, storage tanks, and finished water reservoirs;

(d) A Sampling Plan for each regulatory provision covered by the integrated system. Each sampling plan shall meet all requirements of the respective provision and shall also identify the responsibilities of each party;

(e) A copy of each agreement between the wholesale system and each qualifying consecutive systems. This shall include the common set of operation and maintenance standards that the wholesale system has established for each regulatory requirement for which an integrated system is being created; and (f) A statement that clearly assigns legal responsibility to one of the participating systems for compliance with each individual regulatory provision in the integrated system.

1.10.2 Integrated System Approval and Modification

(a) The Department shall have 90 days to notify the applicant of any area where the application for creation of an integrated system is incomplete.

(b) Upon submittal of a complete application for creation or revision of an integrated system, the Department shall have 150 days to approve or deny the request and shall provide a rationale for the action taken. If the Department denies the request for a new or modified integrated system, the applicant may request a hearing to contest the denial. Requests for such a hearing must be filed in writing with the Department within thirty (30) days after service of the statement of denial. Such requests shall state the grounds upon which the denial is being contested and state the amount of time the public water system estimates will be required for the hearing. Hearing on the denial shall be held in accordance with applicable provisions of Article 4 of Title 24, Colorado Revised Statute.

(c) Where a new and proposed qualifying consecutive system is added to an integrated system, 30 days notice shall be provided to the Department. The notice shall be signed by the qualifying consecutive system and the wholesale system. A revised sampling plan and map consistent with the requirements of sections 1.10.1 shall be included. The addition of the new qualifying consecutive system will be automatically approved unless the Department notifies the wholesale system of specific concerns with the revised sampling plan within forty-five (45) days of receipt of the request.

1.10.3 Integrated System Responsibilities

Until an integrated system is created, the consecutive system remains responsible for compliance with all regulatory requirements listed in sections 1.9.1 and 1.9.2.

1.10.4 Removal of a Consecutive System from the Integrated System

A wholesale system may remove a consecutive system from the integrated system provided that the wholesale system has given the consecutive system and the division thirty (30) days notice of the cause for such removal. The Department may, through written notice to the wholesale system within the aforementioned 30-day period, intervene in an attempt to resolve the issue(s) between the two systems. In this case, the period after which the consecutive system may be removed from the integrated system shall be extended from thirty (30) days to ninety (90) days. Where the Department has conducted a sanitary survey of a distribution system for a consecutive system that is part of an integrated system, the division shall notify the wholesale system of any deficiencies, regulatory or otherwise, that are noted in the final report for the sanitary survey.

1.10.5 Separation of a Consecutive System from an Integrated System

Where a consecutive system voluntarily separates from an integrated system, the consecutive system must immediately notify the Department of the date of separation and the regulatory provision(s) for which the consecutive system was included in that integrated system.

1.10.6 Dissolution of an Integrated System

The Department may, after providing thirty (30) days notice to the wholesale system and any affected consecutive systems, revoke the approval of an integrated system for good cause shown. If the Department revokes the approval of an integrated system, the applicant may request a hearing to contest the revocation. Requests for such a hearing must be filed in writing with the Department within 30 days after service of the statement of revocation. Such requests shall state the grounds upon which the revocation is being contested and state the amount of time the public water system estimates will be required for the hearing. The hearing on the revocation shall be held in accordance with applicable provisions of Article 4 of Title 24, Colorado Revised Statute. Upon appeal, the applicant may request the Department to grant a stay until the administrative decision is rendered on the appeal.

1.11 Plans Approval for the Location and the Construction of Waterworks

1.11.1 Introduction

Decisions regarding the review and approval of plans and specifications for new waterworks or improvements or modifications to existing waterworks shall be based upon compliance with design criteria developed by the Department.

Copies of the “State of Colorado Design Criteria for Potable Water Systems” 1-1 are available electronically on the Department’s web site at www.cdphe.state.co.us or by request to 303-692-3500 or a written request may be sent to:

CPDHE-WQCD ATTN: Technical Services Unit Manager 4300 Cherry Creek Drive South Denver, CO 80246-1530 1-1 There is a charge for paper copies.

1.11.2 Prior Approval Required

(a) No person shall commence construction of a new community or non-transient, non-community public water system unless such system performs and receives Department approval of a capacity (technical, managerial and financial) assessment conducted in accordance with the criteria of the New Public Water System Capacity Planning Manual.

(b) No person shall commence construction of any new waterworks, or make improvements to or modify the treatment process of an existing waterworks, or initiate the use of a new source, until plans and specifications for such construction, improvements, modifications or use have been submitted to, and approved by the Department. A Professional Engineer registered in the State of Colorado shall design all treatment systems serving a community water supply. The Department shall grant such approval when it finds that the proposed facilities are capable of complying, on a continuous basis, with design criteria as stated above, and with all applicable laws, standards, rules and regulations.

1.11.3 Siting Requirements

No waterworks shall be located at a site which:

(a) Is subject to a significant risk from earthquakes, floods, fires or other disasters which could cause a breakdown of the public water system or a portion thereof; or (b) Except for intake structures, is within the floodplain of a 100-year flood. 1-2 The Department will not seek to override land use decisions affecting public water systems siting which are made at the local government level.

1-2 Records of the 100-year projections are available at the office of the Colorado Water Conservation Board, 1313 Sherman Street, Denver, Colorado 80203

1.11.4 Processing by the Department

(a) The Department shall, within forty-five (45) days after the receipt of a request for approval of the complete set of final plans and specifications, review the documents submitted and, based thereon, shall approve or conditionally approve the plans and specifications in writing, or issue a written denial of approval, stating the reason for any such denial, or submit in writing to the project engineer, a list of items which must be addressed prior to further action regarding review and approval.

(b) Where commencement of construction of the project has not occurred within one year of approval, such approval shall expire. An expired approval may be reinstated by submittal of the former plans and specifications to the Department for review and approval.

1.11.5 Procedures Upon Denial

If the Department denies approval of plans and specifications submitted pursuant to this section 1.11.1 through 1.11.4, or if an applicant refuses to accept any conditions or terms pursuant to which said approval was conditionally granted, which shall constitute a denial, the applicant may request a hearing to contest the denial. Requests for such a hearing must be filed in writing with the Department within thirty (30) days after service of the statement of denial. Such requests shall state the grounds upon which the denial is being contested and state the amount of time the public water system estimates will be required for the hearing. Hearing on the denial shall be held in accordance with applicable provisions of Article 4 of Title 24, Colorado Revised Statutes.

1.12 Monitoring Plan

Each public water system shall develop and implement a monitoring plan. The public water system shall maintain the plan and make it available for inspection by the Department. The monitoring plan shall be designed and implemented to ensure that the water quality monitoring performed by the system is representative of the water distributed to consumers and is consistent with regulatory requirements of the Colorado Primary Drinking Water Regulations.

In accordance with section 1.12.2 each public water system is required to submit two copies of the monitoring plan to:

Colorado Department of Public Health and Environment Water Quality Control Division ATTN: Public Water System Monitoring Plan Coordinator 4300 Cherry Creek Drive South Denver, CO 80246-1530

1.12.1 Monitoring Plan Required Elements

Each public water system’s monitoring plan shall include the information specified in Sections 1.12.1(a) - (e), except that, one schematic may be sufficient if that schematic includes all sources, treatment processes and distribution system details as specified in sections 1.12.1(b) - (d). The monitoring plan consists of five parts:

(a) Part 1 - System Summary: Identify the public water system and provide all of the following:

(1) The Colorado public water system identification number (PWSID);

(2) The full name of the legal entity (that is, the owner of the system. For example, the name of a corporation, LLC, partnership, sole proprietor, HOA, etc.);

(3) The legal entity’s address;

(4) The name of the legal entity’s authorized contact person(s) responsible for the development and implementation of the monitoring plan (if other than the owner);

(5) The telephone number of the legal entity or the legal entity’s authorized monitoring plan contact person;

(6) The system’s classification (that is, community, non-transient, non-community, or transient, non-community);

(7) The total population-served by the system, by population type (that is, the total of resident, non-transient, and transient consumers);

(8) The physical addresses of all system facilities (including master meters) and the latitude and longitude of all facilities, and (9) The physical location of all records required by section 1.6.3.

(b) Part 2 - Water Sources Details: Identify all water sources capable of being used by the system, (i.e., those connected by conveyances, whether currently producing or not) and a schematic, diagram, or sketch depicting how the flow from each source is connected to the treatment processes and the distribution system.

(c) Part 3 - Water Treatment Details: Provide a summary of the system’s operating characteristics, including a schematic of all treatment processes and their associated temporal utilization that was assumed in the design of the monitoring plan (e.g., use of peaking facilities, alternative water sources, maintenance schedules that take facilities off line, etc.).

(d) Part 4 - Distribution System Details: Provide a schematic of the distribution system identifying:

(1) All entry points to the distribution system;

(2) All post entry point treatment facilities;

(3) All storage facilities and other finished water reservoirs;

(4) All distribution system monitoring points;

(5) Any master meters; and (6) All pump stations.

(e) Part 5 - Individual Rule Sampling Plans: Each sampling plan shall meet all requirements of the respective provision, including:

(1) Frequency and approximate time of collection;

(2) Sample site location identification and associated identification number;

(3) If appropriate, justification for the site selection;

(4) Sample preservation, quality assurance, and quality control procedures, including procedures for equipment calibration;

(5) Analysis procedure (certified laboratory or on-site by a party approved by the Department);

(6) Monitoring results presentation format;

(7) Procedures to assess and report compliance status for MCLs, ALs, MRDLs, TTs and, if applicable, disinfection byproduct precursor removal efficiency;

(8) The rationale used by the system to identify the sampling locations selected to represent the distribution system, and (9) A process to review and update the selected distribution system sampling locations to account for changes due to growth or other significant changes to the distribution system.

1.12.2 Monitoring Plan Submission Requirements

(a) All Public water systems must submit Sections 1.12.1(a) - (d), which correlates to Parts 1 - 4 of the monitoring plan, to the Department according to the following schedule:

(1) Systems using surface water or groundwater under the direct influence of surface water, serving a population of greater than 10,000 persons - no later than April 10, 2002, or ten

1. (10) calendar days following the end of the first required monitoring quarter thereafter.

(2) All groundwater systems serving a population of greater than 3,300 persons, and all systems using surface water or groundwater under the direct influence of surface water serving a population of greater than 3,300, but less than 10,001 persons and using a disinfectant in their treatment process no later than April 10, 2004, or ten (10) calendar days following the end of the first required monitoring quarter thereafter.

(3) All other community water systems no later than April 10, 2005, or ten (10) calendar days following the end of the first required monitoring quarter thereafter.

(4) All other non-community water systems no later than April 10, 2006, or ten (10) calendar days following the end of the first required monitoring quarter thereafter.

(b) Section 1.12.1(e), which correlates to Part 5 of a public water system’s monitoring plan, must be submitted to the Department according to the requirements as may be stipulated in Articles 5, 6, 7 and 8.

1.12.3 Monitoring Plan Revisions

A public water system is required to submit any changes related to the monitoring plan under Sections 1.12.1(a), (b), (c), (d) or (e) to the Department within thirty (30) calendar days following the effective date of the change.

1.13 Guidance Documents and Policy Documents

1.13.1 Guidance Document Availability

(a) The Department has developed guidance documents designed to assist public water systems with understanding the regulations and to explain the specific requirements systems must meet to maintain compliance.

(b) Copies of the available guidance documents may be obtained by requesting them from the Department at:

1. Colorado Department of Public Health and Environment Water Quality Control Division 4300 Cherry Creek Drive South Denver, Colorado 80246-1530 Guidance documents are also available on the Department’s Internet web site at the following address: www.cdphe.state.co.us.

1.13.2 Policy Document Availability

(a) The Department has developed a number of internal policy documents designed to address special primacy requirements, which are defined in 40 CFR 142. These documents are developed by the Department in order to maintain primary enforcement responsibility in the State of Colorado and are; therefore, not included in the regulation.

(b) While not regulatory in nature, these policies are public record and copies may be obtained by requesting them from the Department at the address listed in section 1.13.1(b).

1.14 Materials Incorporated by Reference

(a) All materials incorporated by reference in the drinking water regulations include only those volumes or editions cited and not later amendments to or editions of, incorporated material. The incorporated material may be examined at any state publications depository library, the Laboratory Services Division of the Department, or:

1. Drinking Water Program Manager Colorado Department of Public Health And Environment Water Quality Control Division 4300 Cherry Creek Drive South Denver, Colorado 80246-1530 (303) 692-3500

(b) In instances where material incorporated by reference refers to other sections of the referenced document that conflict with current language of the Colorado Primary Drinking Water Regulations, the current language of the Colorado Primary Drinking Water Regulations shall take precedence.

Article 2 MCLs, MCLGs, TTs, ALs, MRDLs, and MRDLGs [Eff. 09/30/2007] Maximum Contaminant Levels (MCLs), Maximum Contaminant Level Goals (MCLGs), Treatment Technique (TT) Requirements, Action Levels (AL), Maximum Residual Disinfectant Levels (MRDLs), and Maximum Residual Disinfectant Level Goals (MRDLGs)

2.1 MCLs and MCLGs for Organic Chemical Contaminants

(a) The following maximum contaminant levels for volatile organic chemical contaminants apply to community and non-transient, non-community water systems. Table 2-1 MCLs and MCLGs for Volatile Organic Chemical Contaminants . CAS No. Contaminant MCL (mg/L)

(1) 75-01-4 Vinyl chloride 0.002 (2) 71-43-2 Benzene 0.005 (3) 56-23-5 Carbon tetrachloride 0.005 (4) 107-06-2 1,2-Dichloroethane 0.005 (5) 79-01-6 Trichloroethylene 0.005 (6) 106-46-7 Para-Dichlorobenzene 0.075 (7) 75-35-4 1,1-Dichloroethylene 0.007 (8) 71-55-6 1,1,1-Trichloroethane 0.2 (9) 156-59-2 cis-1,2 Dichloroethylene 0.07 (10) 78-87-5 1,2-Dichloropropane 0.005 (11) 100-41-4 Ethylbenzene 0.7 (12) 108-90-7 Monochlorobenzene 0.1 (13) 95-50-1 o-Dichlorobenzene 0.6 (14) 100-42-5 Styrene 0.1 (15) 127-18-4 Tetrachloroethylene 0.005 (16) 108-88-3 Toluene 1 (17) 156-60-5 Trans-1,2 0.1 Dichloroethylene (18) 1330-20-7 Xylenes (total) 10 (19) 75-09-2 Dichloromethane 0.005 (methylene chloride)

(20) 120-82-1 1,2,4-Trichlorobenzene 0.07 (21) 79-00-5 1,1,2-Trichloroethane 0.005 (b) The following maximum contaminant levels for synthetic organic chemical contaminants apply to community water systems and non-transient, non-community water systems: Table 2-2 MCLs and MCLGs for Synthetic Organic Chemical Contaminants . CAS No. Contaminant MCL (mg/L)

(1) 15972-60-8 Alachlor 0.002 (2) 116-06-3 1 0.003 Aldicarb (3) 1646-87-3 Aldicarb sulfoxide 0.004 (4) 1646-87-4 Aldicarb sulfone 0.002 (5) 1912-24-9 Atrazine 0.003 (6) 1563-66-2 Carbofuran 0.04 (7) 57-74-9 Chlordane 0.002 (8) 96-12-8 Dibromochloropropane 0.0002 (9) 94-75-7 2,4-D 0.07 (10) 106-93-4 Ethylene dibromide 0.00005 (11) 76-44-8 Heptachlor 0.0004 (12) 1024-57-3 Heptachlor epoxide 0.0002 (13) 58-89-9 Lindane 0.0002 (14) 72-43-5 Methoxychlor 0.04 (15) 1336-36-3 Polychlorinated biphenyls 0.0005 (16) 87-86-5 Pentachlorophenol 0.001 (17) 8001-35-2 Toxaphene 0.003 (18) 93-72-1 2,4,5-TP (Silvex) 0.05 (19) 50-32-8 Benzo[a]pyrene 0.0002 (20) 75-99-0 Dalapon 0.2 (21) 103-23-1 Di(2-ethylhexyl)adipate 0.4 (22) 117-81-7 Di(2-ethylhexyl)phthalate 0.006 (23) 88-85-7 Dinoseb 0.007 (24) 85-00-7 Diquat 0.02 (25) 145-73-3 Endothall 0.1 (26) 72-20-8 Endrin 0.002 (27) 1071-53-6 Glyphosate 0.7 (28) 118-74-1 Hexachlorobenzene 0.001 (29) 77-47-4 Hexachlorocyclopentadie 0.05 ne (30) 23135-22-0 Oxamyl (Vydate) 0.2 (31) 1918-02-1 Picloram 0.5 (32) 122-34-9 Simazine 0.004 (33) 1746-01-6 2,3,7,8-TCDD (Dioxin) -8 3 x 10 1 The Aldicarbs are currently under "administrative stay" as a result of litigation. They are therefore treated as unregulated contaminants until further notice.

2.2 MCLs and MCLGs for Inorganic Chemical Contaminants

(a) The maximum contaminant level for arsenic for community water systems is 0.05 milligrams per liter (mg/L) until January 23, 2006.

(b) The following maximum contaminant levels for inorganic chemical contaminants apply to all community and non-transient, non-community water systems. The fluoride maximum contaminant level (MCL) applies only to community water systems and may be applied to non- community water systems when found by the Department to be necessary to protect the public health. In addition, the maximum contaminant levels for nitrate, nitrite and total nitrate/nitrite also apply to transient, non-community water systems.

Table 2-3 MCLs and MCLGs for Inorganic Chemicals . Contaminant MCL (mg/L) MCLG (mg/L)

(1) Antimony 0.006 0.006 (2) Arsenic 1 1

1. 0.010 Zero

(3) Asbestos 7 Million Fibers/liter 7 Million Fibers/liter (Longer than 10 µm) (Longer than 10 µm)

(4) Barium 2 2 (5) Beryllium 0.004 0.004 (6) Cadmium 0.005 0.005 (7) Chromium 0.1 0.1 (8) Cyanide (as free Cyanide) 0.2 0.2 (9) Fluoride 4.0 4.0 (10) Mercury 0.002 0.002 (11) Nitrate 10 (as Nitrogen) 10 (as Nitrogen)

(12) Nitrite 1 (as Nitrogen) 1 (as Nitrogen)

(13) Total Nitrate and Nitrite 10 (as Nitrogen) 10 (as Nitrogen) (14) Selenium 0.05 0.05 (15) Thallium 0.002 0.0005 1 The effective date for the arsenic MCL and its corresponding MCLG as listed is January 23, 2006. Until then, the MCL is 0.05 mg/L and there is no MCLG.

2.3 MCLs, MCLGs and Treatment Technique Requirements for Microbiological Contaminants The following maximum contaminant levels apply to all public water systems regardless of size or type. The treatment technique (TT) requirements apply to all public water systems that use surface water or groundwater under the direct influence of surface water regardless of system size or type. Table 2-4 MCLs, MCLGs and TTs for Microbiological Contaminants

2.4 MCLs and MCLGs for Disinfection Byproducts

The following maximum contaminant levels for disinfection byproduct apply to all community and non- transient, non-community water systems.

Table 2-5 MCLs and MCLGs for Disinfection Byproducts . Disinfection Byproduct MCL (mg/L) MCLG (mg/L)

(1) Total trihalomethanes 1 .

1. 0.080
   1. (TTHM)

(a) Bromodichloromethane . Zero (b) Bromoform . Zero (c) Chloroform . 0.07 (d) Dibromochloromethane . 0.06 (2) Haloacetic acids (five) 1 .

1. 0.060
   1. (HAA5)

(a) Bromoacetic acid . N/A (b) Dibromoacetic acid . N/A (c) Dichloroacetic acid . Zero (d) Monochloroacetic acid . 0.07 (e) Trichloroacetic acid . 0.02 (3) 2 0.010 Zero Bromate (4) 3 1.0 0.8 Chlorite 1 All systems must comply with these MCLs as a RRA until the date specified in section 7.8. After the dates specified in 7.8 systems must comply with these MCLs as a LRRA.

2 The MCL and MCLG for bromate only apply to those systems that use ozone as a disinfectant or oxidant somewhere in their treatment process.

3 The MCL and MCLG for chlorite only apply to those systems that use chlorine dioxide as a disinfectant or oxidant somewhere in the treatment process.

2.5 MRDLs and MRDLGs for Disinfectants

The following maximum residual disinfectant levels for disinfectant residuals apply to all community and non-transient, non-community water systems. In addition, the maximum residual disinfectant level for chlorine dioxide applies to transient, non-community water systems. Table 2-6 MRDLs and MRDLGs for Disinfectants . Disinfectant Residual MRDL (mg/L) MRDLG (mg/L)

(1) Chlorine 4.0 (as Cl 2 ). 4.0 (as Cl 2 ).

(2) Chloramines 4.0 (as Cl 2 ). 4.0 (as Cl 2 ).

(3) Chlorine dioxide 1 0.8 (as ClO 2 ) 0.8 (as ClO 2 )

1 The MCL and MCLG for chlorine dioxide only apply to those systems that use chlorine dioxide as a disinfectant or oxidant somewhere in the treatment process.

2.6 MCLs and MCLGs for Radionuclides

The following maximum contaminant levels for radionuclides apply to all community water systems. Table 2-7 MCLs and MCLGs for Radionuclides . Contaminant MCL MCLG (1) Combined radium-226 5 pCi/L Zero and radium-228 (2) Gross alpha particle 15 pCi/L Zero activity (including radium-226 but, excluding radon and uranium)

(3) Beta particle and photon 3 Zero 4 mrem/yr radioactivity (4) Uranium 30 µg/L Zero 1 The combined radium-226 and radium-228 value is determined by the addition of the results of the analysis for radium-226 and the analysis for radium-228.

2 The average annual concentration of beta particle and photon radioactivity from man-made radionuclides in drinking water must not produce an annual dose equivalent to the total body or any internal organ greater than 4 millirem/year (mrem/year) 3 Except for the radionuclides listed in Table 6-4 of section 6.3.6, the concentration of man-made radionuclides causing 4 mrem total body or organ dose equivalents must be calculated on the basis of 2 liter per day drinking water intake using the 168 hour data list in “Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air and in Water for Occupational Exposure,” NBS (National Bureau of Standards) Handbook 69 as amended August 1963, U.S. Department of Commerce. If two or more radionuclides are present, the sum of their annual dose equivalent to the total body or to any organ shall not exceed 4 mrem/year.

2.7 Action Levels (ALs) and MCLGs for Lead and Copper

The following action levels for lead and copper apply to all community and non-transient, non-community water systems.

Table 2-8 Action Levels and MCLGs for Lead & Copper . Contaminant AL (mg/L) MCLG (mg/L)

(1) Copper 1.3 1.3 (2) Lead 0.015 Zero

2.8 Filtration (Turbidity) Treatment for Surface Water Systems

The following treatment technique requirements apply to all public water systems that use surface water or groundwater under the direct influence of surface water. Table 2-9 Required Turbidity Levels . Treatment Technique System Size (in Turbidity Level (NTU) population served)

(1) Conventional or Direct 1 less than or equal to ( ≤ ) Less than 10,000 Filtration 0.5 NTU in at least 95% of the measurement taken each month (2) Conventional, Direct, or 2 less than or equal to ( ≤ ) All sizes Membrane Filtration 0.3 NTU in at least 95% of the measurement taken each month (3) Slow Sand Filtration All sizes less than or equal to ( ≤ ) 1 NTU in at least 95% of the measurement taken each month (4) Diatomaceous Earth and All sizes less than or equal to ( ≤ ) Cartridge & Bag 1 NTU in at least 95% of Filtration the measurement taken each month (5) Other Filtration Less than 10,000 Department approved Technologies technology must consistently achieve 99.9% (3-log) removal and/or inactivation of Giardia lamblia cysts, and 99.99% (4-log) removal and/or inactivation of viruses , 99% (2-log)

1. removal of Cryptosporidium oocysts

(6) Other Filtration greater than or equal to Department approved Technologies ( ≥ ) 10,000 technology must consistently achieve 99.9% (3-log) removal and/or inactivation of Giardia lamblia cysts, and 99.99% (4-log) removal and/or inactivation of viruses, and 99% (2-log)

1. removal of Cryptosporidium oocysts 1 Surface water or ground water under direct influence of surface water systems serving less than 10,000 using direct or conventional filtration must comply with these standards through January 1, 2005 2 The standards in this row do not apply to surface water systems serving less than 10,000 people using direct or conventional filtration until January 1, 2005.

2.9 Treatment Techniques for Acrylamide and Epichlorohydrin

The following treatment technique requirements for acrylamide and epichlorohydrin apply to all public water systems. When determining compliance, the combination (or product) of dose and monomer level does not exceed the levels specified in Table 2-9.

Table 2-10 Treatment Techniques for Acrylamide and Epichlorohydrin . Contaminant Maximum combination MCLG (mg/L)

1. (or product) of dose and monomer level

(1) Acrylamide 0.05% dosed at 1 ppm (or Zero equivalent)

(2) Epichlorohydrin 0.01% dosed at 20 ppm Zero (or equivalent)

2.10 Treatment Technique for Control of Disinfection Byproduct (DBP) Precursors

(a) The table below lists the required TOC removals for surface water systems using conventional filtration based on a system’s source water alkalinity and TOC. Table 2-11 Required Removal of TOC by Enhanced Coagulation and Enhanced Softening for Surface Water Systems Using Conventional Treatment (b) Systems meeting at least one of the conditions in section 7.6.6(a)(2) are not required to operate with enhanced coagulation.

(c) Softening systems meeting one of the alternative compliance criteria in section 7.6.6(a)(3) are not required to operate with enhanced softening.

(d) Systems practicing softening must meet the TOC removal requirements in the last column on the right in the table above.

(e) Compliance for TOC is based on a removal ratio of the actual amount a public water system removes versus the amount required as indicated in the table above. The compliance calculation can be found in section 7.6.6(c).

(f) The TOC removal ratio must be greater than or equal to 1.00. Article 3 Secondary Maximum Contaminant Levels

3.1 Introduction

These contaminants in drinking water primarily affect the aesthetic qualities relating to the public acceptance of drinking water. At considerably higher concentrations of these contaminants, health implications may also exist as well as aesthetic degradation. The secondary maximum contaminant levels are not enforceable, but are intended as guidelines.

3.2 Secondary Maximum Contaminant Levels

These levels represent reasonable goals for drinking water quality. The secondary maximum contaminant levels for public water systems are as follows: Table 3-1 Secondary Maximum Contaminant Levels . Contaminant Level 1 Aluminum 0.05 to 0.2 mg/L 2 Chloride 250 mg/L 3 Color 15 color units 4 Copper 1.0 mg/L 5 Corrosivity Non-corrosive 6 Fluoride 1

1. 2.0 mg/L

7 Foaming agents 0.5 mg/L 8 Iron 0.3 mg/L 9 Manganese 0.05 mg/L 10 Odor 3 threshold odor number 11 pH 6.5-8.5 12 Silver 0.1 mg/L 13 Sulfate 250 mg/L 14 Total dissolved solids 500 mg/L (TDS)

15 Zinc 5 mg/L 1 When the fluoride level exceeds the SMCL of 2.0 mg/L public notification in accordance with Article 9 is required.

3.3 Monitoring

It is recommended that the parameters in these regulations be monitored at intervals no less frequent than the monitoring performed for inorganic chemical contaminants as applicable to community water systems. More frequent monitoring would be appropriate for specific parameters such as pH, color, odor or others under certain circumstances.

3.4 Analytical Methods

Measurement of pH, copper and fluoride to determine compliance under section 3.3 may be conducted with one of the methods in section 10.2.2. Analyses of aluminum, chloride, foaming agents, iron, manganese, odor, silver, sulfate, total dissolved solids (TDS) and zinc to determine secondary contaminant concentrations under section 3.3 may be conducted with the methods in the following table. Criteria for analyzing aluminum, copper, iron, manganese, silver and zinc samples with digestion or directly without digestion, and other analytical test procedures are contained in Technical Notes on Drinking Water Methods, EPA-600/R-94-173, October 1994, which is available at NTIS PB95-104766. Table 3-2 Analytical Methods for Secondary Contaminants Article 4 Variances and Exemptions

4.1 Introduction

(a) The Department may grant variances or exemptions from certain provisions of the Colorado Primary Drinking Water Regulations subject to such terms and conditions as the EPA Administrator shall deem appropriate to protect the public health.

(b) Circumstances under which a variance or exemption may not be granted include:

(1) No variances or exemptions from the MCL for total coliform (2) No variances from any of the treatment technique requirements for filtration for surface water sources (3) No exemptions to the disinfection residual requirement at point of entry to the distribution system for systems using surface water.

(c) The effective date has been stayed for the section relating to the total coliform MCL for systems that demonstrate to the Department that the violation of the total coliform MCL is due to a persistent growth of total coliforms in the distribution system rather than fecal or pathogenic contamination, a treatment lapse or deficiency, or a problem in the operation or maintenance of the distribution system.

4.2 Variances

The Department may grant one or more variances from an applicable Colorado primary drinking water regulation to a public water system, which because of characteristics of the raw water sources that are reasonably available to the system cannot meet the requirements respecting the maximum contaminant levels of the Colorado Primary Drinking Water Regulations.

(a) A variance may only be issued to a system after the system’s application of the best available technology (BATs), treatment techniques, or other means identified by the EPA Administrator and based upon an evaluation satisfactory to the Department that indicates that alternative sources of water are not reasonably available to the system after taking costs into consideration. Before a variance is granted, the Department must find that the variance will not result in an unreasonable risk to health.

(b) The Department shall prescribe at the time the variance is granted, a schedule for:

(1) Compliance (including increments of progress) by the public water system with each contaminant level requirement with respect to which the variance was granted.

(2) Implementation by the public water system of such additional control measures as the Department may require for each contaminant, subject to such contaminant level requirement, during the period ending on the date compliance with such requirement is required. Before a schedule prescribed by the Department pursuant to this subparagraph may take effect, the Department shall provide notice and opportunity for a public hearing on the schedule. A schedule prescribed for a public water system granted a variance shall require compliance by the system with each contaminant level requirement with respect to which the variance was granted as expeditiously as practicable (as the Department may reasonably determine).

(c) The Department may grant to a public water system one or more variances from any provision of the Colorado Primary Drinking Water Regulations which requires the use of a specified treatment technique with respect to a contaminant, if the public water system applying for the variance demonstrates to the satisfaction of the Department that such treatment technique is not necessary to protect the health of persons because of the nature of the raw water source of such system. A variance granted shall be conditioned on such monitoring and other requirements as the Department may prescribe.

(d) Before a variance proposed to be granted by the Department under section 4.2(a) or (b) may take effect, the Department shall provide notice and opportunity for public hearing on the proposed variance.

(e) Each public water system's variance granted by the Department shall be conditioned upon compliance by the public water system with the schedule prescribed by the Department.

(f) Any schedule or other requirement, on which a variance granted under this section is conditioned, may be enforced as if such schedule or other requirement was part of a Colorado primary drinking water regulation.

4.3 Small System Variances

(a) The Department may grant a variance under section 4.3 for compliance with a requirement specifying a maximum contaminant level or treatment technique contained in a Colorado primary drinking water regulation to:

(1) Public water systems serving 3,300 or fewer persons.

(2) With the approval of the EPA Administrator, public water systems serving more than 3,300 persons but fewer than 10,000 persons.

(b) A public water system may receive a small system variance under section 4.3(a), if:

(1) A variance technology that is applicable to the size and source water quality conditions of the public water system has been identified by the EPA Administrator, (2) The public water system installs, operates, and maintains, in accordance with guidance or regulations issued by the EPA Administrator, such treatment technology, treatment technique, or other means, and (3) The Department determines that the conditions of section 4.3(c) are met.

(c) A small system variance shall be available only to a system:

(1) That cannot afford to comply, in accordance with affordability criteria established by the Department, with a Colorado primary drinking water regulation, including compliance through:

1. (i) Treatment (ii) Alternative source of water supply (iii) Restructuring or consolidation, unless the Department makes a written determination that restructuring or consolidation is not practicable, and

(2) For which the Department determines that the terms of the small system variance ensure adequate protection of human health, considering the quality of the source water for the system and the removal efficiencies and expected useful life of the treatment technology required by the variance.

(d) A small system variance shall not be available for:

(1) Any maximum contaminant level or treatment technique for a contaminant with respect to which a national primary drinking water regulation was promulgated prior to January 1, 1986.

(2) A Colorado primary drinking water regulation for a microbial contaminant (including a bacterium, virus, or other organism) or an indicator or treatment technique for a microbial contaminant.

(e) A small system variance shall require compliance with the conditions of the variance not later than 3 years after the date on which the variance is granted, except that the Department may allow up to 2 additional years to comply with a variance technology, secure an alternative source of water, restructure or consolidate if the Department determines that additional time is necessary for capital improvements, or to allow for financial assistance provided pursuant to a federal or state program.

(f) The Department shall review each small system variance granted under section 4.3 not less often than every 5 years after the compliance date established in the variance to determine whether the system remains eligible for the variance and is conforming to each condition of the variance.

(g) Prior to granting a variance under section 4.3 to a public water system serving more than 3,300 and fewer than 10,000 persons the Department must submit the variance to the EPA Administrator for review and approval. The EPA Administrator must approve or disapprove the variance within 90 days of the day of submittal by the Department. If the EPA Administrator disapproves a variance under this paragraph, the EPA Administrator must notify the Department in writing of the reasons for disapproval. Objections to variances:

(1) By the EPA Administrator: the Administrator may review and object to any variance proposed to be granted by the Department, if the objection is communicated to the Department not later than 90 days after the Department proposes to grant the variance. If the EPA Administrator objects to the granting of a variance, the EPA Administrator shall notify the Department in writing of each basis for the objection and propose a modification to the variance to resolve the concerns of the EPA Administrator. The Department shall make the recommended modification or respond in writing to each objection.

(2) Petition by consumers: not later than 30 days after the Department proposes to grant a variance for a public water system, any person served by the system may petition the EPA Administrator to object to the granting of a variance. The EPA Administrator shall respond to the petition and determine whether to object to the variance under 4.3(f) not later than 60 days after the receipt of the petition.

4.4 Exemptions

(a) The Department may exempt any public water system from any requirement respecting a maximum contaminant level or any treatment technique requirement, or from both, of an applicable Colorado primary drinking water regulation upon a finding that:

(1) Due to compelling factors (which may include economic factors, including qualification of the public water system as a system serving a disadvantaged community), the public water system is unable to comply with such contaminant level or treatment technique requirement, or to implement measures to develop an alternative source of water supply.

(2) The public water system was in operation on the effective date of such contaminant level or treatment technique requirement, or, for a system that was not in operation by that date, only if no reasonable alternative source of drinking water is available to such new system.

(3) The granting of the exemption will not result in an unreasonable risk to health.

(4) Management or restructuring changes (or both) cannot reasonably be made that will result in compliance with the Colorado Primary Drinking Water Regulations or, if compliance cannot be achieved, improve the quality of the drinking water.

(b) If the Department grants a public water system an exemption under section 4.4(a), the Department shall prescribe, at the time the exemption is granted, a schedule for:

(1) Compliance (including increments of progress or measures to develop an alternative source of water supply) by the public water system with each contaminant level requirement or treatment technique requirement with respect to which the exemption was granted, and (2) Implementation by the public water system of such control measures as the Department may require for each contaminant, subject to such contaminant level requirement or treatment technique requirement, during the period ending on the date compliance with such requirement is required. Before a schedule prescribed by the Department pursuant to this subsection may take effect, the Department shall provide notice and opportunity for a public hearing on the schedule.

(c) A schedule prescribed pursuant to 4.4(b) for a public water system granted an exemption shall require compliance by the system with each contaminant level and treatment technique requirement with respect to which the exemption was granted as expeditiously as practicable (as the Department may reasonably determine), but not later than 3 years after the otherwise applicable compliance date established in the Colorado Primary Drinking Water Regulations.

(d) No exemption shall be granted unless the public water system establishes that:

(1) The system cannot meet the standard without capital improvements, which cannot be completed prior to the date established in the Colorado Primary Drinking Water Regulations.

(2) In the case of a system which needs financial assistance for necessary improvements, the system has entered into an agreement to obtain such financial assistance or any federal or state program is reasonably likely to be available within the period of the exemption.

(3) The system has entered into an enforceable agreement to become a part of a regional public water system; and the system is taking all practicable steps to meet the standard.

(4) In the case of a system which does not serve more than a population of 3,300 and which needs financial assistance for the necessary improvements, an exemption granted under 4.4(d)(1) or (2) may be renewed for one or more additional 2-year periods, but not to exceed a total of 6 years, if the system establishes that it is taking all practicable steps to meet the requirements of 4.4(d).

(5) A public water system may not receive an exemption under this section if the system was granted a variance under sections 4.2 or 4.3.

(e) Each exemption granted by the Department under 4.4(a) shall be conditioned upon compliance by the public water system with the schedule prescribed by the Department. Any requirement of a schedule on which an exemption is conditioned may be enforced as if such requirement was part of a Colorado primary drinking water regulation.

(f) All exemptions and schedules prescribed by the Department are subject to review by the EPA Administrator.

4.5 Applications for Variances or Exemptions

All applications for variances or exemptions must be submitted in writing to the Department. The application must be complete and signed by the owner or the owner’s authorized representative listed with the Department.

(a) The completed and signed application must be submitted to: Colorado Department of Public Health and Environment Water Quality Control Division ATTN: Drinking Water Program Manager 4300 Cherry Creek Drive South Denver, CO 80246-1530 (b) Requests for variances or exemptions shall be in writing and include the following information:

(1) The nature and duration of the variance or exemption requested;

(2) Relevant analytical results of water quality samples taken from the system, including results of relevant tests conducted pursuant to the requirements of the Colorado Primary Drinking Water Regulations;

(3) The interim measures to be continuously applied during the requested exemption or variance period to adequately protect the health of the persons served by the public water system;

(4) For purposes of an exemption provide an explanation of the compelling factors pursuant to section 4.4, and (5) For purposes of a variance provide an explanation of the compelling factors pursuant to sections 4.2 or 4.3.

4.6 Disposition of Variances and Exemptions

The Department shall act on any exemption or variance request within 90 days after receipt of a complete application therefore.

(a) If an application submitted to the Department is incomplete, within 20 days of receipt of the application the Department shall advise the applicant in writing of items needed to complete the application.

(b) The Department shall consider written comments and requests for a public meeting regarding the proposed granting of a variance or exemption filed within 30 days after the date the Department provides public notification pursuant to sections 4.2, 4.3, or 4.4.

(c) Within 90 days of receipt of a complete application, the Department shall make an initial determination to approve or deny the application. The procedures set out below in section 4.6(c)(1) through (3) will then follow:

(1) If the Department determines that the application complies with the criteria for a variance or exemption and if there has not been an expression of interest in a public meeting sufficient to warrant holding such a meeting, and the EPA Administrator has approved the variance or exemption request (for systems serving more than 3,300 persons), the Department shall issue an order granting the exemption or variance pursuant to section 4.8.

(2) If the Department makes a tentative determination that the application complies with the criteria for a variance or exemption and sufficient interest has been expressed in a public meeting to warrant holding such a meeting the following procedure shall be utilized:

1. (i) The Department shall hold a public meeting in accordance with the procedures set out in section 4.7, and there is no compelling evidence to deny the variance or exemption request;
   1. (ii) The EPA Administrator has approved the variance or exemption request (for systems serving more than 3,300 persons); and (iii) The Department shall issue an order granting or denying the variance or exemption.

(3) If the Department makes a tentative determination to deny the application the following procedure shall be utilized:

1. (i) The Department shall notify the applicant in writing of its tentative determination to deny the application and state the grounds therefore;
   1. (ii) Within 15 days after receipt of such notice the applicant may submit in writing a response of intent to provide additional argument or information to the Department;
      1. (iii) If sufficient interest has been expressed in a public meeting to warrant holding such a meeting, the Department shall do so, and there is no compelling evidence to grant the variance or exemption; and (iv) The Department shall issue an order denying the variance or exemption.

4.7 Public Meetings

(a) Within 30 days after the Department has issued public notification required by sections 4.2, 4.3, or 4.4, any person may file a written request for the Department to hold a public meeting concerning such application for a variance or exemption. The Department shall hold such a meeting if there is sufficient interest to warrant doing so.

(b) At least 15 days prior to the public meeting the Department shall arrange for publication of notice of that meeting. Notice of public meeting shall include:

(1) Name, address and telephone number of the public water system for which the variance or exemption is sought;

(2) The provision of the drinking water regulations from which a variance or exemption is sought;

(3) The tentative determination of the Department regarding the variance or exemption, and the Department's address and telephone number;

(4) A statement that a copy of the application is available for inspection at the Department during regular business hours, and (5) The date, time, and location of the public meeting.

(c) A representative of the Department shall preside at the meeting. The Department shall also record the oral statements made at the public meeting. The person conducting a meeting shall have discretion to fix reasonable limits upon the time for oral statements.

(d) At the meeting, any person shall be permitted to submit oral or written statements concerning the variance or exemption application.

(e) The person(s) presiding at the public meeting shall maintain a list consisting of the name, address and telephone number of each person who submits an oral or written statement.

4.8 Final Order to Grant or Deny Variance or Exemption

(a) In determining whether to grant or deny a variance or an exemption, the Department shall consider the following:

(1) The completed application;

(2) Any written comments regarding the application received by the Department within 30 days of public notification pursuant to sections 4.2, 4.3, or 4.4;

(3) If a notice of tentative decision to deny application has been issued, any written response by the applicant to this notice; and (4) If a public meeting is held regarding the application, any written or oral statements submitted at the public meeting.

(b) The final order of the Department shall either grant or deny the variance or the exemption. Any such order granting the variance or exemption shall include the following information:

(1) The provision of the drinking water regulations from which the variance or exemption is granted;

(2) The duration of the variance or exemption; and (3) The prescribed schedules pursuant to sections 4.2, 4.3, or 4.4.

(c) The Department may revoke any variance or exemption where the supplier fails to comply with the terms of the order granting the variance or exemption. The Department may summarily revoke variances or exemptions pursuant section 24-4-104, Colorado Revised Statutes, and shall conduct hearings regarding such revocations in accordance with the requirements of section 24- 4-105, Colorado Revised Statutes.

(d) A copy of the Department's order shall be mailed to the applicant, all persons who submit written comments in timely fashion, and all persons who submit statements at any public meeting concerning the variance or exemption if such a meeting is held.

(e) The variance or exemption shall become effective 90 days after issuance of the Department's final order. Any person adversely affected or aggrieved by the Department's final order may request an adjudicatory hearing on the order. Such hearing shall be conducted in accordance with the requirements of section 24-4-105, Colorado Revised Statutes. A request for such a hearing shall be filed in writing within 60 days after the effective date of the Department's order granting the variance or exemption, or within 60 days of the service of the order denying the variance or exemption. If a variance or exemption is granted, and a request for a hearing regarding the variance or exemption is filed in a timely fashion, the variance or exemption shall remain in effect prior to any determination made at such a hearing.

(f) Following the issuance of a variance or exemption the supplier shall issue consumer notifications pursuant to Article 9 of the Colorado Primary Drinking Water Regulations. Article 5 Microbiological Contaminants

5.1 Coliform Sampling

5.1.1 Routine Monitoring

(a) Public water systems must collect total coliform samples at sites, which are representative of water throughout the distribution system according to a written sample-siting plan. These plans are subject to Department review and revision.

(b) Results of all routine total coliform samples must be submitted to the Department for review.

(c) A public water system must collect samples at regular time intervals throughout the month, except that a system which uses only groundwater [except groundwater under the direct influence of surface water, as defined in section 1.5.2(65)], and serves 4,900 persons or fewer, may collect all required samples on a single day if they are taken from different sites.

(d) Community water systems must monitor for total coliforms at a frequency based on the population served by the system, regardless of the type of water source, according to the following table: Table 5-1 Total Coliform Monitoring Frequency for Community Water Systems Population Served Per Minimum number of Population Served Per Minimum number of Day samples per month Day samples per month 1 1 59,001 to 70,000 70 25 to 1,000 1,001 to 2,500 2 70,001 to 83,000 80 2,501 to 3,300 3 83,001 to 96,000 90 3,301 to 4,100 4 96,001 to 130,000 100 4,101 to 4,900 5 130,001 to 220,000 120 4,901 to 5,800 6 220,001 to 320,000 150 5,801 to 6,700 7 320,001 to 450,000 180 6,701 to 7,600 8 450,001 to 600,000 210 7,601 to 8,500 9 600,001 to 780,000 240 8,501 to 12,900 10 780,001 to 970,000 270 12,901 to 17,200 15 970,001 to 1,230,000 300 17,201 to 21,500 20 1,230,001 to 1,520,000 330 21,501 to 25,000 25 1,520,001 to 1,850,000 360 25,001 to 33,000 30 1,850,001 to 2,270,000 390 33,001 to 41,000 40 2,270,001 to 3,020,000 420 41,001 to 50,000 50 3,020,001 to 3,960,000 450 50,001 to 59,000 60 3,960,001 or more 480 1 Includes public water systems which have at least 15 service connections, but serve fewer than 25 persons.

(e) Non-community water systems must monitor for total coliform at frequencies as specified in the following paragraphs (1) – (5):

(1) A non-community water system using only groundwater (except groundwater under the direct influence of surface water, as defined in section 1.5.2(65)) and serving 1,000 persons or fewer must monitor in each calendar quarter that the system provides water to the public.

(2) A non-community water system using only groundwater [except groundwater under the direct influence of surface water, as defined in section 1.5.2(65)] and serving more than 1,000 persons must monitor at the same frequency as a like-sized community water system, as specified in Table 5-1.

(3) A non-community water system using groundwater under the direct influence of surface water, as defined in section 1.5.2(65) must monitor at the same frequency as a like-sized community water system, as specified in Table 5-1. The system must begin monitoring at this frequency beginning with the next monitoring period following written determination that the groundwater is under the direct influence of surface water.

(4) A non-community water system using surface water, in total or in part, must monitor at the same frequency as a like-sized community water system, as specified in Table 5-1, during the period surface water is being used, regardless of the number of persons it serves.

(5) A non-community water system that is not open year around must monitor for total coliforms at least ten days prior to opening for the season.

(f) Special purpose samples, such as those taken to determine whether disinfection practices are sufficient following pipe placement, replacement, or repair, shall not be used to determine compliance with the MCL for total coliforms in Table 2-4. Repeat samples taken pursuant to section 5.1.2 are not considered special purpose samples, and must be used to determine compliance with the MCL for total coliforms in Table 2-4.

5.1.2 Repeat Monitoring

(a) If a routine sample is total coliform-positive, the public water system must collect a set of repeat samples within 24 hours of being notified of the positive result. The Department may extend the 24-hour limit on a case-by-case basis if the system has a logistical problem in collecting the repeat samples within 24 hours that is beyond its control. In the case of an extension, the Department must specify how much time the system has to collect the repeat samples and will notify the system of that time frame by the end of the next business day.

(1) If a system believes they have extenuating circumstances that would qualify them for an extension, the system must notify the Department as soon as practical, but no later than 24 hours of being notified of the positive result.

(b) A system required to collect one routine sample per month or fewer must collect no fewer than four repeat samples for each total coliform-positive sample found. A system required to collect more than one routine sample per month must collect no fewer than three repeat samples for each total coliform-positive sample found.

(c) The system must collect at least one repeat sample from the sampling tap where the original total coliform-positive sample was taken, and at least one repeat sample at a tap within five service connections upstream and at least one repeat sample at a tap within five service connections downstream of the original sampling site. If a total coliform-positive sample is at the end of the distribution system, or one tap away from the end of the distribution system, the Department may waive the requirement to collect at least one repeat sample upstream or downstream of the original sampling site and specify more appropriate sampling locations for the repeat sample monitoring.

(d) The system must collect all repeat samples on the same day, except that the Department may allow a system with a single service connection to collect the required set of repeat samples over a four- day period.

(e) If one or more repeat samples in the set is total coliform-positive, the public water system must collect an additional set of repeat samples in the manner specified in sections 5.1.2(a)-(d). The additional samples must be collected within 24 hours of being notified of the positive result, unless the Department extends the limit as provided in section 5.1.2(a). The system must repeat this process until either total coliforms are not detected in one complete set of repeat samples or the system determines that the maximum contaminant level for total coliforms in Table 2-4 has been exceeded and the system notifies the Department of such non-compliance.

(f) If a system collecting fewer than five routine samples per month has one or more total coliform- positive sample(s) and the Department does not invalidate the sample(s) under section 5.3, it must collect at least five routine samples during the next month the system provides water to the public, except that the Department may waive this requirement if the conditions of section 5.1.2(f) (1) or (2) are met. The Department cannot waive the requirement for a system to collect repeat samples in section 5.1.2(a) - (e).

(1) The Department may waive the requirement to collect five samples the next month the system provides water to the public if the Department, or an agent approved by the Department, performs a site visit before the end of the next month the system provides water to the public. Although a sanitary survey need not be performed, the site visit must be sufficiently detailed to allow the Department to determine whether additional monitoring and/or any corrective action is needed. The Department cannot approve an employee of the system to perform this site visit, even if the employee is an agent approved by the Department to perform sanitary surveys.

(2) The Department may waive the requirement to collect five routine samples the next month the system provides water to the public if the Department has determined why the sample was total coliform-positive and establishes that the system has corrected the problem or will correct the problem before the end of the next month the system serves water to the public. In this case, the Department must document this decision to waive the following month’s additional monitoring requirement in writing, have it approved and signed by the supervisor of the Department official who recommends such a decision, and make this document available to the EPA and public. The written documentation must describe the specific cause of the total coliform-positive sample and what action the system has taken and/or will take to correct this problem. The Department cannot waive the requirement to collect five routine samples the next month the system provides water to the public solely on the grounds that all repeat samples are total coliform- negative. Under this paragraph, a system must still take at least one routine sample before the end of the next month it serves water to the public and use it to determine compliance with the MCL for total coliforms in Table 2-4, unless the Department has determined that the system has corrected the contamination problem before the system took the set of repeat samples required in section 5.1.2(a) - (e), and all repeat samples were total coliform-negative (g) If a system collects a routine sample, which after analysis is found to be total coliform-positive, but prior to receiving results of that analysis the system collected another routine sample(s) within five adjacent service connections of the initial sample, the system may use the subsequent sample(s) as a repeat sample(s) instead of as a routine sample(s).

(h) Failure to submit the required number of repeat samples is a violation of section 5.1.2 and may subject the system to a Tier 2 public notification requirement per section 9.2.3, Table 9-5, as required by the Department.

(i) Results of all repeat total coliform samples must be submitted to the Department for review.

5.2 Investigation of Total Coliform-Positive Routine Microbiological Sample(s)

(a) After appropriate repeat samples are taken in accordance with section 5.1.2, systems must investigate the reason for any total coliform-positive routine sample(s).

(1) The scope of the investigation required under section 5.2 is to include conditions at the sources, treatment facilities, storage sites and distribution system including an evaluation of the potential for unprotected cross connections.

(2) The scope of the investigation may be modified by the system to take into account conditions unique to the system’s size, sources and distribution system layout and cross connection control devices relative to the location of the total coliform-positive sample result(s).

(b) The results of the investigation must be available at the time that repeat sample results become available and will be used by the Department in the event that the system has an acute violation of the total coliform maximum contaminant level requiring consultation with the Department, in accordance with section 9.2.2(b)(2), to determine the efficacy of requiring the public to boil their water or to use alternative sources of water, or other public notice requirements.

5.3 Invalidation of Total Coliform Samples

A total coliform-positive sample invalidated under this section 5.3 does not count towards meeting the minimum monitoring requirements of this Article 5.

(a) The Department may invalidate a total coliform-positive sample only if the conditions of the following paragraphs (1), (2) or (3) are met.

(1) The laboratory establishes that improper sample analysis caused the total coliform-positive result.

(2) The Department, on the basis of the results of repeat samples collected in accordance with sections 5.1.2(a) - (e), determines that the total coliform-positive sample resulted from a domestic or other non-distribution system plumbing problem. The Department cannot invalidate a sample on the basis of repeat sample results unless all repeat sample(s) collected at the same tap as the original total coliform-positive sample are also total coliform-positive, and all repeat samples collected within five service connections of the original tap are total coliform-negative (e.g., the Department cannot invalidate a total coliform-positive sample on the basis of repeat samples if all the repeat samples are total coliform-negative, or if the public water system has only one service connection).

(3) The Department has substantial grounds to believe that a total coliform-positive result is due to a circumstance or condition which does not reflect water quality in the distribution system. In this case, the system must still collect all repeat samples required under section 5.1.2(a) - (e), and use them to determine compliance with the MCL for total coliforms in Table 2-4. To invalidate a total coliform-positive sample under this paragraph, the decision with the rationale for the decision must be documented in writing, and approved and signed by the supervisor of the department official who recommended the decision. The Department must make this document available to EPA and the public. The written documentation must state the specific cause of the total coliform-positive sample, and what action the system has taken, or will take, to correct this problem. The Department may not invalidate a total coliform-positive sample solely on the grounds that all repeat samples are total coliform-negative.

(b) A laboratory must invalidate a total coliform sample (unless total coliforms are detected) if any of the following conditions in paragraphs (1)-(3) are met:

(1) The sample produces a turbid culture in the absence of gas production using an analytical method where gas formation is examined (e. g., the Multiple-Tube Fermentation Technique);

(2) The sample produces a turbid culture in the absence of an acid reaction in the Presence- Absence (P-A) Coliform Test; or (3) The sample exhibits confluent growth or produces colonies too numerous to count with an analytical method using a membrane filter (e.g., Membrane Filter Technique).

(c) If a laboratory invalidates a sample, the system must collect another sample from the same location as the original sample within 24 hours of being notified of the interference problem and have it analyzed for the presence of total coliforms. The system must continue to re-sample within 24 hours and have the samples analyzed until it obtains a valid result. The Department may waive the 24-hour time limit on a case-by-case basis when the system, for logistical reasons outside the system's control, cannot have the sample collected within 24 hours. In that case, the Department will specify how much time the system has to collect the sample.

5.4 Fecal Coliforms/Escherichia coli (E. coli) Testing

(a) If any routine or repeat sample is total coliform-positive, the system must analyze that total coliform- positive culture medium to determine if fecal coliforms are present, except that the system may test for E. coli in lieu of fecal coliforms.

(b) If fecal coliforms or E. coli are present, the system must notify the Department as soon as possible but not later than the end of the next business day following the day on which the system was notified of the test result.

(c) The Department has the discretion to allow a public water system, on a case-by-case basis, to forgo fecal coliform or E. coli testing on a total coliform-positive sample if that system assumes that the total coliform-positive sample is fecal coliform-positive or E. coli -positive. Accordingly, the system must notify the Department as specified in Sections 5.6(a) - (b) and the provisions of section 5.7(b) apply.

5.5 Analytical Requirements

(a) The standard sample volume required for total coliform analysis, regardless of analytical method used, is 100 ml.

(b) Public water systems need only determine the presence or absence of total coliforms; a determination of total coliform density is not required.

(c) When fecal coliform analysis is performed subsequent to a positive total coliform sample, the public water systems need only determine the presence or absence of fecal coliforms; a determination of fecal coliform density is not required.

(d) For the purpose of determining compliance with this Article 5 regarding microbiological contaminants, samples may be considered only if the conditions specified in this section 5.5(d)(1) and (2) are met.

(1) The sample must have been analyzed by a laboratory certified by the Department. A current list of certified laboratories is available upon request from: Colorado Department of Public Health and Environment Laboratory Services Division Laboratory Certification Program 8100 Lowry Boulevard Denver, CO 80230-6928 Phone: 303-692-3090 or by Internet at the following web address:

1. www.cdphe.state.co.us/lr/Certification/SDWLIST.pdf

(2) The sample must have been analyzed by a method conducted in accordance with Article 10, section 10.1.

5.6 Response to Violation

(a) A public water system which has exceeded the MCL for total coliforms as listed in Table 2-4 must report the violation to the Department no later than the end of the next business day after it learns of the violation, and notify the public in accordance with Article 9.

(b) A public water system, which has failed to comply with a coliform monitoring requirement, must report the monitoring violation to the Department within ten days after the system discovers the violation, and notify the public in accordance with Article 9.

5.7 Microbiological Contaminant Maximum Contaminant Level (MCL) Determination

(a) The MCL, as listed in Table 2-4, is based on the presence or absence of total coliforms in a sample, rather than coliform density.

(1) For a system that collects at least 40 samples per month, if no more than 5.0 percent of the samples collected during a month are total coliform-positive, the system is in compliance with the MCL for total coliforms.

(2) For a system collecting fewer than 40 samples per month, if no more than one sample collected during a month is total coliform-positive, the system is in compliance with the MCL for total coliforms.

(b) Any fecal coliform-positive repeat sample or E. coli-positive repeat sample, or any total coliform- positive repeat sample following a fecal coliform-positive or E. coli-positive routine sample constitutes a violation of the MCL for total coliforms. For purposes of the public notification requirements in Article 9, this is a violation that may pose an acute risk to health.

(c) A public water system must determine compliance with the MCL, as listed in Table 2-4, for total coliforms for each month in which it is required to monitor for total coliforms.

(d) Results of all routine and repeat samples not invalidated by the Department or the laboratory must be included in determining compliance with the MCL for total coliforms listed in Table 2-4.

5.8 Best Available Technologies (BATs) for Microbiological Contaminants

(a) The EPA Administrator hereby identifies the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant level for total coliforms in section 2..3 Table 2-4:

(1) Protection of wells from contamination by coliforms by appropriate placement and construction;

(2) Maintenance of a disinfectant residual throughout the distribution system;

(3) Proper maintenance of the distribution system including appropriate pipe replacement and repair procedures, main flushing programs, proper operation and maintenance of storage tanks and reservoirs, and continual maintenance of positive water pressure in all parts of the distribution system;

(4) Filtration and/or disinfection of surface water, as described in Article 7, or disinfection of groundwater using strong oxidants such as chlorine, chlorine dioxide, or ozone; and (5) For systems using groundwater, compliance with the requirements of the Departments Wellhead Protection Program, which was developed and implemented under section 1428 of the Safe Drinking Water Act.

Article 6 Chemical Contaminants and Radionuclides

6.1 Inorganic Chemical Contaminants

6.1.1 Applicability

(a) These regulations shall apply to all community and non-transient, non-community water systems in Colorado, except:

(1) The fluoride maximum contaminant level (MCL) applies only to community water systems and may be applied to non-community water systems when found by the Department to be necessary to protect the public health; and (2) The MCLs for nitrate, nitrite, and total nitrate and nitrite apply to all public water systems.

(3) The arsenic MCL applies only to community water systems, until January 23, 2006 when it will also apply to non-transient, non-community water systems.

(b) The maximum contaminant levels for antimony, asbestos, barium, beryllium, cadmium, chromium, cyanide, mercury, selenium, and thallium apply to community water systems and non-transient, non-community water systems.

(c) At the discretion of the Department, nitrate levels not to exceed 20 mg/L may be allowed in a non- community water system if the public water system demonstrates to the satisfaction of the Department that:

(1) Such water will not be available to children under 6 months of age; and (2) The non-community water system is meeting the public notification requirements under section 9.2.2, including continuous posting of the fact that nitrate levels exceed 10 mg/L and the potential health effects of exposure; and (3) Local and State public health authorities will be notified annually of nitrate levels that exceed 10 mg/L; and (4) No adverse health effects shall result.

6.1.2 Reporting requirements

Reporting requirements shall be those in section 1.6.4, unless otherwise noted in section 6.1.

6.1.3 Compliance Determination

(a) Compliance with section 2.2, MCLs and MCLGs for Inorganic Chemical Contaminants, shall be determined based on the analytical result(s) obtained at each sampling point.

(1) For systems which are conducting monitoring at a frequency greater than annual, compliance with the maximum contaminant levels for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium or thallium is determined by a running annual average at any sampling point. If the average at any sampling point is greater than the MCL, then the system is out of compliance. If any one sample would cause the annual average to be exceeded, then the system is out of compliance immediately. Any sample below the method detection limit shall be calculated at zero for the purpose of determining the annual average. If a system fails to collect the required number of samples, compliance (average concentration) will be based on the total number of samples collected.

(2) For systems which are monitoring annually, or less frequently, the system is out of compliance with the maximum contaminant levels for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium or thallium if the level of a contaminant is greater than the MCL. If confirmation samples are required by the Department the determination of compliance will be based on the annual average of the initial MCL exceedance and any Department-required confirmation samples. If a system fails to collect the required number of samples, compliance (average concentration) will be based on the total number of samples collected. If a sample result is less than the detection limit, zero will be used to calculate compliance.

(3) Compliance with the maximum contaminant levels for nitrate and nitrite is determined based on one sample if the levels of these contaminants are below the MCLs. If the levels of nitrate and/or nitrite exceed the MCLs in the initial sample, a confirmation sample is required in accordance with section 6.1.5(g)(2), and compliance shall be determined based on the average of the initial and confirmation samples.

(4) Arsenic sampling results will be reported to the nearest 0.001mg/L.

(b) The provisions of sections 6.1.5(k)(2) and (3) notwithstanding, compliance with the maximum contaminant level for nitrate shall be determined on the basis of the mean of two analyses.

(c) When a level exceeding the maximum contaminant level for nitrate is found, a second analysis shall be initiated within 24 hours, and if the mean of the two analyses exceeds the maximum contaminant level, the supplier of water shall report to the Department pursuant to section 1.6.4 and shall notify the public pursuant to section 9.2.

6.1.4 Best Available Technology (BAT) and Small System Compliance Technology (SSCT) (a) The EPA Administrator, hereby identifies the following as the best technology, treatment technique, or other means available for achieving compliance with the maximum contaminant levels for inorganic contaminants identified in section 2.2, except fluoride: Table 6-1 BAT for Inorganic Compounds (Listed in section 2.2(2)) Chemical Name BAT(s)

Antimony 2,7 4 5 Arsenic 1, 2, 5, 6, 7, 9, 12 Asbestos 2,3,8 Barium 5,6,7,9 Beryllium 1,2,5,6,7 Cadmium 2,5,6,7 Chromium 2 2,5,6 ,7 Cyanide 5,7,13 Mercury 1 1 1 2 ,4,6 ,7 Nickel 5,6,7 Nitrate 5,7,9 Nitrite 5,7 Selenium 3 1,2 ,6,7,9 Thallium 1,5 1 BAT only if influent Hg concentrations < 10µ g/1.

2 BAT for Chromium III only.

3 BAT for Selenium IV only.

4 BATs for Arsenic V. Pre-oxidation may be required to convert Arsenic III to Arsenic V. 5 To obtain high removals, iron to arsenic ration must be at least 20:1. Key to BATS in Table 6-1 1 = Activated Alumina 2 = Coagulation/Filtration (not BAT for systems with < 500 service connections)

3 = Direct and Diatomite Filtration 4 = Granular Activated Carbon 5 = Ion Exchange 6 = Lime Softening (not BAT for systems with < 500 service connections)

7 = Reverse Osmosis 8 = Corrosion Control 9 = Electrodialysis 10 = Chlorine 11 = Ultraviolet 12 = Oxidation/Filtration 13 = Alkaline Chlorination (pH ≥ 8.5)

(b) The EPA Administrator hereby identifies in the following table the affordable technology, treatment technique, or other means available to systems serving 10,000 persons or fewer for achieving compliance with the maximum contaminant level for arsenic: Table 6-2 Small System Compliance Technologies (SSCTs) 1 for Arsenic 2 Small system Affordable for listed compliance technology small system categories Activated Alumina All size categories.

(centralized)

Activated Alumina All size categories.

(Point-of-Use)

1. 5 501 - 3,300, 3,301 - Coagulation/Filtration 10,000.

Coagulation-assisted 501 - 3,300, 3,301 - Microfiltration 10,000.

1. 6 501 - 3,300, 3,301 - Electrodialysis reversal 10,000.

Enhanced All size categories coagulation/filtration Enhanced lime softening All size categories.

(pH > 10.5)

Ion Exchange All size categories.

1. 5 501 - 3,300, 3,301 - Lime Softening 10,000.
   1. 7 All size categories.

Oxidation/Filtration Reverse Osmosis 501 - 3,300, 3,301 - 6 10,000.

(centralized)

Reverse Osmosis (Point- All size categories.

of-Use)

1 Section 1412(b)(4)(E)(ii) of SDWA specifies that SSCTs must be affordable and technically feasible for small systems. 2 SSCTs for Arsenic V. Pre-oxidation may be required to convert Arsenic III to Arsenic V. 3 The Act (ibid.) specifies three categories of small systems: (i) those serving 25 or more, but fewer than 501, (ii) those serving more than 500, but fewer than 3,301, and (iii) those serving more than 3,300, but fewer than 10,001. 4 When POU or POE devices are used for compliance, programs to ensure proper long-term operation, maintenance, and monitoring must be provided by the water system to ensure adequate performance. 5 Unlikely to be installed solely for arsenic removal. May require pH adjustment to optimal range if high removals are needed. 6 Technologies reject a large volume of water - may not be appropriate for areas where water quantity may be an issue. 7 To obtain high removals, iron to arsenic ratio must be at least 20:1.

6.1.5 Inorganic Chemical Monitoring

(a) Community and non-transient, non-community water systems shall conduct monitoring to determine compliance with the maximum contaminant levels specified in Table 2-3 in accordance with section 6.1.5. Transient, non-community water systems shall conduct monitoring to determine compliance with the nitrate and nitrite maximum contaminant levels in Table 2-3 in accordance with section 6.1.5.

(b) Monitoring shall be conducted as follows:

(1) Groundwater systems shall take a minimum of one sample at every entry point to the distribution system, which is representative of each well after treatment (hereafter called a sampling point). The system shall take each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.

(2) Surface 6-1 water systems shall take a minimum of one sample at every entry point to the distribution system after any application of treatment or in the distribution system at a point, which is representative of each source after treatment (hereafter called a sampling point). The system shall take each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant. 6-1 For purposes of this section, surface water systems include systems with a combination of surface and ground sources.

(3) If a system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water is representative of all sources being used).

(4) The Department may reduce the total number of samples that must be analyzed by allowing the use of compositing. Composite samples from a maximum of five sampling points are allowed, provided that the detection limit of the method used for analysis is less than one- fifth ( <1/5) of the MCL. Compositing of all samples must be done in the laboratory.

1. (i) If the concentration in the composite sample is greater than or equal to one-fifth of the MCL of any inorganic chemical, then a follow-up sample must be taken within 14 days at each sampling point included in the composite. These samples must be analyzed for the contaminants that exceeded one-fifth of the MCL in the composite sample.
   1. (ii) If the population served by the system is greater than ( > ) 3,300 persons, compositing of samples is permitted at sampling points within a single system only. In systems serving less than or equal to (≤) 3,300 persons, compositing of samples is permitted at sampling points among different systems provided the 5- sample limit is maintained.
      1. (iii) If duplicates of the original sample taken from each sampling point used in the composite sample are available, the system may use these instead of re- sampling. The duplicates must be analyzed and the results reported to the Department within 14 days after completing analysis of the composite sample, provided the holding time of the sample is not exceeded.

(5) The frequency of monitoring for asbestos shall be in accordance with section 6.1.5(c); the frequency of monitoring for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium and thallium shall be in accordance with section 6.1.5(d); the frequency of monitoring for nitrate shall be in accordance with section 6.1.5(e); and, the frequency of monitoring for nitrite shall be in accordance with section 6.1.5(f).

(c) Asbestos: The frequency of monitoring conducted to determine compliance with the maximum contaminant level for asbestos specified in Table 2-3 shall be conducted as follows:

(1) Each community and non-transient, non-community water system is required to monitor for asbestos during the first three-year compliance period of each nine-year compliance cycle beginning in the compliance period.

(2) The Department may initiate or the system may apply to the Department for a waiver of the monitoring requirements in section 6.1.5(c)(1) if the system is not vulnerable to either asbestos contamination in its source water or due to corrosion of asbestos-cement pipe, or both. If the Department grants the waiver, the system is not required to monitor.

(3) The Department may grant a waiver based on a consideration of the following factors:

1. (i) Potential asbestos contamination of the water source, and (ii) The use of asbestos-cement pipe for finished water distribution and the corrosive nature of the water.

(4) A waiver remains in effect until the completion of the three-year compliance period. Systems not receiving a waiver must monitor in accordance with the provisions of section 6.1.5(c) (1).

(5) A system vulnerable to asbestos contamination due solely to corrosion of asbestos-cement pipe shall take one sample at a tap served by asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.

(6) A system vulnerable to asbestos contamination due solely to source water shall monitor in accordance with the provision of section 6.1.5(b).

(7) A system vulnerable to asbestos contamination due both to its source water supply and corrosion of asbestos-cement pipe shall take one sample at a tap served by asbestos- cement pipe and under conditions where asbestos contamination is most likely to occur.

(8) A system that exceeds the maximum contaminant levels, as determined in section 6.1.3(a), shall monitor quarterly beginning in the next quarter after the violation occurred.

(9) The Department may decrease the quarterly monitoring requirement to the frequency specified in section 6.1.5(c)(1) provided the Department has determined that the system is reliably and consistently below the maximum contaminant level. In no case will the Department make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface (or combined surface/ground) water system takes a minimum of four quarterly samples.

(d) Antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium and thallium: The frequency of monitoring conducted to determine compliance with the maximum contaminant levels in section 2.2 for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium and thallium shall be as follows:

(1) Groundwater systems shall take one sample at each sampling point during each compliance period. Surface water systems (or combined surface/ground) shall take one sample annually at each sampling point.

(2) The system may apply to the Department for a waiver from the monitoring frequencies specified in section 6.1.5(d)(1).

(3) The Department may grant a public water system a waiver for monitoring of cyanide, provided that the Department determines that the system is not vulnerable due to lack of any industrial source of cyanide.

(4) A condition of the waiver shall require that a system shall take a minimum of one sample while the waiver is effective. The term during which the waiver is effective shall not exceed one compliance cycle (i.e., nine years).

(5) The Department may grant a waiver provided surface water systems have monitored annually for at least three years and groundwater systems have conducted a minimum of three rounds of monitoring. Both surface and groundwater systems shall demonstrate that all previous analytical results were less than the maximum contaminant level. Systems that use a new water source are not eligible for a waiver until three rounds of monitoring from the new source have been completed.

(6) In determining the appropriate reduced monitoring frequency, the Department shall consider:

1. (i) Reported concentrations from all previous monitoring;
   1. (ii) The degree of variation in reported concentrations; and (iii) Other factors which may affect contaminant concentrations such as changes in groundwater pumping rates, changes in the system's configuration, changes in the system's operating procedures, or changes in stream flows or characteristics.

(7) A decision by the Department to grant a waiver shall be made in writing and shall set forth the basis for the determination. The determination may be initiated by the Department or upon an application by the public water system. The public water system shall specify the basis for its request. The Department shall review and, where appropriate, revise its determination of the appropriate monitoring frequency when the system submits new monitoring data or when other data relevant to the system's appropriate monitoring frequency become available.

(8) Systems that exceed the maximum contaminant levels, as calculated in accordance with section 6.1.3(a), shall monitor quarterly beginning in the next quarter after the violation occurred.

(9) The Department may decrease the quarterly monitoring requirement to the frequencies specified in sections 6.1.5(d)(1) and 6.1.5(d)(2) provided it has determined that the system is reliably and consistently below the maximum contaminant level. In no case will the Department make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface water system takes a minimum of four quarterly samples.

(10) All new systems or systems that use a new source of water must demonstrate compliance with the maximum contaminant levels specified in Table 2-3 within one year of beginning operation. The system must also comply with the initial sampling frequencies specified by the Department to ensure a system can demonstrate compliance with the MCL. Routine and increased monitoring frequencies shall be conducted in accordance with the requirements of this section.

(e) Nitrate: All public water systems (community; non-transient non-community; and transient non- community systems) shall monitor to determine compliance with the maximum contaminant level for nitrate in Table 2-3(11).

(1) Community and non-transient, non-community water systems served by groundwater systems shall monitor annually; systems served by surface water shall monitor quarterly.

(2) For community and non-transient, non-community water systems, the repeat monitoring frequency for groundwater systems shall be quarterly for at least one year following any one sample in which the concentration is greater than or equal to (≥) 50 percent of the

1. MCL. The Department may allow a groundwater system to reduce the sampling frequency to annually after four consecutive quarterly samples are reliably and consistently less than the MCL.

(3) For community and non-transient, non-community water systems, the Department may allow a surface water system to reduce the sampling frequency to annually if all analytical results from four consecutive quarters are less than ( <) 50 percent of the MCL. A surface water system shall return to quarterly monitoring if any one sample is greater than or equal to (≥) 50 percent of the MCL.

(4) Each transient, non-community water system shall monitor annually.

(5) After the initial round of quarterly sampling is completed, each community and non-transient, non-community system that is monitoring annually shall take subsequent samples during the quarter(s) that previously resulted in the highest analytical result.

(f) Nitrite: All public water systems (community; non-transient, non-community; and transient, non- community systems) shall monitor to determine compliance with the maximum contaminant level for nitrite in Table 2-3(12).

(1) After the initial sample, systems where an analytical result for nitrite is less than ( <) 50 percent of the MCL shall monitor at least once during each monitoring cycle (i.e. once every nine years), or more frequently as determined by the Department to protect public health.

(2) For community, non-transient, non-community, and transient, non-community water systems, the repeat monitoring frequency for any water system shall be quarterly for at least one year following any one sample in which the concentration is greater than or equal to (≥) 50 percent of the MCL. The Department may allow a system to reduce the sampling frequency to annually after determining the system is reliably and consistently less than the MCL.

(3) Systems that are monitoring annually shall take each subsequent sample during the quarter(s) that previously resulted in the highest analytical result.

(g) Confirmation samples:

(1) Where the results of sampling for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium or thallium indicate an exceedance of the maximum contaminant level, the Department requires one additional sample be collected as soon as possible after the initial sample was taken (but not to exceed two weeks) at the same sampling point.

(2) Where nitrate or nitrite sampling results indicate an exceedance of the maximum contaminant level, the system must take a confirmation sample within 24 hours of the system's receipt of notification of the analytical results of the first sample. Systems unable to comply with the 24-hour sampling requirement must immediately notify persons served by the public water system in accordance with section 9.2 and meet other Tier 1 public notification requirements under Article 9. Systems exercising this option must take and analyze a confirmation sample within two weeks of notification of the analytical results of the first sample.

(3) If the Department-required confirmation sample is taken for any contaminant, then the results of the initial and confirmation sample will be averaged. The resulting average is used to determine the system's compliance in accordance with section 6.1.3(a). The Department has the discretion to invalidate results of sampling or analytic errors.

(h) The Department may require more frequent monitoring than specified in sections 6.1.5(c), (d), (e) and (f) or may require confirmation samples for positive and negative results at its discretion.

(i) Systems may apply to the Department to conduct more frequent monitoring than the minimum monitoring frequencies specified in section 6.1.5.

(j) Each public water system shall monitor at the time designated by the Department during each compliance period.

(k) Requirements for nitrate levels not to exceed 20 mg/L in non-community water systems (section 6.1.1(c)).

(1) Analyses for the purpose of determining compliance with section 6.1.1(c), with respect to nitrate levels not to exceed 20 mg/L in non-community water systems, shall be conducted using the requirements specified in section 6.1.5(k)(1)-(3) as well as the requirements in specified in section 6.1.3(b).

1. (i) Analyses for all community water systems utilizing surface water sources shall be repeated at yearly intervals.
   1. (ii) Analyses for all community water systems utilizing only groundwater sources shall be repeated at three-year intervals.
      1. (iii) For non-community water systems, whether supplied by surface or ground sources, analyses for nitrate shall be repeated at intervals specified by the Department in the Enforcement Compliance Agreement.
         1. (iv) The Department has the authority to determine compliance or initiate enforcement action based upon analytical results and other information compiled by their sanctioned representatives and agencies.

(2) If the result of an analysis made under section 6.1.5(k)(1) indicates that the level of nitrate listed in section 6.1.1(c) exceeds the maximum contaminant level, the supplier of the water shall report to the Department within 7 days and initiate three additional analyses at the same sampling point within one month.

(3) When the average of four analyses made pursuant to section 6.1.5(k)(2), rounded to the same number of significant figures as the maximum contaminant level for the substance in question, exceeds the maximum contaminant level, the supplier of water shall notify the Department pursuant to section 1.6.4 and give notice to the public pursuant to Article

1. 9. Monitoring after public notification shall be at a frequency designated by the Department and shall continue until the maximum contaminant level has not been exceeded in two successive samples or until a monitoring schedule as a condition to a variance, exemption or enforcement action shall become effective.

6.1.6 Monitoring for Systems Purchasing Water in Addition to Utilizing Water from Other Sources (a) The Department may modify the monitoring requirements imposed by section 6.1.5 when a public water system purchases treated water from another public water systems, when:

(1) The purchased water enters the distribution system independent of any other water source owned by the system; and (2) The interconnection of the systems justifies the modification of monitoring requirements.

(b) Any modified monitoring shall be conducted pursuant to a schedule specified by the Department.

6.1.7 Special Monitoring for Sodium

(a) Community public water systems shall collect and analyze one sample per plant at the entry point of the distribution system for the determination of sodium concentration levels; samples must be collected and analyzed annually for systems utilizing surface water sources in whole or in part, and at least every three years for systems utilizing solely groundwater sources. The minimum number of samples required to be taken by the system shall be based on the number of treatment plants used by the system, except that multiple wells drawing raw water from a single aquifer may, with Department approval, be considered one treatment plant for determining the minimum number of samples.

(b) The public water system shall report to the Department the results of the analyses for sodium within the first 10 days of the month following the month in which the sample results were received or within the first 10 days following the end of the required monitoring period as stipulated by the Department, whichever of these is first.

(c) The public water system shall notify appropriate local and State public health officials of the sodium levels by written notice by direct mail each year. A copy of each notice, required by this section 6.1.7(c), shall be sent to the Department within 10 days of its issuance.

(d) Analyses for sodium shall be conducted as directed in Table 10-5(24).

6.2 Organic Chemical Contaminants

6.2.1 Applicability

Section 6.2 applies to all community and non-transient, non-community water systems in Colorado.

6.2.2 Acrylamide and Epichlorohydrin Certification

(a) Each public water system must certify annually in writing to the Department (using third party or manufacturer's certification) that when acrylamide and epichlorohydrin are used in drinking water systems, the combination (or product) of dose and monomer level does not exceed the following levels:

(1) Acrylamide = 0.05% dosed at 1 ppm (or equivalent).

(2) Epichlorohydrin = 0.01% dosed at 20 ppm (or equivalent).

(b) Certifications can rely on manufacturers or third parties, as approved by the Department.

6.2.3 Compliance Determination

(a) VOC: Compliance with the volatile organic chemical contaminants MCLs, listed in Table 2-1(1)-(21), shall be determined based on the analytical results obtained at each sampling point. If one sampling point is in violation of an MCL, the system is in violation of the MCL.

(1) For systems monitoring more than once per year, compliance with the MCL is determined by a running annual average at each sampling point.

(2) Systems monitoring annually or less frequently whose sample result exceeds the MCL must begin quarterly sampling. The system will not be considered in violation of the MCL until it has completed one year of quarterly sampling.

(3) If any sample result will cause the running annual average to exceed the MCL at any sampling point, the system is out of compliance with the MCL immediately.

(4) If a system fails to collect the required number of samples, compliance will be based on the total number of samples collected.

(5) If a sample result is less than the detection limit, zero will be used to calculate the annual average.

(b) SOC: Compliance with the synthetic organic chemical contaminants MCLs, listed in Table 2-2(1) - (33), shall be determined based on the analytical results obtained at each sampling point. If one sampling point is in violation of an MCL, the system is in violation of the MCL.

(1) For systems monitoring more than once per year, compliance with the MCL is determined by a running annual average at each sampling point.

(2) Systems monitoring annually or less frequently whose sample result exceeds the regulatory detection level as defined in section 10.3.3 must begin quarterly sampling. The system will not be considered in violation of the MCL until it has completed one year of quarterly sampling.

(3) If any sample result will cause the running annual average to exceed the MCL at any sampling point, the system is out of compliance with the MCL immediately.

(4) If a system fails to collect the required number of samples, compliance will be based on the total number of samples collected.

(5) If a sample result is less than the detection limit, zero will be used to calculate the annual average.

(c) All new systems or systems that use a new source of water must demonstrate compliance with the maximum contaminant levels specified in Tables 2-1 and 2-2 within one year of beginning operation. The system must also comply with the initial sampling frequencies specified by the Department to ensure a system can demonstrate compliance with the MCL. Routine and increased monitoring frequencies shall be conducted in accordance with the requirements of sections 6.2.5 for volatile organic Chemical contaminants and 6.2.6 for synthetic organic Chemical contaminants.

(d) The Department has the authority to determine compliance or initiate enforcement action based upon analytical results and other information compiled by their sanctioned representatives and agencies.

(e) Each public water system shall monitor at the time designated by the Department within each compliance period.

6.2.4 Best Available Technology (BAT)

The EPA Administrator, hereby identifies the following, as indicated in the table below, granular activated carbon (GAC), packed tower aeration (PTA), or oxidation (OX) as the best technology treatment technique, or other means available for achieving compliance with the MCL for organic chemical contaminants.

Table 6-3 BAT for Organic Chemical Contaminants Listed in Sections 2.1(a) and (b) CAS No. CHEMICAL GAC PTA CONTAMINANTS 15972-60-8 Alachlor X .

116-06-3 Aldicarb X .

1646-88-4 Aldicarb sulfone X .

1646-87-3 Aldicarb sulfoxide X .

1912-24-9 Atrazine X .

71-43-2 Benzene X X 50-32-8 Benzo[a]pyrene X .

1563-66-2 Carbofuran X .

56-23-5 Carbon tetrachloride X X 57-74-9 Chlordane X .

75-99-0 Dalapon X .

94-75-7 2,4-D X .

103-23-1 Di(2-ethylhexyl) adipate X X 117-81-7 Di(2-ethylhexyl) X .

1. phthalate 96-12-8 Dibromochloropropane X X (DBCP)

95-50-1 o-Dichlorobenzene X X 106-46-7 para-Dichlorobenzene X X 107-06-2 1,2-Dichloroethane X X 75-35-4 1,1-Dichloroethylene X X 156-59-2 cis-1,2- X X DichloroethyleneX 156-60-5 trans-1,2- X X Dichloroethylene 75-09-2 Dichloromethane . X 78-87-5 1,2-Dichloropropane X X 88-85-7 Dinoseb X .

85-00-7 Diquat X .

145-73-3 Endothall X .

72-20-8 Endrin X .

100-41-4 Ethylbenzene X X 106-93-4 Ethylene Dibromide X X (EDB)

1071-83-6 Glyphosate . .

76-44-8 Heptachlor X .

1024-57-3 Heptachlor epoxide X .

118-74-1 Hexachlorobenzene X .

77-47-3 Hexachlorocyclopentadie X X ne 58-89-9 Lindane X .

72-43-5 Methoxychlor X .

108-90-7 Monochlorobenzene X X 23135-22-0 Oxamyl (Vydate) X .

87-86-5 Pentachlorophenol X .

1918-02-1 Picloram X .

1336-36-3 Polychlorinated biphenyls X .

1. (PCB)

122-34-9 Simazine X .

100-42-5 Styrene X X 1746-01-6 2,3,7,8-TCDD (Dioxin) X .

127-18-4 Tetrachloroethylene X X 108-88-3 Toluene X X 8001-35-2 Toxaphene X .

93-72-1 2,4,5-TP (Silvex) X .

120-82-1 1,2,4-TrichlorobenzeneX X X 71-55-6 1,1,1-Trichloroethane X X 79-00-5 1,1,2-Trichloroethane X X 79-01-6 Trichloroethylene X X 75-01-4 Vinyl chloride . X 1330-20-7 Xylene X X

6.2.5 Volatile Organic Chemical Contaminants Monitoring Requirements

(a) Beginning with the initial compliance period, analysis of the contaminants listed in Table 2-1(1) through (21) for the purpose of determining compliance with the maximum contaminant level shall be conducted as follows:

(1) Groundwater systems shall take a minimum of one sample at every entry point to the distribution system which is representative of each well after treatment (hereafter called a sampling point). Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source, treatment plant, or within the distribution system.

(2) Surface water systems (or combined surface/ground) shall take a minimum of one sample at points in the distribution system that are representative of each source or at each entry point to the distribution system after treatment (hereafter called a sampling point). Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source, treatment plant, or within the distribution system.

(3) If the system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water representative of all sources is being used).

(4) Each community and non-transient, non-community water system shall take four consecutive quarterly samples for each contaminant listed in Table 2-1(2) through (21) during each compliance period, beginning in the initial compliance period.

(5) If the initial monitoring for contaminants listed in Table 2-1(1) through (8) and the monitoring for the contaminants listed in Table 2-1(9) through (21) as allowed in section 6.2.5(a)(15) has been completed by December 31, 1992, and the system did not detect any contaminant listed in Table 2-1(1) through (21), then each ground and surface water system shall take one sample annually beginning with the initial compliance period.

(6) After a minimum of three years of annual sampling, the Department may allow groundwater systems with no previous detection of any contaminant listed in Table 2-1 to take one sample during each compliance period.

(7) Each community and non-transient, non-community groundwater system which does not detect a chemical contaminant listed in Table 2-1(a)(1) through (21) may apply to the Department for a waiver from the requirements of sections 6.2.5(a)(5) and 6.2.5(a)(6) after completing the initial monitoring. (For purposes of section 6.2.5, detection is defined as greater than ( > ) 0.0005 mg/L.) A waiver shall be effective for no more than six years (two compliance periods). The Department may also issue waivers to small systems for the initial round of monitoring for 1,2,4-trichlorobenzene.

(8) The Department may grant a waiver after evaluating the following factor(s):

1. (i) Knowledge of previous use (including transport, storage, or disposal) of the chemical contaminant within the watershed or zone of influence of the system. If a determination by the Department reveals no previous use of the chemical contaminant within the watershed or zone of influence, a waiver may be granted.
   1. (ii) If previous use of the chemical contaminant is unknown or it has been used previously, then the following factors shall be used to determine whether a waiver is granted.
      1. (A) Previous analytical results.
         1. (B) The proximity of the system to a potential point or non-point source of contamination. Point sources include spills and leaks of chemical contaminants at or near a water treatment facility or at manufacturing, distribution, or storage facilities, or from hazardous and municipal waste landfills and other waste handling or treatment facilities.
         2. (C) The environmental persistence and transport of the chemical contaminants.
         3. (D) The number of persons served by the public water system and the proximity of a smaller system to a larger system.
         4. (E) How well the water source is protected against contamination, such as whether it is a surface or groundwater system. Groundwater systems must consider factors such as depth of the well, the type of soil, and wellhead protection. Surface water systems must consider watershed protection.

(9) As a condition of the waiver a groundwater system must take one sample at each sampling point during the time the waiver is effective (i.e., one sample during two compliance periods or six years) and update its vulnerability assessment considering the factors listed in section 6.2.5(a)(8). Based on this vulnerability assessment the Department must reconfirm that the system is non-vulnerable. If the Department does not make this reconfirmation within three years of the initial determination, then the waiver is invalidated and the system is required to sample annually as specified in section 6.2.5(a)(5).

(10) Each community and non-transient, non-community surface water system that does not detect a volatile organic chemical contaminant listed in Table 2-1(1)-(21), may apply to the Department for a waiver from the requirements of section 6.2.5(a)(5) after completing the initial monitoring. Composite samples from a maximum of five sampling points are allowed, provided that the detection limit of the method used for analysis is less than one- fifth of the MCL. Systems meeting this criterion must be determined by the Department to be non-vulnerable based on a vulnerability assessment completed during each compliance period. Each system receiving a waiver shall sample at the frequency specified by the Department.

(11) If a volatile organic chemical contaminant listed in Table 2-1(2)-(21) is detected at a level exceeding 0.0005 mg/L in any sample, then:

1. (i) The system must monitor quarterly at each sampling point that resulted in a detection.
   1. (ii) The Department may decrease the quarterly monitoring requirement specified in section 6.2.5(a)(11)(i) provided it has determined that the system is reliably and consistently below the maximum contaminant level. In no case shall the Department make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface water system takes a minimum of four quarterly samples.
      1. (iii) If the Department determines that the system is reliably and consistently below the MCL, the Department may allow the system to monitor annually. Systems which monitor annually must monitor during the quarter(s) which previously yielded the highest analytical result.
         1. (iv) Systems that have three consecutive annual samples with no detection of a chemical contaminant may apply to the Department for a waiver as specified in section 6.2.5(a)(7).
         2. (v) Groundwater systems which have detected one or more of the following two-carbon organic compounds: trichloroethylene, tetrachloroethylene, 1,2-dichloroethane, 1,1,1-trichloroethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, or 1,1- dichloroethylene shall monitor quarterly for vinyl chloride. A vinyl chloride sample shall be taken at each sampling point at which one or more of the two- carbon organic compounds were detected. If the results of the first analysis do not detect vinyl chloride, the Department may reduce the quarterly monitoring frequency of vinyl chloride monitoring to one sample during each compliance period. Surface water systems are required to monitor for vinyl chloride as specified by the Department.

(12) Systems which violate the volatile organic chemical contaminant MCL requirements of Table 2-1(1)-(21), as determined by section 6.2.3(a), must monitor quarterly. After a minimum of four consecutive quarterly samples which show the system is in compliance as specified in section 6.2.3(a) and the Department determines that the system is reliably and consistently below the maximum contaminant level, the system may monitor at the frequency and times specified in section 6.2.5(a)(11)(iii).

(13) The Department may require a confirmation sample for positive or negative results. If a confirmation sample is required by the Department, the result must be averaged with the first sampling result and the average is used for the compliance determination as specified by section 6.2.3(a). The Department has discretion to invalidate results of sampling or analytic errors.

(14) Compositing of Samples:

1. (i) The Department may reduce the total number of samples a system must analyze by allowing the use of compositing. Composite samples from a maximum of five sampling points are allowed, provided that the detection limit of the method used for analysis is less than one-fifth of the MCL.
   1. (ii) Compositing of samples must be done in the laboratory and analyzed within 14 days of sample collection.
      1. (A) If the concentration in the composite sample is greater than or equal to ( ≥ )
         1. 0.0005 mg/L for any volatile organic chemical contaminant listed in Table

            2-1, then a follow-up sample must be taken within 14 days at each sampling point included in the composite, and be analyzed for that chemical contaminant.

         2. (B) If duplicates of the original sample taken from each sampling point used in the composite sample are available, the system may use these instead of re-sampling. The duplicates must be analyzed and the results reported to the Department within 14 days after completing analysis of the composite sample, provided the holding time of the sample is not exceeded.
         3. (C) If the population served by the system is greater than ( > ) 3,300 persons, compositing is only permitted at sampling points within a single system. In systems serving less than or equal to (≤) 3,300 persons, the compositing is permitted among different systems provided the 5-sample limit is maintained.

(15) The Department may allow the use of monitoring data collected after January 1, 1988, required under section 1445 of the Safe Drinking Water Act for purposes of initial monitoring compliance. If the data are generally consistent with the other requirements of section 6.2.5, the Department may use these data (i.e., a single sample rather than four quarterly samples) to satisfy the initial monitoring requirements of section 6.2.5(a)(4). Systems which use grandfathered samples and did not detect any chemical contaminant listed in Table 2-1(1) through (21) shall begin monitoring annually in accordance with section 6.2.5(a)(5) beginning with the initial compliance period.

(16) States may increase required monitoring where necessary to detect variations within the system.

6.2.6 Synthetic Organic Chemical Contaminant Monitoring Requirements

(a) Analysis of the synthetic organic chemical contaminants, listed in Table 2-2, for the purposes of determining compliance with the maximum contaminant level shall be conducted as follows: 6-2 6-2 Monitoring for the contaminants aldicarb, aldicarb sulfoxide, and aldicarb sulfone shall be conducted in accordance with §141.40 (Unregulated Contaminant Monitoring Rule).

(1) Groundwater systems shall take a minimum of one sample at every entry point to the distribution system, which is representative of each well after treatment (hereafter called a sampling point). Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.

(2) Surface 6-3 water systems shall take a minimum of one sample at points in the distribution system that are representative of each source or at each entry point to the distribution system after treatment (hereafter called a sampling point). Each sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.

6-3 For purposes of this paragraph, surface water systems include systems with a combination of surface and ground sources.

(3) If the system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water representative of all sources is being used).

(4) Monitoring frequency:

1. (i) Each community and non-transient, non-community water system shall take four consecutive quarterly samples for each synthetic organic chemical contaminant, listed in Table 2-2, during each compliance period beginning with the initial compliance period.
   1. (ii) Systems serving more than 3,300 persons that do not detect a chemical contaminant in the initial compliance period may reduce the sampling frequency to a minimum of two quarterly samples in one year during each repeat compliance period.
      1. (iii) Systems serving less than or equal to 3,300 persons which do not detect a chemical contaminant in the initial compliance period may reduce the sampling frequency to a minimum of one sample during each repeat compliance period.

(5) Each community and non-transient water system may apply to the Department for a waiver from the requirement of section 6.2.6(a)(4). A system must reapply for a waiver for each compliance period.

(6) The Department may grant a waiver after evaluating the following factor(s):

1. (i) Knowledge of previous use (including transport, storage, or disposal) of the chemical contaminant within the watershed or zone of influence of the system. If a determination by the Department reveals no previous use of the chemical contaminant within the watershed or zone of influence, a waiver may be granted.
   1. (ii) If previous use of the chemical contaminant is unknown or it has been used previously, then the following factors shall be used to determine whether a waiver is granted.
      1. (A) Previous analytical results.
         1. (B) The proximity of the system to a potential point or non-point source of contamination. Point sources include spills and leaks of chemical contaminants at or near a water treatment facility or at manufacturing, distribution, or storage facilities, or from hazardous and municipal waste landfills and other waste handling or treatment facilities. Non-point sources include the use of pesticides to control insect and weed pests on agricultural areas, forest lands, home and gardens, and other land application uses.
         2. (C) The environmental persistence and transport of the pesticide or PCBs.
         3. (D) How well the water source is protected against contamination due to such factors as depth of the well and the type of soil and the integrity of the well casing.
         4. (E) Elevated nitrate levels at the water supply source.
         5. (F) Use of PCBs in equipment used in the production, storage, or distribution of water (i.e., PCBs used in pumps, transformers, etc.).

(7) If a synthetic organic chemical contaminant listed in Table 2-2 is detected (as defined by section 10.3.3) in any sample, then:

1. (i) Each system must monitor quarterly at each sampling point that resulted in a detection.
   1. (ii) The Department may decrease the quarterly monitoring requirement specified in section 6.2.6(a)(7)(i) provided it has determined that the system is reliably and consistently below the maximum contaminant level. In no case will the Department make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface water system takes a minimum of four quarterly samples.
      1. (iii) After the Department determines the system is reliably and consistently below the maximum contaminant level the Department may allow the system to monitor annually. Systems that monitor annually must monitor during the quarter that previously yielded the highest analytical result.
         1. (iv) Systems that have 3 consecutive annual samples with no detection of a chemical contaminant, may apply to the Department for a waiver as specified in section 6.2.6(a)(6).
         2. (v) If monitoring results in detection of one or more of certain related chemical contaminants (aldicarb, aldicarb sulfone, aldicarb sulfoxide and heptachlor, heptachlor epoxide), then subsequent monitoring shall analyze for all related chemical contaminants.

(8) Systems which violate the synthetic organic chemical contaminant MCL requirements of Table 2-2 as determined by section 6.2.3(b) must monitor quarterly. After a minimum of four quarterly samples show the system is in compliance and the Department determines the system is reliably and consistently below the MCL, as specified in section 6.2.3(b), the system shall monitor at the frequency specified in section 6.2.6(a)(7)(iii).

(9) The Department may require a confirmation sample for positive results and may require a confirmation sample for negative results. If required by the Department, the confirmation sample result must be averaged with the first sampling result and the average used for the compliance determination as specified by section 6.2.3(b). The Department has discretion to invalidate results of sampling or analytic errors.

(10) The Department may reduce the total number of samples a system must analyze by allowing the use of compositing. Composite samples from a maximum of five sampling points are allowed, provided that the detection limit of the method used for analysis is less than one-fifth ( < 1/5) of the MCL. Compositing of samples must be done in the laboratory and analyzed within 14 days of sample collection.

1. (i) If the concentration in the composite sample detects one or more chemical contaminants listed in Table 2-2, then a follow-up sample must be taken within 14 days at each sampling point included in the composite, and be analyzed for that chemical contaminant.
   1. (ii) If duplicates of the original sample taken from each sampling point used in the composite sample are available, the system may use these instead of re- sampling. The duplicates must be analyzed and the results reported to the Department within 14 days after completion of the composite analysis or before the holding time for the initial sample is exceeded whichever is sooner.
      1. (iii) If the population served by the system is greater than ( > ) 3,300 persons, compositing is only permitted at sampling points within a single system. In systems serving less than or equal to (≤) 3,300 persons, compositing is permitted among different systems provided the 5-sample limit is maintained.

(11) The Department may increase the required monitoring frequency, where necessary, to detect variations within the system (e.g., fluctuations in concentration due to seasonal use, changes in water source).

6.3 Radionuclides

6.3.1 Applicability

Section 6.3 applies to all community public water systems in Colorado.

6.3.2 Monitoring Requirements for Gross Alpha Particle Activity, Radium-226, Radium-228, and Uranium (a) Community water systems must conduct initial monitoring to determine compliance with the MCLs and MCLGs for Radionuclides, Table 2-7(1), (2), and (4) by December 31, 2007. For the purposes of monitoring for gross alpha particle activity, radium-226, radium-228, and uranium in drinking water, "detection limit" is defined in section 10.4.1(c)(1).

(1) All existing community water systems using groundwater, surface water or systems using both ground and surface water (for the purpose of this section hereafter referred to as systems) must sample at every entry point to the distribution system that is representative of all sources being used (hereafter called a sampling point) under normal operating conditions. The system must take each sample at the same sampling point unless conditions make another sampling point more representative of each source.

(2) All new community water systems or community water systems that use a new source of water must begin to conduct initial monitoring for the new source within the first quarter after initiating use of the source. Community water systems must conduct more frequent monitoring when ordered by the Department in the event of possible contamination or when changes in the distribution system or treatment processes occur which may increase the concentration of radioactivity in finished water.

(b) Systems must conduct initial monitoring for gross alpha particle activity, radium-226, radium-228, and uranium as follows:

(1) Systems without acceptable historical data, as defined below, must collect four consecutive quarterly samples at all sampling points before December 31, 2007.

(2) The Department may allow historical monitoring data collected at a sampling point to satisfy the initial monitoring requirements for that sampling point, for the following situations.

1. (i) To satisfy initial monitoring requirements, a community water system having only one entry point to the distribution system may use the monitoring data from the last compliance monitoring period that began between June 2000 and December 8, 2003.
   1. (ii) To satisfy initial monitoring requirements, a community water system with multiple entry points and having appropriate historical monitoring data for each entry point to the distribution system may use the monitoring data from the last compliance monitoring period that began between June 2000 and December 8, 2003.

(3) For gross alpha particle activity, uranium, radium-226, and radium-228 monitoring, the Department may waive the final two quarters of initial monitoring for a sampling point if the results of the samples from the previous two quarters are below the detection limit.

(4) If the average of the initial monitoring results for a sampling point is above the MCL, the system must collect and analyze quarterly samples at that sampling point until the system has results from four consecutive quarters that are at or below the MCL, unless the system enters into another schedule as part of a formal compliance agreement with the Department.

(c) The Department may allow community water systems to reduce the future frequency of monitoring from once every three years to once every six or nine years at each sampling point, based on the following criteria.

(1) If the average of the initial monitoring results for each contaminant (i.e., gross alpha particle activity, uranium, radium-226, or radium-228) is below the detection limit specified in section 10.4.1(c)(1), the system must collect and analyze for that contaminant using at least one sample at that sampling point every nine years.

(2) For gross alpha particle activity and uranium, if the average of the initial monitoring results for each contaminant is at or above the detection limit but at or below 1/2 the MCL, the system must collect and analyze for that contaminant using at least one sample at that sampling point every six years. For combined radium-226 and radium-228, the analytical results must be combined. If the average of the combined initial monitoring results for radium-226 and radium-228 is at or above the detection limit but at or below 1/2 the MCL, the system must collect and analyze for that contaminant using at least one sample at that sampling point every six years.

(3) For gross alpha particle activity and uranium, if the average of the initial monitoring results for each contaminant is above 1/2 the MCL but at or below the MCL, the system must collect and analyze at least one sample at that sampling point every three years. For combined radium-226 and radium-228, the analytical results must be combined. If the average of the combined initial monitoring results for radium-226 and radium-228 is above 1/2 the MCL but at or below the MCL, the system must collect and analyze at least one sample at that sampling point every three years.

(4) Systems must use the samples collected during the reduced monitoring period to determine the monitoring frequency for subsequent monitoring periods (e.g., if a system's sampling point is on a nine year monitoring period, and the sample result is above 1/2 MCL, then the next monitoring period for that sampling point is three years).

(5) If a system has a monitoring result that exceeds the MCL while on reduced monitoring, the system must collect and analyze quarterly samples at that sampling point until the system has results from four consecutive quarters that are below the MCL, unless the system enters into another schedule as part of a formal compliance agreement with the Department.

(d) COMPOSITING: To fulfill quarterly monitoring requirements for gross alpha particle activity, radium- 226, radium-228, or uranium, a system may composite up to four consecutive quarterly samples from a single entry point if analysis is done within a year of the first sample. The Department will treat analytical results from the composited as the average analytical result to determine compliance with the MCLs and the future monitoring frequency. If the analytical result from the composited sample is greater than 1/2 MCL, the Department may direct the system to take additional quarterly samples before allowing the system to sample under a reduced monitoring schedule.

(e) A gross alpha particle activity measurement may be substituted for the required radium-226 measurement provided that the measured gross alpha particle activity does not exceed 5 pCi/L. A gross alpha particle activity measurement may be substituted for the required uranium measurement provided that the measured gross alpha particle activity does not exceed 15 pCi/L. The gross alpha measurement shall have a confidence interval of 95% (1.65σ, where σ is the standard deviation of the net counting rate of the sample) for radium-226 and uranium. When a system uses a gross alpha particle activity measurement in lieu of a radium-226 and/or uranium measurement, the gross alpha particle activity analytical result will be used to determine the future monitoring frequency for radium-226 and/or uranium. If the gross alpha particle activity result is less than detection, 1/2 the detection limit will be used to determine compliance and the future monitoring frequency.

6.3.3 Monitoring and Compliance Requirements for Beta Particle and Photon Radioactivity For the purposes of monitoring for beta particle and photon radioactivity in drinking water, "detection limit" is defined in section 10.4.1(c)(2). To determine compliance with the maximum contaminant levels in Table 2-7(3) for beta particle and photon radioactivity, a system must monitor at a frequency as follows:

(a) Community water systems (both surface and groundwater) designated by the Department as vulnerable must sample for beta particle and photon radioactivity. Systems must collect quarterly samples for beta emitters and annual samples for tritium and strontium-90 at each entry point to the distribution system (hereafter called a sampling point), beginning within one quarter after being notified by the Department. Systems already designated by the Department must continue to sample until the Department reviews and either reaffirms or removes the designation.

(1) If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity at a sampling point has a running annual average (computed quarterly) less than or equal to 15 pCi/L (screening level), the Department may reduce the frequency of monitoring at that sampling point to once every 3 years. Systems must collect all samples required in section 6.3.3(a) during the reduced monitoring period.

(2) For systems in the vicinity of a nuclear facility, the Department may allow the community water system to utilize environmental surveillance data collected by the nuclear facility in lieu of monitoring at the system's entry point(s), where the Department determines if such data is applicable to a particular water system. In the event that there is a release from a nuclear facility, systems that are using surveillance data must begin monitoring at the community water system's entry point(s) in accordance with section 6.3.3(a).

(b) Community water systems (both surface and groundwater) designated by the Department as utilizing waters contaminated by effluents from nuclear facilities must sample for beta particle and photon radioactivity. Systems must collect quarterly samples for beta emitters and iodine-131 and annual samples for tritium and strontium-90 at each entry point to the distribution system (hereafter called a sampling point), beginning within one quarter after being notified by the Department. Systems already designated by the Department as systems using waters contaminated by effluents from nuclear facilities must continue to sample until the Department reviews and either reaffirms or removes the designation.

(1) Quarterly monitoring for gross beta particle activity shall be based on the analysis of monthly samples or the analysis of a composite of three monthly samples. The former is recommended.

(2) For iodine-131, a composite of five consecutive daily samples shall be analyzed once each quarter. As ordered by the Department, more frequent monitoring shall be conducted when iodine-131 is identified in the finished water.

(3) Annual monitoring for strontium-90 and tritium shall be conducted by means of the analysis of a composite of four consecutive quarterly samples or analysis of four quarterly samples. The latter procedure is recommended.

(4) If the gross beta particle activity beta minus the naturally occurring potassium-40 beta particle activity at a sampling point has a running annual average (computed quarterly) less than or equal to 15 pCi/L, the Department may reduce the frequency of monitoring at that sampling point to every 3 years. Systems must collect all samples required in section 6.3.3(b) during the reduced monitoring period.

(5) For systems in the vicinity of a nuclear facility, the Department may allow the community water system to utilize environmental surveillance data collected by the nuclear facility in lieu of monitoring at the system's entry point(s), where the Department determines if such data is applicable to a particular water system. In the event that there is a release from a nuclear facility, systems that are using surveillance data must begin monitoring at the community water system's entry point(s) in accordance with section 6.3.3(b).

(c) Community water systems designated by the Department to monitor for beta particle and photon radioactivity cannot apply to the Department for a waiver from the monitoring frequencies specified in sections 6.3.3(a) or 6.3.3(b).

(d) Community water systems may analyze for naturally occurring potassium-40 beta particle activity from the same or equivalent sample used for the gross beta particle activity analysis. Systems are allowed to subtract the potassium-40 beta particle activity value from the total gross beta particle activity value to determine if the screening level is exceeded. The potassium-40 beta particle activity must be calculated by multiplying elemental potassium concentrations (in mg/L) by a factor of 0.82.

(e) If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity exceeds the appropriate screening level, an analysis of the sample must be performed to identify the major radioactive constituents present in the sample and the appropriate doses must be calculated and summed to determine compliance with Table 2-7(3), using the formula in section 6.3.6. Doses must also be calculated and combined for measured levels of tritium and strontium to determine compliance.

(f) Systems must monitor monthly at the sampling point(s) that exceed the maximum contaminant level in Table 2-7(3) beginning the month after the exceedance occurs. Systems must continue monthly monitoring until the system has established, by a rolling average of three (3) monthly samples, that the MCL is being met. Systems who establish that the MCL is being met must return to quarterly monitoring until they meet the requirements set forth in section 6.3.3(a)(2) or 6.3.3(b)(1).

6.3.4 General Monitoring and Compliance Requirements for Radionuclides

(a) The Department may require more frequent monitoring than specified in sections 6.3.2 and 6.3.3, or may require confirmation samples at its discretion. The results of the initial and confirmation samples will be averaged for use in compliance determinations.

(b) Each public water system shall monitor at the time designated by the Department during each compliance period.

6.3.5 Compliance Determination

(a) Compliance with MCLs of Table 2-7 will be determined based on the analytical result(s) obtained at each sampling point. If one sampling point is in violation of an MCL, the system is in violation of the MCL.

(1) For systems monitoring more than once per year, compliance with the MCL is determined by a running annual average at each sampling point. If the average of any sampling point is greater than the MCL, then the system is out of compliance with the MCL.

(2) For systems monitoring more than once per year, if any sample result will cause the running average to exceed the MCL at any sample point, the system is out of compliance with the MCL immediately.

(3) Systems must include all samples taken and analyzed under the provisions of this section in determining compliance, even if that number is greater than the minimum required.

(4) If a system does not collect all required samples when compliance is based on a running annual average of quarterly samples, compliance will be based on the running average of the samples collected.

(5) If a sample result is less than the detection limit, zero will be used to calculate the annual average, unless a gross alpha particle activity is being used in lieu of radium-226 and/or uranium. If the gross alpha particle activity result is less than detection, 1/2 the detection limit will be used to calculate the annual average.

(b) The Department may, at its discretion, invalidate results of sampling or analytic errors.

(c) If the MCL for a radionuclide, listed in Table 2-7, is exceeded, the operator of a community water system must give notice to the Department pursuant to section 1.6.4 and to the public as required by Article 9.

(d) To judge compliance with the MCLs listed in Table 2-7, averages of data shall be used and shall be rounded to the same number of significant figures as the maximum contaminant level for the substance in question.

(e) The Department may determine compliance or initiate enforcement action based upon analytical results or other information compiled by Department representatives and agencies.

6.3.6 Calculation of Maximum Contaminant Levels for Beta Particle and Photon Radioactivity Except for the radionuclides listed in Table 6-4, the concentration of man-made radionuclides causing 4 mrem total body or organ dose equivalents must be calculated on the basis of 2 liter per day drinking water intake using the 168 hour data list in “Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air and in Water for Occupational Exposure,” NBS (National Bureau of Standards) Handbook 69 as amended August 1963, U.S. Department of Commerce 6- 4 . If two or more radionuclides are present, the sum of their annual dose equivalent to the total body or to any organ shall not exceed 4 mrem/year.

6-4 Copies of this document are available from the National Technical Information Service, NTIS ADA 280 282, U.S. Department of Commerce, 5285 Port Royal Road, Springfield, Virginia 22161. The toll-free number is 800-553-6847. Copies may be inspected at EPA’s Drinking Water Docket, 401 M Street, SW, Washington, DC 20460; or at the Office of the Federal Register, 800 North Capitol Street, NW, Suite 700, Washington, DC.

Table 6-4 Average Annual Concentrations Assumed to Produce a Total Body or Organ Dose of 4 mrem/yr Radionuclide Critical Organ picoCurie per liter (pCi/L)

Tritium Total body 20,000 Strontium-90 Bone Marrow 8 6.3.7 Best Available Technologies (BATs) and Small Systems Compliance Technologies (SSCTs) for Radionuclides (a) The EPA Administrator hereby identifies in the following table the best technology available for achieving compliance with the maximum contaminant levels for combined radium-226 and -228, uranium, gross alpha particle activity, and beta particle and photon radioactivity. Table 6-5 BAT for Combined Radium-226 and Radium-228, Uranium, Gross Alpha Particle Activity, and Beta Particle and Photon Radioactivity . Contaminant BAT 1 Combined radium-226 Ion exchange, reverse and radium-228 osmosis, lime softening.

2 Uranium Ion exchange, reverse osmosis, lime softening, coagulation/filtration.

3 Gross alpha particle Reverse osmosis.

1. activity (excluding radon and uranium)

4 Beta particle and photon Ion exchange, reverse radioactivity osmosis.

(b) Small systems compliance technologies list for radionuclides. Table 6-6 List of Small Systems Compliance Technologies for Radionuclides and Limitations to Use . Unit technologies Limitations Operator skill level required 1 Ion exchange (IE) (a) Intermediate 2 2 (b) Basic Point of use (POU ) IE 3 Reverse osmosis (RO) (c) Advanced 4 2 (b) Basic POU RO 5 Lime softening (d) Advanced 6 Green sand filtration (e) Basic 7 Co-precipitation with (f) Intermediate to Advanced Barium sulfate 8 Electrodialysis/ . Basic to Intermediate electrodialysis reversal 9 Pre-formed hydrous (g) Intermediate Manganese oxide filtration 10 Activated alumina (a), (h) Advanced 11 Enhanced (i) Advanced coagulation/filtration 1 National Research Council (NRC). Safe Water from Every Tap: Improving Water Service to Small Communities. National Academy Press. Washington, D.C. 1997.

2 POU devices are typically installed at the kitchen faucet or other point of end use (i.e. drinking fountain, ice maker, etc.). See the April 21, 2000 NODA for more details.

1. Limitations of “Unit Technologies” Listed in Table 6-6:

(a) The regeneration solution contains high concentrations of the contaminant ions. Disposal options should be carefully considered before choosing this technology.

(b) When POU devices are used for compliance, programs for long-term operation, maintenance, and monitoring must be provided by water utility to ensure proper performance.

(c) Reject water disposal options should be carefully considered before choosing this technology. See other RO limitations described in the SWTR Compliance Technologies Table.

(d) The combination of variable source water quality and the complexity of the water chemistry involved may make this technology too complex for small surface water systems.

(e) Removal efficiencies can vary depending on water quality.

(f) This technology may be very limited in application to small systems. Since the process requires static mixing, detention basins, and filtration, it is most applicable to systems with sufficiently high sulfate levels that already have a suitable filtration treatment train in place.

(g) This technology is most applicable to small systems that already have filtration in place.

(h) Handling of chemicals required during regeneration and pH adjustment may be too difficult for small systems without an adequately trained operator.

(i) Assumes modification to a coagulation/filtration process already in place. Table 6-7 Compliance Technologies by System Size Category Contaminant Compliance Compliance Compliance 1 1 1 Technologies For Technologies For Technologies For System Size Categories System Size Categories System Size Categories (population served) (population served) (population served) . 25 - 500 501 - 3,300 3,301 - 10,000 Combined radium-226 1, 2, 3, 4, 5, 6, 7, 8, 9 1, 2, 3, 4, 5, 6, 7, 8, 9 1, 2, 3, 4, 5, 6, 7. 8, 9 and radium-228 Gross alpha particle 3, 4 3, 4 3, 4.

activity Beta particle activity and 1, 2, 3, 4 1, 2, 3, 4 1, 2, 3, 4. photon activity Uranium 1, 2, 4, 10, 11 1, 2, 3, 4, 5, 10, 11 1, 2, 3, 4, 5, 10, 11. 1 These numbers correspond to the “Unit Technologies” listed in the Table 6-6 of section 6.3.7(b). These numbers correspond to the “Unit Technologies” listed in the Table 6-6 of section 6.3.7(b).

6.4 Unregulated Contaminant Monitoring

All community and non-transient, non-community water systems shall monitor for the unregulated contaminants as described in 40 CFR 141.40.

Article 7 Filtration, Disinfection, and Disinfection Byproducts

7.1 Filtration and Disinfection for Surface Water

7.1.1 General Requirements

(a) The requirements of this section 7.1 establish criteria under which filtration is required as a treatment technique for public water systems supplied by a surface water source and public water systems supplied by a groundwater source under the direct influence of surface water. In addition, these regulations establish treatment technique requirements for the following contaminants: Giardia lamblia, viruses, heterotrophic plate count bacteria, Legionella, and turbidity. Each public water system with a surface water source or a groundwater source under the direct influence of surface water must provide treatment of that source water that complies with these treatment technique requirements. The treatment technique requirements consist of installing and properly operating water treatment processes which reliably achieve:

(1) At least 99.9 percent (3-log) removal and/or inactivation of Giardia lamblia cysts between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer; and (2) At least 99.99 percent (4-log) removal and/or inactivation of viruses between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer.

(b) A public water system using a surface water source or a groundwater source under the direct influence of surface water is considered to be in compliance with the requirements of section 7.1.1(a) if it meets the filtration requirements in section 7.1.3 and the disinfection requirements in section 7.1.2.

(c) Each public water system using a surface water source or a groundwater source under the direct influence of surface water must be operated by qualified personnel who meet the requirements of Regulation 100 for operator certification.

(d) In addition to complying with requirements in this section 7.1, public water systems serving 10,000 or more people must also comply with the requirements in section 7.2 of this Article 7.

(e) In addition to complying with requirements in this section 7.1, public water systems serving fewer than 10,000 people must also comply with the requirements in section 7.3 of this Article 7 beginning on January 1, 2005 unless otherwise specified.

7.1.2 Disinfection

(a) If the Department has determined that a system must install filtration, the system shall take such action to protect the public health as the Department determines to be necessary before filtration is installed. A system that uses a surface water source or a groundwater source under the direct influence of surface water must provide the disinfection treatment specified in section 7.1.2(c).

(1) Once a groundwater source has been determined, through the results of an microscopic particulate analysis (MPA), visual well inspection or correlation of source water parameters with surface conditions, to be under the direct influence of surface water, the system must provide disinfection treatment as specified in section 7.1.2(c) beginning 60 days from the date the system has been reclassified.

(b) Failure to meet any requirement of this section 7.1.2 is a treatment technique violation.

(c) Disinfection requirements for public water systems which provide filtration. Each public water system that provides filtration treatment must provide disinfection treatment as follows.

(1) The disinfection treatment must be sufficient to ensure that the total treatment processes of that system achieve at least 99.9 percent (3-log) inactivation and/or removal of Giardia lamblia cysts and at least 99.99 percent (4-log) inactivation and/or removal of viruses, as determined by the Department.

(2) The residual disinfectant concentration in the water entering the distribution system, measured as specified in sections 7.1.4(a)(2) and 10.5.1(a)(2), cannot be less than 0.2 mg/L for more than 4 hours.

(3) The residual disinfectant concentration in the distribution system:

1. (i) The residual disinfectant concentration in the distribution system, measured as total chlorine, free chlorine or chlorine dioxide, as specified in sections 7.1.4(a)(3) and 10.5.1(a)(2), cannot be undetectable in more than 5 percent of the samples each month, for any two consecutive months that the system serves water to the public. Water in the distribution system with a heterotrophic bacteria concentration less than or equal to 500/mL, measured as heterotrophic plate count (HPC) as specified in section 10.5.1, is deemed to have a detectable disinfectant residual for purposes of determining compliance with this requirement. Thus, the value "V" in the following formula cannot exceed 5 percent in one month, for any two consecutive months:
   1. V=((c+d+e)/(a+b)) * 100 where:
      1. a = number of instances where the residual disinfectant concentration is measured;
         1. b = number of instances where the residual disinfectant concentration is not measured but heterotrophic bacteria plate count (HPC) is measured; c = number of instances where the residual disinfectant concentration is measured but not detected and no HPC is measured;

            d = number of instances where no residual disinfectant concentration is detected and where the HPC is > 500/mL; and e = number of instances where the residual disinfectant concentration is not measured and HPC is > 500/mL.

         2. (ii) If the Department determines, based on site-specific considerations, that a system has no means for having a sample transported and analyzed for HPC by a certified laboratory under the requisite time and temperature conditions specified in section 10.5.1(a)(1) and that the system is providing adequate disinfection in the distribution system, the requirements of section 7.1.2(c)(3)(i) do not apply.

7.1.3 Filtration

(a) A public water system that uses a surface water source or a groundwater source under the direct influence of surface water and serves 10,000 or more people must provide treatment consisting of both disinfection, as specified in section 7.1.2, and filtration treatment which complies with the requirements of Sections 7.1.3(f) or (g) or Sections 7.2.3(a), (b) or (c).

(b) A public water system that uses a surface water source or a groundwater source under the direct influence of surface water and serves fewer than 10,000 people must provide treatment consisting of both disinfection, as specified in section 7.1.2, and filtration treatment which complies with the requirements of section 7.1.3(e), (f), (g) or (h) through December 31, 2004. Beginning January 1, 2005, these systems must provide treatment consisting of both disinfection, as specified in section 7.1.2, and filtration treatment which complies with the requirements of Sections 7.1.3(f) or (g) or Sections 7.3.4(a), (b) or (c).

(c) Failure to meet any requirement of this section 7.1.3 is a treatment technique violation (d) Once a groundwater source has been determined, through the results of an MPA, visual well inspection or correlation of source water parameters with surface conditions, to be under the direct influence of surface water, the system must install filtration treatment designed to meet the turbidity requirements specified in section 7.1.3(e), (f), (g) or (h), section 7.2.3(a), (b) or (c), or section 7.3.4(a), (b), or (c) within 18 months of written notice from the Department.

(e) Conventional filtration treatment or direct filtration.

(1) For systems using conventional filtration or direct filtration, the turbidity level of representative samples of a system's filtered water must be less than or equal to 0.5 NTU in at least 95 percent of the measurements taken each month, measured as specified in sections 7.1.4(a)(1) and 10.5.1(a)(1), except that if the Department determines that the system is capable of achieving at least 99.9 percent removal and/or inactivation of Giardia lamblia cysts at some turbidity level higher than 0.5 NTU in at least 95 percent of the measurements taken each month, the Department may substitute this higher turbidity limit for that system. However, in no case may the Department approve a turbidity limit that allows more than 1 NTU in more than 5 percent of the samples taken each month, measured as specified in sections 7.1.4(a)(1) and 10.5.1(a)(1).

(2) The turbidity level of representative samples of a system's filtered water must at no time exceed 5 NTU, measured as specified in sections 7.1.4(a)(1) and 10.5.1(a)(1).

(f) Slow sand filtration.

(1) For systems using slow sand filtration, the turbidity level of representative samples of a system's filtered water must be less than or equal to 1 NTU in at least 95 percent of the measurements taken each month, measured as specified in sections 7.1.4(a)(1) and 10.5.1(a)(1), except that if the Department determines there is no significant interference with disinfection at a higher turbidity level, the Department may substitute this higher turbidity limit for that system.

(2) The turbidity level of representative samples of a system's filtered water must at no time exceed 5 NTU, measured as specified in sections 7.1.4(a)(1) and 10.5.1(a)(1).

(g) Diatomaceous earth filtration.

(1) For systems using diatomaceous earth filtration, the turbidity level of representative samples of a system's filtered water must be less than or equal to 1 NTU in at least 95 percent of the measurements taken each month, measured as specified in sections 7.1.4(a)(1) and 10.5.1(a)(1).

(2) The turbidity level of representative samples of a system's filtered water must at no time exceed 5 NTU, measured as specified in sections 7.1.4(a)(1) and 10.5.1(a)(1).

(h) Other filtration technologies. A public water system may use a filtration technology not listed in sections 7.1.3(e) -(g) if it demonstrates to the Department, using pilot plant studies or other means, that the alternative filtration technology, in combination with disinfection treatment that meets the requirements of section 7.1.3, consistently achieves 99.9 percent removal and/or inactivation of Giardia lamblia cysts and 99.99 percent removal and/or inactivation of viruses. For a system that makes this demonstration, the requirements of section 7.1.3(f) shall apply.

7.1.4 Monitoring Requirements

(a) Monitoring requirements for systems using filtration treatment. A public water system that uses a surface water source or a groundwater source under the influence of surface water must monitor in accordance with this section 7.1.4. Groundwater systems found to be under the influence must begin monitoring in accordance with this section 7.1.4 beginning 18 months following written notification from the Department.

(1) Turbidity measurements as required by section 7.1.3 must be performed every four hours (or more frequently) on samples of water collected from a location representative of the combined filtered water provided to the public. A public water system may substitute continuous turbidity monitoring for grab sample monitoring if it validates the continuous measurement for accuracy on a regular basis using a protocol approved by the Department. For any systems using slow sand filtration or filtration treatment other than conventional treatment, direct filtration, or diatomaceous earth filtration, the Department may reduce the sampling frequency to once per day if it determines that less frequent monitoring is sufficient to indicate effective filtration performance. For systems serving 500 or fewer persons, the Department may reduce the turbidity sampling frequency to once per day, regardless of the type of filtration treatment used, if the Department determines that less frequent monitoring is sufficient to indicate effective filtration performance.

(2) The residual disinfectant concentration of the water entering the distribution system must be monitored continuously, and the lowest value must be recorded each day, except that if there is a failure in the continuous monitoring equipment, grab sampling every 4 hours may be conducted in lieu of continuous monitoring, but for no more than 5 working days following the failure of the equipment, and systems serving 3,300 or fewer persons may take grab samples in lieu of providing continuous monitoring on an ongoing basis at the frequencies each day prescribed below:

Table 7-1 Minimum Grab Samples in the Event of Continuous Monitor Equipment Failure System size by 1 Samples/day population ≤ 500 1 501 - 1,000 2 1,001 - 2,500 3 2,501 - 3,300 4 1 When more than one sample is required, each sample must be taken at a different time during the day. The sampling intervals are subject to Department review and approval.

1. If at any time the residual disinfectant concentration entering the distribution system falls below 0.2 mg/L in a system using grab sampling in lieu of continuous monitoring, the system must take a grab sample every 4 hours until the residual disinfectant concentration is equal to or greater than 0.2 mg/L.

(3) (i) The residual disinfectant concentration must be measured at least at the same points in the distribution system and at the same time as total coliforms are sampled, as specified in section 5.1.1, except that the Department may allow a public water system which uses both a surface water source or a groundwater source under direct influence of surface water, and a groundwater source to take disinfectant residual samples at points other than the total coliform sampling points if the Department determines that such points are more representative of treated (disinfected) water quality within the distribution system. Heterotrophic bacteria, measured as heterotrophic plate count (HPC) as specified in section 10.5.1(a)(1), may be measured in lieu of residual disinfectant concentration.

1. (ii) If the Department determines, based on site-specific considerations, that a system has no means for having a sample transported and analyzed for HPC by a certified laboratory under the requisite time and temperature conditions specified by section 10.5.1(a)(1) and that the system is providing adequate disinfection in the distribution system, the requirements of section 7.1.4(a)(3)(i) do not apply to that system.

7.1.5 Reporting and Recordkeeping Requirements

(a) A public water system that uses a surface water source or a groundwater source under the direct influence of surface water and provides filtration treatment must report monthly to the Department the information specified in this section 7.1.5.

(1) Turbidity measurements as required by section 7.1.4(a)(1) must be reported within 10 days after the end of each month the system serves water to the public. Information that must be reported includes:

1. (i) The total number of filtered water turbidity measurements recorded during the month.
   1. (ii) The number and percentage of filtered water turbidity measurements recorded during the month which are less than or equal to the turbidity limits specified in section
      1. 7.1.3 for the filtration technology being used.
         1. (iii) The date and value of any turbidity measurements taken during the month, which exceed 5 NTU.

(2) Disinfection information specified in section 7.1.4(a)(2) - (3) must be reported to the Department within 10 days after the end of each month the system serves water to the public. Information that must be reported includes:

1. (i) For each day, the lowest measurement of residual disinfectant concentration in mg/L in water entering the distribution system.
   1. (ii) The date and duration of each period when the residual disinfectant concentration in water entering the distribution system fell below 0.2 mg/L and when the Department was notified of the occurrence.
      1. (iii) The following information on the samples taken in the distribution system in conjunction with total coliform monitoring pursuant to section 7.1.2:
         1. (A) Number of instances where the residual disinfectant concentration is measured;
         2. (B) Number of instances where the residual disinfectant concentration is not measured but heterotrophic bacteria plate count (HPC) is measured;
         3. (C) Number of instances where the residual disinfectant concentration is measured but not detected and no HPC is measured;
         4. (D) Number of instances where no residual disinfectant concentration is detected and where HPC is > 500/mL;
         5. (E) Number of instances where the residual disinfectant concentration is not measured and HPC is > 500/mL;
         6. (F) For the current and previous month the system serves water to the public, the value of "V" in the following formula:

            V=((c+d+e)/(a+b)) * 100 where:

            a = the value in section 7.1.5(a)(2)(iii)(A), b = the value in section 7.1.5(a)(2)(iii)(B), c = the value in section 7.1.5(a)(2)(iii)(C), d = the value in section 7.1.5(a)(2)(iii)(D), and e = the value in section 7.1.5(a)(2)(iii)(E).

         7. (G) If the Department determines, based on site-specific considerations, that a system has no means for having a sample transported and analyzed for HPC by a certified laboratory within the requisite time and temperature conditions specified by section 10.5.1(a)(1) and that the system is providing adequate disinfection in the distribution system, the requirements of Sections 7.1.5(a)(2)(iii) (A)-(F) do not apply.
         8. (iv) A system need not report the data listed in section 7.1.5(a)(2)(i) if all data listed in section 7.1.5(a)(2) (i)-(iii) remain on file at the system and the Department determines that the system has submitted all the information required by section 7.1.5(a)(2) (i)-(iii) for at least 12 months.

(3) (i) Each system, upon discovering that a waterborne disease outbreak potentially attributable to that water system has occurred, must report that occurrence to the Department as soon as possible, but no later than by the end of the next business day.

1. (ii) If at any time the turbidity exceeds 5 NTU, the system must consult with the Department as soon as practical, but no later than 24 hours after the exceedance is known, in accordance with the public notification requirements under Article 9.
   1. (iii) If at any time the residual falls below 0.2 mg/L in the water entering the distribution system, the system must notify the Department as soon as possible, but no later than by the end of the next business day. The system also must notify the Department by the end of the next business day whether or not the residual was restored to at least 0.2 mg/L within 4 hours.

7.2 Enhanced Surface Water Treatment - Systems Serving 10,000 or More

7.2.1 General Requirements

(a) The requirements of this section 7.2 constitute national primary drinking water regulations. These regulations establish requirements for filtration and disinfection that are in addition to criteria under which filtration and disinfection are required under section 7.1. The requirements of this section 7.2 are applicable to surface water or groundwater under the direct influence of surface water systems serving 10,000 or more people. The regulations in this section 7.2 establish or extend treatment technique requirements in lieu of maximum contaminant levels for the following contaminants: Giardia lamblia, viruses, heterotrophic plate count bacteria, Legionella, Cryptosporidium, and turbidity. Each surface water or groundwater under the direct influence of surface water system serving 10,000 or more people must provide treatment of its source water that complies with these treatment technique requirements and are in addition to those identified in section 7.1. The treatment technique requirements consist of installing and properly operating water treatment processes which reliably achieve:

(1) At least 99 percent (2-log) removal of Cryptosporidium between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer.

(2) Compliance with the profiling and benchmark requirements under the provisions of section 7.2.2.

(b) A public water system subject to the requirements of this section 7.2 is considered to be in compliance with the requirements of section 7.2.1(a) if:

(1) It meets the applicable filtration requirements in either section 7.1.3 or section 7.2.3, the disinfection requirements in section 7.1.2 and the disinfection profiling requirements in section 7.2.2.

(c) Systems are not permitted to begin construction of uncovered finished water storage facilities.

(d) Surface water or groundwater under the direct influence of surface water systems that did not conduct optional monitoring under section 7.2.2 because they served fewer than 10,000 persons when such monitoring was required, but serve 10,000 or more persons prior to January 1, 2005 must comply with sections 7.2.1, 7.2.3, 7.2.4, and 7.2.5. These systems must also consult with the Department to establish a disinfection benchmark. A system that decides to make a significant change to its disinfection practice, as described in section 7.2.2(c)(1)(i) - (iv) must consult with the Department prior to making such change

7.2.2 Disinfection Profiling and Benchmarking

(a) Disinfection Profiling (1) The system must monitor daily for a period of 12 consecutive calendar months to determine the total logs of inactivation for each day of operation, based on the CT99.9 values in section 10.6, as appropriate, through the entire treatment plant. As a minimum, the system with a single point of disinfectant application prior to entrance to the distribution system must conduct the monitoring in sections 7.2.2(a)(1)(i) -(iv). A system with more than one point of disinfectant application must conduct the monitoring in sections 7.2.2(a) (1)(i) - (iv) for each disinfection segment. The system must monitor the parameters necessary to determine the total inactivation ratio, using analytical methods in sections 10.2.2(a) and 10.5.1(a)(2), as follows:

1. (i) The temperature of the disinfected water must be measured once per day at each residual disinfectant concentration sampling point during peak hourly flow.
   1. (ii) If the system uses chlorine, the pH of the disinfected water must be measured once per day at each chlorine residual disinfectant concentration sampling point during peak hourly flow.
      1. (iii) The disinfectant contact time(s) ("T") must be determined for each day during peak hourly flow.
         1. (iv) The residual disinfectant concentration(s) ("C") of the water before or at the first customer and prior to each additional point of disinfection must be measured each day during peak hourly flow.

(2) In lieu of the monitoring conducted under the provisions of section 7.2.2(a)(1) to develop the disinfection profile, the system may elect to meet the requirements of section 7.2.2 (a)(2) (i). In addition to the monitoring conducted under the provisions of section 7.2.2(a)(1) to develop the disinfection profile, the system may elect to meet the requirements of section 7.2.2(a)(2)(ii).

1. (i) A PWS that has three years of existing operational data may submit that data, a profile generated using that data, and a request that the Department approve use of that data in lieu of monitoring under the provisions of section 7.2.2(a)(1). The Department must determine whether these operational data are substantially equivalent to data collected under the provisions of section 7.2.2(a)(1). These data must also be representative of Giardia lamblia inactivation through the entire treatment plant and not just of certain treatment segments. Until the Department approves this request, the system is required to conduct monitoring under the provisions of section 7.2.2(a)(1).
   1. (ii) In addition to the disinfection profile generated under section 7.2.2(a)(1) of this section, a PWS that has existing operational data may use those data to develop a disinfection profile for additional years. Such systems may use these additional yearly disinfection profiles to develop a benchmark under the provisions of section 7.2.2(b) of this section. The Department must determine whether these operational data are substantially equivalent to data collected under the provisions of section 7.2.2(a)(1). These data must also be representative of inactivation through the entire treatment plant and not just of certain treatment segments.

(3) The system must calculate the total inactivation ratio as follows:

1. (i) If the system uses only one point of disinfectant application, the system may determine the total inactivation ratio for the disinfection segment based on either of the methods in section 7.2.2(a)(3)(i)(A) or (B).
   1. (A) Determine one inactivation ratio (CTcalc/CT ) before or at the first

99.9

1. customer during peak hourly flow.
   1. (B) Determine successive CTcalc/CT values, representing sequential

99.9

1. inactivation ratios, between the point of disinfectant application and a point before or at the first customer during peak hourly flow. Under this alternative, the system must calculate the total inactivation ratio by determining (CTcalc/CT ) for each sequence and then adding the

99.9

1. (CTcalc/CT ) values together to determine (∑ (CTcalc/CT )).
   1. 99.9 99.9
      1. (ii) If the system uses more than one point of disinfectant application before the first customer, the system must determine the CT value of each disinfection segment immediately prior to the next point of disinfectant application, or for the final segment, before or at the first customer, during peak hourly flow. The (CTcalc/CT ) value of each segment and (∑ (CTcalc/CT )) must be
         1. 99.9 99.9

            calculated using the method in section 7.2.2(a)(3)(i)(B).

         2. (iii) The system must determine the total logs of inactivation by multiplying the value calculated in section 7.2.2(a)(3)(i) or (ii) by 3.0.

(4) A system that uses either chloramines or ozone for primary disinfection must also calculate the logs of inactivation for viruses using a method approved by the Department.

(5) The system must retain disinfection profile data in graphic form, as a spreadsheet, or in some other format acceptable to the Department for review as part of sanitary surveys conducted by the Department.

(b) Disinfection benchmarking.

(1) Any system required to develop a disinfection profile, in accordance with section 7.2.2(a), that decides to make a significant change to its disinfection practice must consult with the Department prior to making such change. Significant changes to disinfection practice are:

1. (i) Changes to the point of disinfection;
   1. (ii) Changes to the disinfectant(s) used in the treatment plant;
      1. (iii) Changes to the disinfection process; and (iv) Any other modification identified by the Department.

(2) Any system, required to develop a disinfection profile in accordance with 7.2.2(a), that is modifying its disinfection practice must calculate its disinfection benchmark using the procedure specified in Sections 7.2.2(b)(2)(i) through (ii).

1. (i) For each year of profiling data collected, the system must determine the lowest average monthly Giardia lamblia inactivation in each year of profiling data. The system must determine the average Giardia lamblia inactivation for each calendar month for each year of profiling data by dividing the sum of daily Giardia lamblia of inactivation by the number of values calculated for that month.
   1. (ii) The disinfection benchmark is the lowest monthly average value (for systems with one year of profiling data) or average of lowest monthly average values (for systems with more than one year of profiling data) of the monthly logs of Giardia lamblia inactivation in each year of profiling data.

(3) A system that uses either chloramines or ozone for primary disinfection must also calculate the disinfection benchmark for viruses using a method approved by the Department.

(4) The system must submit the following information to the Department as part of its consultation process:

1. (i) A description of the proposed change;
   1. (ii) The disinfection profile for Giardia lamblia (and, if necessary, viruses) under section 7.2.2(a) and benchmark as required by section 7.2.2(b)(2); and (iii) An analysis of how the proposed change will affect the current levels of disinfection.

7.2.3 Filtration

A public water system subject to the requirements of this section 7.2 must provide treatment consisting of both disinfection, as specified in section 7.1.2, and filtration treatment which complies with the requirements of section 7.2.3(a), (b) or (c) or section 7.1.3 (f) or (g).

(a) Conventional filtration treatment or direct filtration.

(1) For systems using conventional filtration or direct filtration, the turbidity level of representative samples of a system's filtered water must be less than or equal to 0.3 NTU in at least 95 percent of the measurements taken each month, measured as specified in section 10.5.1(a).

(2) The turbidity level of representative samples of a system's filtered water must at no time exceed 1 NTU, measured as specified in section 10.5.1(a).

(3) A system that uses lime softening may acidify representative samples prior to analysis using a protocol approved by the Department.

(b) Alternative Filtration Technologies (1) The following table describes the maximum combined filter effluent turbidity limit that a system must not exceed at any time during the month a system serves water to the public. Table 7-2 details the required limits depending upon a specific filtration technology.

Table 7-2 Maximum Turbidity Limits If your system consists Your maximum of * * * turbidity value is * * * (i) Membrane 1 NTU Filtration1 (ii) Cartridge Filtration 5 NTU (iii) Bag Filtration 5 NTU 1 Membrane Filtration includes cross-flow membrane filtration (CMF) technologies, such as Microfiltration, Ultrafiltration, Nanofiltration and Reverse Osmosis.

(2) Table 7-3 describes the combined filter effluent “95 th percentile” turbidity limit that a system must meet in at least 95 percent of the turbidity measurements taken each month a system serves water to the public. Table 7-3 details the required limits depending upon a specific filtration technology.

Table 7-3 95th Percentile Turbidity Levels If your system consists of th Your 95 percentile * * * turbidity value is * * * (i) Membrane Filtration 0.3 NTU (ii) Cartridge Filtration 1 NTU (iii) Bag Filtration 1 NTU 1 Membrane Filtration includes cross-flow membrane filtration (CMF) technologies, such Microfiltration, Ultrafiltration, Nanofiltration and Reverse Osmosis.

(c) Filtration technologies other than conventional filtration treatment, direct filtration, slow sand filtration or diatomaceous earth filtration. A public water system may use a filtration technology not listed in Sections 7.2.3(a) or (b) or in section 7.1.3 (f) or (g) if it demonstrates to the Department, using pilot plant studies or other means, that the other filtration technology, in combination with disinfection treatment that meets the requirements of section 7.1.2, consistently achieves 99.9 percent removal and/or inactivation of Giardia lamblia cysts and 99.99 percent removal and/or inactivation of viruses, and 99 percent removal of Cryptosporidium oocysts, and the Department approves the use of the other filtration technology. For each approval, the Department will set turbidity performance requirements that the system must meet at least 95 percent of the time and that the system may not exceed at any time at a level that consistently achieves 99.9 percent removal and/or inactivation of Giardia lamblia cysts, 99.99 percent removal and/or inactivation of viruses, and 99 percent removal of Cryptosporidium oocysts.

7.2.4 Filtration Sampling Requirements

(a) Monitoring requirements for systems using filtration treatment. In addition to monitoring required by section 7.1.4, a public water system subject to the requirements of this section 7.2 that provides conventional filtration treatment or direct filtration must conduct continuous monitoring of turbidity for each individual filter using an approved method in section 10.5.1(a) and must calibrate turbidimeters using the procedure specified by the manufacturer. Systems must record the results of individual filter monitoring every 15 minutes.

(b) If there is a failure in the continuous turbidity monitoring equipment, the system must conduct grab sampling every four hours in lieu of continuous monitoring, but for no more than five working days following the failure of the equipment.

7.2.5 Reporting and Recordkeeping Requirements

In addition to the reporting and recordkeeping requirements in section 7.1.5, a public water system subject to the requirements of this section 7.2 that provides conventional filtration treatment or direct filtration must report monthly to the Department the information specified in sections 7.2.5(a) and (b). In addition to the reporting and recordkeeping requirements in section 7.1.5, a public water system subject to the requirements of this section 7.2 that provides filtration approved under sections 7.2.3(b) or (c) must report monthly to the Department the information specified in section 7.2.5(a). The reporting in section 7.2.5(a) is in lieu of the reporting specified in section 7.1.5.

(a) Turbidity measurements as required by Section 7.2.3 must be reported within 10 days after the end of each month the system serves water to the public. Information that must be reported includes:

(1) The total number of filtered water turbidity measurements taken during the month.

(2) The number and percentage of filtered water turbidity measurements taken during the month which are less than or equal to the turbidity limits specified in Sections 7.2.3(a), (b) or (c).

(3) The date and value of any turbidity measurements taken during the month which exceed 1 NTU for systems using conventional filtration treatment or direct filtration, or which exceed the maximum level set by the Department under section 7.2.3(b) or (c).

(b) Systems must maintain the results of individual filter monitoring taken under section 7.2.4 for at least three years. Systems must report that they have conducted individual filter turbidity monitoring under section 7.2.4 within 10 days after the end of each month the system serves water to the public. Systems must report individual filter turbidity measurement results taken under section 7.2.4 within 10 days after the end of each month the system serves water to the public only if measurements demonstrate one or more of the conditions in sections 7.2.5(b)(1) through (4). Systems that use lime softening may apply to the Department for alternative exceedance levels for the levels specified in sections 7.2.5(b)(1) through (4) if they can demonstrate that higher turbidity levels in individual filters are due to lime carryover only and not due to degraded filter performance.

(1) For any individual filter that has a measured turbidity level of greater than 1.0 NTU in two consecutive measurements taken 15 minutes apart, the system must report the filter number, the turbidity measurement, and the date(s) on which the exceedance occurred. In addition, the system must either produce a filter profile for the filter within 7 days of the exceedance (if the system is not able to identify an obvious reason for the abnormal filter performance) and report that the profile has been produced or report the obvious reason for the exceedance.

(2) For any individual filter that has a measured turbidity level of greater than 0.5 NTU in two consecutive measurements taken 15 minutes apart at the end of the first four hours of continuous filter operation after the filter has been backwashed or otherwise taken offline, the system must report the filter number, the turbidity, and the date(s) on which the exceedance occurred. In addition, the system must either produce a filter profile for the filter within 7 days of the exceedance (if the system is not able to identify an obvious reason for the abnormal filter performance) and report that the profile has been produced or report the obvious reason for the exceedance.

(3) For any individual filter that has a measured turbidity level of greater than 1.0 NTU in two consecutive measurements taken 15 minutes apart at any time in each of three consecutive months, the system must report the filter number, the turbidity measurement, and the date(s) on which the exceedance occurred. In addition, the system must conduct a self-assessment of the filter within 14 days of the exceedance and report that the self-assessment was conducted. The self assessment must consist of at least the following components: assessment of filter performance; development of a filter profile; identification and prioritization of factors limiting filter performance; assessment of the applicability of corrections; and preparation of a filter self-assessment report.

(4) For any individual filter that has a measured turbidity level of greater than 2.0 NTU in two consecutive measurements taken 15 minutes apart at any time in each of two consecutive months, the system must report the filter number, the turbidity measurement, and the date(s) on which the exceedance occurred. In addition, the system must arrange for the conduct of a comprehensive performance evaluation by the Department or a third party approved by the Department no later than 30 days following the exceedance and have the evaluation completed and submitted to the Department no later than 90 days following the exceedance.

(c) Additional reporting requirements.

(1) If at any time the combined filter effluent turbidity exceeds 1 NTU in representative samples of filtered water in a system using conventional filtration treatment or direct filtration, the system must inform the Department as soon as possible, but no later than the end of the next business day.

(2) If at any time the combined filter effluent turbidity in representative samples of filtered water exceeds the maximum level set by the Department under section 7.2.3(b) or (c) for filtration technologies other than conventional filtration treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration, the system must inform the Department as soon as possible, but no later than the end of the next business day.

7.3 Enhanced Surface Water Treatment - Systems Serving Fewer Than 10,000

7.3.1 General Requirements

(a) These regulations establish requirements for filtration and disinfection that are in addition to criteria under which filtration and disinfection are required under section 7.1. The regulations in this Article establish or extend treatment technique requirements in lieu of maximum contaminant levels for the following contaminants: Giardia lamblia, viruses, heterotrophic plate count bacteria, Legionella, Cryptosporidium and turbidity. The requirements of this section 7.3 are applicable to surface water or groundwater under the direct influence of surface water systems serving fewer than 10,000 people, beginning January 1, 2005 unless otherwise specified. The treatment technique requirements consist of installing and properly operating water treatment processes which reliably achieve:

(1) At least 99 percent (2-log) removal of Cryptosporidium between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer.

(2) Compliance with the profiling and benchmark requirements under the provisions of section 7.3.2.

(b) There are six requirements of this Article, and systems must comply with all requirements that are applicable. These requirements are:

(1) Systems must cover any finished water reservoir that they began to construct as described in section 7.3.1(c);

(2) Community and non-transient, non-community water systems must develop a disinfection profile as described in section 7.3.2(a) through (g);

(3) Systems considering making a significant change to their disinfection practices must develop a disinfection benchmark and consult with the Department for approval of the change as described in section 7.3.3;

(4) Systems must comply with the combined filter effluent requirements as described in section 7.3.4;

(5) Systems using conventional or direct filtration must comply with the individual filter turbidity requirements as described section 7.3.5; and (6) Systems must comply with the applicable reporting and recordkeeping requirements as described in sections 7.3.6 and 1.6.3.

(c) Construction of uncovered finished water storage facilities is prohibited.

7.3.2 Disinfection Profile

(a) If you are a community or non-transient, non-community surface water or groundwater under the direct influence of surface water system which serves fewer than 10,000 persons, your system must develop a disinfection profile unless the Department determines in accordance with section 7.3.2 (b) that your system’s profile is unnecessary. The Department may approve the use of a more representative data set for disinfection profiling than the data set required under section

7.3.2 (c) - (g).

(b) The Department may only determine that a system’s profile is unnecessary if a system’s TTHM and HAA5 levels are below 0.064 mg/L and 0.048 mg/L, respectively. These samples must be taken in accordance with the following:

(1) TTHM and HAA5 samples must be collected after January 1, 1998.

(2) The samples must be taken during the month with the warmest water temperature.

(3) The samples must be taken at the point of maximum residence time in the systems distribution system.

(c) A disinfection profile consists of three steps:

(1) First, a system must collect data for several parameters from the plant as discussed in section 7.3.2(d) over the course of 12 months.

1. (i) If your system serves between 500 and 9,999 persons you were to begin to collect data no later than July 1, 2003.
   1. (ii) If your system serves fewer than 500 persons you were to begin to collect data no later than January 1, 2004.

(2) Second, a system must use this data to calculate weekly log inactivation as discussed in section 7.3.2(e) - (f).

(3) Third, a system must use these weekly log inactivations to develop a disinfection profile as specified in section 7.3.2(g).

(d) Systems must monitor the following parameters to determine the total log inactivation using the analytical methods in section 10.2.2(a), once per week on the same calendar day, over 12 consecutive months.

(1) The temperature of the disinfected water at each residual disinfectant concentration sampling point during peak hourly flow.

(2) If a system uses chlorine, the pH of the disinfected water at each residual disinfectant concentration sampling point during peak hourly flow.

(3) The disinfectant contact time(s) (“T” ) during peak hourly flow.

(4) The residual disinfectant concentration(s) (“C” ) of the water before or at the first customer and prior to each additional point of disinfection during peak hourly flow.

(e) Systems must calculate the total inactivation ration as follows, and multiply the value by 3.0 to determine log inactivation of Giardia lamblia (1) If the system uses only one point of disinfectant application:

1. (i) Determine one inactivation ratio (CTcalc/CT ) before or at the first customer during
   1. 99.9
      1. peak hourly flow, or (ii) Determine successive CTcalc/CT values, representing sequential inactivation
         1. 99.9

            ratios, between the point of disinfectant application and a point before or at the first customer during peak hourly flow. Under this alternative, the system must calculate the total inactivation ratio by determining (CTcalc/CT ) for each

99.9

1. sequence and then adding the (CTcalc/CT ) values together to determine (∑
   1. 99.9
      1. (CTcalc/CT )).
         1. 99.9

(2) If the system uses more than one point of disinfectant application before the first customer, the system must determine the (CTcalc/CT ) value of each disinfection segment

99.9

1. immediately prior to the next point of disinfectant application, or for the final segment, before or at the first customer, during peak hourly flow using the procedure specified in section 7.3.2(e)(1)(ii).

(f) A system that uses chloramines, ozone, or chlorine dioxide for primary disinfection must also calculate the logs of inactivation for viruses and develop an additional disinfection profile for viruses using methods approved by the Department.

(g) Each log inactivation serves as a data point in the system’s disinfection profile. Systems will have obtained 52 measurements (one for every week of the year). This will allow a system and the Department the opportunity to evaluate how microbial inactivation varied over the course of the year by looking at all 52 measurements (the system’s Disinfection Profile). Systems must retain the Disinfection Profile data in graphic form, such as a spreadsheet, which must be available for review by the Department as part of a sanitary survey. Systems must use this data to calculate a benchmark if they are considering changes to disinfection practices.

7.3.3 Disinfection Benchmark

(a) Any system required to develop a disinfection profile under the provisions of section 7.3.2, must develop a disinfection benchmark if you decide to make a significant change to your disinfection practice. Your system must consult with the Department for approval prior to making such change.

(b) Significant changes to disinfection practice include the following:

(1) Changes to the point of disinfection;

(2) Changes to the disinfectant(s) used in the treatment plant;

(3) Changes to the disinfection process; or (4) Any other modification identified by the Department.

(c) Systems considering a significant change to its disinfection practice must calculate a disinfection benchmark(s) as described in section 7.3.3(d) - (e) and provide the benchmark(s) to the Department. A system may only make a significant disinfection practice change after consulting with the Department for approval. The system must submit the following information as part of its consultation and approval process.

(1) A description of the proposed change;

(2) The disinfection profile for Giardia lamblia (and, if necessary, viruses) and disinfection benchmark;

(3) An analysis of how the proposed change will affect the current levels of disinfection; and (4) Any additional information requested by the Department.

(d) Any system that is making a significant change to its disinfection practice must calculate its disinfection benchmark using the procedure specified in sections 7.3.3(d)(1) through (2) and provide the benchmark(s) to the Department.

(1) Using the data collected to develop the Disinfection Profile, determine the average Giardia lamblia inactivation for each calendar month by dividing the sum of all Giardia lamblia inactivations for that month by the number of values calculated for that month.

(2) Determine the lowest monthly average value out of the twelve values. This value becomes the disinfection benchmark.

(e) A system that uses chloramines, ozone, or chlorine dioxide for primary disinfection must calculate the disinfection benchmark from the data the system collected for viruses to develop the disinfection profile in addition to the Giardia lamblia disinfection benchmark calculated under section 7.3.3(d). This viral benchmark must be calculated in the same manner used to calculate the Giardia lamblia disinfection benchmark in section 7.3.3(d).

7.3.4 Combined Filter Effluent Requirements

(a) All surface water or groundwater under the direct influence of surface water systems which serve populations fewer than 10,000 and utilize filtration other than slow sand filtration or diatomaceous earth filtration must meet the combined filter effluent turbidity requirements of section 7.3.4(b) - (d). If your system uses slow sand or diatomaceous earth filtration you are not required to meet the combined filter effluent turbidity limits of section 7.3, but you must continue to meet the combined filter effluent turbidity limits in section 7.1.3(f) and (g).

(b) Systems required to meet the provisions of this section 7.3 must meet two strengthened combined filter effluent turbidity limits.

(1) The first combined filter effluent turbidity limit is a “95 th percentile” turbidity limit that a system must meet in at least 95 percent of the turbidity measurements taken each month. Measurements must continue to be taken as described in section 10.5.1(a). Monthly reporting must be completed according to section 7.3.6. Table 7-4 describes the required limits for specific filtration technologies.

Table 7-4 95 th Percentile Turbidity Levels If your system consists th Your 95 percentile of * * * turbidity value is * * * (i) Conventional 0.3 NTU Filtration (ii) Direct Filtration 0.3 NTU (iii) Membrane 0.3 NTU Filtration (iv) Cartridge Filtration 1 NTU (v) Bag Filtration 1 NTU 1 Membrane Filtration includes cross-flow membrane filtration (CMF) technologies, such as Microfiltration, Ultrafiltration, Nanofiltration and Reverse Osmosis.

(2) The second combined filter effluent turbidity is a “maximum” turbidity limit which a system may at no time exceed during the month. Measurements must continue to be taken as described in section 10.5.1(a). Monthly reporting must be completed according to section 7.3.6. Table 7-5 describes the required limits for specific filtration technologies. Table 7-5 Maximum Turbidity Limits If your system consists Your maximum of * * * turbidity value is * * * (i) Conventional 1 NTU Filtration (ii) Direct Filtration 1 NTU (iii) Membrane 1 NTU Filtration (iv) Cartridge Filtration 5 NTU (v) Bag Filtration 5 NTU 1 Membrane Filtration includes cross-flow membrane filtration (CMF) technologies, such as Microfiltration, Ultrafiltration, Nanofiltration and Reverse Osmosis.

(c) Public water systems that use a filtration technology other than slow sand, diatomaceous earth or those listed in section 7.3.4 (b) must demonstrate to the Department, using pilot plant studies or other means, that the filtration technology, in combination with disinfection treatment, consistently achieves 99.9 percent removal and/or inactivation of Giardia lamblia cysts, 99.99 percent removal and/or inactivation of viruses, and 99 percent removal of Cryptosporidium oocysts. Based on this demonstration, the Department will set to following two turbidity performance requirements:

(1) A turbidity value that the system must meet in at least 95 percent of the measurements taken each month (not to exceed 1 NTU) and, (2) A turbidity value that the system may not exceed at any time (not to exceed 5 NTU).

(d) Systems practicing lime softening may acidify representative combined filter effluent turbidity samples prior to analysis using a protocol approved by the Department.

7.3.5 Individual Filter Turbidity Requirements

(a) Surface water or groundwater under the direct influence of surface water systems serving fewer than 10,000 people and utilizing conventional filtration or direct filtration, must conduct continuous monitoring of turbidity for each individual filter at the system. The following requirements apply to continuous turbidity monitoring:

(1) Monitoring must be conducted using an approved method in section 10.5.1(a);

(2) Calibration of turbidimeters must be conducted using procedures specified by the manufacturer;

(3) Results of turbidity monitoring must be recorded at least every 15 minutes;

(4) Monthly reporting must be completed according to section 7.3.6; and (5) Records must be maintained according to section 1.6.3.

(b) If there is a failure in the continuous turbidity monitoring equipment, the system must conduct grab sampling every four hours in lieu of continuous monitoring until the turbidimeter is back on-line. The system has 14 days to resume continuous monitoring before a violation is incurred.

(c) Systems that consist of two or fewer filters may conduct continuous monitoring of combined filter effluent turbidity in lieu of individual filter effluent turbidity monitoring. Continuous monitoring must meet the same requirements set forth in sections 7.3.5(a) and (b).

(d) Follow-up action based on the continuous turbidity monitoring required in section 7.3.5 shall be according to Table 7-6:

Table 7-6 Individual Filter Turbidity Follow-up Actions If * * * Your system must * * * (1) The turbidity of an Report to the Department individual filter (or the by the 10th of the turbidity of combined following month and filter effluent (CFE) for include the filter systems with 2 filters that number(s), corresponding monitor CFE in lieu of date(s), turbidity value(s)

individual filters) exceeds which exceeded 1.0 NTU,

1.0 NTU in two and the cause (if known)

consecutive recordings 15 for the exceedance(s).

minutes apart.

. .

If a system was required Your system must * * * to report to the Department * * * (2) For three months in a Conduct a self-assessment row and turbidity of the filter(s) within 14 exceeded 1.0 NTU in two days of the day the filter consecutive recordings 15 exceeded 1.0 NTU in two minutes apart at the same consecutive filter (or CFE for systems measurements for the with 2 filters that monitor third straight month CFE in lieu of individual unless a CPE as specified filters). in paragraph (c) of this section was required.

1. Systems with 2 filters that monitor CFE in lieu of individual filters must conduct a self-assessment on both filters. The self- assessment must consist of at least the following components: assessment of filter performance;
   1. development of a filter profile; identification and prioritization of factors limiting filter performance; assessment of the applicability of corrections; and preparation of a filter self- assessment report. If a self-assessment is required, the date that it was triggered and the date that it was completed.

(3) For two months in a Arrange to have a row and turbidity comprehensive exceeded 2.0 NTU in 2 performance evaluation consecutive recordings 15 (CPE) conducted by the minutes apart at the same Department or a third filter (or CFE for systems party approved by the with 2 filters that monitor Department not later than CFE in lieu of individual 60 days following the day filters). the filter exceeded 2.0 NTU in two consecutive measurements for the second straight month. If a CPE has been completed by the Department or a third party approved by the Department within the 12 prior months or the system and Department are jointly participating in an ongoing Comprehensive Technical Assistance (CTA) project at the system, a new CPE is not required. If conducted, a CPE must be completed and submitted to the Department no later than 120 days following the day the filter exceeded

1. 2.0 NTU in two
   1. consecutive measurements for the second straight month.

(e) Systems utilizing lime softening may apply to the Department for alternative turbidity exceedance levels for the levels specified in section 7.3.5(d)(1) - (3). Systems must demonstrate that higher turbidity levels are due to lime carryover only, and not due to degraded filter performance.

7.3.6 Reporting Requirements

A system is required to report the information in the following table if it is subject to the requirement shown in the first column.

Table 7-7 Turbidity Reporting Requirements

7.4 Enhanced Treatment for Cryptosporidium

7.4.1 General Requirements

(a) The requirements in this section establish or extend treatment technique requirements in lieu of maximum contaminant levels for Cryptosporidium. These requirements are in addition to requirements for filtration and disinfection in sections 7.1, 7.2, and 7.3.

(b) Applicability. The requirements in section 7.4 apply to all Surface Water and GWUDI systems, which are public water systems supplied by a surface water source and public water systems supplied by a ground water source under the direct influence of surface water.

(1) Wholesale systems, as defined in section 1.5.2(155), must comply with the requirements of this section based on the population of the largest system in the combined distribution system.

(2) The requirements of this section apply to systems required by the Colorado Primary Drinking Water Regulations to provide filtration treatment, whether or not the system is currently operating a filtration system.

(c) Requirements. Systems subject to this section must comply with the following requirements:

(1) Systems must conduct an initial and a second round of source water monitoring for each plant that treats a surface water or GWUDI source. This monitoring may include sampling for Cryptosporidium, E. coli, and turbidity as described in section 7.4.2 through 7.4.5, to determine what level, if any, of additional Cryptosporidium treatment they must provide.

(2) Systems that plan to make a significant change to their disinfection practice must develop disinfection profiles and calculate disinfection benchmarks, as described in sections 7.4.7 through 7.4.8.

(3) Filtered systems must determine their Cryptosporidium treatment bin classification as described in section 7.4.9 and provide additional treatment for Cryptosporidium, if required, as described in section 7.4.10. Filtered systems must implement Cryptosporidium treatment according to the schedule in section 7.4.11.

(4) Systems with uncovered finished water storage facilities must comply with the requirements to cover the facility or treat the discharge from the facility as described in section 7.4.12.

(5) Systems required to provide additional treatment for Cryptosporidium must implement microbial toolbox options that are designed and operated as described in sections 7.4.13 through 7.4.18.

(6) Systems must comply with the applicable recordkeeping and reporting requirements described in sections 1.6.3 and 7.4.19.

7.4.2 Source Water Monitoring

(a) Initial round of source water monitoring. Systems must conduct the following monitoring on the schedule in paragraph (c) of this section unless they meet the monitoring exemption criteria in paragraph (d) of this section.

(1) Filtered systems serving at least 10,000 people must sample their source water for Cryptosporidium, E. coli, and turbidity at least monthly for 24 months.

(2) (i) Filtered systems serving fewer than 10,000 people must sample their source water for E. coli at least once every two weeks for 12 months.

1. (i) A filtered system serving fewer than 10,000 people may avoid E. coli monitoring if the system notifies the Department that it will monitor for Cryptosporidium as described in paragraph (a)(3) of this section. The system must notify the Department no later than 3 months prior to the date the system is otherwise required to start E. coli monitoring under section 7.4.2(c).

(3) Filtered systems serving fewer than 10,000 people must sample their source water for Cryptosporidium at least twice per month for 12 months or at least monthly for 24 months if they meet one of the following, based on monitoring conducted under paragraph (a)(2) of this section:

1. (i) For systems using lake/reservoir sources, the annual mean E. coli concentration is greater than 10 E. coli /100 mL.
   1. (ii) For systems using flowing stream sources, the annual mean E. coli concentration is greater than 50 E. coli /100 mL.
      1. (iii) The system does not conduct E. coli monitoring as described in paragraph (a)(2) of this section.
         1. (iv) Systems using ground water under the direct influence of surface water (GWUDI) must comply with the requirements of paragraph (a)(3) of this section based on the E. coli level that applies to the nearest surface water body. If no surface water body is nearby, the system must comply based on the requirements that apply to systems using lake/reservoir sources.

(4) For filtered systems serving fewer than 10,000 people, the Department may approve monitoring for an indicator other than E. coli under paragraph (a)(2) of this section. The Department also may approve an alternative to the E. coli concentration in paragraph (a)(3)(i), (ii) or (iv) of this section to trigger Cryptosporidium monitoring. This approval by the Department must be provided to the system in writing and must include the basis for the Department's determination that the alternative indicator and/or trigger level will provide a more accurate identification of whether a system will exceed the Bin 1 Cryptosporidium level in Section 7.4.9.

(5) Systems may sample more frequently than required under this section if the sampling frequency is evenly spaced throughout the monitoring period.

(b) Second round of source water monitoring. Systems must conduct a second round of source water monitoring that meets the requirements for monitoring parameters, frequency, and duration described in paragraph (a) of this section, unless they meet the monitoring exemption criteria in paragraph (d) of this section. Systems must conduct this monitoring on the schedule in paragraph (c) of this section.

(c) Monitoring schedule. Systems must begin the monitoring required in paragraphs (a) and (b) of this section no later than the month beginning with the date listed in Table 7-8: Table 7-8 Source Water Monitoring Starting Dates Systems that serve..... Must begin the first And must begin the round of source water second round of source monitoring no later water monitoring no than the month later than the month beginning….. beginning…..

(1) At least 100,000 (i) October 1, 2006 (ii) April 1, 2015 people (2) From 50,000 to (i) April 1, 2007 (ii) October 1, 2015 99,999 people (3) From 10,000 to (i) April 1, 2008 (ii) October 1, 2016 49,999 people (4) Fewer than 10,000 (i) October 1, 2008 (ii) October 1, 2017 and monitor for E. coli (5) Fewer than 10,000 (i) April 1, 2010 (ii) April 1, 2019 and monitor for Cryptosporidium 1 Applies only to filtered systems.

2 Applies to filtered systems that meet the conditions of paragraph (a)(3).

(d) Monitoring avoidance.

(1) Filtered systems are not required to conduct source water monitoring under this section if the system will provide a total of at least 5.5-log of treatment for Cryptosporidium, equivalent to meeting the treatment requirements of Bin 4 in Section 7.4.10.

(2) If a system chooses to provide the level of treatment in paragraph (d)(1), as applicable, rather than start source water monitoring, the system must notify the Department in writing no later than the date the system is otherwise required to submit a sampling schedule for monitoring under Section 7.4.3. Alternatively, a system may choose to stop sampling at any point after it has initiated monitoring if it notifies the Department in writing that it will provide this level of treatment. Systems must install and operate technologies to provide this level of treatment by applicable treatment compliance date in Section 7.4.11.

(e) Plants operating only part of the year. Systems with Surface Water and GWUDI plants that operate for only part of the year must conduct source water monitoring in accordance with this section, but with the following modifications:

(1) Systems must sample their source water only during the months that the plant operates unless the Department specifies another monitoring period based on plant operating practices.

(2) Systems with plants that operate less than six months per year and that monitor for Cryptosporidium must collect at least six Cryptosporidium samples per year during each of two years of monitoring. Samples must be evenly spaced throughout the period the plant operates.

(f) (1) New sources. A system that begins using a new source of surface water or GWUDI after the system is required to begin monitoring under paragraph (c) of this section must monitor the new source on a schedule the Department approves. Source water monitoring must meet the requirements of this section. The system must also meet the bin classification and Cryptosporidium treatment requirements of sections 7.4.9 and 7.4.10, as applicable, for the new source on a schedule the Department approves.

(2) The requirements of section 7.4.2(f) apply to Surface Water and GWUDI systems that begin operation after the monitoring start date applicable to the system's size under paragraph

1. (c) of this section.

(3) The system must begin a second round of source water monitoring no later than 6 years following initial bin classification under section 7.4.9.

(g) Failure to collect any source water sample required under this section in accordance with the sampling schedule, sampling location, analytical method, approved laboratory, and reporting requirements of sections 7.4.3 through 7.4.5 and Article 10 is a monitoring violation.

(h) Grandfathering monitoring data. Systems may use (grandfather) monitoring data collected prior to the applicable monitoring start date in paragraph (c) of this section to meet the initial source water monitoring requirements in paragraph (a) of this section. Grandfathered data may substitute for an equivalent number of months at the end of the monitoring period. All data submitted under this paragraph must meet the requirements in Section 7.4.6.

7.4.3 Sampling schedules

(a) Systems required to conduct source water monitoring under section 7.4.2 must submit a sampling schedule that specifies the calendar dates when the system will collect each required sample.

(1) Systems must submit sampling schedules no later than 3 months prior to the applicable date listed in section 7.4.2(c) for each round of required monitoring.

(2) (i) Systems serving at least 10,000 people must submit their sampling schedule for the initial round of source water monitoring under section 7.4.2(a) to EPA electronically at https://intranet.epa.gov/lt2/.

1. (ii) If a system is unable to submit the sampling schedule electronically, the system may use an alternative approach for submitting the sampling schedule that EPA approves.

(3) Systems serving fewer than 10,000 people must submit their sampling schedules for the initial round of source water monitoring section 7.4.2(a) to the Department.

(4) Systems must submit sampling schedules for the second round of source water monitoring section 7.4.2(b) to the Department.

(5) If EPA or the Department does not respond to a system regarding its sampling schedule, the system must sample at the reported schedule.

(b) Systems must collect samples within two days before or two days after the dates indicated in their sampling schedule (i.e., within a five-day period around the schedule date) unless one of the conditions of paragraph (b)(1) or (2) of this section applies.

(1) If an extreme condition or situation exists that may pose danger to the sample collector, or that cannot be avoided and causes the system to be unable to sample in the scheduled five-day period, the system must sample as close to the scheduled date as is feasible unless the Department approves an alternative sampling date. The system must submit an explanation for the delayed sampling date to the Department concurrent with the shipment of the sample to the laboratory.

(2) (i) If a system is unable to report a valid analytical result for a scheduled sampling date due to equipment failure, loss of or damage to the sample, failure to comply with the analytical method requirements, including the quality control requirements in Article 10, or the failure of an approved laboratory to analyze the sample, then the system must collect a replacement sample.

1. (ii) The system must collect the replacement sample not later than 21 days after receiving information that an analytical result cannot be reported for the scheduled date unless the system demonstrates that collecting a replacement sample within this time frame is not feasible or the Department approves an alternative re-sampling date. The system must submit an explanation for the delayed sampling date to the Department concurrent with the shipment of the sample to the laboratory.

(c) Systems that fail to meet the criteria of paragraph (b) of this section for any source water sample required under section 7.4.2 must revise their sampling schedules to add dates for collecting all missed samples. Systems must submit the revised schedule to the Department for approval prior to when the system begins collecting the missed samples.

7.4.4 Sampling Locations

(a) Systems required to conduct source water monitoring under section 7.4.2 must collect samples for each plant that treats a surface water or GWUDI source. Where multiple plants draw water from the same influent, such as the same pipe or intake, the Department may approve one set of monitoring results to be used to satisfy the requirements of section 7.4.2 for all plants.

(b) (1) Systems must collect source water samples prior to chemical treatment, such as coagulants, oxidants and disinfectants, unless the system meets the condition of paragraph (b)(2) of this section.

(2) The Department may approve a system to collect a source water sample after chemical treatment. To grant this approval, the Department must determine that collecting a sample prior to chemical treatment is not feasible for the system and that the chemical treatment is unlikely to have a significant adverse effect on the analysis of the sample.

(c) Systems that recycle filter backwash water must collect source water samples prior to the point of filter backwash water addition.

(d) Bank filtration.

(1) Systems that receive Cryptosporidium treatment credit for bank filtration under Section 7.2.3(b) or Section 7.3.4(c), as applicable, must collect source water samples in the surface water prior to bank filtration.

(2) Systems that use bank filtration as pretreatment to a filtration plant must collect source water samples from the well (i.e., after bank filtration). Use of bank filtration during monitoring must be consistent with routine operational practice. Systems collecting samples after a bank filtration process may not receive treatment credit for the bank filtration under Section 7.4.15(c).

(e) Multiple sources. Systems with plants that use multiple water sources, including multiple surface water sources and blended surface water and ground water sources, must collect samples as specified in paragraph (e)(1) or (2) of this section. The use of multiple sources during monitoring must be consistent with routine operational practice.

(1) If a sampling tap is available where the sources are combined prior to treatment, systems must collect samples from the tap.

(2) If a sampling tap where the sources are combined prior to treatment is not available, systems must collect samples at each source near the intake on the same day and must follow either paragraph (e)(2)(i) or (ii) of this section for sample analysis.

1. (i) Systems may composite samples from each source into one sample prior to analysis. The volume of sample from each source must be weighted according to the proportion of the source in the total plant flow at the time the sample is collected.
   1. (ii) Systems may analyze samples from each source separately and calculate a weighted average of the analysis results for each sampling date. The weighted average must be calculated by multiplying the analysis result for each source by the fraction the source contributed to total plant flow at the time the sample was collected and then summing these values.

(f) Additional Requirements. Systems must submit a description of their sampling location(s) to the Department at the same time as the sampling schedule required under Section 7.4.3. This description must address the position of the sampling location in relation to the system's water source(s) and treatment processes, including pretreatment, points of chemical treatment, and filter backwash recycle. If the Department does not respond to a system regarding sampling location(s), the system must sample at the reported location(s).

7.4.5 Reporting Source Water Monitoring Results

(a) Systems must report results from the source water monitoring required under Section 7.4.2 no later than 10 days after the end of the first month following the month when the sample is collected.

(b) (1) All systems serving at least 10,000 people must report the results from the initial source water monitoring required under Section 7.4.2(a) to EPA electronically at https://intranet.epa.gov/lt2/.

(2) If a system is unable to report monitoring results electronically, the system may use an alternative approach for reporting monitoring results that EPA approves.

(c) Systems serving fewer than 10,000 people must report results from the initial source water monitoring required under Section 7.4.2(a) to the Department.

(d) All systems must report results from the second round of source water monitoring required under Section 7.4.2 (b) to the Department.

(e) Systems must report the applicable information in paragraphs (e)(1) and (2) of this section for the source water monitoring required under Section 7.4.2.

(1) Systems must report the following data elements for each Cryptosporidium analysis: Data element.

1. 1. PWS ID.
   1. 2. Facility ID.
      1. 3. Sample collection date.
         1. 4. Sample type (field or matrix spike).
         2. 5. Sample volume filtered (L), to nearest 1/4 L.
         3. 6. Was 100% of filtered volume examined.
         4. 7. Number of oocysts counted.
         5. (i) For matrix spike samples, systems must also report the sample volume spiked and estimated number of oocysts spiked. These data are not required for field samples.
         6. (ii) For samples in which less than 10 L is filtered or less than 100% of the sample volume is examined, systems must also report the number of filters used and the packed pellet volume.
         7. (iii) For samples in which less than 100% of sample volume is examined, systems must also report the volume of resuspended concentrate and volume of this resuspension processed through immunomagnetic separation.

(2) Systems must report the following data elements for each E. coli analysis: Data element.

1. 1. PWS ID.
   1. 2. Facility ID.
      1. 3. Sample collection date.
         1. 4. Analytical method number.
         2. 5. Method type.
         3. 6. Source type (flowing stream, lake/reservoir, GWUDI).
         4. 7. E. coli /100 mL.
         5. 8. Turbidity 7-1 7-1 Systems serving fewer than 10,000 people that are not required to monitor for turbidity under Section 7.4.2 are not required to report turbidity with their E. coli results.

7.4.6 Grandfathering Previously Collected Data

(a) (1) Systems may comply with the initial source water monitoring requirements of Section 7.4.2(a) by grandfathering sample results collected before the system is required to begin monitoring (i.e., previously collected data). To be grandfathered, the sample results and analysis must meet the criteria in this section and the Department must approve.

(2) A filtered system may grandfather Cryptosporidium samples to meet the requirements of Section 7.4.2(a) when the system does not have corresponding E. coli and turbidity samples. A system that grandfathers Cryptosporidium samples without E. coli and turbidity samples is not required to collect E. coli and turbidity samples when the system completes the requirements for Cryptosporidium monitoring under Section 7.4.2(a).

(b) E. coli sample analysis. The analysis of E. coli samples must meet the analytical method and approved laboratory requirements of Article 10.

(c) Cryptosporidium sample analysis. The analysis of Cryptosporidium samples must meet the analytical method and approved laboratory requirements of Article 10.

(d) Sampling location. The sampling location must meet the conditions in Section 7.4.4.

(e) Sampling frequency. Cryptosporidium samples were collected no less frequently than each calendar month on a regular schedule, beginning no earlier than January 1999. Sample collection intervals may vary for the conditions specified in Section 7.4.3(b)(1) and (2) if the system provides documentation of the condition when reporting monitoring results.

(1) The Department may approve grandfathering of previously collected data where there are time gaps in the sampling frequency if the system conducts additional monitoring the Department specifies to ensure that the data used to comply with the initial source water monitoring requirements of Section 7.4.2(a) are seasonally representative and unbiased.

(2) Systems may grandfather previously collected data where the sampling frequency within each month varied. If the Cryptosporidium sampling frequency varied, systems must follow the monthly averaging procedure in Section 7.4.9(b)(5) when calculating the bin classification for filtered systems.

(f) Reporting monitoring results for grandfathering. Systems that request to grandfather previously collected monitoring results must report the following information by the applicable dates listed in this paragraph. Systems serving at least 10,000 people must report this information to EPA unless the Department approves reporting to the Department rather than EPA. Systems serving fewer than 10,000 people must report this information to the Department.

(1) Systems must report that they intend to submit previously collected monitoring results for grandfathering. This report must specify the number of previously collected results the system will submit, the dates of the first and last sample, and whether a system will conduct additional source water monitoring to meet the requirements of Section 7.4.2(a). Systems must report this information no later than the date the sampling schedule under Section 7.4.3 is required.

(2) Systems must report previously collected monitoring results for grandfathering, along with the associated documentation listed in paragraphs (f)(2)(i) through (iv) of this section, no later than two months after the applicable date listed in Section 7.4.2(c).

1. (i) For each sample result, systems must report the applicable data elements in Section 7.4.5.
   1. (ii) Systems must certify that the reported monitoring results include all results the system generated during the time period beginning with the first reported result and ending with the final reported result. This applies to samples that were collected from the sampling location specified for source water monitoring under this section, not spiked, and analyzed using the laboratory's routine process for the analytical methods listed in this section.
      1. (iii) Systems must certify that the samples were representative of a plant's source water(s) and the source water(s) have not changed. Systems must report a description of the sampling location(s), which must address the position of the sampling location in relation to the system's water source(s) and treatment processes, including points of chemical addition and filter backwash recycle.
         1. (iv) For Cryptosporidium samples, the laboratory or laboratories that analyzed the samples must provide a letter certifying that the quality control criteria specified in the methods listed in paragraph (c)(1) of this section were met for each sample batch associated with the reported results. Alternatively, the laboratory may provide bench sheets and sample examination report forms for each field, matrix spike, IPR, OPR, and method blank sample associated with the reported results.

(g) If the Department determines that a previously collected data set submitted for grandfathering was generated during source water conditions that were not normal for the system, such as a drought, the Department may disapprove the data. Alternatively, the Department may approve the previously collected data if the system reports additional source water monitoring data, as determined by the Department, to ensure that the data set used under Section 7.4.9 represents average source water conditions for the system.

(h) If a system submits previously collected data that fully meet the number of samples required for initial source water monitoring under Section 7.4.2(a) and some of the data are rejected due to not meeting the requirements of this section, systems must conduct additional monitoring to replace rejected data on a schedule the Department approves. Systems are not required to begin this additional monitoring until two months after notification that data have been rejected and additional monitoring is necessary.

Disinfection Profiling and Benchmarking Requirements

7.4.7 Requirements When Making a Significant Change in Disinfection Practice

(a) Following the completion of initial source water monitoring under Section 7.4.2(a), a system that plans to make a significant change to its disinfection practice, as defined in paragraph (b) of this section, must develop disinfection profiles and calculate disinfection benchmarks for Giardia lamblia and viruses as described in Section 7.4.8. Prior to changing the disinfection practice, the system must notify the Department and must include in this notice the information in paragraphs (a)(1) through (3) of this section.

(1) A completed disinfection profile and disinfection benchmark for Giardia lamblia and viruses as described in Section 7.4.8.

(2) A description of the proposed change in disinfection practice.

(3) An analysis of how the proposed change will affect the current level of disinfection.

(b) Significant changes to disinfection practice are defined as follows:

(1) Changes to the point of disinfection;

(2) Changes to the disinfectant(s) used in the treatment plant;

(3) Changes to the disinfection process; or (4) Any other modification identified by the Department as a significant change to disinfection practice.

7.4.8 Developing the Disinfection Profile and Benchmark

(a) Systems required to develop disinfection profiles under Section 7.4.7 must follow the requirements of this section. Systems must monitor at least weekly for a period of 12 consecutive months to determine the total log inactivation for Giardia lamblia and viruses. If systems monitor more frequently, the monitoring frequency must be evenly spaced. Systems that operate for fewer than 12 months per year must monitor weekly during the period of operation. Systems must determine log inactivation for Giardia lamblia through the entire plant, based on CT values in

99.9

Tables 10-14 through 10-21 of Section 10.6(b) as applicable. Systems must determine log inactivation for viruses through the entire treatment plant based on a protocol approved by the Department.

(b) Systems with a single point of disinfectant application prior to the entrance to the distribution system must conduct the monitoring in paragraphs (b)(1) through (4) of this section. Systems with more than one point of disinfectant application must conduct the monitoring in paragraphs (b)(1) through (4) of this section for each disinfection segment. Systems must monitor the parameters necessary to determine the total inactivation ratio, using analytical methods in Section 10.6(a).

(1) For systems using a disinfectant other than UV, the temperature of the disinfected water must be measured at each residual disinfectant concentration sampling point during peak hourly flow or at an alternative location approved by the Department.

(2) For systems using chlorine, the pH of the disinfected water must be measured at each chlorine residual disinfectant concentration sampling point during peak hourly flow or at an alternative location approved by the Department.

(3) The disinfectant contact time(s) (t) must be determined during peak hourly flow.

(4) The residual disinfectant concentration(s) (C) of the water before or at the first customer and prior to each additional point of disinfectant application must be measured during peak hourly flow.

(c) In lieu of conducting new monitoring under paragraph (b) of this section, systems may elect to meet the requirements of paragraphs (c)(1) or (2) of this section.

(1) Systems that have at least one year of existing data that are substantially equivalent to data collected under the provisions of paragraph (b) of this section may use these data to develop disinfection profiles as specified in this section if the system has neither made a significant change to its treatment practice nor changed sources since the data were collected. Systems may develop disinfection profiles using up to three years of existing data.

(2) Systems may use disinfection profile(s) developed under Section 7.2.2 or Section 7.3.2 in lieu of developing a new profile if the system has neither made a significant change to its treatment practice nor changed sources since the profile was developed. Systems that have not developed a virus profile under Section 7.2.2 or Section 7.3.2 must develop a virus profile using the same monitoring data on which the Giardia lamblia profile is based.

(d) Systems must calculate the total inactivation ratio for Giardia lamblia as specified in paragraphs (d) (1) through (3) of this section.

(1) Systems using only one point of disinfectant application may determine the total inactivation ratio for the disinfection segment based on either of the methods in paragraph (d)(1)(i) or

1. (ii) of this section.
   1. (i) Determine one inactivation ratio (CTcalc/CT ) before or at the first customer during
      1. 99.9
         1. peak hourly flow.
         2. (ii) Determine successive CTcalc/CT values, representing sequential inactivation

            99.9

            ratios, between the point of disinfectant application and a point before or at the first customer during peak hourly flow. The system must calculate the total inactivation ratio by determining (CTcalc/CT ) for each sequence and then

            99.9

            adding the (CTcalc/CT ) values together to determine ([Sigma](CTcalc/CT

            99.9

            )).

            99.9

(2) Systems using more than one point of disinfectant application before the first customer must determine the CT value of each disinfection segment immediately prior to the next point of disinfectant application, or for the final segment, before or at the first customer, during peak hourly flow. The (CTcalc/CT ) value of each segment and ([Sigma](CTcalc/CT

1. 99.9 99.9
   1. )) must be calculated using the method in paragraph (d)(1)(ii) of this section.

(3) The system must determine the total logs of inactivation by multiplying the value calculated in paragraph (d)(1) or (d)(2) of this section by 3.0.

(4) Systems must calculate the log of inactivation for viruses using a protocol approved by the Department.

(e) Systems must use the procedures specified in paragraphs (e)(1) and (2) of this section to calculate a disinfection benchmark.

(1) For each year of profiling data collected and calculated under paragraphs (a) through (d) of this section, systems must determine the lowest mean monthly level of both Giardia lamblia and virus inactivation. Systems must determine the mean Giardia lamblia and virus inactivation for each calendar month for each year of profiling data by dividing the sum of daily or weekly Giardia lamblia and virus log inactivation by the number of values calculated for that month.

(2) The disinfection benchmark is the lowest monthly mean value (for systems with one year of profiling data) or the mean of the lowest monthly mean values (for systems with more than one year of profiling data) of Giardia lamblia and virus log inactivation in each year of profiling data.

Treatment Technique Requirements

7.4.9 Bin Classification for Filtered Systems

(a) Following completion of the initial round of source water monitoring required under Section 7.4.2(a), filtered systems must calculate an initial Cryptosporidium bin concentration for each plant for which monitoring was required. Calculation of the bin concentration must use the Cryptosporidium results reported under Section 7.4.2(a) and must follow the procedures in paragraphs (b)(1) through (5) of this section.

(b) (1) For systems that collect a total of at least 48 samples, the bin concentration is equal to the arithmetic mean of all sample concentrations.

(2) For systems that collect a total of at least 24 samples, but not more than 47 samples, the bin concentration is equal to the highest arithmetic mean of all sample concentrations in any 12 consecutive months during which Cryptosporidium samples were collected.

(3) For systems that serve fewer than 10,000 people and monitor for Cryptosporidium for only one year (i.e., collect 24 samples in 12 months), the bin concentration is equal to the arithmetic mean of all sample concentrations.

(4) For systems with plants operating only part of the year that monitor fewer than 12 months per year under Section 7.4.2(e), the bin concentration is equal to the highest arithmetic mean of all sample concentrations during any year of Cryptosporidium monitoring.

(5) If the monthly Cryptosporidium sampling frequency varies, systems must first calculate a monthly average for each month of monitoring. Systems must then use these monthly average concentrations, rather than individual sample concentrations, in the applicable calculation for bin classification in paragraphs (b)(1) through (4) of this section.

(c) Filtered systems must determine their initial bin classification from Table 7-9 and using the Cryptosporidium bin concentration calculated under paragraphs (a)-(b) of this section: Table 7-9 Bin Classification for Filtered Systems For systems that are: With a Cryptosporidium The bin classification is: bin concentration of:

Required to monitor for less than 0.075 oocyst/L Bin 1 Cryptosporidium under section 7.4.2 . 0.075 oocyst/L to less Bin 2 than 1.0 oocyst/L . 1.0 oocyst/L to less than Bin 3

1. 3.0 oocyst/L

. ≥ 3.0 oocyst/L Bin 4 Serving fewer than N/A Bin 1 10,000 people and NOT required to monitor for Cryptosporidium under section 7.4.2(a)(4)

1 Based on calculations in paragraph (a) or (d) of this section, as applicable.

(d) Following completion of the second round of source water monitoring required under Section 7.4.2(b), filtered systems must recalculate their Cryptosporidium bin concentration using the Cryptosporidium results reported under Section 7.4.2(b) and following the procedures in paragraphs (b)(1) through (4) of this section. Systems must then re-determine their bin classification using this bin concentration and the table in paragraph (c) of this section.

(e) (1) Filtered systems must report their initial bin classification under paragraph (c) of this section to the Department for approval no later than 6 months after the system is required to complete initial source water monitoring based on the schedule in Section 7.4.2(c).

(2) Systems must report their bin classification under paragraph (d) of this section to the Department for approval no later than 6 months after the system is required to complete the second round of source water monitoring based on the schedule in Section 7.4.2(c).

(3) The bin classification report to the Department must include a summary of source water monitoring data and the calculation procedure used to determine bin classification.

(f) Failure to comply with the conditions of paragraph (e) of this section is a violation of the treatment technique requirement.

7.4.10 Filtered System Additional Cryptosporidium Treatment Requirements

(a) Filtered systems must provide the level of additional treatment for Cryptosporidium specified in Table 7-10 based on their bin classification as determined under Section 7.4.9 and according to the schedule in Section 7.4.11.

7-10 Additional Treatment Requirements for Filtered Systems . Conventional filtration Direct filtration Slow sand or treatment (including diatomaceous earth softening) filtration Bin 1 No additional treatment No additional treatment No additional treatment Bin 2 1-log treatment 1.5-log treatment 1-log treatment Bin 3 2-log treatment 2.5 log treatment 2-log treatment Bin 4 2.5-log treatment 3-log treatment 2.5-log treatment 1 As determined by the Department such that the total Cryptosporidium removal and inactivation is at least 4.0-log. 2 As determined by the Department such that the total Cryptosporidium removal and inactivation is at least 5.0-log. 3 As determined by the Department such that the total Cryptosporidium removal and inactivation is at least 5.5-log.

(b) (1) Filtered systems must use one or more of the treatment and management options listed in Section 7.4.13, termed the microbial toolbox, to comply with the additional Cryptosporidium treatment required in paragraph (a) of this section.

(2) Systems classified in Bin 3 and Bin 4 must achieve at least 1-log of the additional Cryptosporidium treatment required under paragraph (a) of this section using either one or a combination of the following: bag filters, bank filtration, cartridge filters, chlorine dioxide, membranes, ozone, or UV, as described in Section 7.4.14 through 7.4.18.

(c) Failure by a system in any month to achieve treatment credit by meeting criteria in Section 7.4.14 through 7.4.18 for microbial toolbox options that is at least equal to the level of treatment required in paragraph (a) of this section is a violation of the treatment technique requirement.

(d) If the Department determines during a sanitary survey or an equivalent source water assessment that after a system completed the monitoring conducted under Section 7.4.2(a) or (b), significant changes occurred in the system's watershed that could lead to increased contamination of the source water by Cryptosporidium, the system must take actions specified by the Department to address the contamination. These actions may include additional source water monitoring and/or implementing microbial toolbox options listed in Section 7.4.13.

7.4.11 Schedule for Compliance with Cryptosporidium Treatment Requirements

(a) Following initial bin classification under Section 7.4.9(c), filtered systems must provide the level of treatment for Cryptosporidium required under Section 7.4.10 according to the schedule in paragraph (c) of this section.

(b) Cryptosporidium treatment compliance dates.

Table 7-11 Cryptosporidium Treatment Compliance Dates Table Systems that serve Must comply with Cryptosporidium treatment requirements no later than (1) At least 100,000 (i) April 1, 2012 people (2) From 50,000 to (i) October 1, 2012 99,999 people (3) From 10,000 to (i) October 1, 2013 49,999 people (4) Fewer than 10,000 (i) October 1, 2014 people 1 Departments may allow up to an additional two years for complying with the treatment requirement for systems making capital improvements.

(c) If the bin classification for a filtered system changes following the second round of source water monitoring, as determined under Section 7.4.9(d), the system must provide the level of treatment for Cryptosporidium required under Section 7.4.10 on a schedule the Department approves.

7.4.12 Requirements for Uncovered Finished Water Storage Facilities

(a) Systems must notify the Department of the use of each uncovered finished water storage facility no later than April 1, 2008.

(b) Systems must cover any uncovered finished water storage facility.

(c) Failure to comply with the requirements of this section is a violation of the treatment technique requirement.

Requirements for Microbial Toolbox Components 7.4.13 Microbial Toolbox Options for Meeting Cryptosporidium Treatment Requirements (a) Systems receive the treatment credits listed in the table in paragraph (b) of this section by meeting the conditions for microbial toolbox options described in Sections 7.4.14 through 7.4.18. Systems apply these treatment credits to meet the treatment requirements in Section 7.4.10, as applicable.

(b) The following table summarizes options in the microbial toolbox: Table 7-12 Microbial Toolbox Summary Table: Options, Treatment Credits and Criteria Toolbox Option Cryptosporidium treatment credit with design and implementation criteria Source Protection and .

Management Toolbox Options (1) Watershed control 0.5-log credit for program Department-approved program comprising required elements, annual program status report to Department, and regular watershed survey.

(2) Alternative No prescribed credit.

source/intake Systems may conduct management simultaneous monitoring for treatment bin classification at alternative intake locations or under alternative intake management strategies.

1. Specific criteria are in Section 7.4.14(b).

Pre Filtration Toolbox .

Options (3) Presedimentation 0.5-log credit during any basin with coagulation month that presedimentation basins achieve a monthly mean reduction of 0.5-log or greater in turbidity or alternative Department- approved performance criteria. To be eligible, basins must be operated continuously with coagulant addition and all plant flow must pass through basins. Specific criteria are in Section 7.4.15(a).

(4) Two-stage lime 0.5-log credit for two- Softening stage softening where chemical addition and hardness precipitation occur in both stages. All plant flow must pass through both stages.

1. Single-stage softening is credited as equivalent to conventional treatment.
   1. Specific criteria are in Section 7.4.15(b).

(5) Bank Filtration 0.5-log credit for 25-foot setback; 1.0-log credit for 50-foot setback; aquifer must be unconsolidated sand containing at least 10 percent fines; average turbidity in wells must be less than 1 NTU. Systems using wells followed by filtration when conducting source water monitoring must sample the well to determine bin classification and are not eligible for additional credit. Specific criteria are in Section 7.4.15(c).

Treatment Performance .

Toolbox Options (6) Combined filter 0.5-log credit for performance combined filter effluent turbidity less than or equal to 0.15 NTU in at least 95 percent of measurements each month. Specific criteria are in Section 7.4.16(a).

(7) Individual filter 0.5-log credit (in addition performance to 0.5-log combined filter performance credit) if individual filter effluent turbidity is less than or equal to 0.15 NTU in at least 95 percent of samples each month in each filter and is never greater than 0.3 NTU in two consecutive measurements in any filter. Specific criteria are in Section 7.4.16(b).

(8) Demonstration of Credit awarded to unit performance process or treatment train based on a demonstration to the Department with a Department- approved protocol. Specific criteria are in Section 7.4.16(c).

Additional Filtration .

Toolbox Options (9) Bag or cartridge filters Up to 2-log credit based (individual filters) on the removal efficiency demonstrated during challenge testing with a 1.0-log factor of safety.

1. Specific criteria are in Section 7.4.17(a).

(10) Bag or cartridge Up to 2.5-log credit based filters (in series) on the removal efficiency demonstrated during challenge testing with a 0.5-log factor of safety.

1. Specific criteria are in Section 7.4.17(a).

(11) Membrane filtration Log credit equivalent to removal efficiency demonstrated in challenge test for device if supported by direct integrity testing. Specific criteria are in Section 7.4.17(b).

(12) Second stage 0.5-log credit for second filtration separate granular media filtration stage if treatment train includes coagulation prior to first filter. Specific criteria are in Section 7.4.17(c).

(13) Slow sand filters 2.5-log credit as a secondary filtration step;

1. 3.0-log credit as a primary filtration process. No prior chlorination for either option. Specific criteria are in Section 7.4.17(d).

Inactivation Toolbox .

Options (14) Chlorine dioxide Log credit based on measured CT in relation to CT table. Specific criteria in Section 7.4.18(b).

(15) Ozone Log credit based on measured CT in relation to CT table. Specific criteria in Section 7.4.18(b).

(16) UV Log credit based on validated UV dose in relation to UV dose table;

1. reactor validation testing required to establish UV dose and associated operating conditions.
   1. Specific criteria in Section 7.4.18(c).

7.4.14 Source Toolbox Components

(a) Watershed control program. Systems receive 0.5-log Cryptosporidium treatment credit for implementing a watershed control program that meets the requirements of this section.

(1) Systems that intend to apply for the watershed control program credit must notify the Department of this intent no later than two years prior to the treatment compliance date applicable to the system in section 7.4.11.

(2) Systems must submit to the Department a proposed watershed control plan no later than one year before the applicable treatment compliance date in section 7.4.11. The Department must approve the watershed control plan for the system to receive watershed control program treatment credit. The watershed control plan must include the elements in paragraphs (a)(2)(i) through (iv) of this section.

1. (i) Identification of an “area of influence” outside of which the likelihood of Cryptosporidium or fecal contamination affecting the treatment plant intake is not significant. This is the area to be evaluated in future watershed surveys under paragraph (a)(5)(ii) of this section.
   1. (ii) Identification of both potential and actual sources of Cryptosporidium contamination and an assessment of the relative impact of these sources on the system's source water quality.
      1. (iii) An analysis of the effectiveness and feasibility of control measures that could reduce Cryptosporidium loading from sources of contamination to the system's source water.
         1. (iv) A statement of goals and specific actions the system will undertake to reduce source water Cryptosporidium levels. The plan must explain how the actions are expected to contribute to specific goals, identify watershed partners and their roles, identify resource requirements and commitments, and include a schedule for plan implementation with deadlines for completing specific actions identified in the plan.

(3) Systems with existing watershed control programs (i.e., programs in place on January 5, 2006) are eligible to seek this credit. Their watershed control plans must meet the criteria in paragraph (a)(2) of this section and must specify ongoing and future actions that will reduce source water Cryptosporidium levels.

(4) If the Department does not respond to a system regarding approval of a watershed control plan submitted under this section and the system meets the other requirements of this section, the watershed control program will be considered approved and 0.5 log Cryptosporidium treatment credit will be awarded unless and until the Department subsequently withdraws such approval.

(5) Systems must complete the actions in paragraphs (a)(5)(i) through (iii) of this section to maintain the 0.5-log credit.

1. (i) Submit an annual watershed control program status report to the Department. The annual watershed control program status report must describe the system's implementation of the approved plan and assess the adequacy of the plan to meet its goals. It must explain how the system is addressing any shortcomings in plan implementation, including those previously identified by the Department or as the result of the watershed survey conducted under paragraph (a)(5)(ii) of this section. It must also describe any significant changes that have occurred in the watershed since the last watershed sanitary survey. If a system determines during implementation that making a significant change to its approved watershed control program is necessary, the system must notify the Department prior to making any such changes. If any change is likely to reduce the level of source water protection, the system must also list in its notification the actions the system will take to mitigate this effect.
   1. (ii) Undergo a watershed sanitary survey every three years for community water systems and every five years for noncommunity water systems and submit the survey report to the Department. The survey must be conducted according to Department guidelines and by persons the Department approves.
      1. (A) The watershed sanitary survey must meet the following criteria: encompass the region identified in the Department-approved watershed control plan as the area of influence; assess the implementation of actions to reduce source water Cryptosporidium levels; and identify any significant new sources of Cryptosporidium.
         1. (B) If the Department determines that significant changes may have occurred in the watershed since the previous watershed sanitary survey, systems must undergo another watershed sanitary survey by a date the Department requires, which may be earlier than the regular date in paragraph (a)(5)(ii) of this section.
         2. (iii) The system must make the watershed control plan, annual status reports, and watershed sanitary survey reports available to the public upon request. These documents must be in a plain language style and include criteria by which to evaluate the success of the program in achieving plan goals. The Department may approve systems to withhold from the public portions of the annual status report, watershed control plan, and watershed sanitary survey based on water supply security considerations.

(6) If the Department determines that a system is not carrying out the approved watershed control plan, the Department may withdraw the watershed control program treatment credit.

(b) Alternative source.

(1) A system may conduct source water monitoring that reflects a different intake location (either in the same source or for an alternate source) or a different procedure for the timing or level of withdrawal from the source (alternative source monitoring). If the Department approves, a system may determine its bin classification under Section 7.4.9 based on the alternative source monitoring results.

(2) If systems conduct alternative source monitoring under paragraph (b)(1) of this section, systems must also monitor their current plant intake concurrently as described in Section 7.4.2.

(3) Alternative source monitoring under paragraph (b)(1) of this section must meet the requirements for source monitoring to determine bin classification, as described in Sections 7.4.2 through 7.4.5 and Article 10. Systems must report the alternative source monitoring results to the Department, along with supporting information documenting the operating conditions under which the samples were collected.

(4) If a system determines its bin classification under Section 7.4.9 using alternative source monitoring results that reflect a different intake location or a different procedure for managing the timing or level of withdrawal from the source, the system must relocate the intake or permanently adopt the withdrawal procedure, as applicable, no later than the applicable treatment compliance date in Section 7.4.11.

7.4.15 Pre-filtration Treatment Toolbox Components

(a) Presedimentation. Systems receive 0.5-log Cryptosporidium treatment credit for a presedimentation basin during any month the process meets the criteria in this paragraph.

(1) The presedimentation basin must be in continuous operation and must treat the entire plant flow taken from a surface water or GWUDI source.

(2) The system must continuously add a coagulant to the presedimentation basin.

(3) The presedimentation basin must achieve the performance criteria in paragraph (3)(i) or (ii) of this section.

1. (i) Demonstrates at least 0.5-log mean reduction of influent turbidity. This reduction must be determined using daily turbidity measurements in the presedimentation process influent and effluent and must be calculated as follows: log (monthly mean of daily influent turbidity)-log (monthly mean of daily effluent turbidity).
   1. (ii) Complies with Department-approved performance criteria that demonstrate at least 0.5-log mean removal of micron-sized particulate material through the presedimentation process.

(b) Two-stage lime softening. Systems receive an additional 0.5-log Cryptosporidium treatment credit for a two-stage lime softening plant if chemical addition and hardness precipitation occur in two separate and sequential softening stages prior to filtration. Both softening stages must treat the entire plant flow taken from a surface water or GWUDI source.

(c) Bank filtration. Systems receive Cryptosporidium treatment credit for bank filtration that serves as pretreatment to a filtration plant by meeting the criteria in this paragraph. Systems using bank filtration when they begin source water monitoring under Section 7.4.2(a) must collect samples as described in Section 7.4.4(d) and are not eligible for this credit.

(1) Wells with a ground water flow path of at least 25 feet receive 0.5-log treatment credit; wells with a ground water flow path of at least 50 feet receive 1.0-log treatment credit. The ground water flow path must be determined as specified in paragraph (c)(4) of this section.

(2) Only wells in granular aquifers are eligible for treatment credit. Granular aquifers are those comprised of sand, clay, silt, rock fragments, pebbles or larger particles, and minor cement. A system must characterize the aquifer at the well site to determine aquifer properties. Systems must extract a core from the aquifer and demonstrate that in at least 90 percent of the core length, grains less than 1.0 mm in diameter constitute at least 10 percent of the core material.

(3) Only horizontal and vertical wells are eligible for treatment credit.

(4) For vertical wells, the ground water flow path is the measured distance from the edge of the surface water body under high flow conditions (determined by the 100 year floodplain elevation boundary or by the floodway, as defined in Federal Emergency Management Agency flood hazard maps) to the well screen. For horizontal wells, the ground water flow path is the measured distance from the bed of the river under normal flow conditions to the closest horizontal well lateral screen.

(5) Systems must monitor each wellhead for turbidity at least once every four hours while the bank filtration process is in operation. If monthly average turbidity levels, based on daily maximum values in the well, exceed 1 NTU, the system must report this result to the Department and conduct an assessment within 30 days to determine the cause of the high turbidity levels in the well. If the Department determines that microbial removal has been compromised, the Department may revoke treatment credit until the system implements corrective actions approved by the Department to remediate the problem.

(6) Springs and infiltration galleries are not eligible for treatment credit under this section, but are eligible for credit under section 7.4.16(c).

(7) Bank filtration demonstration of performance. The Department may approve Cryptosporidium treatment credit for bank filtration based on a demonstration of performance study that meets the criteria in this paragraph. This treatment credit may be greater than 1.0-log and may be awarded to bank filtration that does not meet the criteria in paragraphs (c)(1)-(5) of this section.

1. (i) The study must follow a Department-approved protocol and must involve the collection of data on the removal of Cryptosporidium or a surrogate for Cryptosporidium and related hydrogeologic and water quality parameters during the full range of operating conditions.
   1. (ii) The study must include sampling both from the production well(s) and from monitoring wells that are screened and located along the shortest flow path between the surface water source and the production well(s).

7.4.16 Treatment Performance Toolbox Components

(a) Combined filter performance. Systems using conventional filtration treatment or direct filtration treatment receive an additional 0.5-log Cryptosporidium treatment credit during any month the system meets the criteria in this paragraph. Combined filter effluent (CFE) turbidity must be less than or equal to 0.15 NTU in at least 95 percent of the measurements. Turbidity must be measured as described in Section 10.5.

(b) Individual filter performance. Systems using conventional filtration treatment or direct filtration treatment receive 0.5-log Cryptosporidium treatment credit, which can be in addition to the 0.5- log credit under paragraph (a) of this section, during any month the system meets the criteria in this paragraph. Compliance with these criteria must be based on individual filter turbidity monitoring as described in Section 7.2.4 or Section 7.3.5, as applicable.

(1) The filtered water turbidity for each individual filter must be less than or equal to 0.15 NTU in at least 95 percent of the measurements recorded each month.

(2) No individual filter may have a measured turbidity greater than 0.3 NTU in two consecutive measurements taken 15 minutes apart.

(3) Any system that has received treatment credit for individual filter performance and fails to meet the requirements of paragraph (b)(1) or (2) of this section during any month does not receive a treatment technique violation under Section 7.4.10(c) if the Department determines the following:

1. (i) The failure was due to unusual and short-term circumstances that could not reasonably be prevented through optimizing treatment plant design, operation, and maintenance.
   1. (ii) The system has experienced no more than two such failures in any calendar year.

(c) Demonstration of performance. The Department may approve Cryptosporidium treatment credit for drinking water treatment processes based on a demonstration of performance study that meets the criteria in this paragraph. This treatment credit may be greater than or less than the prescribed treatment credits in Section 7.4.10 or Sections 7.4.15 through 7.4.18 and may be awarded to treatment processes that do not meet the criteria for the prescribed credits.

(1) Systems cannot receive the prescribed treatment credit for any toolbox box option in Sections

1. 7.4.15 through 7.4.18 if that toolbox option is included in a demonstration of performance study for which treatment credit is awarded under this paragraph.

(2) The demonstration of performance study must follow a Department-approved protocol and must demonstrate the level of Cryptosporidium reduction the treatment process will achieve under the full range of expected operating conditions for the system.

(3) Approval by the Department must be in writing and may include monitoring and treatment performance criteria that the system must demonstrate and report on an ongoing basis to remain eligible for the treatment credit. The Department may designate such criteria where necessary to verify that the conditions under which the demonstration of performance credit was approved are maintained during routine operation.

7.4.17 Additional Filtration Toolbox Components

(a) Bag and cartridge filters. Systems receive Cryptosporidium treatment credit of up to 2.0-log for individual bag or cartridge filters and up to 2.5-log for bag or cartridge filters operated in series by meeting the criteria in paragraphs (a)(1) through (10) of this section. To be eligible for this credit, systems must report the results of challenge testing that meets the requirements of paragraphs (a)(2) through (9) of this section to the Department. The filters must treat the entire plant flow taken from a Surface Water and GWUDI source.

(1) The Cryptosporidium treatment credit awarded to bag or cartridge filters must be based on the removal efficiency demonstrated during challenge testing that is conducted according to the criteria in paragraphs (a)(2) through (a)(9) of this section. A factor of safety equal to 1-log for individual bag or cartridge filters and 0.5-log for bag or cartridge filters in series must be applied to challenge testing results to determine removal credit. Systems may use results from challenge testing conducted prior to January 5, 2006 if the prior testing was consistent with the criteria specified in paragraphs (a)(2) through (9) of this section.

(2) Challenge testing must be performed on full-scale bag or cartridge filters, and the associated filter housing or pressure vessel, that are identical in material and construction to the filters and housings the system will use for removal of Cryptosporidium. Bag or cartridge filters must be challenge tested in the same configuration that the system will use, either as individual filters or as a series configuration of filters.

(3) Challenge testing must be conducted using Cryptosporidium or a surrogate that is removed no more efficiently than Cryptosporidium. The microorganism or surrogate used during challenge testing is referred to as the challenge particulate. The concentration of the challenge particulate must be determined using a method capable of discreetly quantifying the specific microorganism or surrogate used in the test; gross measurements such as turbidity may not be used.

(4) The maximum feed water concentration that can be used during a challenge test must be based on the detection limit of the challenge particulate in the filtrate (i.e., filtrate detection limit) and must be calculated using the following equation: Maximum Feed Concentration = 1 x 10 4 x (Filtrate Detection Limit) (5) Challenge testing must be conducted at the maximum design flow rate for the filter as specified by the manufacturer.

(6) Each filter evaluated must be tested for a duration sufficient to reach 100 percent of the terminal pressure drop, which establishes the maximum pressure drop under which the filter may be used to comply with the requirements of this section.

(7) Removal efficiency of a filter must be determined from the results of the challenge test and expressed in terms of log removal values using the following equation: LRV = LOG (C )-LOG (C )

1. 10 f 10 p Where:
   1. LRV = log removal value demonstrated during challenge testing; C = the feed concentration measured during the challenge test; and f C = the filtrate concentration measured during the challenge test. In p applying this equation, the same units must be used for the feed and filtrate concentrations. If the challenge particulate is not detected in the filtrate, then the term C must be set equal to the detection limit. p

(8) Each filter tested must be challenged with the challenge particulate during three periods over the filtration cycle: within two hours of start-up of a new filter; when the pressure drop is between 45 and 55 percent of the terminal pressure drop; and at the end of the cycle after the pressure drop has reached 100 percent of the terminal pressure drop. An LRV must be calculated for each of these challenge periods for each filter tested. The LRV for the filter (LRV ) must be assigned the value of the minimum LRV observed during the filter three challenge periods for that filter.

(9) If fewer than 20 filters are tested, the overall removal efficiency for the filter product line must be set equal to the lowest LRV among the filters tested. If 20 or more filters are filter tested, the overall removal efficiency for the filter product line must be set equal to the 10th percentile of the set of LRV values for the various filters tested. The percentile is filter defined by (i/(n+1)) where i is the rank of n individual data points ordered lowest to highest. If necessary, the 10th percentile may be calculated using linear interpolation.

(10) If a previously tested filter is modified in a manner that could change the removal efficiency of the filter product line, challenge testing to demonstrate the removal efficiency of the modified filter must be conducted and submitted to the Department.

(b) Membrane filtration.

(1) Systems receive Cryptosporidium treatment credit for membrane filtration that meets the criteria of this paragraph. Membrane cartridge filters that meet the definition of membrane filtration in Section 1.5.2 are eligible for this credit. The level of treatment credit a system receives is equal to the lower of the values determined under paragraph (b)(1)(i) and (ii) of this section.

1. (i) The removal efficiency demonstrated during challenge testing conducted under the conditions in paragraph (b)(2) of this section.
   1. (ii) The maximum removal efficiency that can be verified through direct integrity testing used with the membrane filtration process under the conditions in paragraph (b) (3) of this section.

(2) Challenge Testing. The membrane used by the system must undergo challenge testing to evaluate removal efficiency, and the system must report the results of challenge testing to the Department. Challenge testing must be conducted according to the criteria in paragraphs (b)(2)(i) through (vii) of this section. Systems may use data from challenge testing conducted prior to January 5, 2006 if the prior testing was consistent with the criteria in paragraphs (b)(2)(i) through (vii) of this section.

1. (i) Challenge testing must be conducted on either a full-scale membrane module, identical in material and construction to the membrane modules used in the system's treatment facility, or a smaller-scale membrane module, identical in material and similar in construction to the full-scale module.
   1. (ii) Challenge testing must be conducted using Cryptosporidium oocysts or a surrogate that is removed no more efficiently than Cryptosporidium oocysts. The organism or surrogate used during challenge testing is referred to as the challenge particulate. The concentration of the challenge particulate, in both the feed and filtrate water, must be determined using a method capable of discretely quantifying the specific challenge particulate used in the test; gross measurements such as turbidity may not be used.
      1. (iii) The maximum feed water concentration that can be used during a challenge test is based on the detection limit of the challenge particulate in the filtrate and must be determined according to the following equation:
         1. Maximum Feed Concentration = 3.16 x 10 6 x (Filtrate Detection Limit) (iv) Challenge testing must be conducted under representative hydraulic conditions at the maximum design flux and maximum design process recovery specified by the manufacturer for the membrane module. Flux is defined as the throughput of a pressure driven membrane process expressed as flow per unit of membrane area. Recovery is defined as the volumetric percent of feed water that is converted to filtrate over the course of an operating cycle uninterrupted by events such as chemical cleaning or a solids removal process (i.e., backwashing).
         2. (v) Removal efficiency of a membrane module must be calculated from the challenge test results and expressed as a log removal value according to the following equation:

            LRV = LOG (C ) x LOG (C )

            10 f 10 p Where:

            LRV = log removal value demonstrated during the challenge test; C = the feed concentration measured during the challenge test; and f C = the filtrate concentration measured during the challenge test. p Equivalent units must be used for the feed and filtrate concentrations. If the challenge particulate is not detected in the filtrate, the term C is set p equal to the detection limit for the purpose if calculating the LRV. An LRV must be calculated for each membrane module evaluated during the challenge test.

         3. (vi) The removal efficiency of a membrane filtration process demonstrated during challenge testing must be expressed as a log removal value (LRV ). If fewer C-Test than 20 modules are tested, then LRV is equal to the lowest of the C-Test representative LRVs among the modules tested. If 20 or more modules are tested, then LRV is equal to the 10th percentile of the representative LRVs C-Test among the modules tested. The percentile is defined by (i/(n+1)) where i is the rank of n individual data points ordered lowest to highest. If necessary, the 10th percentile may be calculated using linear interpolation.
         4. (vii) The challenge test must establish a quality control release value (QCRV) for a non- destructive performance test that demonstrates the Cryptosporidium removal capability of the membrane filtration module. This performance test must be applied to each production membrane module used by the system that was not directly challenge tested in order to verify Cryptosporidium removal capability. Production modules that do not meet the established QCRV are not eligible for the treatment credit demonstrated during the challenge test.
         5. (viii) If a previously tested membrane is modified in a manner that could change the removal efficiency of the membrane or the applicability of the non-destructive performance test and associated QCRV, additional challenge testing to demonstrate the removal efficiency of, and determine a new QCRV for, the modified membrane must be conducted and submitted to the Department.

(3) Direct integrity testing. Systems must conduct direct integrity testing in a manner that demonstrates a removal efficiency equal to or greater than the removal credit awarded to the membrane filtration process and meets the requirements described in paragraphs (b) (3)(i) through (vi) of this section. A direct integrity test is defined as a physical test applied to a membrane unit in order to identify and isolate integrity breaches (i.e., one or more leaks that could result in contamination of the filtrate).

1. (i) The direct integrity test must be independently applied to each membrane unit in service. A membrane unit is defined as a group of membrane modules that share common valving that allows the unit to be isolated from the rest of the system for the purpose of integrity testing or other maintenance.
   1. (ii) The direct integrity method must have a resolution of 3 micrometers or less, where resolution is defined as the size of the smallest integrity breach that contributes to a response from the direct integrity test.
      1. (iii) The direct integrity test must have a sensitivity sufficient to verify the log treatment credit awarded to the membrane filtration process by the Department, where sensitivity is defined as the maximum log removal value that can be reliably verified by a direct integrity test. Sensitivity must be determined using the approach in either paragraph (b)(3)(iii)(A) or (B) of this section as applicable to the type of direct integrity test the system uses.
         1. (A) For direct integrity tests that use an applied pressure or vacuum, the direct integrity test sensitivity must be calculated according to the following equation:

            LRV = LOG (Q /(VCF x Q ))

            DIT 10 p breach Where:

            LRV = the sensitivity of the direct integrity test;

            DIT Q = total design filtrate flow from the membrane unit;

            p Q = flow of water from an integrity breach associated with the breach smallest integrity test response that can be reliably measured, and VCF = volumetric concentration factor. The volumetric concentration factor is the ratio of the suspended solids concentration on the high pressure side of the membrane relative to that in the feed water.

         2. (B) For direct integrity tests that use a particulate or molecular marker, the direct integrity test sensitivity must be calculated according to the following equation:

            LRV = LOG (C )-LOG (C )

            DIT 10 f 10 p Where:

            LRV = the sensitivity of the direct integrity test;

            DIT C = the typical feed concentration of the marker used in the test; and f C = the filtrate concentration of the marker from an integral membrane p unit.

         3. (iv) Systems must establish a control limit within the sensitivity limits of the direct integrity test that is indicative of an integral membrane unit capable of meeting the removal credit awarded by the Department.
         4. (v) If the result of a direct integrity test exceeds the control limit established under paragraph (b)(3)(iv) of this section, the system must remove the membrane unit from service. Systems must conduct a direct integrity test to verify any repairs, and may return the membrane unit to service only if the direct integrity test is within the established control limit.
         5. (vi) Systems must conduct direct integrity testing on each membrane unit at a frequency of not less than once each day that the membrane unit is in operation. The Department may approve less frequent testing, based on demonstrated process reliability, the use of multiple barriers effective for Cryptosporidium, or reliable process safeguards.

(4) Indirect integrity monitoring. Systems must conduct continuous indirect integrity monitoring on each membrane unit according to the criteria in paragraphs (b)(4)(i) through (v) of this section. Indirect integrity monitoring is defined as monitoring some aspect of filtrate water quality that is indicative of the removal of particulate matter. A system that implements continuous direct integrity testing of membrane units in accordance with the criteria in paragraphs (b)(3)(i) through (v) of this section is not subject to the requirements for continuous indirect integrity monitoring. Systems must submit a monthly report to the Department summarizing all continuous indirect integrity monitoring results triggering direct integrity testing and the corrective action that was taken in each case.

1. (i) Unless the Department approves an alternative parameter, continuous indirect integrity monitoring must include continuous filtrate turbidity monitoring.
   1. (ii) Continuous monitoring must be conducted at a frequency of no less than once every 15 minutes.
      1. (iii) Continuous monitoring must be separately conducted on each membrane unit.
         1. (iv) If indirect integrity monitoring includes turbidity and if the filtrate turbidity readings are above 0.15 NTU for a period greater than 15 minutes (i.e., two consecutive 15- minute readings above 0.15 NTU), direct integrity testing must immediately be performed on the associated membrane unit as specified in paragraphs (b)(3)(i) through (v) of this section.
         2. (v) If indirect integrity monitoring includes a Department-approved alternative parameter and if the alternative parameter exceeds a Department-approved control limit for a period greater than 15 minutes, direct integrity testing must immediately be performed on the associated membrane units as specified in paragraphs (b)(3)(i) through (v) of this section.

(c) Second stage filtration. Systems receive 0.5-log Cryptosporidium treatment credit for a separate second stage of filtration that consists of sand, dual media, GAC, or other fine grain media following granular media filtration if the Department approves. To be eligible for this credit, the first stage of filtration must be preceded by a coagulation step and both filtration stages must treat the entire plant flow taken from a surface water or GWUDI source. A cap, such as GAC, on a single stage of filtration is not eligible for this credit. The Department must approve the treatment credit based on an assessment of the design characteristics of the filtration process.

(d) Slow sand filtration (as secondary filter). Systems are eligible to receive 2.5-log Cryptosporidium treatment credit for a slow sand filtration process that follows a separate stage of filtration if both filtration stages treat entire plant flow taken from a surface water or GWUDI source and no disinfectant residual is present in the influent water to the slow sand filtration process. The Department must approve the treatment credit based on an assessment of the design characteristics of the filtration process. This paragraph does not apply to treatment credit awarded to slow sand filtration used as a primary filtration process.

7.4.18 Inactivation Toolbox Components

(a) Calculation of CT values.

(1) CT is the product of the disinfectant contact time (T, in minutes) and disinfectant concentration (C, in milligrams per liter). Systems with treatment credit for chlorine dioxide or ozone under paragraph (b) or (c) of this section must calculate CT at least once each day, with both C and T measured during peak hourly flow as specified in Sections 10.5.

(2) Systems with several disinfection segments in sequence may calculate CT for each segment, where a disinfection segment is defined as a treatment unit process with a measurable disinfectant residual level and a liquid volume. Under this approach, systems must add the Cryptosporidium CT values in each segment to determine the total CT for the treatment plant.

(b) CT values for chlorine dioxide and ozone.

(1) Systems receive the Cryptosporidium treatment credit listed in this table by meeting the corresponding chlorine dioxide CT value for the applicable water temperature, as described in paragraph (a) of this section.

Table 7-13 CT Values (mg-min/L) for Cryptosporidium inactivation by Chlorine Dioxide 1 Log Credit Water Temperature, ° C . ≤ 1 2 3 5 7 10 15 20 25 30

1. 0.5

(i) 159 153 140 128 107 90 69 45 29 19 12

0.25

(ii) 319 305 279 256 214 180 138 89 58 38 24

0.5

(iii) 637 610 558 511 429 360 277 179 116 75 49

1.0

(iv) 956 915 838 767 643 539 415 268 174 113 73

1.5

(v) 127 122 111 102 858 719 553 357 232 150 98

2.0 5 0 7 3

(vi) 159 152 139 127 107 899 691 447 289 188 122

2.5 4 5 6 8 2

(vii) 191 183 167 153 128 107 830 536 347 226 147

3.0 2 0 5 4 6 9

1 Systems may use this equation to determine log credit between the indicated values: Log credit = (0.001506 x (1.09116) Temp) x CT.

(2) Systems receive the Cryptosporidium treatment credit listed in this table by meeting the corresponding ozone CT values for the applicable water temperature, as described in paragraph (a) of this section.

Table 7-14 CT Values (mg-min/L) for Cryptosporidium inactivation by Ozone 1 Log Credit Water Temperature, °C . ≤ 1 2 3 5 7 10 15 20 25 30

1. 0.5

(i) 6.0 5.8 5.2 4.8 4.0 3.3 2.5 1.6 1.0 0.6 0.39

0.25

(ii) 12 12 10 9.5 7.9 6.5 4.9 3.1 2.0 1.2 0.78

0.5

(iii) 24 23 21 19 16 13 9.9 6.2 3.9 2.5 1.6

1.0

(iv) 36 35 31 29 24 20 15 9.3 5.9 3.7 2.4

1.5

(v) 48 46 42 38 32 26 20 12 7.8 4.9 3.1

2.0

(vi) 60 58 52 48 40 33 25 16 9.8 6.2 3.9

2.5

(vii) 72 69 63 57 47 39 30 19 12 7.4 4.7

3.0

1 Systems may use this equation to determine log credit between the indicated values: Log credit = (0.0397 x (1.09757)Temp) x CT.

(c) Ultraviolet light. Systems receive Cryptosporidium, Giardia lamblia, and virus treatment credits for ultraviolet (UV) light reactors by achieving the corresponding UV dose values shown in paragraph (c)(1) of this section. Systems must validate and monitor UV reactors as described in paragraphs (c)(2) and (3) of this section to demonstrate that they are achieving a particular UV dose value for treatment credit.

(1) UV dose table. The treatment credits listed in this table are for UV light at a wavelength of 254 nm as produced by a low pressure mercury vapor lamp. To receive treatment credit for other lamp types, systems must demonstrate an equivalent germicidal dose through reactor validation testing, as described in paragraph (c)(2) of this section. The UV dose values in this table are applicable only to post-filter applications of UV in filtered systems. Table 7-15 UV Dose Table for Cryptosporidium, Giardia lamblia, and Virus Inactivation Credit Log Credit Cryptosporidium UV Giardia lamblia UV Virus UV dose (mJ/cm2) dose (mJ/cm2) dose (mJ/cm2)

(i) 0.5 1.6 1.5 39 (ii) 1.0 2.5 2.1 58 (iii) 1.5 3.9 3.0 79 (iv) 2.0 5.8 5.2 100 (v) 2.5 8.5 7.7 121 (vi) 3.0 12 11 143 (vii) 3.5 15 15 163 (viii) 4.0 22 22 186 (2) Reactor validation testing. Systems must use UV reactors that have undergone validation testing to determine the operating conditions under which the reactor delivers the UV dose required in paragraph (c)(1) of this section (i.e., validated operating conditions). These operating conditions must include flow rate, UV intensity as measured by a UV sensor, and UV lamp status.

1. (i) When determining validated operating conditions, systems must account for the following factors: UV absorbance of the water; lamp fouling and aging; measurement uncertainty of on-line sensors; UV dose distributions arising from the velocity profiles through the reactor; failure of UV lamps or other critical system components; and inlet and outlet piping or channel configurations of the UV reactor.
   1. (ii) Validation testing must include the following: Full scale testing of a reactor that conforms uniformly to the UV reactors used by the system and inactivation of a test microorganism whose dose response characteristics have been quantified with a low pressure mercury vapor lamp.

(3) Reactor monitoring.

1. (i) Systems must monitor their UV reactors to determine if the reactors are operating within validated conditions, as determined under paragraph (c)(2) of this section. This monitoring must include UV intensity as measured by a UV sensor, flow rate, lamp status, and other parameters the Department designates based on UV reactor operation. Systems must verify the calibration of UV sensors and must recalibrate sensors in accordance with a protocol the Department approves.
   1. (ii) To receive treatment credit for UV light, systems must treat at least 95 percent of the water delivered to the public during each month by UV reactors operating within validated conditions for the required UV dose, as described in paragraphs (c)(1) and (2) of this section. Systems must demonstrate compliance with this condition by the monitoring required under paragraph (c)(3)(i) of this section. Reporting Requirements

7.4.19 Reporting Requirements

(a) Systems must report sampling schedules under Section 7.4.3 and source water monitoring results under Section 7.4.5 unless they notify the Department that they will not conduct source water monitoring due to meeting the criteria of Section 7.4.2(d).

(b) Systems must report the use of uncovered finished water storage facilities to the Department as described in Section 7.4.12 (a).

(c) Filtered systems must report their Cryptosporidium bin classification as described in Section 7.4.9.

(d) Systems must report disinfection profiles and benchmarks to the Department as described in Sections 7.4.7 through 7.4.8 prior to making a significant change in disinfection practice.

(e) Systems must report to the Department in accordance with the following table for any microbial toolbox options used to comply with treatment requirements under Section 7.4.10. Alternatively, the Department may approve a system to certify operation within required parameters for treatment credit rather than reporting monthly operational data for toolbox options. Table 7-16 Microbial Toolbox Reporting Requirements Toolbox Option Systems must submit On the following the following schedule:

1. information:

(1) Watershed control (i) Notice of intention to No later than two years program (WCP) develop a new or before the applicable continue an existing treatment compliance date water shed control in 7.4.11.

1. program.

. (ii) Watershed control No later than one year plan. before the applicable treatment compliance date in 7.4.11.

. (iii) Annual watershed Every 12 months, control program status beginning one year after report. the applicable treatment compliance date in 7.4.11.

. (iv) Watershed sanitary For community water survey report. systems, every three years beginning three years after the applicable treatment compliance date in 7.4.11. For non- community water systems, every five years beginning five years after the applicable compliance date in 7.4.11.

(2) Alternative Verification that system No later than the source/intake has relocated the intake or applicable treatment management adopted the intake compliance date in 7.4.11. withdrawal procedure reflected in monitoring results.

(3) Presedimentation Monthly verification of Monthly reporting within the following: (i) 10 days following the Continuous basin month in which the operation (ii) Treatment monitoring was of 100% of the flow (iii) conducted, beginning on Continuous addition of a the applicable treatment coagulant (iv) At least compliance date in 0.5-log mean reduction of Section 7.4.11.

1. influent turbidity or compliance with alternative State- approved performance criteria.

(4) Two-stage lime Monthly verification of Monthly reporting within Softening the following: (i) 10 days following the Chemical addition and month in which the hardness precipitation monitoring was occurred in two separate conducted, beginning on and sequential softening the applicable treatment stages prior to filtration compliance date in

1. (ii) Both stages treated Section 7.4.11.
   1. 100% of the plant flow.

(5) Bank Filtration (i) Initial demonstration No later than the of the following: (A) applicable treatment Unconsolidated, compliance date in predominantly sandy Section 7.4.11.

1. aquifer (B) Setback distance of at least 25 ft.
   1. (0.5-log credit) or 50 ft.
      1. (1.0-log credit . (ii) If monthly average of Report within 30 days daily max turbidity is following the month in greater than 1 NTU then which the monitoring was system must report result conducted, beginning on and submit an assessment the applicable treatment of the cause. compliance date in Section 7.4.11.

(6) Combined filter Monthly verification of Monthly reporting within performance combined filter effluent 10 days following the

1. (CFE) turbidity levels month in which the less than or equal to 0.15 monitoring was NTU in at least 95 conducted, beginning on percent of the 4 hour CFE the applicable treatment measurements taken each compliance date in month. Section 7.4.11.

(7) Individual filter Monthly verification of Monthly reporting within performance the following: (i) 10 days following the Individual filter effluent month in which the (IFE ) turbidity levels less monitoring was than or equal to 0.15 conducted, beginning on NTU in at least 95 the applicable treatment percent of samples each compliance date in month in each filter (ii) Section 7.4.11.

1. No individual filter greater than 0.3 NTU in two consecutive readings 15 minutes apart.

(8) Demonstration of (i) Results from testing No later than the performance following a Department applicable treatment approved protocol. compliance date in Section 7.4.11.

. (ii) As required by the Within 10 days following Department, monthly the month in which verification of operation monitoring was within conditions of conducted, beginning on Department approval for the applicable treatment demonstration of compliance date in performance credit. Section 7.4.11.

(9) Bag or cartridge filters (i) Demonstration that the No later than the following criteria are met: applicable treatment

1. (A) Process meets the compliance date in definition of bag or Section 7.4.11.
   1. cartridge filtration; (B)
      1. Removal efficiency established through challenge testing that meets criteria in this section.

. (ii) Monthly verification Within 10 days following that 100% of plant flow the month in which was filtered. monitoring was conducted, beginning on the applicable treatment compliance date in Section 7.4.11.

(10) Membrane filtration (i) Results of verification No later than the testing demonstrating the applicable treatment following: (A) Removal compliance date in efficiency established Section 7.4.11.

1. through challenge testing that meets criteria in this section; (B) Integrity test method and parameters, including resolution, sensitivity, test frequency, control limits, and associated baseline.

. (ii) Monthly report Within 10 days following summarizing the the month in which following: (A) All direct monitoring was integrity tests above the conducted, beginning on control limit; (B) If the applicable treatment applicable, any turbidity compliance date in or alternative Section 7.4.11.

1. Department-approved indirect integrity monitoring results triggering direct integrity testing and the corrective action that was taken.

(11) Second stage Monthly verification that Within 10 days following filtration 100% of flow was filtered the month in which through both stages and monitoring was that first stage was conducted, beginning on preceded by coagulation the applicable treatment step. compliance date in Section 7.4.11.

(12) Slow sand filters Monthly verification that Within 10 days following Inactivation Toolbox both a slow sand filter the month in which Options and a preceding separate monitoring was stage of filtration treated conducted, beginning on 100% of flow from the applicable treatment Surface Water and compliance date in GWUDI sources. Section 7.4.11.

(13) Chlorine dioxide Summary of CT values Within 10 days following for each day as described the month in which in Section 7.4.18. monitoring was conducted, beginning on the applicable treatment compliance date in Section 7.4.11.

(14) Ozone Summary of CT values Within 10 days following for each day as described the month in which in Section 7.4.18. monitoring was conducted, beginning on the applicable treatment compliance date in Section 7.4.11.

(15) UV (i) Validation test results No later than the demonstrating operating applicable treatment conditions that achieve compliance date in required UV dose. Section 7.4.11.

. (ii) Monthly report Within 10 days following summarizing the the month in which percentage of water monitoring was entering the distribution conducted, beginning on system that was not the applicable treatment treated by UV reactors compliance date in operating within validated Section 7.4.11.

1. conditions for the required dose as specified in 7.4.18(c).

7.5 Recycle Provisions

7.5.1 Applicability

All surface water or groundwater under the direct influence of surface water systems that employ conventional filtration or direct filtration treatment and that recycle spent filter backwash water, thickener supernatant, or liquids from dewatering processes must meet the requirements in sections 7.5.2 through

7.5.4 of this Article 7.

7.5.2 Reporting

(a) A system must notify the Department in writing by December 8, 2003, if the system recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes. This notification must include, at a minimum, the information specified in sections 7.5.2(a)(1) and (2) below.

(1) A plant schematic showing the origin of all flows which are recycled (including, but not limited to, spent filter backwash water, thickener supernatant, and liquids from dewatering processes), the hydraulic conveyance used to transport them, and the location where they are re-introduced back into the treatment plant.

(2) Typical recycle flow in gallons per minute (gpm), the highest observed plant flow experienced in the previous year (gpm), design flow for the treatment plant (gpm), and Department- approved operating capacity for the plant where the Department has made such determinations.

7.5.3 Treatment technique requirement

(a) Any system that recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes must return these flows at the head-works prior to the processes of a system's existing conventional or direct filtration system as defined in Article 1 or at an alternate location approved by the Department by June 8, 2004. If capital improvements are required to modify the recycle location to meet this requirement, all capital improvements must be completed no later than June 8, 2006.

7.6 Disinfectant Residuals, Disinfection Byproducts, and Disinfection Byproduct Precursors

7.6.1 General

(a) Requirements.

(1) The regulations in this section 7.6 establish criteria under which community water systems and non-transient, non-community water systems which add a chemical disinfectant to the water in any part of the drinking water treatment process must modify their practices to meet MCLs and MRDLs in Tables 2-5 and 2-6, respectively, and must meet the treatment technique requirements for disinfection byproduct precursors in section 7.6.4(d).

(2) The regulations in this section 7.6 establish criteria under which transient, non-community water systems that use chlorine dioxide as a disinfectant or oxidant must modify their practices to meet the MRDL for chlorine dioxide in Table 2-6.

(3) The Department has established MCLs for TTHM and HAA5 and treatment technique requirements for disinfection byproduct precursors to limit the levels of known and unknown disinfection byproducts which may have adverse health effects. These disinfection byproducts may include chloroform; bromodichloromethane; dibromochloromethane; bromoform; dichloroacetic acid; and trichloroacetic acid.

(b) Compliance applicability.

(1) Community water systems and non-transient, non-community water systems. Unless otherwise noted, all community water systems and non-transient, non-community water systems must comply with the requirements of this section 7.6 and the MCLs and MRDLs in Tables 2-5 and 2-6.

(2) Transient, non-community water systems that use chlorine dioxide as a disinfectant or oxidant must comply with the MRDL for chlorine dioxide in Table 2-6 and the corresponding requirements of this section 7.6.

(c) Each community water system and non-transient, non-community water system regulated under section 7.6.1(a) must be operated by qualified personnel who meet the requirements of Regulation 100 and are included in a State register of qualified operators.

(d) Control of disinfectant residuals. Notwithstanding the MRDLs in Table 2-6, systems may increase residual disinfectant levels in the distribution system of chlorine or chloramines (but not chlorine dioxide) to a level and for a time necessary to protect public health, to address specific microbiological contamination problems caused by circumstances such as, but not limited to, distribution line breaks, storm run-off events, source water contamination events, or cross- connection events.

(e) The Department hereby identifies in Table 7-17 the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for disinfection byproducts identified in Table 2-5: Table 7-17 BAT for Disinfection Byproducts Disinfection byproduct Best available technology TTHM Enhanced coagulation or enhanced softening or GAC10, with chlorine as the primary and residual disinfectant HAA5 Enhanced coagulation or enhanced softening or GAC10, with chlorine as the primary and residual disinfectant.

Bromate Control of ozone treatment process to reduce production of bromate.

Chlorite Control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to reduce disinfectant levels.

(f) The Department hereby identifies the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum residual disinfectant levels identified in Table 2-6 Control Of Treatment Processes to Reduce Disinfectant Demand and Control of Disinfection Treatment Processes to Reduce Disinfectant Levels.

7.6.2 Analytical Requirements

Systems must only use the analytical method(s) specified in section 10.7 to demonstrate compliance with the requirements of this section 7.6.

7.6.3 Monitoring Requirements

(a) General requirements.

(1) Systems must take all samples during normal operating conditions.

(2) Systems may consider multiple wells drawing water from a single aquifer as one treatment plant for determining the minimum number of TTHM and HAA5 samples required, with Department approval.

(3) Failure to monitor in accordance with the monitoring plan required under section 7.6.3(f) is a monitoring violation.

(4) Failure to monitor will be treated as a violation for the entire period covered by the annual average where compliance is based on a running annual average of monthly or quarterly samples or averages and the system's failure to monitor makes it impossible to determine compliance with MCLs or MRDLs.

(5) Systems may use only data collected under the provisions of this section 7.6 to qualify for reduced monitoring.

(b) Monitoring requirements for disinfection byproducts.

(1) TTHMs and HAA5.

1. (i) Routine monitoring. Systems must monitor at the frequency indicated in the following table:

Table 7-18 Routine Monitoring Frequency for TTHM And HAA5 Type of System Minimum Monitoring Sample Location in the Frequency Distribution System Surface water or Four water samples per At least 25 percent of all groundwater under the quarter per treatment samples collected each direct influence of surface plant. quarter at locations water system serving representing maximum 10,000 or more persons. residence time.

1. Remaining samples taken at locations representative of at least average residence time in the distribution system and representing the entire distribution system, taking into account number of persons served, different sources of water, and different treatment methods.

Surface water or One water sample per Locations representing groundwater under the quarter per treatment maximum residence time. direct influence of surface plant. 1 water system serving from 500 to 9,999 persons.

Surface water or One sample per year per Locations representing groundwater under the treatment plant during maximum residence time. direct influence of surface month of warmest water 1 If the sample (or water system serving temperature.

1. average of annual fewer than 500 persons.
   1. samples, if more than one sample is taken) exceeds the MCL, the system must increase monitoring to one sample per treatment plant per quarter, taken at a point reflecting the maximum residence time in the distribution system, until the system meets criteria in paragraph (b)
      1. (1)(iv) of this section.

System using only One water sample per Locations representing groundwater not under quarter per treatment maximum residence time. direct influence of surface 2 1 plant.

water using chemical disinfectant and serving 10,000 or more persons.

System using only One sample per year per Locations representing groundwater not under 2 maximum residence time.

1. treatment plant during direct influence of surface 1 month of warmest water If the sample (or water using chemical temperature. average of annual disinfectant and serving samples, if more than one fewer than 10,000 sample is taken) exceeds persons.
   1. the MCL, the system must increase monitoring to one sample per treatment plant per quarter, taken at a point reflecting the maximum residence time in the distribution system, until the system meets criteria in paragraph (b)
      1. (1)(iv) of this section.

1 If a system elects to sample more frequently than the minimum required, at least 25 percent of all samples collected each quarter (including those taken in excess of the required frequency) must be taken at locations that represent the maximum residence time of the water in the distribution system. The remaining samples must be taken at locations representative of at least average residence time in the distribution system.

2 Multiple wells drawing water from a single aquifer may be considered one treatment plant for determining the minimum number of samples required, with Department approval.

1. (ii) Systems may reduce monitoring, except as otherwise provided, in accordance with the following table:

Table 7-19 Reduced Monitoring Frequency for TTHM and HAA5 If you are a . . . You may reduce To this level monitoring if you have monitored at least one year and your . . .

Surface water or TTHM annual average One sample per treatment groundwater under the less than or equal to ( ≤ ) plant per quarter at direct influence of surface 0.040 mg/L and HAA5 distribution system water system serving annual average less than location reflecting 10,000 or more persons or equal to ( ≤ ) 0.030 maximum residence time. which has a source water mg/L.

annual average TOC level, before any treatment, less than or equal to ( ≤ ) 4.0 mg/L.

Surface water or TTHM annual average One sample per treatment groundwater under the less than or equal to ( ≤ ) plant per year at direct influence of surface 0.040 mg/L and HAA5 distribution system water system serving annual average less than location reflecting from 500 to 9,999 or equal to ( ≤ ) 0.030 maximum residence time persons which has a mg/L. during month of warmest source water annual water temperature.

average TOC level, NOTE: Any surface before any treatment, less water or groundwater than or equal to ( ≤ ) 4.0 under the direct influence mg/L. of surface water system serving fewer than 500 persons may not reduce its monitoring to less than one sample per treatment plant per year.

System using only TTHM annual average One sample per treatment groundwater not under less than or equal to ( ≤ ) plant per year at direct influence of surface 0.040 mg/L and HAA5 distribution system water using chemical annual average less than location reflecting disinfectant and serving or equal to ( ≤ ) 0.030 maximum residence time 10,000 or more persons. mg/L. during month of warmest water temperature System using only TTHM annual average One sample per treatment groundwater not under less than or equal to ( ≤ ) plant per three year direct influence of surface 0.040 mg/L and HAA5 monitoring cycle at water using chemical annual average less than distribution system disinfectant and serving or equal to ( ≤ ) 0.030 location reflecting fewer than 10,000 mg/L for two consecutive maximum residence time persons. years OR TTHM annual during month of warmest average less than or equal water temperature, with to ( ≤ ) 0.020 mg/L and the three-year cycle HAA5 annual average beginning on January 1 of less than or equal to ( ≤ ) the following calendar

1. 0.015 mg/L for one year. year.
   1. (iii) Monitoring requirements for source water TOC. In order to qualify for reduced monitoring for TTHM and HAA5 under paragraph (b)(1)(ii) of this section, Surface Water and GWUDI systems not monitoring under the provisions of paragraph (d) of this section must take monthly TOC samples every 30 days at a location prior to any treatment, beginning April 1, 2008 or earlier, if specified by the Department. In addition to meeting other criteria for reduced monitoring in paragraph (b)(1)(ii) of this section, the source water TOC running annual average must be ≤4.0 mg/L (based on the most recent four quarters of monitoring) on a continuing basis at each treatment plant to reduce or remain on reduced monitoring for TTHM and HAA5. Once qualified for reduced monitoring for TTHM and HAA5 under paragraph (b)(1)(ii) of this section, a system may reduce source water TOC monitoring to quarterly TOC samples taken every 90 days at a location prior to any treatment.
      1. (iv) Systems on a reduced monitoring schedule may remain on that reduced schedule as long as the average of all samples taken in the year (for systems which must monitor quarterly) or the result of the sample (for systems which must monitor no more frequently than annually) is no more than 0.060 mg/L and 0.045 mg/L for TTHMs and HAA5, respectively. Systems that do not meet these levels must resume monitoring at the frequency identified in paragraph (b)(1)(i) of this section (minimum monitoring frequency column) in the quarter immediately following the monitoring period in which the system exceeds 0.060 mg/L or 0.045 mg/L for TTHMs and HAA5, respectively. For systems using only ground water not under the direct influence of surface water and serving fewer than 10,000 persons, if either the TTHM annual average is > 0.080 mg/L or the HAA5 annual average is > 0.060 mg/L, the system must go to the increased monitoring identified in paragraph (b)(1)(i) of this section (sample location column) in the quarter immediately following the monitoring period in which the system exceeds 0.080 mg/L or 0.060 mg/L for TTHMs or HAA5 respectively. A system on a reduced monitoring schedule may remain on that schedule as long as annual average of all samples taken in the year or the result of the sample is no more than 0.060 mg/L for TTHM and 0.045 mg/L for HAA5; systems that do not meet these levels must resume monitoring at the frequency identified in section 7.5.3(b)(1)(i) (minimum monitoring frequency column) in the quarter immediately following the monitoring period in which the system exceeds 0.060 mg/L or 0.045 mg/L for TTHM or HAA5 respectively. For systems using only groundwater not under the direct influence of surface water and serving fewer than 10,000 persons, if either the TTHM annual average is greater than ( > ) 0.080 mg/L or the HAA5 annual average is greater than ( > ) 0.060 mg/L, the system must go to the increased monitoring identified in section 7.6.3(b)(1)(i) (sample location column) in the quarter immediately following the monitoring period in which the system exceeds
         1. 0.080 mg/L or 0.060 mg/L for TTHMs or HAA5 respectively.
         2. (v) Systems on increased monitoring may return to routine monitoring if, after at least one year of monitoring their T THM annual average is less than 0.060 mg/L and their HA A5 annual average is less than 0.045 mg/L.
         3. (vi) The Department may return a system to routine monitoring at the Department's discretion.

(2) Chlorite. Community and non-transient, non-community water systems using chlorine dioxide for disinfection or oxidation must conduct monitoring for chlorite.

1. (i) Routine monitoring.
   1. (A) Daily monitoring. Systems must take daily samples at the entrance to the distribution system. For any daily sample that exceeds the chlorite MCL, the system must take additional samples in the distribution system the following day at the locations required by section 6.3(b)(2)(ii), in addition to the sample required at the entrance to the distribution system.
      1. (B) Monthly monitoring. Systems must take a three-sample set each month in the distribution system. The system must take one sample at each of the following locations: near the first customer, at a location representative of average residence time, and at a location reflecting maximum residence time in the distribution system. Any additional routine sampling must be conducted in the same manner (as three-sample sets, at the specified locations). The system may use the results of additional monitoring conducted under section 6.3(b)(2)(ii) to meet the requirement for monitoring in this paragraph.
         1. (ii) Additional monitoring. On each day following a routine sample monitoring result that exceeds the chlorite MCL at the entrance to the distribution system, the system is required to take three chlorite distribution system samples at the following locations: as close to the first customer as possible, in a location representative of average residence time, and as close to the end of the distribution system as possible (reflecting maximum residence time in the distribution system).
         2. (iii) Reduced monitoring.
         3. (A) Chlorite monitoring at the entrance to the distribution system required by section 6.3(b)(2)(i)(A) may not be reduced.
         4. (B) Chlorite monitoring in the distribution system required by section 6.3(b)(2)(i) (B) may be reduced to one three-sample set per quarter after one year of monitoring where no individual chlorite sample taken in the distribution system under section 6.3(b)(2)(i)(B) has exceeded the chlorite MCL and the system has not been required to conduct monitoring under section 6.3(b)(2)(ii). The system may remain on the reduced monitoring schedule until either any of the three individual chlorite samples taken quarterly in the distribution system under section 6.3(b)(2)(i)(B) exceeds the chlorite MCL or the system is required to conduct monitoring under section 6.3(b)(2)(ii), at which time the system must revert to routine monitoring.

(3) Bromate.

1. (i) Routine monitoring. Community and non-transient, non-community systems using ozone for disinfection or oxidation must take one sample per month for each treatment plant in the system using ozone. Systems must take samples monthly at the entrance to the distribution system while the ozonation system is operating under normal conditions.
   1. (ii) Reduced monitoring.
      1. (A) Until March 31, 2009, systems required to analyze for bromate may reduce monitoring from monthly to quarterly, if the system's average source water bromide concentration is less than 0.05 mg/L based on representative monthly bromide measurements for one year. The system may remain on reduced bromate monitoring until the running annual average source water bromide concentration, computed quarterly, is equal to or greater than 0.05 mg/L based on representative monthly measurements. If the running annual average source water bromide concentration is ≥0.05 mg/L, the system must resume routine monitoring required by paragraph (b)(3)(i) of this section in the following month.
         1. (B) Beginning April 1, 2009, systems may no longer use the provisions of paragraph (b)(3)(ii)(A) of this section to qualify for reduced monitoring. A system required to analyze for bromate may reduce monitoring from monthly to quarterly, if the system's running annual average bromate concentration is ≤0.0025 mg/L based on monthly bromate measurements under paragraph (b)(3)(i) of this section for the most recent four quarters, with samples analyzed using Method 317.0 Revision 2.0, 326.0 or 321.8. If a system has qualified for reduced bromate monitoring under paragraph (b)(3)(ii)(A) of this section, that system may remain on reduced monitoring as long as the running annual average of quarterly bromate samples ≤0.0025 mg/L based on samples analyzed using Method 317.0 Revision 2.0, 326.0, or 321.8. If the running annual average bromate concentration is > 0.0025 mg/L, the system must resume routine monitoring required by paragraph (b)(3)(i) of this section.

(c) Monitoring requirements for disinfectant residuals.

(1) Chlorine and chloramines.

1. (i) Routine monitoring. Community and non-transient, non-community water systems that use chlorine or chloramines must measure the residual disinfectant level in the distribution system at the same point in the distribution system and at the same time as total coliforms are sampled, as specified in Article 5. Surface water or groundwater under the direct influence of surface water systems may use the results of residual disinfectant concentration sampling conducted under section 7.1.4(a)(3)(i) for systems which filter, in lieu of taking separate samples.
   1. (ii) Reduced monitoring. Monitoring may not be reduced.

(2) Chlorine dioxide.

1. (i) Routine monitoring. Community, non-transient non-community, and transient non- community water systems that use chlorine dioxide for disinfection or oxidation must take daily samples at the entrance to the distribution system. For any daily sample that exceeds the MRDL, the system must take samples in the distribution system the following day at the locations required by section 7.6.3(c)(2)(ii), in addition to the sample required at the entrance to the distribution system.
   1. (ii) Additional monitoring. On each day following a routine sample monitoring result that exceeds the MRDL, the system is required to take three chlorine dioxide distribution system samples. If chlorine dioxide or chloramines are used to maintain a disinfectant residual in the distribution system, or if chlorine is used to maintain a disinfectant residual in the distribution system and there are no disinfection addition points after the entrance to the distribution system (i.e., no booster chlorination), the system must take three samples as close to the first customer as possible, at intervals of at least six hours. If chlorine is used to maintain a disinfectant residual in the distribution system and there are one or more disinfection addition points after the entrance to the distribution system (i.e., booster chlorination), the system must take one sample at each of the following locations: as close to the first customer as possible, in a location representative of average residence time, and as close to the end of the distribution system as possible (reflecting maximum residence time in the distribution system).
      1. (iii) Reduced monitoring. Chlorine dioxide monitoring may not be reduced.

(d) Monitoring requirements for disinfection byproduct precursors (DBPP).

(1) Routine monitoring. Surface water or groundwater under the direct influence of surface water systems which use conventional filtration treatment [as defined in section 1.5.2(27)] must monitor each treatment plant for TOC no later than the point of combined filter effluent turbidity monitoring and representative of the treated water. All systems required to monitor under this section 7.6.3(d)(1) must also monitor for TOC in the source water prior to any treatment at the same time as monitoring for TOC in the treated water. These samples (source water and treated water) are referred to as paired samples. At the same time as the source water sample is taken, all systems must monitor for alkalinity in the source water prior to any treatment. Systems must take one paired sample and one source water alkalinity sample per month per plant at a time representative of normal operating conditions and influent water quality.

(2) Reduced monitoring. Surface water or groundwater under the direct influence of surface water systems with an average treated water TOC of less than ( <) 2.0 mg/L for two consecutive years, or less than 1.0 mg/L for one year, may reduce monitoring for both TOC and alkalinity to one paired sample and one source water alkalinity sample per plant per quarter. The system must revert to routine monitoring in the month following the quarter when the annual average treated water TOC greater than or equal to ( ≥ ) 2.0 mg/L.

(e) Bromide. Systems required to analyze for bromate may reduce bromate monitoring from monthly to once per quarter, if the system demonstrates that the average source water bromide concentration is less than ( <) 0.05 mg/L based upon representative monthly measurements for one year. The system must continue bromide monitoring to remain on reduced bromate monitoring.

(f) Monitoring plans. Each system required to monitor under this section 7.6 must develop and implement a monitoring plan. The system must maintain the plan and make it available for inspection by the Department. All Surface water or groundwater under the direct influence of surface water systems serving more than 3,300 people must submit a copy of the monitoring plan to the Department no later than the date of the first report required under section 7.6.5(a). The Department may also require the plan to be submitted by any other system. If the Department has not requested additional information or approved the submitted plan within 60 days of its receipt, the plan shall be deemed to be approved. The Department however reserves the right to review the plan and request information at any time, and may require changes to the plan. After review, the Department may require changes in any plan elements. The plan must include at least the following elements.

(1) Specific locations and schedules for collecting samples for any parameters included in this Article.

(2) How the system will calculate compliance with MCLs, MRDLs, and treatment techniques.

(3) If approved for monitoring as a consecutive system, or if providing water to a consecutive system, under the provisions of sections 1.9 through 1.10, the sampling plan must reflect the entire distribution system.

7.6.4 Compliance Requirements

(a) General requirements.

(1) Where compliance is based on a running annual average of monthly or quarterly samples or averages and the system fails to monitor for TTHM, HAA5, or bromate, this failure to monitor will be treated as a monitoring violation for the entire period covered by the annual average. Where compliance is based on a running annual average of monthly or quarterly samples or averages and the system failure to monitor makes it impossible to determine compliance with MRDLs for chlorine and chloramines, this failure to monitor will be treated as a monitoring violation for the entire period covered by the annual average.

(2) All samples taken and analyzed under the provisions of this section 7.6 must be included in determining compliance, even if that number is greater than the minimum required.

(3) If, during the first year of monitoring under section 7.6.3, any individual quarter's average will cause the running annual average of that system to exceed the MCL for total trihalomethanes, haloacetic acids (five), or bromate; or the MRDL for chlorine or chloramine, the system is out of compliance at the end of that quarter.

(b) Disinfection byproducts.

(1) TTHMs and HAA5.

1. (i) For systems monitoring quarterly, compliance with MCLs in Table 2-5 must be based on a running annual arithmetic average, computed quarterly, of quarterly arithmetic averages of all samples collected by the system as prescribed by section 7.6.3(b)(1).
   1. (ii) For systems monitoring less frequently than quarterly, systems demonstrate MCL compliance if the average of samples taken that year under the provisions of section 7.6.3(b)(1) does not exceed the MCLs in Table 2-5. If the average of these samples exceeds the MCL, the system must increase monitoring to once per quarter per treatment plant and such a system is not in violation of the MCL until it has completed one year of quarterly monitoring, unless the result of fewer than four quarters of monitoring will cause the running annual average to exceed the MCL, in which case the system is in violation at the end of that quarter. Systems required to increase monitoring frequency to quarterly monitoring must calculate compliance by including the sample which triggered the increased monitoring plus the following three quarters of monitoring.
      1. (iii) If the running annual arithmetic average of quarterly averages covering any consecutive four-quarter period exceeds the MCL, the system is in violation of the MCL and must notify the public pursuant to Article 9, section 9.2 - Public Notification in addition to reporting to the Department pursuant to section 7.6.5.
         1. (iv) If a PWS fails to complete four consecutive quarters of monitoring, compliance with the MCL for the last four-quarter compliance period must be based on an average of the available data.

(2) Bromate. Compliance must be based on a running annual arithmetic average, computed quarterly, of monthly samples (or, for months in which the system takes more than one sample, the average of all samples taken during the month) collected by the system as prescribed by section 7.6.3(b)(3). If the average of samples covering any consecutive four-quarter period exceeds the MCL, the system is in violation of the MCL and must notify the public pursuant to Article 9, section 9.2 - Public Notification, in addition to reporting to the Department pursuant to section 7.6.5. If a PWS fails to complete 12 consecutive months' monitoring, compliance with the MCL for the last four-quarter compliance period must be based on an average of the available data.

(3) Chlorite. Compliance must be based on an arithmetic average of each three sample set taken in the distribution system as prescribed by section 7.6.3(b)(2)(i)(B) and section 7.6.3(b)(2)(ii). If the arithmetic average of any three sample set exceeds the MCL, the system is in violation of the MCL and must notify the public pursuant to Article 9, section

1. 9.2 - Public Notification, in addition to reporting to the Department pursuant to section 7.6.5.

(c) Disinfectant residuals.

(1) Chlorine and chloramines.

1. (i) Compliance must be based on a running annual arithmetic average, computed quarterly, of monthly averages of all samples collected by the system under section 7.6.3(c)(1). If the average covering any consecutive four-quarter period exceeds the MRDL, the system is in violation of the MRDL and must notify the public pursuant to Article 9, section 9.2 - Public Notification, in addition to reporting to the Department pursuant to section 7.6.5.
   1. (ii) In cases where systems switch between the use of chlorine and chloramines for residual disinfection during the year, compliance must be determined by including together all monitoring results of both chlorine and chloramines in calculating compliance. Reports submitted pursuant to section 7.6.5 must clearly indicate which residual disinfectant was analyzed for each sample.

(2) Chlorine dioxide.

1. (i) Acute violations. Compliance must be based on consecutive daily samples collected by the system under section 7.6.3(c)(2). If any daily sample taken at the entrance to the distribution system exceeds the MRDL, and on the following day one (or more) of the three samples taken in the distribution system exceed the MRDL, the system is in violation of the MRDL and must take immediate corrective action to lower the level of chlorine dioxide below the MRDL and must notify the public pursuant to the procedures for acute health risks in Article 9, section 9.2 - Public Notification in addition to reporting to the Department pursuant to section 7.6.5. Failure to take samples in the distribution system the day following an exceedance of the chlorine dioxide MRDL at the entrance to the distribution system will also be considered an MRDL violation and the system must notify the public of the violation in accordance with the provisions for acute violations under Article 9, section 9.2.2 in addition to reporting to the Department pursuant to section 7.6.5.
   1. (ii) Non-acute violations. Compliance must be based on consecutive daily samples collected by the system under section 7.5.3(c)(2). If any two consecutive daily samples taken at the entrance to the distribution system exceed the MRDL and all distribution system samples taken are below the MRDL, the system is in violation of the MRDL and must take corrective action to lower the level of chlorine dioxide below the MRDL at the point of sampling and will notify the public pursuant to the procedures for non-acute health risks in Article 9, section 9.2 - Public Notification in addition to reporting to the Department pursuant to section 7.5.5. Failure to monitor at the entrance to the distribution system the day following an exceedance of the chlorine dioxide MRDL at the entrance to the distribution system is also an MRDL violation and the system must notify the public of the violation in accordance with the provisions in Article 9, section 9.2 - Public Notification in addition to reporting to the Department pursuant to section 7.6.5.

(d) Disinfection byproduct precursors (DBPP). Compliance must be determined as specified by section 7.6.6(c). Systems may begin monitoring to determine whether Step 1 TOC removals can be met 12 months prior to the compliance date for the system. This monitoring is not required and failure to monitor during this period is not a violation. However, any system that does not monitor during this period, and then determines in the first 12 months after the compliance date that it is not able to meet the Step 1 requirements in section 7.6.6(b)(2) and must therefore apply for alternate minimum TOC removal (Step 2) requirements, is not eligible for retroactive approval of alternate minimum TOC removal (Step 2) requirements as allowed pursuant to section 7.6.6(b)(3) and is in violation. Systems may apply for alternate minimum TOC removal (Step 2) requirements any time after the compliance date. For systems required to meet Step 1 TOC removals, if the value calculated under section 7.6.6(c)(1)(iv) is less than 1.00, the system is in violation of the treatment technique requirements and must notify the public pursuant to Article 9, section 9.2 - Public Notification, in addition to reporting to the Department pursuant to section 7.6.5.

7.6.5 Reporting and Recordkeeping Requirements

(a) Systems required to sample quarterly or more frequently must report to the Department within 10 days after the end of each quarter in which samples were collected, notwithstanding the provisions of Article 1, section 1.6.4. Systems required to sample less frequently than quarterly must report to the Department within 10 days after the end of each monitoring period in which samples were collected.

(b) Disinfection byproducts. Systems must report the information specified in the following table: Table 7-20 Disinfection Byproduct Reporting Requirements If you are a * * * 1 You must report * * * (1) System monitoring (i) The number of for TTHMs and HAA5 samples taken during the under the requirements of last quarter.

section 7.6.3(b) on a quarterly or more frequent basis.

. (ii) The location, date, and result of each sample taken during the last quarter.

. (iii) The arithmetic average of all samples taken in the last quarter.

. (iv) The annual arithmetic average of the quarterly arithmetic averages of this section for the last four quarters.

. (v) Whether, based on section 7.6.4(b)(1), the MCL was violated.

(2) System monitoring (i) The number of for TTHMs and HAA5 samples taken during the under the requirements of last year.

section 7.6.3(b) less frequently than quarterly (but as least annually).

. (ii) The location, date, and result of each sample taken during the last monitoring period.

. (iii) The arithmetic average of all samples taken over the last year.

. (iv) Whether, based on section 7.6.4(b)(1), the MCL was violated.

(3) System monitoring (i) The location, date, and for TTHMs and HAA5 result of each sample under the requirements of taken section 7.6.3(b) less frequently than annually.

. (ii) Whether, based on section 7.6.4(b)(1), the MCL was violated.

(4) System monitoring (i) The number of entry for chlorite under the point samples taken each requirements of section month for the last 3 7.6.3(b). months.

. (ii) The location, date, and result of each sample (both entry point and distribution system) taken during the last quarter.

. (iii) For each month in the reporting period, the arithmetic average of all samples taken in each three samples set taken in the distribution system.

. (iv) Whether, based on section 7.6.4(b)(3), the MCL was violated, in which month, and how many times it was violated each month.

(5) System monitoring (i) The number of for bromate under the samples taken during the requirements of section last quarter.

7.6.3(b).

. (ii) The location, date, and result of each sample taken during the last quarter.

. (iii) The arithmetic average of the monthly arithmetic averages of all samples taken in the last year.

. (iv) Whether, based on section 7.6.4(b)(2), the MCL was violated.

1 The Department may perform calculations and determine whether the MCL was exceeded, in lieu of having the system report that information.

(d) Disinfectants. Systems must report the information specified in the following table: Table 7-21 Disinfectant Reporting Requirements If you are a * * * 1 You must report * * * (1) System monitoring (i) The number of for chlorine or samples taken during each chloramines under the month of the last quarter.

requirements of section 7.6.3(c).

. (ii) The month arithmetic average of all samples taken in each month for the last 12 months.

. (iii) The arithmetic average of the monthly averages for the last 12 months.

. (iv) Whether, based on section 7.6.4(c)(1), the MRD was violated.

(2) System monitoring (i) The dates, result, and for chlorine dioxide under locations of samples taken the requirements of during the last quarter.

section 7.6.3(c).

. (ii) Whether, based on section 7.6.4(c)(2), the MRDL was violated.

. (iii) Whether the MRDL was exceeded in any two consecutive daily samples and whether the resulting violation was acute or nonacute.

1 The Department may perform calculations and determine whether the MRDL was exceeded, in lieu of having the system report that information.

(d) Disinfection byproduct precursors and enhanced coagulation or enhanced softening. Systems must report the information specified in the following table: Table 7-22 Disinfection Byproduct Precursor Reporting Requirements If you are a * * * 1 You must report * * * (1) System monitoring (i) The number of monthly or quarterly for paired (source water and TOC under the treated water) samples requirements of section taken during the last 7.6.3(d) and required to quarter.

meet the enhanced coagulation or enhanced softening requirements in section 7.6.6(b)(2) or (3).

. (ii) The location, date, and results of each paired sample and associated alkalinity taken during the last quarter.

. (iii) For each month in the reporting period that paired samples were taken, the arithmetic average of the percent reduction of TOC for each paired sample and the required TOC percent removal.

. (iv) Calculations for determining compliance with the TOC percent removal requirements, as provided in section 7.6.6(c)(1).

. (v) Whether the system is in compliance with the enhanced coagulation or enhanced softening percent removal requirements in section 7.6.6(b) for the last four quarters.

(2) System monitoring (i) The alternative monthly or quarterly for compliance criterion that TOC under the the system is using.

requirements of section 7.6.3(d) and meeting one or more of the alternative compliance criteria in section 7.6.6(a)(2) or (3).

. (ii) The number of paired samples taken during the last quarter.

. (iii) The location, date, and result of each paired sample and associated alkalinity taken during the last quarter.

. (iv) The running annual arithmetic average based on monthly averages (or quarterly samples) of source water TOC for systems meeting a criterion in Sections 15.3.3(a)(2)(i) or (iii) or of treated water TOC for systems meeting the criterion in section 7.6.6(a)(2)(ii).

. (v) The running annual arithmetic average based on monthly averages (or quarterly samples) of source water SUVA for systems meeting the criterion in section 7.6.6(a)(2)(v) or of treated water SUVA for systems meeting the criterion in section 7.6.6(a)(2)(vi).

. (vi) The running annual average of source water alkalinity for systems meeting the criterion in section 7.5.6(a)(2)(iii) and of treated water alkalinity for systems meeting the criterion in section 7.5.6(a)(3)(i).

. (vii) The running annual average for both TTHM and HAA5 for systems meeting the criterion in section 7.6.6(a)(2)(iii) or (iv).

. (viii) The running annual average of the amount of magnesium hardness removal (as CaCO3, in mg/L) for systems meeting the criterion in section 7.6.6(a)(3)(ii).

. (ix) Whether the system is in compliance with the particular alternative compliance criterion in section 7.6.6(a)(2) or (3).

1 The Department may perform calculations and determine whether the treatment technique was met, in lieu of having the system report that information.

7.6.6 Treatment Technique for Control of Disinfection Byproduct (DBP) Precursors (a) Applicability (1) Surface water or groundwater under the direct influence of surface water systems using conventional filtration treatment (as defined in section 1.5.2(27)) must operate with enhanced coagulation or enhanced softening to achieve the TOC percent removal levels specified in section 7.6.6(b) unless the system meets at least one of the alternative compliance criteria listed in section 7.6.6(a)(2) or (a)(3).

(2) Alternative compliance criteria for enhanced coagulation and enhanced softening systems. Surface water or groundwater under the direct influence of surface water systems using conventional filtration treatment may use the alternative compliance criteria in sections 7.6.6(a)(2)(i) through (vi) to comply with this section in lieu of complying with section 7.6.6(b). Systems must still comply with monitoring requirements in section 7.6.3(d).

1. (i) The system's source water TOC level, measured according to section 10.7.4(c), is less than 2.0 mg/L, calculated quarterly as a running annual average.
   1. (ii) The system's treated water TOC level, measured according to section 10.7.4(c), is less than 2.0 mg/L, calculated quarterly as a running annual average.
      1. (iii) The system's source water TOC level, measured according to section 10.7.4(c), is less than 4.0 mg/L, calculated quarterly as a running annual average; the source water alkalinity, measured according to section 10.2.2 (a), is greater than 60 mg/L (as CaCO ), calculated quarterly as a running annual average; and either the TTHM and HAA5 running annual averages are no greater than 0.040 mg/L and 0.030 mg/L, respectively; or prior to the effective date for compliance in section 7.6.1 (b), the system has made a clear and irrevocable financial commitment not later than the effective date for compliance in section 7.6.1(b) to use of technologies that will limit the levels of TTHMs and HAA5 to no more than
         1. 0.040 mg/L and 0.030 mg/L, respectively. Systems must submit evidence of a

            clear and irrevocable financial commitment, in addition to a schedule containing milestones and periodic progress reports for installation and operation of appropriate technologies, to the Department for approval not later than the effective date for compliance in section 7.6.1(b). These technologies must be installed and operating not later than June 30, 2005. Failure to install and operate these technologies by the date in the approved schedule will constitute a violation of Colorado Primary Drinking Water Regulations.

         2. (iv) The TTHM and HAA5 running annual averages are no greater than 0.040 mg/L and
         3. 0.030 mg/L, respectively, and the system uses only chlorine for primary

            disinfection and maintenance of a residual in the distribution system.

         4. (v) The system's source water SUVA, prior to any treatment and measured monthly according to section 10.7.4(d), is less than or equal to ( ≤ ) 2.0 L/mg-m, calculated quarterly as a running annual average.
         5. (vi) The system's finished water SUVA, measured monthly according to section 10.7.4(d), is less than or equal to ( ≤ ) 2.0 L/mg-m, calculated quarterly as a running annual average.

(3) Additional alternative compliance criteria for softening systems. Systems practicing enhanced softening that cannot achieve the TOC removals required by section 7.6.6(b)(2) may use the alternative compliance criteria in section 7.6.6(a)(3)(i) and (ii) in lieu of complying with section 7.6.6(b). Systems must still comply with monitoring requirements in section 7.6.3(d).

1. (i) Softening that results in lowering the treated water alkalinity to less than 60 mg/L (as CaCO ), measured monthly according to section 10.2.2(a) and calculated quarterly as a running annual average.
   1. (ii) Softening that results in removing at least 10 mg/L of magnesium hardness (as CaCO ), measured monthly according to section 10.7.4(f) and calculated quarterly as an annual running average.

(b) Enhanced coagulation and enhanced softening performance requirements (1) Systems must achieve the percent reduction of TOC specified in section 7.6.6(b)(2) between the source water and the combined filter effluent, unless the Department approves a system's request for alternate minimum TOC removal (Step 2) requirements under section 7.6.6(b)(3).

(2) Required Step 1 TOC reductions, indicated in the following table, are based upon specified source water parameters measured in accordance with section 10.7.4. Systems practicing softening are required to meet the Step 1 TOC reductions in the far-right column (Source water alkalinity 120 mg/L) for the specified source water TOC: Table 7-23 3 x 3 Table for Step1 TOC Removal Requirements (3) Surface water or ground water under the direct influence of surface water conventional treatment systems that cannot achieve the Step 1 TOC removals required by section 7.6.6(b)(2) due to water quality parameters or operational constraints must apply to the Department, within three months of failure to achieve the TOC removals required by section 7.6.6(b)(2), for approval of alternative minimum TOC (Step 2) removal requirements submitted by the system. If the Department approves the alternative minimum TOC removal (Step 2) requirements, the Department may make those requirements retroactive for the purposes of determining compliance. Until the Department approves the alternate minimum TOC removal (Step 2) requirements, the system must meet the Step 1 TOC removals contained in section 7.6.6(b)(2).

(4) Alternate minimum TOC removal (Step 2) requirements. Applications made to the Department by enhanced coagulation systems for approval of alternate minimum TOC removal (Step 2) requirements under section 7.6.6(b)(3) must include, at a minimum, results of bench- or pilot-scale testing conducted under section 7.6.6(b)(4)(i). The submitted bench- or pilot-scale testing must be used to determine the alternate enhanced coagulation level.

1. (i) Alternate enhanced coagulation level is defined as coagulation at a coagulant dose and pH as determined by the method described in sections 7.6.6(b)(4)(i) through (v) such that an incremental addition of 10 mg/L of alum (or equivalent amount of ferric salt) results in a TOC removal of <0.3 mg/L. The percent removal of TOC at this point on the "TOC removal versus coagulant dose" curve is then defined as the minimum TOC removal required for the system. Once approved by the Department, this minimum requirement supersedes the minimum TOC removal required by the table in section 7.6.6(b)(2). This requirement will be effective until such time as the Department approves a new value based on the results of a new bench- and pilot-scale test. Failure to achieve Department-set alternative minimum TOC removal levels is a violation of Colorado Primary Drinking Water Regulations.
   1. (ii) Bench- or pilot-scale testing of enhanced coagulation must be conducted by using representative water samples and adding 10 mg/L increments of alum (or equivalent amounts of ferric salt) until the pH is reduced to a level less than or equal to the enhanced coagulation Step 2 target pH shown in the following table: Table 7-24 Target pH for Step 2 Enhanced Coagulation .

STEP 2 - Target pH Alkalinity (mg/L as Target pH CaCO 3 )

0 - 60 5.5 > 60 - 120 6.3 > 120 - 240 7.0 > 240 7.5

1. (iii) For waters with alkalinities of less than 60 mg/L for which addition of small amounts of alum or equivalent addition of iron coagulant drives the pH below 5.5 before significant TOC removal occurs, the system must add necessary chemicals to maintain the pH between 5.3 and 5.7 in samples until the TOC removal of 0.3 mg/L per 10 mg/L alum added (or equivalent addition of iron coagulant) is reached.
   1. (iv) The system may operate at any coagulant dose or pH necessary (consistent with other requirements of the CPDWR) to achieve the minimum TOC percent removal approved under section 7.5.6(b)(3).
      1. (v) If the TOC removal is consistently less than 0.3 mg/L of TOC per 10 mg/L of incremental alum dose at all dosages of alum (or equivalent addition of iron coagulant), the water is deemed to contain TOC not amenable to enhanced coagulation. The system may then apply to the Department for a waiver of enhanced coagulation requirements.

(c) Compliance calculations (1) Surface water or groundwater under the direct influence of surface water systems other than those identified in section 7.6.6(a)(2) or (a)(3) must comply with requirements contained in section 7.6.6(b)(2) or (b)(3). Systems must calculate compliance quarterly, beginning after the system has collected 12 months of data, by determining an annual average using the following method:

1. (i) Determine actual monthly TOC percent removal, equal to:(1-(treated water TOC/source water TOC)) x 100 (ii) Determine the required monthly TOC percent removal (from either the table in section 7.6.6(b)(2) or from section 7.6.6(b)(3).
   1. (iii) Divide the value in section 7.5.6(c)(1)(i) by the value in section 7.6.6(c)(1)(ii).
      1. (iv) Add together the results of section 7.6.6 (c)(1)(iii) for the last 12 months and divide by 12.
         1. (v) If the value calculated in section 7.6.6 (c)(1)(iv) is less than 1.00, the system is not in compliance with the TOC percent removal requirements.

(2) Systems may use the provisions in Sections 7.6.6(c)(2)(i) through (v) in lieu of the calculations in section 7.6.6(c)(1)(i) through (v) to determine compliance with TOC percent removal requirements.

1. (i) In any month that the system's treated or source water TOC level, measured according to section 10.7.4(c), is less than 2.0 mg/L, the system may assign a monthly value of 1.0 [in lieu of the value calculated in section 7.6.6(c)(1)(iii)] when calculating compliance under the provisions of section 7.6.6(c)(1).
   1. (ii) In any month that a system practicing softening removes at least 10 mg/L of magnesium hardness (as CaCO ), the system may assign a monthly value of 1.0 (in lieu of the value calculated in section 7.6.6 (c)(1)(iii)) when calculating compliance under the provisions of section 7.6.6(c)(1).
      1. (iii) In any month that the system's source water SUVA, prior to any treatment and measured according to section 10.7.4(d), is <2.0 L/mg-m, the system may assign a monthly value of 1.0 (in lieu of the value calculated in section 7.6.6(c)(1) (iii)) when calculating compliance under the provisions of section 7.6.6(c)(1).
         1. (iv) In any month that the system's finished water SUVA, measured according to section 10.7.4(d), is <2.0 L/mg-m, the system may assign a monthly value of 1.0 (in lieu of the value calculated in section 7.6.6(c)(1)(iii)) when calculating compliance under the provisions of section 7.6.6(c)(1).
         2. (v) In any month that a system practicing enhanced softening lowers alkalinity below 60 mg/L (as CaCO ), the system may assign a monthly value of 1.0 (in lieu of the value calculated in section 7.6.6 (c)(1)(iii)) when calculating compliance under the provisions of section 7.6.6(c)(1).

(3) Surface water or groundwater under the direct influence of surface water systems using conventional treatment may also comply with the requirements by meeting the criteria in section 7.6.6(a)(2) or (3).

(d) Treatment technique requirements for DBP precursors. The Department identifies the following as treatment techniques to control the level of disinfection byproduct precursors in drinking water treatment and distribution systems: For Surface water or groundwater under the direct influence of surface water systems using conventional treatment, enhanced coagulation or enhanced softening.

7.7 Initial Distribution System Evaluations (IDSE)

7.7.1 General Requirements

(a) The requirements of section 7.7 establish monitoring and other requirements for identifying monitoring locations for determining compliance with maximum contaminant levels for total trihalomethanes (TTHM) and haloacetic acids (five)(HAA5) in section 7.8 of these regulations. The system must use an Initial Distribution System Evaluation (IDSE) to determine locations with representative high TTHM and HAA5 concentrations throughout the distribution system. IDSEs are used in conjunction with, but separate from, section 7.6 compliance monitoring, to identify and select section 7.8 compliance monitoring locations.

(b) Applicability. You are subject to the requirements of this section 7.7 if your system is a community water system that uses a primary or residual disinfectant other than ultraviolet light or delivers water that has been treated with a primary or residual disinfectant other than ultraviolet light; or if your system is a nontransient noncommunity water system that serves at least 10,000 people and uses a primary or residual disinfectant other than ultraviolet light or delivers water that has been treated with a primary or residual disinfectant other than ultraviolet light.

(c) Schedule.

(1) You must comply with the requirements of section 7.7 in accordance with the schedule outlined in Table 7-25.

Table 7-25 Early Implementation Schedule (2) For the purpose of the schedule in paragraph (c)(1) of this section, the Department may determine that the combined distribution system does not include certain consecutive systems based on factors such as receiving water from a wholesale system only on an emergency basis as defined in section 1.5.2 or receiving less than 5 percent of the receiving system’s total annual volume of water from a wholesale system. The Department may also determine that the combined distribution system does not include certain wholesale systems based on factors such as delivering water to a consecutive system only on an emergency basis or delivering only a small percentage and small volume of water to a consecutive system.

(d) The system must conduct standard monitoring that meets the requirements in Section 7.7.2, or a system specific study that meets the requirements in Section 7.7.3, or certify to the Department that you meet 40/30 certification criteria under Section 7.7.4, or qualify for a very small system waiver under Section 7.7.5.

(1) You must have taken the full complement of routine TTHM and HAA5 compliance samples required of a system with your population and source water under Section 7.6 of this part (or you must have taken the full complement of reduced TTHM and HAA5 compliance samples required of a system with your population and source water under Section 7.6 if you meet reduced monitoring criteria under Section 7.6 of this part) during the period specified in Section 7.7.4(a) to meet the 40/30 certification criteria in Section 7.7.4. You must have taken TTHM and HAA5 samples under Sections 7.6.2 and 7.6.3 to be eligible for the very small system waiver in Section 7.7.5.

(2) If you have not taken the required samples, you must conduct standard monitoring that meets the requirements in Section 7.7.2, or a system specific study that meets the requirements in Section 7.7.3.

(e) You must use only the analytical methods specified in Section 7.6.2, or otherwise approved by EPA for monitoring under this section, to demonstrate compliance with the requirements of section 7.7.

(f) IDSE results will not be used for the purpose of determining compliance with MCLs in section 2.4.

7.7.2 Standard monitoring

(a) Standard monitoring plan. Your standard monitoring plan must comply with paragraphs (a)(1) through (a)(4) of this section. You must prepare and submit your standard monitoring plan to the Department according to the schedule in Section 7.7.1.

(1) Your standard monitoring plan must include a schematic of your distribution system (including distribution system entry points and their sources, and storage facilities), with notes indicating locations and dates of all projected standard monitoring, and all projected Section 7.6 compliance monitoring.

(2) Your standard monitoring plan must include justification of standard monitoring location selection and a summary of data you relied on to justify standard monitoring location selection.

(3) Your standard monitoring plan must specify the population served and system type (Surface Water or GWUDI or ground water).

(4) You must retain a complete copy of your standard monitoring plan submitted under this paragraph (a), including any Department modification of your standard monitoring plan, for as long as you are required to retain your IDSE report under paragraph (c)(4) of this section.

(b) Standard monitoring.

(1) You must monitor as indicated in the table in this paragraph (b)(1). You must collect dual sample sets at each monitoring location. One sample in the dual sample set must be analyzed for TTHM. The other sample in the dual sample set must be analyzed for HAA5. You must conduct one monitoring period during the peak historical month for TTHM levels or HAA5 levels or the month of warmest water temperature. You must review available compliance, study, or operational data to determine the peak historical month for TTHM or HAA5 levels or warmest water temperature. Table 7-26 Monitoring Locations and Frequencies for Standard Monitoring (2) You must take samples at locations other than the existing Section 7.6 monitoring locations. Monitoring locations must be distributed throughout the distribution system.

(3) If the number of entry points to the distribution system is fewer than the specified number of entry point monitoring locations, excess entry point samples must be replaced equally at high TTHM and HAA5 locations. If there is an odd extra location number, you must take a sample at a high TTHM location. If the number of entry points to the distribution system is more than the specified number of entry point monitoring locations, you must take samples at entry points to the distribution system having the highest annual water flows.

(4) Your monitoring under this paragraph (b) may not be reduced under the provisions of Section 1.9.

(c) IDSE report. Your IDSE report must include the elements required in paragraphs (c)(1) through (c)(3) of this section. You must submit your IDSE report to the Department according to the schedule in Section 7.7.1(c).

(1) Your IDSE report must include all TTHM and HAA5 analytical results from Section 7.6 compliance monitoring and all standard monitoring conducted during the period of the IDSE as individual analytical results and LRAAs presented in a tabular or spreadsheet format acceptable to the Department. If changed from your standard monitoring plan submitted under paragraph (a) of this section, your report must also include a schematic of your distribution system, the population served, and system type (Surface Water and GWUDI or ground water).

(2) Your IDSE report must include an explanation of any deviations from your approved standard monitoring plan.

(3) You must recommend and justify section 7.8 compliance monitoring locations and timing based on the protocol in Section 7.7.6.

7.7.3 System specific studies

(a) System specific study plan. Your system specific study plan must be based on either existing monitoring results as required under paragraph (a)(1) of this section or modeling as required under paragraph (a)(2) of this section. You must prepare and submit your system specific study plan to the Department according to the schedule in section 7.7.1(c).

(1) Existing monitoring results. You may comply by submitting monitoring results collected before you are required to begin monitoring under section 7.7.1(c). The monitoring results and analysis must meet the criteria in paragraphs (a)(1)(i) and (a)(1)(ii) of this section.

1. (i) Minimum requirements.
   1. (A) TTHM and HAA5 results must be based on samples collected and analyzed in accordance with Section 7.6.2. Samples must be collected no earlier than five years prior to the study plan submission date.
      1. (B) The monitoring locations and frequency must meet the conditions identified in Table 7-27. Each location must be sampled once during the peak historical month for TTHM levels or HAA5 levels or the month of warmest water temperature for every 12 months of data submitted for that location. Monitoring results must include all Section 7.6 compliance monitoring results plus additional monitoring results as necessary to meet minimum sample requirements.

Table 7-27 Monitoring Locations and Frequencies for System Specific Studies

1. (ii) Reporting monitoring results. You must report the information in this paragraph (a) (1)(ii).
   1. (A) You must report previously collected monitoring results and certify that the reported monitoring results include all compliance and non-compliance results generated during the time period beginning with the first reported result and ending with the most recent Section 7.6 results.
      1. (B) You must certify that the samples were representative of the entire distribution system and that treatment, and distribution system have not changed significantly since the samples were collected.
         1. (C) Your study monitoring plan must include a schematic of your distribution system (including distribution system entry points and their sources, and storage facilities), with notes indicating the locations and dates of all completed or planned system specific study monitoring.
         2. (D) Your system specific study plan must specify the population served and system type (Surface Water and GWUDI or ground water).
         3. (E) You must retain a complete copy of your system specific study plan submitted under this paragraph (a)(1), including any Department modification of your system specific study plan, for as long as you are required to retain your IDSE report under paragraph (b)(5) of this section.
         4. (F) If you submit previously collected data that fully meet the number of samples required under paragraph (a)(1)(i)(B) of this section and the Department rejects some of the data, you must either conduct additional monitoring to replace rejected data on a schedule the Department approves or conduct standard monitoring under Section 7.7.2.

(2) Modeling. You may comply through analysis of an extended period simulation hydraulic model. The extended period simulation hydraulic model and analysis must meet the criteria in this paragraph (a)(2).

1. (i) Minimum requirements.
   1. (A) The model must simulate 24 hour variation in demand and show a consistently repeating 24 hour pattern of residence time.
      1. (B) The model must represent the criteria listed in paragraphs (a)(2)(i)(B)(1) through (9) of this section.
         1. (1) 75% of pipe volume;
         2. (2) 50% of pipe length;
         3. (3) All pressure zones;
         4. (4) All 12-inch diameter and larger pipes;
         5. (5) All 8-inch and larger pipes that connect pressure zones, influence zones from different sources, storage facilities, major demand areas, pumps, and control valves, or are known or expected to be significant conveyors of water;
         6. (6) All 6-inch and larger pipes that connect remote areas of a distribution system to the main portion of the system;
         7. (7) All storage facilities with standard operations represented in the model; and (8) All active pump stations with controls represented in the model; and (9) All active control valves.
         8. (C) The model must be calibrated, or have calibration plans, for the current configuration of the distribution system during the period of high TTHM formation potential. All storage facilities must be evaluated as part of the calibration process. All required calibration must be completed no later than 12 months after plan submission.
         9. (ii) Reporting modeling. Your system specific study plan must include the information in this paragraph (a)(2)(ii).
         10. (A) Tabular or spreadsheet data demonstrating that the model meets requirements in paragraph (a)(2)(i)(B) of this section.
         11. (B) A description of all calibration activities undertaken, and if calibration is complete, a graph of predicted tank levels versus measured tank levels for the storage facility with the highest residence time in each pressure zone, and a time series graph of the residence time at the longest residence time storage facility in the distribution system showing the predictions for the entire simulation period (i.e., from time zero until the time it takes to for the model to reach a consistently repeating pattern of residence time).
         12. (C) Model output showing preliminary 24 hour average residence time predictions throughout the distribution system.
         13. (D) Timing and number of samples representative of the distribution system planned for at least one monitoring period of TTHM and HAA5 dual sample monitoring at a number of locations no less than would be required for the system under standard monitoring in Section 7.7.2 during the historical month of high TTHM. These samples must be taken at locations other than existing Section 7.6 compliance monitoring locations.
         14. (E) Description of how all requirements will be completed no later than 12 months after you submit your system specific study plan.
         15. (F) Schematic of your distribution system (including distribution system entry points and their sources, and storage facilities), with notes indicating the locations and dates of all completed system specific study monitoring (if calibration is complete) and all Section 7.6 compliance monitoring.
         16. (G) Population served and system type (Surface Water and GWUDI or ground water).
         17. (H) You must retain a complete copy of your system specific study plan submitted under paragraph (a)(2) of this section, including any Department modification of your system specific study plan, for as long as you are required to retain your IDSE report under paragraph (b)(7) of this section.
         18. (iii) If you submit a model that does not fully meet the requirements under paragraph (a) (2) of this section, you must correct the deficiencies and respond to Department inquiries concerning the model. If you fail to correct deficiencies or respond to inquiries to the Department's satisfaction, you must conduct standard monitoring under Section 7.7.2.

(b) IDSE report. Your IDSE report must include the elements required in paragraphs (b)(1) through (b) (6) of this section. You must submit your IDSE report according to the schedule in section 7.7.1(c).

(1) Your IDSE report must include all TTHM and HAA5 analytical results from section 7.6 compliance monitoring and all system specific study monitoring conducted during the period of the system specific study presented in a tabular or spreadsheet format acceptable to the Department. If changed from your system specific study plan submitted under paragraph (a) of this section, your IDSE report must also include a schematic of your distribution system, the population served, and system type (Surface Water and GWUDI or ground water).

(2) If you used the modeling provision under paragraph (a)(2) of this section, you must include final information for the elements described in paragraph (a)(2)(ii) of this section, and a 24-hour time series graph of residence time for each section 7.8 compliance monitoring location selected.

(3) You must recommend and justify section 7.8 compliance monitoring locations and timing based on the protocol in section 7.7.6.

(4) Your IDSE report must include an explanation of any deviations from your approved system specific study plan.

(5) Your IDSE report must include the basis (analytical and modeling results) and justification you used to select the recommended section 7.8 monitoring locations.

(6) You may submit your IDSE report in lieu of your system specific study plan on the schedule identified in section 7.7.1(c) for submission of the system specific study plan if you believe that you have the necessary information by the time that the system specific study plan is due. If you elect this approach, your IDSE report must also include all information required under paragraph (a) of this section.

(7) You must retain a complete copy of your IDSE report submitted under this section for 10 years after the date that you submitted your IDSE report. If the Department modifies the Section 7.8 monitoring requirements that you recommended in your IDSE report or if the Department approves alternative monitoring locations, you must keep a copy of the Department's notification on file for 10 years after the date of the Department's notification. You must make the IDSE report and any Department notification available for review by the Department or the public.

7.7.4 40/30 Certification

(a) Eligibility. You are eligible for 40/30 certification if you had no TTHM or HAA5 monitoring violations under Section 7.6 and no individual sample exceeded 0.040 mg/L for TTHM or 0.030 mg/L for HAA5 during an eight (8) consecutive calendar quarter period beginning no earlier than the date specified in section 7.7.4(b).

Table 7-28 40/30 Certification Submittal Dates If your 40/30 Then your eligibility for certification is due 40/30 certification is based on eight consecutive calendar quarters of section 7.6 compliance monitoring results beginning no earlier than (1) October 1, 2006 January 2004 (2) April 1, 2007 January 2004 (3) October 1, 2007 January 2005 (4) April 1, 2008 January 2005 1 Unless you are on reduced monitoring under section 7.6 of this part and were not required to monitor during the specified period. If you did not monitor during the specified period, you must base your eligibility on compliance samples taken during the 12 months preceding the specified period.

(b) 40/30 certification.

(1) You must certify to the Department that every individual compliance sample taken under section 7.6 of this part during the periods specified in paragraph (a) of this section were ≤

1. 0.040 mg/L for TTHM and ≤ 0.030 mg/L for HAA5, and that you have not had any TTHM or HAA5 monitoring violations during the period specified in paragraph (a) of this section.

(2) The Department may require you to submit compliance monitoring results, distribution system schematics, and/or recommended section 7.8 compliance monitoring locations in addition to your certification. If you fail to submit the requested information, the Department may require standard monitoring under section 7.7.2 or a system specific study under section 7.7.3.

(3) The Department may still require standard monitoring under section 7.7.2 or a system specific study under section 7.7.3 even if you meet the criteria in paragraph (a) of this section.

(4) You must retain a complete copy of your certification submitted under this section for 10 years after the date that you submitted your certification. You must make the certification, all data upon which the certification is based, and any Department notification available for review by the Department or the public.

7.7.5 Very small system waivers

(a) If you serve fewer than 500 people and you have taken TTHM and HAA5 samples under Section 7.6 of this part, you are not required to comply with this section unless the Department notifies you that you must conduct standard monitoring under section 7.7.2 or a system specific study under Section 7.7.3.

(b) If you have not taken TTHM and HAA5 samples under section 7.6 of this part or if the Department notifies you that you must comply with this section, you must conduct standard monitoring under section 7.7.2 or a system specific study under section 7.7.3.

7.7.6 Section 7.8 compliance monitoring location recommendations

(a) Your IDSE report must include your recommendations and justification for where and during what month(s) TTHM and HAA5 monitoring for section 7.8 of this part should be conducted. You must base your recommendations on the criteria in paragraphs (b) through (e) of this section.

(b) You must select the number of monitoring locations specified in Table 7-29 in this paragraph (b). You will use these recommended locations as section 7.8 routine compliance monitoring locations, unless Department requires different or additional locations. You should distribute locations throughout the distribution system to the extent possible. Table 7-29 Recommended Compliance Monitoring Locations and Frequencies (c) You must recommend section 7.8 compliance monitoring locations based on standard monitoring results, system specific study results, and section 7.6 compliance monitoring results. You must follow the protocol in paragraphs (c)(1) through (c)(8) of this section. If required to monitor at more than eight locations, you must repeat the protocol as necessary. If you do not have existing section 7.6 compliance monitoring results or if you do not have enough existing section 7.6 compliance monitoring results, you must repeat the protocol, skipping the provisions of paragraphs (c)(3) and (c)(7) of this section as necessary, until you have identified the required total number of monitoring locations.

(1) Location with the highest TTHM LRAA not previously selected as a section 7.8 monitoring location.

(2) Location with the highest HAA5 LRAA not previously selected as a section 7.8 monitoring location.

(3) Existing section 7.6 average residence time compliance monitoring location (maximum residence time compliance monitoring location for ground water systems) with the highest HAA5 LRAA not previously selected as a Section 7.8 monitoring location.

(4) Location with the highest TTHM LRAA not previously selected as a section 7.8 monitoring location.

(5) Location with the highest TTHM LRAA not previously selected as a section 7.8 monitoring location.

(6) Location with the highest HAA5 LRAA not previously selected as a section 7.8 monitoring location.

(7) Existing section 7.6 average residence time compliance monitoring location (maximum residence time compliance monitoring location for ground water systems) with the highest TTHM LRAA not previously selected as a section 7.8 monitoring location.

(8) Location with the highest HAA5 LRAA not previously selected as a section 7.8 monitoring location.

(d) You may recommend locations other than those specified in paragraph (c) of this section if you include a rationale for selecting other locations. If the Department approves the alternate locations, you must monitor at these locations to determine compliance under section 7.8 of this part.

(e) Your recommended schedule must include section 7.8 monitoring during the peak historical month for TTHM and HAA5 concentration, unless the Department approves another month. Once you have identified the peak historical month, and if you are required to conduct routine monitoring at least quarterly, you must schedule section 7.8 compliance monitoring at a regular frequency of every 90 days or fewer.

7.8 Stage 2 Disinfection Byproducts Requirement

7.8.1 General requirements

(a) The requirements of section 7.8 establish monitoring and other requirements for achieving compliance with the maximum contaminant levels listed in section 2.4 based on locational running annual averages (LRAA) for total trihalomethanes (TTHM) and haloacetic acids (five) (HAA5), and for achieving compliance with maximum residual disinfectant residuals for chlorine and chloramine for certain consecutive systems.

(b) You are subject to the requirements of section 7.8 if your system is a community water system or a nontransient noncommunity water system that uses a primary or residual disinfectant other than ultraviolet light or delivers water that has been treated with a primary or residual disinfectant other than ultraviolet light.

(c) You must comply with the requirements of section 7.8 in accordance with the schedule in the Table 7- 30.

Table 7-30 Compliance Dates (1) Your monitoring frequency is specified in section 7.8.2(a)(2).

1. (i) If you are required to conduct quarterly monitoring, you must begin monitoring in the first full calendar quarter that includes the compliance date in Table 7-30.
   1. (ii) If you are required to conduct monitoring at a frequency that is less than quarterly, you must begin monitoring in the calendar month recommended in the IDSE report prepared under section 7.7.2 or section 7.7.3 or the calendar month identified in the section 7.8 monitoring plan developed under section 7.8.3 no later than 12 months after the compliance date in this table.

(2) If you are required to conduct quarterly monitoring, you must make compliance calculations at the end of the fourth calendar quarter that follows the compliance date and at the end of each subsequent quarter (or earlier if the LRAA calculated based on fewer than four quarters of data would cause the MCL to be exceeded regardless of the monitoring results of subsequent quarters). If you are required to conduct monitoring at a frequency that is less than quarterly, you must make compliance calculations beginning with the first compliance sample taken after the compliance date.

(3) For the purpose of the schedule in this paragraph (c), the Department may determine that the combined distribution system does not include certain consecutive systems based on factors such as receiving water from a wholesale system only on an emergency basis or receiving only a small percentage and small volume of water from a wholesale system. The Department may also determine that the combined distribution system does not include certain wholesale systems based on factors such as delivering water to a consecutive system only on an emergency basis or delivering only a small percentage and small volume of water to a consecutive system.

(d) Monitoring and compliance.

(1) Systems required to monitor quarterly. To comply with disinfection byproducts MCLs in Table 2-5, you must calculate LRAAs for TTHM and HAA5 using monitoring results collected under this section and determine that each LRAA does not exceed the MCL. If you fail to complete four consecutive quarters of monitoring, you must calculate compliance with the MCL based on the average of the available data from the most recent four quarters. If you take more than one sample per quarter at a monitoring location, you must average all samples taken in the quarter at that location to determine a quarterly average to be used in the LRAA calculation.

(2) Systems required to monitor yearly or less frequently. To determine compliance with section

1. 2.4 MCLs, you must determine that each sample taken is less than the MCL. If any sample exceeds the MCL, you must comply with the requirements of Section 7.8.6. If no sample exceeds the MCL, the sample result for each monitoring location is considered the LRAA for that monitoring location.

(e) Violation. You are in violation of the monitoring requirements for each quarter that a monitoring result would be used in calculating an LRAA if you fail to monitor.

(f) Best Available Technologies (1) The Department hereby identifies the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for TTHM and HAA5 as a locational running annual average for all systems that disinfect their source water:

Table 7-31 Wholesale System Best Available Technology (BAT) Disinfection byproduct Best available technology TTHM & HAA5 Enhanced coagulation or enhanced softening, plus GAC10; or nanofiltration with a molecular weight cutoff ≤ 1000 Daltons; or GAC20 (2) The Department hereby identifies the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for TTHM and HAA5 as a locational running annual average for consecutive systems and applies only to the disinfected water that consecutive systems buy or otherwise receive: Table 7-32 Consecutive System Best Available Technology (BAT) Disinfection byproduct Best available technology TTHM & HAA5 Systems serving ≥ 10,000: Improved distribution system and storage tank management to reduce residence time, plus the use of chloramines for disinfectant residual maintenance.

TTHM & HAA5 Systems serving < 10,000: Improved distribution system and storage tank management to reduce residence time.

7.8.2 Routine monitoring

(a) Monitoring.

(1) If you submitted an IDSE report, you must begin monitoring at the locations and months you have recommended in your IDSE report submitted under section 7.7.6 following the schedule in section 7.8.1(c), unless the Department requires other locations or additional locations after its review. If you submitted a 40/30 certification under section 7.7.4 or you qualified for a very small system waiver under section 7.7.5 or you are a nontransient noncommunity water system serving < 10,000, you must monitor at the location(s) and dates identified in your monitoring plan in Section 7.6.3(f), updated as required by section 7.8.3.

(2) You must monitor at no fewer than the number of locations identified in this paragraph (a)(2). Table 7-33 Compliance Monitoring Locations and Frequencies (3) If you are an undisinfected system that begins using a disinfectant other than UV light after the dates in section 7.7 for complying with the Initial Distribution System Evaluation requirements, you must consult with the Department to identify compliance monitoring locations for this section. You must then develop a monitoring plan under section 7.8.3 that includes those monitoring locations.

(b) Analytical methods. You must use an approved method listed in section 7.6.2 for TTHM and HAA5 analyses in this section. Analyses must be conducted by laboratories that have received certification by EPA or the Department as specified in section 7.6.2.

7.8.3 Section 7.8 monitoring plan

(a) (1) You must develop and implement a monitoring plan to be kept on file for Department and public review. The monitoring plan must contain the elements in paragraphs (a)(1)(i) through (a)(1)(iv) of this section and be complete no later than the date you conduct your initial monitoring under this section.

1. (i) Monitoring locations;
   1. (ii) Monitoring dates;
      1. (iii) Compliance calculation procedures; and (iv) Monitoring plans for any other systems in the combined distribution system if the Department has reduced monitoring requirements under the Department authority in section 1.9.

(2) If you were not required to submit an IDSE report under either section 7.7.2 or section 7.7.3, and you do not have sufficient section 7.6 monitoring locations to identify the required number of section 7.8 compliance monitoring locations indicated in section 7.7.6(b), you must identify additional locations by alternating selection of locations representing high TTHM levels and high HAA5 levels until the required number of compliance monitoring locations have been identified. You must also provide the rationale for identifying the locations as having high levels of TTHM or HAA5. If you have more section 7.6 monitoring locations than required for section 7.8 compliance monitoring in section 7.7.6(b), you must identify which locations you will use for section 7.8 compliance monitoring by alternating selection of locations representing high TTHM levels and high HAA5 levels until the required number of section 7.8 compliance monitoring locations have been identified.

(b) If you are a Surface Water and GWUDI system serving > 3,300 people, you must submit a copy of your monitoring plan to the Department prior to the date you conduct your initial monitoring under this section, unless your IDSE report submitted under section 7.7 of this part contains all the information required by this section.

(c) You may revise your monitoring plan to reflect changes in treatment, distribution system operations and layout (including new service areas), or other factors that may affect TTHM or HAA5 formation, or for Department-approved reasons, after consultation with the Department regarding the need for changes and the appropriateness of changes. If you change monitoring locations, you must replace existing compliance monitoring locations with the lowest LRAA with new locations that reflect the current distribution system locations with expected high TTHM or HAA5 levels. The Department may also require modifications in your monitoring plan. If you are a Surface Water and GWUDI system serving > 3,300 people, you must submit a copy of your modified monitoring plan to the Department prior to the date you are required to comply with the revised monitoring plan.

7.8.4 Reduced monitoring

(a) You may reduce monitoring to the level specified in the table in this paragraph (a) any time the LRAA is ≤ 0.040 mg/L for TTHM and ≤0.030 mg/L for HAA5 at all monitoring locations. You may only use data collected under the provisions of this section or section 7.6 of this part to qualify for reduced monitoring. In addition, the source water annual average TOC level, before any treatment, must be ≤ 4.0 mg/L at each treatment plant treating surface water or ground water under the direct influence of surface water, based on monitoring conducted under either section 7.6.3(b)(1)(iii) or Section 7.6.3(d).

Table 7-34 Reduced Monitoring Frequencies (b) You may remain on reduced monitoring as long as the TTHM LRAA ≤ 0.040 mg/L and the HAA5 LRAA ≤ 0.030 mg/L at each monitoring location (for systems with quarterly reduced monitoring) or each TTHM sample ≤ 0.060 mg/L and each HAA5 sample ≤ 0.045 mg/L (for systems with annual or less frequent monitoring). In addition, the source water annual average TOC level, before any treatment, must be ≤4.0 mg/L at each treatment plant treating surface water or ground water under the direct influence of surface water, based on monitoring conducted under either Section 7.6.3(b)(1)(iii) or Section 7.6.3(d).

(c) If the LRAA based on quarterly monitoring at any monitoring location exceeds either 0.040 mg/L for TTHM or 0.030 mg/L for HAA5 or if the annual (or less frequent) sample at any location exceeds either 0.060 mg/L for TTHM or 0.045 mg/L for HAA5, or if the source water annual average TOC level, before any treatment, > 4.0 mg/L at any treatment plant treating surface water or ground water under the direct influence of surface water, you must resume routine monitoring under Section 7.8.2 or begin increased monitoring if section 7.8.6 applies.

7.8.5 Additional requirements for consecutive systems

If you are a consecutive system that does not add a disinfectant but delivers water that has been treated with a primary or residual disinfectant other than ultraviolet light, you must comply with analytical and monitoring requirements for chlorine and chloramines in section 7.6.3 (c) and Section 7.6.3(c)(1) and the compliance requirements in section 7.6.4(c)(1) beginning April 1, 2009, unless required earlier by the Department, and report monitoring results under section 7.6.5(c).

7.8.6 Conditions requiring increased monitoring

(a) If you are required to monitor at a particular location annually or less frequently than annually under section 7.8.2 or section 7.8.4, you must increase monitoring to dual sample sets taken every 90 days at all locations if a TTHM sample is > 0.080 mg/L or a HAA5 sample is > 0.060 mg/L at any location.

(b) You are in violation of the MCL when the LRAA exceeds the disinfection byproducts MCLs in Table 2- 5, calculated based on four consecutive quarters of monitoring (or the LRAA calculated based on fewer than four quarters of data if the MCL would be exceeded regardless of the monitoring results of subsequent quarters). You are in violation of the monitoring requirements for each quarter that a monitoring result would be used in calculating an LRAA if you fail to monitor.

(c) You may return to routine monitoring once you have conducted increased monitoring for at least four consecutive quarters and the LRAA for every monitoring location is ≤ 0.060 mg/L for TTHM and ≤ 0.045 mg/L for HAA5.

7.8.7 Operational evaluation levels

(a) You have exceeded the operational evaluation level at any monitoring location where the sum of the two previous quarters' TTHM results plus twice the current quarter's TTHM result, divided by 4 to determine an average, exceeds 0.080 mg/L, or where the sum of the two previous quarters' HAA5 results plus twice the current quarter's HAA5 result, divided by 4 to determine an average, exceeds 0.060 mg/L.

(b) (1) If you exceed the operational evaluation level, you must conduct an operational evaluation and submit a written report of the evaluation to the Department no later than 90 days after being notified of the analytical result that causes you to exceed the operational evaluation level. The written report must be made available to the public upon request.

(2) Your operational evaluation must include an examination of system treatment and distribution operational practices, including storage tank operations, excess storage capacity, distribution system flushing, changes in sources or source water quality, and treatment changes or problems that may contribute to TTHM and HAA5 formation and what steps could be considered to minimize future exceedences.

7.8.8 Requirements for remaining on reduced TTHM and HAA5 monitoring based on Section 7.8 results (a) You may remain on reduced monitoring after the dates identified in section 7.8.1(c) for compliance with this section only if you qualify for a 40/30 certification under section 7.7.4 or have received a very small system waiver under section 7.7.5, plus you meet the reduced monitoring criteria in section 7.8.4(a), and you do not change or add monitoring locations from those used for compliance monitoring under section 7.6 of this part. If your monitoring locations under this section differ from your monitoring locations under section 7.6 of this part, you may not remain on reduced monitoring after the dates identified in section 7.8.1(c) for compliance with this section.

7.8.9 Requirements for remaining on increased TTHM and HAA5 monitoring based on Section 7.6 results (a) If you were on increased monitoring under section 7.6.3(b)(1), you must remain on increased monitoring until you qualify for a return to routine monitoring under section 7.8.6(c). You must conduct increased monitoring under Section 7.8.6 at the monitoring locations in the monitoring plan developed under section 7.8.3 beginning at the date identified in section 7.8.1(c) for compliance with this section and remain on increased monitoring until you qualify for a return to routine monitoring under section 7.8.6(c).

7.8.10 Reporting and recordkeeping requirements

(a) Reporting.

(1) You must report the following information for each monitoring location to the Department within 10 days of the end of any quarter in which monitoring is required:

1. (i) Number of samples taken during the last quarter.
   1. (ii) Date and results of each sample taken during the last quarter.
      1. (iii) Arithmetic average of quarterly results for the last four quarters for each monitoring location (LRAA), beginning at the end of the fourth calendar quarter that follows the compliance date and at the end of each subsequent quarter. If the LRAA calculated based on fewer than four quarters of data would cause the MCL to be exceeded regardless of the monitoring results of subsequent quarters, you must report this information to the Department as part of the first report due following the compliance date or anytime thereafter that this determination is made. If you are required to conduct monitoring at a frequency that is less than quarterly, you must make compliance calculations beginning with the first compliance sample taken after the compliance date, unless you are required to conduct increased monitoring under Section 7.8.6.
         1. (iv) Whether, based on Table 2-5 and this section, the MCL was violated at any monitoring location.
         2. (v) Any operational evaluation levels that were exceeded during the quarter and, if so, the location and date, and the calculated TTHM and HAA5 levels.

(2) If you are a Surface Water and GWUDI system seeking to qualify for or remain on reduced TTHM/HAA5 monitoring, you must report the following source water TOC information for each treatment plant that treats surface water or ground water under the direct influence of surface water to the Department within 10 days of the end of any quarter in which monitoring is required:

1. (i) The number of source water TOC samples taken each month during last quarter.
   1. (ii) The date and result of each sample taken during last quarter.
      1. (iii) The quarterly average of monthly samples taken during last quarter or the result of the quarterly sample.
         1. (iv) The running annual average (RAA) of quarterly averages from the past four quarters.
         2. (v) Whether the RAA exceeded 4.0 mg/L.

(3) The Department may choose to perform calculations and determine whether the MCL was exceeded or the system is eligible for reduced monitoring in lieu of having the system report that information.

(b) Recordkeeping. You must retain any section 7.8 monitoring plans and your section 7.8 monitoring results as required by section 1.6.3.

7.9 Disinfection for Groundwater [Repealed ]

Repealed Eff. 09/30/2008 Article 8 Lead and Copper Control

8.1 General Requirements

Unless otherwise indicated, the provisions of Article 8 apply to community water systems and non- transient, non-community water systems.

These regulations establish a treatment technique that includes requirements for corrosion control treatment, source water treatment, lead service line replacement, and public education. These requirements are triggered, in some cases, by lead and copper action levels measured in samples collected at consumers’ taps.

(a) Lead and copper action levels.

(1) The lead action level is exceeded if the concentration of lead in more than 10 percent of tap water samples collected during any monitoring period conducted in accordance with section 8.7 is greater than 0.015 mg/L (i.e., if the "90th percentile" lead level is greater than 0.015 mg/L).

(2) The copper action level is exceeded if the concentration of copper in more than 10 percent of tap water samples collected during any monitoring period conducted in accordance with section 8.7 is greater than 1.3 mg/L (i.e., if the "90th percentile" copper level is greater than 1.3 mg/L).

(3) The 90th percentile lead and copper levels shall be computed as follows:

1. (i) The results of all lead or copper samples taken during a monitoring period shall be placed in ascending order from the sample with the lowest concentration to the sample with the highest concentration. Each sampling result shall be assigned a number, ascending by single integers beginning with the number 1 for the sample with the lowest contaminant level. The number assigned to the sample with the highest contaminant level shall be equal to the total number of samples taken.
   1. (ii) The number of samples taken during the monitoring period shall be multiplied by 0.9.
      1. (iii) The contaminant concentration in the numbered sample yielded by the calculation in section 8.1(a)(3)(ii) is the 90th percentile contaminant level.
         1. (iv) For water systems serving a population of fewer than 100 that collect 5 samples per monitoring period, the 90th percentile is computed by taking the average of the highest and second highest concentrations.

(b) Corrosion control treatment requirements.

(1) All water systems shall install and operate optimal corrosion control treatment as defined in section 1.5.2(96).

(2) Any water system that complies with the applicable corrosion control treatment requirements specified by the Department under sections 8.2 and 8.3 shall be deemed in compliance with the treatment requirement contained in section 8.1(b)(1).

(c) Any system exceeding the lead or copper action level shall implement all applicable source water treatment requirements specified by the Department under section 8.4.

(d) Any system exceeding the lead action level after implementation of applicable corrosion control and source water treatment requirements shall complete the lead service line replacement requirements contained in section 8.5.

(e) Any system exceeding the lead action level shall implement the public education requirements contained in section 8.6.

(f) Tap water monitoring for lead and copper, monitoring for water quality parameters, source water monitoring for lead and copper, and analyses of the monitoring results under Article 8 shall be completed in compliance with sections 8.7, 8.8, 8.9, and 10.8.

(g) Systems shall report to the Department any information required by the treatment provisions of Article 8 in addition to the requirements of section 8.10.

(h) Systems shall maintain records in accordance with section 8.11.

(i) Failure to comply with the applicable requirements of sections 8.1-8.12 shall constitute a violation of the Colorado Primary Drinking Water Regulations.

8.2 Corrosion Control Treatment Steps

(a) Systems shall complete the applicable corrosion control treatment requirements described in section

8.3 by the deadlines established in this section 8.2(a).

(1) A system serving a population of greater than ( > ) 50,000 shall complete the corrosion control treatment steps specified in section 8.2(d), unless it is deemed to have optimized corrosion control under section 8.2(b)(2) or 8.2(b)(3).

(2) Systems serving a population of less than or equal to (≤) 50,000 shall complete the corrosion control treatment steps specified in section 8.2(d), unless it is deemed to have optimized corrosion control under section 8.2(b)(1), (b)(2), or (b)(3).

(b) A system is deemed to have optimized corrosion control and is not required to complete the applicable corrosion control treatment steps identified in Article 8 if the system satisfies one of the criteria specified in sections 8.2(b)(1)-(3). Any such system deemed to have optimized corrosion control under Article 8, and which has treatment in place, shall continue to operate and maintain optimal corrosion control treatment and meet any requirements that the Department determines appropriate to ensure optimal corrosion control treatment is maintained.

(1) A system serving a population of less than or equal to (≤) 50,000 is deemed to have optimized corrosion control if the system meets the lead and copper action levels during each of two consecutive six-month monitoring periods conducted in accordance with section 8.7.

(2) Any water system may be deemed by the Department to have optimized corrosion control treatment if the system demonstrates to the satisfaction of the Department that it has conducted activities equivalent to the corrosion control steps applicable to such system under section 8.2. If the Department makes this determination, it shall provide the system with written notice explaining the basis for its decision and shall specify the water quality control parameters representing optimal corrosion control in accordance with section 8.3(f). Water systems deemed to have optimized corrosion control under Article 8 shall operate in compliance with the Department-designated optimal water quality control parameters in accordance with section 8.3(g) and continue to conduct lead and copper tap and water quality parameter sampling in accordance with section 8.7(d)(3) and section 8.8(d), respectively. A system shall provide the Department with the following information in order to support a determination under section 8.2(b)(2):

1. (i) The results of all test samples collected for each of the water quality parameters in section 8.3(c)(3).
   1. (ii) A report explaining the test methods used by the water system to evaluate the corrosion control treatments listed in section 8.3(c)(1), the results of all tests conducted, and the basis for the system's selection of optimal corrosion control treatment;
      1. (iii) A report explaining how corrosion control has been installed and how it is being maintained to insure minimal lead and copper concentrations at consumers' taps; and (iv) The results of tap water samples collected in accordance with section 8.7 at least once every six months for one year after corrosion control has been installed.

(3) Any water system is deemed to have optimized corrosion control if it submits results of tap water monitoring conducted in accordance with section 8.7 and source water monitoring conducted in accordance with section 8.9 that demonstrates for two consecutive 6-month monitoring periods that the difference between the 90th percentile tap water lead level computed under section 8.1(a)(3), and the highest source water lead concentration is less than the Practical Quantitation Level for lead specified in section 10.8.1(a)(1)(ii).

1. (i) Those systems whose highest source water lead level is below the Method Detection Limit may also be deemed to have optimized corrosion control under Article 8 if the 90th percentile tap water lead level is less than or equal to the Practical Quantitation Level for lead for two consecutive 6-month monitoring periods.
   1. (ii) Any water system deemed to have optimized corrosion control in accordance with Article 8 shall continue monitoring for lead and copper at the tap no less frequently than once every three calendar years using the reduced number of sites specified in section 8.7(c) and collecting the samples at times and locations specified in section 8.7(d)(4)(iv).
      1. (iii) Any water system deemed to have optimized corrosion control under section 8.2(b) must notify the Department in writing, as required by section 8.10(a)(3) of any change in treatment or the addition of a new source. The Department may require any such system to conduct additional monitoring or to take other action the Department determines appropriate to ensure that such systems maintain minimal levels of corrosion in the distribution system.
         1. (iv) A system is not deemed to have optimized corrosion control under section 8.2(b), and shall implement corrosion control treatment pursuant to section 8.2(b)(3)(v), unless it meets the copper action level.
         2. (v) Any system triggered into corrosion control because it is no longer deemed to have optimized corrosion control under section 8.2(b), shall implement corrosion control treatment in accordance with the deadlines in section 8.2(d). The time periods for completing each step are triggered by the date the system is no longer deemed to have optimized corrosion control under section 8.2(b).

(c) Any system serving a population of ≤ 50,000 that is required to complete the corrosion control steps due to its exceedance of the lead or copper action level may cease completing the treatment steps whenever the system meets both action levels during each of two consecutive monitoring periods conducted pursuant to section 8.7 and submits the results to the Department. If any such water system thereafter exceeds the lead or copper action level during any monitoring period, the system shall recommence completion of the applicable treatment steps, beginning with the first treatment step that was not previously completed in its entirety. The Department may require a system to repeat treatment steps previously completed by the system where the Department determines that this is necessary to implement properly the treatment requirements of section 8.2. The Department shall notify the system in writing of such a determination and explain the basis for its decision. The requirement for any system serving a population of ≤ 50,000 to implement corrosion control treatment steps in accordance with section 8.2(d), including systems deemed to have optimized corrosion control under section 8.2(b)(1), is triggered whenever any system serving a population of less than or equal to (≤) 50,000 exceeds the lead or copper action level.

(d) Except as provided in section 8.2(b), systems shall complete the following corrosion control treatment steps (described in the referenced portions of section 8.3, section 8.7 and section 8.8) by the indicated time periods.

(1) Step 1: The system shall conduct initial tap sampling (section 8.7(d)(1) and section 8.8(b)) until the system either exceeds the lead or copper action level or becomes eligible for reduced monitoring under section 8.7(d)(4). A system exceeding the lead or copper action level shall recommend optimal corrosion control treatment (section 8.3(a)) within six months after it exceeds one of the action levels.

(2) Step 2: Within 12 months after a system exceeds the lead or copper action level, the Department may require the system to perform corrosion control studies (section 8.3(b)). If the Department does not require the system to perform such studies, the Department shall specify optimal corrosion control treatment (section 8.3(d)) within the following timeframes:

1. (i) For systems serving a population greater than ( > ) 50,000, within 6 months after such system exceeds the lead or copper action level, (ii) For systems serving a population of greater than ( > ) 3,300 but less than or equal to (≤) 50,000, within 18 months after such system exceeds the lead or copper action level, (iii) For systems serving a population of less than or equal to (≤) 3,300, within 24 months after such system exceeds the lead or copper action level.

(3) Step 3: If the Department requires a system to perform corrosion control studies under step 2, the system shall complete the studies (section 8.3(c)) within 18 months after the Department requires that such studies be conducted.

(4) Step 4: If the system has performed corrosion control studies under step 2, the Department shall designate optimal corrosion control treatment (section 8.3(d)) within 6 months after completion of step 3.

(5) Step 5: The system shall install optimal corrosion control treatment (section 8.3(e)) within 24 months after the Department designates such treatment.

(6) Step 6: The system shall complete follow-up sampling (section 8.7(d)(2) and section 8.8(c)) within 36 months after the Department designates optimal corrosion control treatment.

(7) Step 7: The Department shall review the system's installation of treatment and designate optimal water quality control parameters (section 8.3(f)) within 6 months after completion of step 6.

(8) Step 8: The system shall operate in compliance with the Department-designated optimal water quality control parameters (section 8.3(g)) and continue to conduct tap sampling (section 8.7(d)(3) and section 8.8(d)).

8.3 Description of Corrosion Control Treatment Requirements

Each system shall complete the corrosion control treatment requirements described below which are applicable to such system under section 8.2.

(a) Based upon the results of lead and copper tap monitoring and water quality parameter monitoring, systems serving a population of less than or equal to (≤) 50,000 exceeding the lead or copper action level shall recommend installation of one or more of the corrosion control treatments listed in section 8.3(c)(1) which the system believes constitutes optimal corrosion control for that system. The Department may require the system to conduct additional water quality parameter monitoring in accordance with section 8.8(b) to assist the Department in reviewing the system's recommendation.

(b) The Department may require any system serving a population of less than or equal to (≤) 50,000 that exceeds the lead or copper action level to perform corrosion control studies under section 8.3(c) to identify optimal corrosion control treatment for the system.

(c) Performance of corrosion control studies.

(1) Any public water system performing corrosion control studies shall evaluate the effectiveness of each of the following treatments, and, if appropriate, combinations of the following treatments to identify the optimal corrosion control treatment for that system:

1. (i) Alkalinity and pH adjustment;
   1. (ii) Calcium hardness adjustment; and (iii) The addition of a phosphate or silicate based corrosion inhibitor at a concentration sufficient to maintain an effective residual concentration in all test tap samples.

(2) The water system shall evaluate each of the corrosion control treatments using either pipe rig/loop tests, metal coupon tests, partial-system tests, or analyses based on documented analogous treatments with other systems of similar size, water chemistry and distribution system configuration.

(3) The water system shall measure the following water quality parameters in any tests conducted under section 8.3(c) before and after evaluating the corrosion control treatments listed above:

1. (i) Lead;
   1. (ii) Copper;
      1. (iii) pH;
         1. (iv) Alkalinity;
         2. (v) Calcium;
         3. (vi) Conductivity;
         4. (vii) Orthophosphate (when an inhibitor containing a phosphate compound is used);
         5. (viii) Silicate (when an inhibitor containing a silicate compound is used); and (ix) Water temperature.

(4) The water system shall identify all chemical or physical constraints that limit or prohibit the use of a particular corrosion control treatment and document such constraints with at least one of the following:

1. (i) Data and documentation showing that a particular corrosion control treatment has adversely affected other water treatment processes when used by another water system with comparable water quality characteristics; and/or (ii) Data and documentation demonstrating that the water system has previously attempted to evaluate a particular corrosion control treatment and has found that the treatment is ineffective or adversely affects other water quality treatment processes.

(5) The water system shall evaluate the effect of the chemicals used for corrosion control treatment on other water quality treatment processes.

(6) On the basis of an analysis of the data generated during each evaluation, the water system shall recommend to the Department in writing the treatment option that the corrosion control studies indicate constitutes optimal corrosion control treatment for that system. The water system shall provide a rationale for its recommendation along with all supporting documentation specified in sections 8.3(c)(1)-(5).

(d) Department designation of optimal corrosion control treatment.

(1) Based upon consideration of available information including, where applicable, studies performed under section 8.3(c) and a system's recommended treatment alternative, the Department shall either approve the corrosion control treatment option recommended by the system or designate alternative corrosion control treatment(s) from among those listed in section 8.3(c)(1). When designating optimal treatment the Department shall consider the effects that additional corrosion control treatment will have on water quality parameters and on other water quality treatment processes.

(2) The Department shall notify the system of its decision on optimal corrosion control treatment in writing and explain the basis for this determination. If the Department requests additional information to aid its review, the water system shall provide the information.

(e) Each system shall properly install and operate throughout its distribution system the optimal corrosion control treatment designated by the Department under section 8.3(d).

(f) The Department shall evaluate the results of all lead and copper tap samples and water quality parameter samples submitted by the water system and determine whether the system has properly installed and operated the optimal corrosion control treatment designated by the Department in section 8.3(d). Upon reviewing the results of tap water and water quality parameter monitoring by the system, both before and after the system installs optimal corrosion control treatment, the Department shall designate:

(1) A minimum value or a range of values for pH measured at each entry point to the distribution system;

(2) A minimum pH value, measured in all tap samples. Such value shall be equal to or greater than 7.0, unless the Department determines that meeting a pH level of 7.0 is not technologically feasible or is not necessary for the system to optimize corrosion control;

(3) If a corrosion inhibitor is used, a minimum concentration or a range of concentrations for the inhibitor, measured at each entry point to the distribution system and in all tap samples required by section 8.8(a), that the Department determines is necessary to form a passivating film on the interior walls of the pipes of the distribution system;

(4) If alkalinity is adjusted as part of optimal corrosion control treatment, a minimum concentration or a range of concentrations for alkalinity, measured at each entry point to the distribution system and in all tap samples;

(5) If calcium carbonate stabilization is used as part of corrosion control, a minimum concentration or a range of concentrations for calcium, measured in all tap samples.

(g) The values for the applicable water quality control parameters listed above shall be those that the Department determines to reflect optimal corrosion control treatment for the system. The Department may designate values for additional water quality control parameters determined by the Department to reflect optimal corrosion control for the system. The Department shall notify the system in writing of these determinations and explain the basis for its decisions.

(h) All systems optimizing corrosion control shall continue to operate and maintain optimal corrosion control treatment, including maintaining water quality parameters at or above minimum values or within ranges designated by the Department under section 8.3(f), in accordance with Article 8 for all samples collected under section 8.8(d)-(f). Compliance with the requirements of Article 8 shall be determined every six months, as specified under section 8.8(d). A water system is out of compliance with the requirements of section 8.3(g) for a six-month period if it has excursions for any Department-specified parameter on more than nine days during the period. An excursion occurs whenever the daily value for one or more of the water quality parameters measured at a sampling location is below the minimum value or outside the range designated by the Department. Daily values are calculated as follows. The Department has the discretion to delete results of sampling or analytic errors from this calculation.

(1) On days when more than one measurement for the water quality parameter is collected at the sampling location, the daily value shall be the average of all results collected during the day regardless of whether they are collected through continuous monitoring, grab sampling, or a combination of both.

(2) On days when only one measurement for the water quality parameter is collected at the sampling location, the daily value shall be the result of that measurement.

(3) On days when no measurement is collected for the water quality parameter at the sampling location, the daily value shall be the daily value calculated on the most recent day on which the water quality parameter was measured at the sample site.

1. (i) Upon its own initiative or in response to a request by a water system or other interested party, the Department may modify its determination of the optimal corrosion control treatment under section 8.3(d) or optimal water quality control parameters under section 8.3(f). A request for modification by a system or other interested party shall be in writing, explain why the modification is appropriate, and provide supporting documentation. The Department may modify its determination where it concludes that such change is necessary to ensure that the system continues to optimize corrosion control treatment. A revised determination shall be made in writing, set forth the new treatment requirements, explain the basis for the Department's decision, and provide an implementation schedule for completing the treatment modifications.

8.4 Source Water Treatment Requirements

Systems shall complete the applicable source water monitoring and treatment requirements (described in the referenced portions of sections 8.4(b), 8.7, and 8.9) if determined by the Department to be appropriate, by the following deadlines.

(a) Deadlines for completing source water treatment steps:

(1) Step 1: A system exceeding the lead or copper action level shall complete lead and copper source water monitoring (section 8.9(b)) and make a treatment recommendation to the Department (section 8.4(b)(1)) within 6 months after exceeding the lead or copper action level.

(2) Step 2: The Department shall make a determination regarding source water treatment (section 8.4(b)(2)) within 6 months after submission of monitoring results under Step 1.

(3) Step 3: If the Department requires installation of source water treatment, the system shall install the treatment (section 8.4(b)(3)) within 24 months after completion of Step 2.

(4) Step 4: The system shall complete follow-up tap water monitoring (section 8.7(d)(2) and source water monitoring (section 8.9(c)) within 36 months after completion of Step 2.

(5) Step 5: The Department shall review the system's installation and operation of source water treatment and specify maximum permissible source water levels (section 8.4(b)(4)) within 6 months after completion of Step 4.

(6) Step 6: The system shall operate in compliance with the Department-specified maximum permissible lead and copper source water levels (section 8.4(b)(4)) and continue source water monitoring (section 8.9(d)).

(b) Description of source water treatment requirements:

(1) Any system which exceeds the lead or copper action level shall recommend in writing to the Department the installation and operation of one of the source water treatments listed in section 8.4(b)(2). A system may recommend that no treatment be installed based upon a demonstration that source water treatment is not necessary to minimize lead and copper levels at users' taps.

(2) The Department shall complete an evaluation of the results of all source water samples submitted by the water system to determine whether source water treatment is necessary to minimize lead or copper levels in water delivered to users' taps. If the Department determines that treatment is needed, the Department shall either require installation and operation of the source water treatment recommended by the system (if any) or require the installation and operation of another source water treatment from among the following: Ion exchange, reverse osmosis, lime softening or coagulation/filtration. If the Department requests additional information to aid in its review, the water system shall provide the information by the date specified by the Department in its request. The Department shall notify the system in writing of its determination and set forth the basis for its decision.

(3) Each system shall properly install and operate the source water treatment designated by the Department under section 8.4(b)(2).

(4) The Department shall review the source water samples taken by the water system both before and after the system installs source water treatment, and determine whether the system has properly installed and operated the source water treatment designated by the Department. Based upon its review, the Department shall designate the maximum permissible lead and copper concentrations for finished water entering the distribution system. Such levels shall reflect the contaminant removal capability of the treatment properly operated and maintained. The Department shall notify the system in writing and explain the basis for its decision.

(5) Each water system shall maintain lead and copper levels below the maximum permissible concentrations designated by the Department at each sampling point monitored in accordance with section 8.9. The system is out of compliance with this section 8.4(b)(5) if the level of lead or copper at any sampling point is greater than the maximum permissible concentration designated by the Department.

(6) Upon the Department’s initiative or in response to a request by a water system or other interested party, the Department may modify its determination of the source water treatment under section 8.4(b)(2), or maximum permissible lead and copper concentrations for finished water entering the distribution system under section 8.4(b)(4). A request for modification by a system or other interested party shall be in writing, explain why the modification is appropriate, and provide supporting documentation. The Department may modify its determination where it concludes that such change is necessary to ensure that the system continues to minimize lead and copper concentrations in source water. A revised determination shall be made in writing, set forth the new treatment requirements, explain the basis for the Department's decision, and provide an implementation schedule for completing the treatment modifications.

8.5 Lead Service Line Replacement Requirements

(a) Systems that fail to meet the lead action level in tap samples taken pursuant to section 8.7(d)(2), after installing corrosion control and/or source water treatment (whichever sampling occurs later), shall replace lead service lines in accordance with the requirements of section 8.5. If a system is in violation of section 8.4 for failure to install source water treatment or in violation of section 8.2 for failure to install corrosion control treatment, the Department may require the system to commence lead service line replacement under section 8.5 after the date by which the system was required to conduct monitoring under section 8.7(d)(2) has passed.

(b) A water system shall replace annually at least 7 percent of the initial number of lead service lines in its distribution system. The initial number of lead service lines is the number of lead lines in place at the time the replacement program begins. The system shall identify the initial number of lead service lines in its distribution system, including an identification of the portion(s) owned by the system, based on a materials evaluation, including the evaluation required under section 8.7(a) and relevant legal authorities (e.g., contracts, local ordinances) regarding the portion owned by the system. The first year of lead service line replacement shall begin on the date the action level was exceeded in tap sampling referenced in section 8.5(a).

(c) A system is not required to replace an individual lead service line if the lead concentration in all service line samples from that line, taken pursuant to section 8.7(b)(3), is less than or equal to

0.015 mg/L.

(d) A water system shall replace that portion of the lead service line that it owns. In cases where the system does not own the entire lead service line, the system shall notify the owner of the line, or the owner's authorized agent, that the system will replace the portion of the service line that it owns and shall offer to replace the owner's portion of the line. A system is not required to bear the cost of replacing the privately-owned portion of the line, nor is it required to replace the privately- owned portion where the owner chooses not to pay the cost of replacing the privately-owned portion of the line, or where replacing the privately-owned portion would be precluded by Department, local or common law. A water system that does not replace the entire length of the service line also shall complete the following tasks.

(1) At least 45 days prior to commencing with the partial replacement of a lead service line, the water system shall provide notice to the resident(s) of all buildings served by the line explaining that they may experience a temporary increase of lead levels in their drinking water, along with guidance on measures consumers can take to minimize their exposure to lead. The Department may allow the water system to provide notice under the previous sentence less than 45 days prior to commencing partial lead service line replacement where such replacement is in conjunction with emergency repairs. In addition, the water system shall inform the resident(s) served by the line that the system will, at the system's expense, collect a sample from each partially-replaced lead service line that is representative of the water in the service line for analysis of lead content, as prescribed under section 8.7(b)(3), within 72 hours after the completion of the partial replacement of the service line. The system shall collect the sample and report the results of the analysis to the owner and the resident(s) served by the line within three business days of receiving the results. Mailed notices post-marked within three business days of receiving the results shall be considered "on time."

(2) The water system shall provide the information required by section 8.5(d)(1) to the residents of individual dwellings by mail or by other methods approved by the Department. In instances where multi-family dwellings are served by the line, the water system shall have the option to post the information at a conspicuous location.

(e) The Department shall require a system to replace lead service lines on a shorter schedule than that required by section 8.5, taking into account the number of lead service lines in the system, where such a shorter replacement schedule is feasible. The Department shall make this determination in writing and notify the system of its finding within 6 months after the system is triggered into lead service line replacement based on monitoring referenced in section 8.5(a).

(f) Any system may cease replacing lead service lines whenever first draw samples collected pursuant to section 8.7(b)(2) meet the lead action level during each of two consecutive monitoring periods and the system submits the results to the Department. If first draw tap samples collected in any such system thereafter exceeds the lead action level, the system shall recommence replacing lead service lines pursuant to section 8.5(b).

(g) To demonstrate compliance with section 8.5(a)-(d), a system shall report to the Department the information specified in section 8.10(e).

8.6 Public Education and Supplemental Monitoring Requirements

A water system that exceeds the lead action level based on tap water samples collected in accordance with section 8.7 shall deliver the public education materials contained in sections 8.6(a) and 8.6(b) in accordance with the requirements in section 8.6(c).

(a) Content of written public education materials.

(1) A community water system shall include the following text in all of the printed materials it distributes through its lead public education program. Systems may delete information pertaining to lead service lines, upon approval by the Department, if no lead service lines exist anywhere in the water system service area. Public education language at sections 8.6(a)(1)(iv)(B)(V) and 8.6(a)(1)(iv)(D)(II) may be modified regarding building permit record availability and consumer access to these records, if approved by the Department. Systems may also continue to utilize pre-printed materials that meet the public education language requirements in 40 CFR 141.85, effective November 6, 1991, and contained in the 40 CFR, parts 100 to 149, edition revised as of July 1, 1991. Any additional information presented by a system shall be consistent with the information below and be in plain English that can be understood by lay people.

1. (i) The United States Environmental Protection Agency (EPA) and [insert name of water supplier] are concerned about lead in your drinking water. Although most homes have very low levels of lead in their drinking water, some homes in the community have lead levels above the EPA action level of 15 parts per billion (ppb), or 0.015 milligrams of lead per liter of water (mg/L). Under Federal law we are required to have a program in place to minimize lead in your drinking water by [insert date when corrosion control will be completed for your system]. This program includes corrosion control treatment, source water treatment, and public education. We are also required to replace the portion of each lead service line that we own if the line contributes lead concentrations of more than 15 ppb after we have completed the comprehensive treatment program. If you have any questions about how we are carrying out the requirements of the lead regulation please give us a call at [insert water system's phone number]. This brochure explains the simple steps you can take to protect you and your family by reducing your exposure to lead in drinking water.
   1. (ii) Lead is a common metal found throughout the environment in lead-based paint, air, soil, household dust, food, certain types of pottery porcelain and pewter, and water. Lead can pose a significant risk to your health if too much of it enters your body. Lead builds up in the body over many years and can cause damage to the brain, red blood cells and kidneys. The greatest risk is to young children and pregnant women. Amounts of lead that won't hurt adults can slow down normal mental and physical development of growing bodies. In addition, a child at play often comes into contact with sources of lead contamination - like dirt and dust - that rarely affect an adult. It is important to wash children's hands and toys often, and to try to make sure they only put food in their mouths.
      1. (iii) Lead In Drinking Water (A) Lead in drinking water, although rarely the sole cause of lead poisoning, can significantly increase an individual's total lead exposure, particularly the exposure of infants who drink baby formulas and concentrated juices that are mixed with water. The EPA estimates that drinking water can make up 20 percent or more of an individual's total exposure to lead.
         1. (B) Lead is unusual among drinking water contaminants in that it seldom occurs naturally in water supplies like rivers and lakes. Lead enters drinking water primarily as a result of the corrosion, or wearing away, of materials containing lead in the water distribution system and household plumbing. These materials include lead-based solder used to join copper pipe, brass and chrome plated brass faucets, and in some cases, pipes made of lead that connect your house to the water main (service lines). In 1986, Congress banned the use of lead solder containing greater than 0.2% lead, and restricted the lead content of faucets, pipes and other plumbing materials to 8.0%.
         2. (C) When water stands in lead pipes or plumbing systems containing lead for several hours or more, the lead may dissolve into your drinking water. This means the first water drawn from the tap in the morning, or later in the afternoon after returning from work or school, can contain fairly high levels of lead.
         3. (iv) Steps you can take in the home to reduce exposure to lead in drinking water.
         4. (A) Despite our best efforts mentioned earlier to control water corrosivity and remove lead from the water supply, lead levels in some homes or buildings can be high. To find out whether you need to take action in your own home, have your drinking water tested to determine if it contains excessive concentrations of lead. Testing the water is essential because you cannot see, taste, or smell lead in drinking water. Some local laboratories that can provide this service are listed at the end of this booklet. For more information on having your water tested, please call [insert phone number of water system].
         5. (B) If a water test indicates that the drinking water drawn from a tap in your home contains lead above 15 ppb, then you should take the following precautions:
         6. (I) Let the water run from the tap before using it for drinking or cooking any time the water in a faucet has gone unused for more than six hours. The longer water resides in your home's plumbing the more lead it may contain. Flushing the tap means running the cold water faucet until the water gets noticeably colder, usually about 15-30 seconds. If your house has a lead service line to the water main, you may have to flush the water for a longer time, perhaps one minute, before drinking. Although toilet flushing or showering flushes water through a portion of your home's plumbing system, you still need to flush the water in each faucet before using it for drinking or cooking. Flushing tap water is a simple and inexpensive measure you can take to protect your family's health. It usually uses less than one or two gallons of water and costs less than [insert a cost estimate based on flushing two times a day for 30 days] per month. To conserve water, fill a couple of bottles for drinking water after flushing the tap, and whenever possible use the first flush water to wash the dishes or water the plants. If you live in a high-rise building, letting the water flow before using it may not work to lessen your risk from lead. The plumbing systems have more, and sometimes larger pipes than smaller buildings. Ask your landlord for help in locating the source of the lead and for advice on reducing the lead level.
         7. (II) Try not to cook with, or drink water from the hot water tap. Hot water can dissolve more lead more quickly than cold water. If you need hot water, draw water from the cold tap and heat it on the stove.
         8. (III) Remove loose lead solder and debris from the plumbing materials installed in newly constructed homes, or homes in which the plumbing has recently been replaced, by removing the faucet strainers from all taps and running the water from 3 to 5 minutes. Thereafter, periodically remove the strainers and flush out any debris that has accumulated over time.
         9. (IV) If your copper pipes are joined with lead solder that has been installed illegally since it was banned in 1986, notify the plumber who did the work and request that he or she replace the lead solder with lead-free solder. Lead solder looks dull gray, and when scratched with a key looks shiny. In addition, notify the Colorado Department of Public Health and Environment about the violation.
         10. (V) The best way to determine if your service line is made of lead is by either hiring a licensed plumber to inspect the line or by contacting the plumbing contractor who installed the line. You can identify the plumbing contractor by checking the city's record of building permits which should be maintained in the files of the [insert name of department that issues building permits]. A licensed plumber can at the same time check to see if your home's plumbing contains lead solder, lead pipes, or pipe fittings that contain lead. The public water system that delivers water to your home should also maintain records of the materials located in the distribution system. If the service line that connects your dwelling to the water main contributes more than 15 ppb to drinking water, after our comprehensive treatment program is in place, we are required to replace the portion of the line we own. If the line is only partially owned by the [insert the name of the city, county, or water system that owns the line], we are required to provide the owner of the privately-owned portion of the line with information on how to replace the privately-owned portion of the service line, and offer to replace that portion of the line at the owner's expense. If we replace only the portion of the line that we own, we also are required to notify you in advance and provide you with information on the steps you can take to minimize exposure to any temporary increase in lead levels that may result from the partial replacement, to take a follow-up sample at our expense from the line within 72 hours after the partial replacement, and to mail or otherwise provide you with the results of that sample within three business days of receiving the results. Acceptable replacement alternatives include copper, steel, iron, and plastic pipes.
         11. (VI) If grounding wires from the electrical system are attached to your pipes, corrosion may be greater. Check with a licensed electrician or your local electrical code to determine if your wiring can be grounded elsewhere. DO NOT attempt to change the wiring yourself because improper grounding can cause electrical shock and fire hazards.
         12. (C) The steps described above will reduce the lead concentrations in your drinking water. However, if a water test indicates that the drinking water coming from your tap contains lead concentrations in excess of 15 ppb after flushing, or after we have completed our actions to minimize lead levels, then you may want to take the following additional measures:
         13. (I) Home treatment devices are limited in that each unit treats only the water that flows from the faucet to which it is connected, and all of the devices require periodic maintenance and replacement. Devices such as reverse osmosis systems or distillers can effectively remove lead from your drinking water. Some activated carbon filters may reduce lead levels at the tap, however all lead reduction claims should be investigated. Be sure to check the actual performance of a specific home treatment device before and after installing the unit.
         14. (II) Purchase bottled water for drinking and cooking.
         15. (D) You can consult a variety of sources for additional information. Your family doctor or pediatrician can perform a blood test for lead and provide you with information about the health effects of lead. State and local government agencies that can be contacted include:
         16. (I) [insert the name of city or county department of public utilities] at [insert phone number] can provide you with information about your community's water supply, and a list of local laboratories that have been certified by EPA for testing water quality;
         17. (II) [insert the name of city or county department that issues building permits] at [insert phone number] can provide you with information about building permit records that should contain the names of plumbing contractors that plumbed your home; and (III) The Colorado Department of Public Health and Environment at 303- 692-3500 or the [insert the name of the city or county health department] at [insert phone number] can provide you with information about the health effects of lead and how you can have your child's blood tested.
         18. (E) A list of State approved laboratories that you can call to have your water tested for lead is available at the web site www.cdphe.state.co.us/lr/Certification/SDWLIST.pdf or by contacting the State’s laboratory certification program at (303) 692-3090.

(2) A non-transient, non-community water system shall either include the text specified in section 8.6(a)(1) or shall include the following text in all of the printed materials it distributes through its lead public education program. Water systems may delete information pertaining to lead service lines upon approval by the Department if no lead service lines exist anywhere in the water system service area. Any additional information presented by a system shall be consistent with the information below and be in plain English that can be understood by lay people.

1. (i) The United States Environmental Protection Agency (EPA) and [insert name of water supplier] are concerned about lead in your drinking water. Some drinking water samples taken from this facility have lead levels above the EPA action level of 15 parts per billion (ppb), or 0.015 milligrams of lead per liter of water (mg/L). Under Federal law we are required to have a program in place to minimize lead in your drinking water by [insert date when corrosion control will be completed for your system]. This program includes corrosion control treatment, source water treatment, and public education. We are also required to replace the portion of each lead service line that we own if the line contributes lead concentrations of more than 15 ppb after we have completed the comprehensive treatment program. If you have any questions about how we are carrying out the requirements of the lead regulation please give us a call at [insert water system's phone number]. This brochure explains the simple steps you can take to protect yourself by reducing your exposure to lead in drinking water.
   1. (ii) Lead is found throughout the environment in lead-based paint, air, soil, household dust, food, certain types of pottery porcelain and pewter, and water. Lead can pose a significant risk to your health if too much of it enters your body. Lead builds up in the body over many years and can cause damage to the brain, red blood cells and kidneys. The greatest risk is to young children and pregnant women. Amounts of lead that won't hurt adults can slow down normal mental and physical development of growing bodies. In addition, a child at play often comes into contact with sources of lead contamination - like dirt and dust - that rarely affect an adult. It is important to wash children's hands and toys often, and to try to make sure they only put food in their mouths.
      1. (iii) Lead in Drinking Water (A) Lead in drinking water, although rarely the sole cause of lead poisoning, can significantly increase an individual's total lead exposure, particularly the exposure of infants who drink baby formulas and concentrated juices that are mixed with water. The EPA estimates that drinking water can make up 20 percent or more of an individual's total exposure to lead.
         1. (B) Lead is unusual among drinking water contaminants in that it seldom occurs naturally in water supplies like rivers and lakes. Lead enters drinking water primarily as a result of the corrosion, or wearing away, of materials containing lead in the water distribution system and household plumbing. These materials include lead-based solder used to join copper pipe, brass and chrome-plated brass faucets, and in some cases, pipes made of lead that connect houses and buildings to water mains (service lines). In 1986, Congress banned the use of lead solder containing greater than 0.2% lead, and restricted the lead content of faucets, pipes and other plumbing materials to 8.0%.
         2. (C) When water stands in lead pipes or plumbing systems containing lead for several hours or more, the lead may dissolve into your drinking water. This means the first water drawn from the tap in the morning, or later in the afternoon if the water has not been used all day, can contain fairly high levels of lead.
         3. (iv) Steps you can take to reduce exposure to lead in drinking water.
         4. (A) Let the water run from the tap before using it for drinking or cooking any time the water in a faucet has gone unused for more than six hours. The longer water resides in plumbing the more lead it may contain. Flushing the tap means running the cold-water faucet for about 15-30 seconds. Although toilet flushing or showering flushes water through a portion of the plumbing system, you still need to flush the water in each faucet before using it for drinking or cooking. Flushing tap water is a simple and inexpensive measure you can take to protect your health. It usually uses less than one gallon of water.
         5. (B) Do not cook with, or drink water from the hot water tap. Hot water can dissolve more lead more quickly than cold water. If you need hot water, draw water from the cold tap and then heat it.
         6. (C) The steps described above will reduce the lead concentrations in your drinking water. However, if you are still concerned, you may wish to use bottled water for drinking and cooking.
         7. (D) You can consult a variety of sources for additional information. Your family doctor or pediatrician can perform a blood test for lead and provide you with information about the health effects of lead. State and local government agencies that can be contacted include:
         8. (I) [Insert the name or title of facility official if appropriate] at [insert phone number] can provide you with information about your facility's water supply; and (II) The Colorado Department of Public Health and Environment at (303) 692-3500 or the [insert the name of the city or county health department] at [insert phone number] can provide you with information about the health effects of lead.

(b) A water system shall include the following information in all public service announcements submitted under its lead public education program to television and radio stations for broadcasting:

(1) Why should everyone want to know the facts about lead and drinking water? Because unhealthy amounts of lead can enter drinking water through the plumbing in your home. That's why I urge you to do what I did. I had my water tested for [insert free or $ per sample]. You can contact the [insert the name of the city or water system] for information on testing and on simple ways to reduce your exposure to lead in drinking water.

(2) To have your water tested for lead, or to get more information about this public health concern, please call [insert the phone number of the city or water system].

(c) Delivery of a public education program.

(1) In communities where a significant proportion of the population speaks a language other than English, public education materials shall be communicated in the appropriate language(s).

(2) A community water system that exceeds the lead action level on the basis of tap water samples collected in accordance with section 8.7, and that is not already repeating public education tasks pursuant to sections 8.6(c)(3), 8.6(c)(7), or 8.6(c)(8), shall, within 60 days:

1. (i) Insert notices in each customer's water utility bill containing the information in section 8.6(a)(1), along with the following alert on the water bill itself in large print: "SOME HOMES IN THIS COMMUNITY HAVE ELEVATED LEAD LEVELS IN THEIR DRINKING WATER. LEAD CAN POSE A SIGNIFICANT RISK TO YOUR HEALTH. PLEASE READ THE ENCLOSED NOTICE FOR FURTHER INFORMATION." A community water system having a billing cycle that does not include a billing within 60 days of exceeding the action level, or that cannot insert information in the water utility bill without making major changes to its billing system, may use a separate mailing to deliver the information in section 8.6(a)(1) as long as the information is delivered to each customer within 60 days of exceeding the action level. Such water systems shall also include the "alert" language specified in 8.6(c)(2)(i).
   1. (ii) Submit the information in section 8.6(a)(1) to the editorial departments of the major daily and weekly newspapers circulated throughout the community.
      1. (iii) Deliver pamphlets and/or brochures that contain the public education materials in sections 8.6 (a)(1)(ii) and 8.6(a)(1)(iv) to facilities and organizations, including the following:
         1. (A) Public schools, and/or local school boards (B) City or county health department (C) Women, infants, and children and/or head start program(s) whenever available (D) Public and private hospitals and/or clinics (E) Pediatricians (F) Family planning clinics (G) Local welfare agencies (iv) Submit the public service announcement in section 8.6(b) to at least five of the radio and television stations with the largest audiences that broadcast to the community served by the water system.

(3) A community water system shall repeat the tasks contained in Sections 8.6(c)(2)(i)-(iii) every 12 months, and the tasks contained in section 8.6(c)(2)(iv) every 6 months for as long as the system exceeds the lead action level.

(4) Within 60 days after it exceeds the lead action level (unless it already is repeating public education tasks pursuant to section 8.6(c)(5)), a non-transient, non-community water system shall deliver the public education materials specified by section 8.6(a)(1) or the public education materials specified by section 8.6(a)(2) as follows:

1. (i) Post informational posters on lead in drinking water in a public place or common area in each of the buildings served by the system; and (ii) Distribute informational pamphlets and/or brochures on lead in drinking water to each individual served by the non-transient, non-community water system. The Department may allow the system to utilize electronic transmission in lieu of or combined with printed materials as long as it achieves at least the same coverage.

(5) A non-transient, non-community water system shall repeat the tasks contained in section 8.6(c)(4) at least once during each calendar year in which the system exceeds the lead action level.

(6) A water system may discontinue delivery of public education materials if the system has met the lead action level during the most recent six-month monitoring period conducted pursuant to section 8.7. Such a system shall recommence public education in accordance with section 8.6 if it subsequently exceeds the lead action level during any monitoring period.

(7) A community water system may apply to the Department, in writing, to use the text specified in section 8.6(a)(2) in lieu of the text in section 8.6(a)(1) and to perform the tasks listed in Sections 8.6(c)(4) and 8.6(c)(5) in lieu of the tasks in Sections 8.6(c)(2) and 8.6(c)(3) if:

1. (i) The system is a facility, such as a prison or a hospital, where the population served is not capable of or is prevented from making improvements to plumbing or installing point of use treatment devices; and (ii) The system provides water as part of the cost of services provided and does not separately charge for water consumption.

(8) Community water system serving a population of less than or equal to (≤) 3,300.

1. (i) A community water system serving a population of less than or equal to (≤) 3,300 may omit the task contained in section 8.6(c)(2)(iv). As long as it distributes notices containing the information contained in section 8.6(a)(1) to every household served by the system, such systems may further limit their public education programs as follows:
   1. (A) Systems serving a population of less than or equal to (≤) 500 may forego the task contained in section 8.6(c)(2)(ii). Such a system may limit the distribution of the public education materials required under section 8.6(c)(2)(iii) to facilities and organizations served by the system that are most likely to be visited regularly by pregnant women and children, unless it is notified by the Department in writing that it must make a broader distribution.
      1. (B) If approved by the Department in writing, a system serving a population of 501 to 3,300 may omit the task in section 8.6(c)(2)(ii) and/or limit the distribution of the public education materials required under section 8.6(c)(2)(iii) to facilities and organizations served by the system that are most likely to be visited regularly by pregnant women and children.
         1. (ii) A community water system serving a population of less than or equal to (≤) 3,300 that delivers public education in accordance with section 8.6(c)(8)(i) shall repeat the required public education tasks at least once during each calendar year in which the system exceeds the lead action level.

(d) A water system that fails to meet the lead action level on the basis of tap samples collected in accordance with section 8.7 shall offer to sample the tap water of any customer who requests it. The system is not required to pay for collecting or analyzing the sample, nor is the system required to collect and analyze the sample itself.

8.7 Monitoring Requirements for Lead and Copper in Tap Water

(a) Sample site location.

(1) Each water system shall complete a materials evaluation 8-1 of its distribution system in order to identify a pool of targeted sampling sites that meets the requirements, and which is sufficiently large to ensure that the water system can collect the number of lead and copper tap samples required in section 8.7(c). All sites from which first draw samples are collected shall be selected from this pool of targeted sampling sites. Sampling sites may not include faucets that have point-of-use or point-of-entry treatment devices designed to remove inorganic contaminants.

8-1 See section 1.6.9 for a list of materials that must be reported to the Department.

(2) A water system shall use the information on lead, copper, and galvanized steel that it is required to collect under section 1.6.9 when conducting a materials evaluation. When an evaluation of the information collected pursuant to section 1.6.9 is insufficient to locate the requisite number of lead and copper sampling sites that meet the targeting criteria in section 8.7(a), the water system shall review the sources of information listed below in order to identify a sufficient number of sampling sites. In addition, the system shall seek to collect such information where possible in the course of its normal operations (e.g., checking service line materials when reading water meters or performing maintenance activities):

1. (i) All plumbing codes, permits, and records in the files of the building department(s) which indicate the plumbing materials that are installed within publicly and privately owned structures connected to the distribution system;
   1. (ii) All inspections and records of the distribution system that indicate the material composition of the service connections that connect a structure to the distribution system; and (iii) All existing water quality information, which includes the results of all prior analyses of the system or individual structures connected to the system, indicating locations that may be particularly susceptible to high lead or copper concentrations.

(3) The sampling sites selected for a community water system's sampling pool ("tier l sampling sites") shall consist of single family structures that:

1. (i) Contain copper pipes with lead solder installed after 1982 or contain lead pipes; and/or (ii) Are served by a lead service line. When multiple-family residences comprise at least 20 percent of the structures served by a water system, the system may include these types of structures in its sampling pool.

(4) Any community water system with insufficient tier 1 sampling sites shall complete its sampling pool with "tier 2 sampling sites", consisting of buildings, including multiple-family residences that:

1. (i) Contain copper pipes with lead solder installed after 1982 or contain lead pipes; and/or (ii) Are served by a lead service line.

(5) Any community water system with insufficient tier 1 and tier 2 sampling sites shall complete its sampling pool with "tier 3 sampling sites", consisting of single family structures that contain copper pipes with lead solder installed before 1983. A community water system with insufficient tier 1, tier 2, and tier 3 sampling sites shall complete its sampling pool with representative sites throughout the distribution system. For the purpose of section 8.7(a)(5), a representative site is a site in which the plumbing materials used at that site would be commonly found at other sites served by the water system.

(6) The sampling sites selected for a non-transient, non-community water system ("tier l sampling sites") shall consist of buildings that:

1. (i) Contain copper pipes with lead solder installed after 1982 or contain lead pipes; and/or (ii) Are served by a lead service line.

(7) A non-transient, non-community water system with insufficient tier 1 sites that meet the targeting criteria in section 8.7(a)(6) shall complete its sampling pool with sampling sites that contain copper pipes with lead solder installed before 1983. If additional sites are needed to complete the sampling pool, the non-transient, non-community water system shall use representative sites throughout the distribution system. For the purpose of section 8.7(a)(7), a representative site is a site in which the plumbing materials used at that site would be commonly found at other sites served by the water system.

(8) Any water system whose distribution system contains lead service lines shall draw 50 percent of the samples it collects during each monitoring period from sites that contain lead pipes, or copper pipes with lead solder, and 50 percent of the samples from sites served by a lead service line. A water system that cannot identify a sufficient number of sampling sites served by a lead service line shall collect first-draw samples from all of the sites identified as being served by such lines.

(b) Sample collection methods.

(1) All tap samples for lead and copper collected in accordance with Article 8, with the exception of lead service line samples collected under section 8.5(c) and samples collected under section 8.7(b)(5) shall be first-draw samples.

(2) Each first-draw tap sample for lead and copper shall be one liter in volume and have stood motionless in the plumbing system of each sampling site for at least six hours. First-draw samples from residential housing shall be collected from the cold water kitchen tap or bathroom sink tap. First-draw samples from a nonresidential building shall be one liter in volume and shall be collected at an interior tap from which water is typically drawn for consumption. Non-first-draw samples collected in lieu of first-draw samples pursuant to section 8.7(b)(5) shall be one liter in volume and shall be collected at an interior tap from which water is typically drawn for consumption. First-draw samples may be collected by the system or the system may allow residents to collect first-draw samples after instructing the residents of the sampling procedures specified in section 8.7(b). To avoid problems of residents handling nitric acid, acidification of first-draw samples may be done up to 14 days after the sample is collected. After acidification to resolubilize the metals, the sample must stand in the original container for the time specified in the approved EPA method before the sample can be analyzed. If a system allows residents to perform sampling, the system may not challenge the accuracy of sampling results, based solely on alleged errors in sample collection.

(3) Each service line sample shall be one liter in volume and have stood motionless in the lead service line for at least six hours. Lead service line samples shall be collected in one of the following three ways:

1. (i) At the tap after flushing the volume of water between the tap and the lead service line. The volume of water shall be calculated based on the interior diameter and length of the pipe between the tap and the lead service line;
   1. (ii) Tapping directly into the lead service line; or (iii) If the sampling site is a building constructed as a single-family residence, allowing the water to run until there is a significant change in temperature that would be indicative of water that has been standing in the lead service line.

(4) A water system shall collect each first draw tap sample from the same sampling site from which it collected a previous sample. If, for any reason, the water system cannot gain entry to a sampling site in order to collect a follow-up tap sample, the system may collect the follow-up tap sample from another sampling site in its sampling pool as long as the new site meets the same targeting criteria, and is within reasonable proximity of the original site.

(5) A non-transient, non-community water system, or a community water system that meets the criteria of sections 8.6(c)(7)(i)-(ii), that does not have enough taps that can supply first- draw samples, as defined in section 1.5.2(56), may apply to the Department in writing to substitute non-first-draw samples. Such systems must collect as many first-draw samples from appropriate taps as possible and identify sampling times and locations that would likely result in the longest standing time for the remaining sites.

(c) Water systems shall collect at least one sample during each monitoring period specified in section 8.7(d) from the number of sites listed in the first column ("standard monitoring") of Table 8-1. A system conducting reduced monitoring under section 8.7(d)(4) shall collect at least one sample from the number of sites specified in the second column ("reduced monitoring") of Table 8-1 during each monitoring period specified in section 8.7(d)(4). Such reduced monitoring sites shall be representative of the sites required for standard monitoring. The Department may specify sampling locations when a system is conducting reduced monitoring. Table 8-1 Lead and Copper Monitoring Sampling Sites System size (population Number of sites Number of sites served) (standard monitoring) (reduced monitoring)

Greater than ( > ) 100,000 100 50 10,001 to 100,000 60 30 3,301 to 10,000 40 20 501 to 3,300 20 10 101 to 500 10 5 Less than or equal to (≤) 5 5 (d) Timing of monitoring (1) Initial tap sampling.

1. (i) All systems serving a population of greater than ( > ) 50,000 shall monitor during two consecutive six-month periods.
   1. (ii) All systems serving a population of less than or equal to (≤) 50,000 shall monitor during each six-month monitoring period until:
      1. (A) The system exceeds the lead or copper action level and is therefore required to implement the corrosion control treatment requirements under section 8.2, in which case the system shall continue monitoring in accordance with section 8.7(d)(2), or (B) The system meets the lead and copper action levels during two consecutive six-month monitoring periods, in which case the system may reduce monitoring in accordance with section 8.7(d)(4).

(2) Monitoring after installation of corrosion control and source water treatment.

1. (i) Any system that installs optimal corrosion control treatment pursuant to section 8.2(d) (5) shall monitor during two consecutive six-month monitoring periods.
   1. (ii) Any system that installs source water treatment pursuant to section 8.4(a)(3) shall monitor during two consecutive six-month monitoring periods by the date specified in section 8.4(a)(4).

(3) After the Department specifies the values for water quality control parameters under section 8.3(f), the system shall monitor during each subsequent six-month monitoring period, with the first monitoring period to begin on the date the Department specifies the optimal values under section 8.3(f).

(4) Reduced monitoring.

1. (i) A system serving a population of less than or equal to (≤) 50,000 that meets the lead and copper action levels during each of two consecutive six-month monitoring periods may reduce the number of samples in accordance with section 8.7(c), and reduce the frequency of sampling to once per year.
   1. (ii) Any water system that maintains the range of values for the water quality control parameters reflecting optimal corrosion control treatment specified by the Department under section 8.3(f) during each of two consecutive six-month monitoring periods may reduce the frequency of monitoring to once per year and reduce the number of lead and copper samples in accordance with section 8.7(c) if it receives written approval from the Department. The Department shall review monitoring, treatment, and other relevant information submitted by the water system in accordance with section 8.10, and shall notify the system in writing when it determines the system is eligible to commence reduced monitoring pursuant to section 8.7(d)(4). The Department shall review, and where appropriate, revise its determination when the system submits new monitoring or treatment data, or when other data relevant to the number and frequency of tap sampling becomes available.
      1. (iii) A system serving a population of less than or equal to (≤) 50,000 that meets the lead and copper action levels during three consecutive years of monitoring may reduce the frequency of monitoring for lead and copper from annually to once every three years. Any water system that maintains the range of values for the water quality control parameters reflecting optimal corrosion control treatment specified by the Department under section 8.3(f) during three consecutive years of monitoring may reduce the frequency of monitoring from annually to once every three years if it receives written approval from the Department. The Department shall review monitoring, treatment, and other relevant information submitted by the water system in accordance with section 8.10, and shall notify the system in writing when it determines the system is eligible to reduce the frequency of monitoring to once every three years. The Department shall review, and where appropriate, revise its determination when the system submits new monitoring or treatment data, or when other data relevant to the number and frequency of tap sampling becomes available.
         1. (iv) A water system that reduces the number and frequency of sampling shall collect these samples from representative sites included in the pool of targeted sampling sites identified in section 8.7(a). Systems sampling annually or less frequently shall conduct the lead and copper tap sampling during the months of June, July, August, or September unless the Department has approved a different sampling period in accordance with section 8.7(d)(4)(iv)(A).
         2. (A) The Department, at its discretion, may approve a different period for conducting the lead and copper tap sampling for systems collecting a reduced number of samples. Such a period shall be no longer than four consecutive months and must represent a time of normal operation where the highest levels of lead are most likely to occur. For a non- transient, non-community water system that does not operate during the months of June through September, and for which the period of normal operation where the highest levels of lead are most likely to occur is not known, the Department shall designate a period that represents a time of normal operation for the system.
         3. (B) Systems monitoring annually, that have been collecting samples during the months of June through September and that receive Department approval to alter their sample collection period under section 8.7(d)(4)(iv) (A), must collect their next round of samples during a time period that ends no later than 21 months after the previous round of sampling. Systems monitoring triennially that have been collecting samples during the months of June through September, and receive Department approval to alter the sampling collection period as per section 8.7(d)(4) (iv)(A), must collect their next round of samples during a time period that ends no later than 45 months after the previous round of sampling. Subsequent rounds of sampling must be collected annually or triennially, as required by section 8.7. Systems serving a population of ≤ 3,300 with waivers, granted pursuant to section 8.7(g), that have been collecting samples during the months of June through September and receive Department approval to alter their sample collection period under section 8.7(d)(4)(iv)(A) must collect their next round of samples before the end of the 9-year period.
         4. (v) Any water system that demonstrates for two consecutive 6-month monitoring periods that the tap water lead level computed under section 8.1(a)(3) is less than or equal to 0.005 mg/L and the tap water copper level computed under section 8.1(a)(3) is less than or equal to 0.65 mg/L may reduce the number of samples in accordance with section 8.7(c) and reduce the frequency of sampling to once every three calendar years.
         5. (vi) A system serving a population of less than or equal to (≤) 50,000 subject to reduced monitoring that exceeds the lead or copper action level.
         6. (A) A system serving a population of less than or equal to (≤) 50,000 subject to reduced monitoring that exceeds the lead or copper action level shall resume sampling in accordance with section 8.7(d)(3) and collect the number of samples specified for standard monitoring under section 8.7(c). Such a system shall also conduct water quality parameter monitoring in accordance with section 8.8(b), 8.8(c) or 8.8(d) (as appropriate) during the monitoring period in which it exceeded the action level. Any such system may resume annual monitoring for lead and copper at the tap at the reduced number of sites specified in section 8.7(c) after it has completed two subsequent consecutive six-month rounds of monitoring that meet the criteria of section 8.7(d)(4)(i) and/or may resume triennial monitoring for lead and copper at the reduced number of sites after it demonstrates through subsequent rounds of monitoring that it meets the criteria of either section 8.7(d)(4)(iii) or 8.7(d) (4)(v).
         7. (B) Any water system subject to the reduced monitoring frequency that fails to operate at or above the minimum value or within the range of values for the water quality parameters specified by the Department under section 8.3(f) for more than nine days in any six-month period specified in section 8.8(d) shall conduct tap water sampling for lead and copper at the frequency specified in section 8.7(d)(3), collect the number of samples specified for standard monitoring under section 8.7(c)), and shall resume monitoring for water quality parameters within the distribution system in accordance with section 8.8(d). Such a system may resume reduced monitoring for lead and copper at the tap and for water quality parameters within the distribution system under the following conditions:
         8. (I) The system may resume annual monitoring for lead and copper at the tap at the reduced number of sites specified in section 8.7(c) after it has completed two subsequent six-month rounds of monitoring that meet the criteria of section 8.7(d)(4)(ii) and the system has received written approval from the Department that it is appropriate to resume reduced monitoring on an annual frequency.
         9. (II) The system may resume triennial monitoring for lead and copper at the tap at the reduced number of sites after it demonstrates through subsequent rounds of monitoring that it meets the criteria of either section 8.7(d)(4)(iii) or 8.7(d)(4)(v) and the system has received written approval from the Department that it is appropriate to resume triennial monitoring.
         10. (III) The system may reduce the number of water quality parameter tap water samples required in accordance with section 8.8(e)(1) and the frequency with which it collects such samples in accordance with section 8.8(e)(2). Such a system may not resume triennial monitoring for water quality parameters at the tap until it demonstrates in accordance with the requirements of section 8.8(e)(2) that it has re-qualified for triennial monitoring.
         11. (vii) Any water system subject to a reduced monitoring frequency under section 8.7(d)(4) that either adds a new source of water or changes any water treatment shall inform the Department in writing in accordance with section 8.10(a)(3). The Department may require the system to resume sampling in accordance with section 8.7(d)(3) and collect the number of samples specified for standard monitoring under section 8.7(c) or take other appropriate steps such as increased water quality parameter monitoring or re-evaluation of its corrosion control treatment given the potentially different water quality considerations.

(e) The results of any monitoring conducted in addition to the minimum requirements of section 8.7 shall be considered by the system and the Department in making any determinations (i.e., calculating the 90th percentile lead or copper level) under Article 8.

(f) A sample invalidated under section 8.7(f) does not count toward determining lead or copper 90th percentile levels under section 8.1(a)(3) or toward meeting the minimum monitoring requirements of section 8.7(c).

(1) The Department may invalidate a lead or copper tap water sample if at least one of the following conditions is met.

1. (i) The laboratory establishes that improper sample analysis caused erroneous results.
   1. (ii) The Department determines that the sample was taken from a site that did not meet the site selection criteria of section 8.7.
      1. (iii) The sample container was damaged in transit.
         1. (iv) There is substantial reason to believe that the sample was subject to tampering.
         2. (v) Sampling or analytic errors.

(2) The system must report the results of all samples to the Department and all supporting documentation for samples the system believes should be invalidated.

(3) To invalidate a sample under section 8.7(f)(1), the decision and the rationale for the decision must be documented in writing. The Department may not invalidate a sample solely on the grounds that a follow-up sample result is higher or lower than that of the original sample.

(4) The water system must collect replacement samples for any samples invalidated under section 8.7(f) if, after the invalidation of one or more samples, the system has too few samples to meet the minimum requirements of section 8.7(c). Any such replacement samples must be taken as soon as possible, but no later than 20 days after the date the Department invalidates the sample or by the end of the applicable monitoring period, whichever occurs later. Replacement samples taken after the end of the applicable monitoring period shall not also be used to meet the monitoring requirements of a subsequent monitoring period. The replacement samples shall be taken at the same locations as the invalidated samples or, if that is not possible, at locations other than those already used for sampling during the monitoring period.

(g) Any system serving a population of less than or equal to (≤) 3,300 that meets the criteria may apply to the Department to reduce the frequency of monitoring for lead and copper under section 8.7(g) to once every nine years (i.e., a "full waiver") if it meets all of the materials criteria specified in section 8.7(g)(1) and all of the monitoring criteria specified in section 8.7(g)(2). Any system serving a population of less than or equal to (≤) 3,300 that meets the criteria in section 8.7(g)(1) and 8.7(g)(2) only for lead, or only for copper, may apply to the Department for a waiver to reduce the frequency of tap water monitoring to once every nine years for that contaminant only (i.e., a "partial waiver").

(1) The system must demonstrate that its distribution system and service lines and all drinking water supply plumbing, including plumbing conveying drinking water within all residences and buildings connected to the system, are free of lead-containing materials and/or copper-containing materials, as those terms are defined in section 1.5.2(74), as follows:

1. (i) To qualify for a full waiver, or a waiver of the tap water monitoring requirements for lead (i.e., a "lead waiver"), the water system must provide certification and supporting documentation to the Department that the system is free of all lead- containing materials, as follows:
   1. (A) It contains no plastic pipes which contain lead plasticizers, or plastic service lines which contain lead plasticizers; and (B) It is free of lead service lines, lead pipes, lead soldered pipe joints, and leaded brass or bronze alloy fittings and fixtures, unless such fittings and fixtures meet the specifications of any standard established pursuant to 42 United States Code (U.S.C.) 300g-6(e) (SDWA section 1417(e)).
      1. (ii) To qualify for a full waiver, or a waiver of the tap water monitoring requirements for copper (i.e., a "copper waiver"), the water system must provide certification and supporting documentation to the Department that the system contains no copper pipes or copper service lines.

(2) The system must have completed at least one 6-month round of standard tap water monitoring for lead and copper at sites approved by the Department and from the number of sites required by section 8.7(c) and demonstrate that the 90th percentile levels for any and all rounds of monitoring conducted since the system became free of all lead- containing and/or copper-containing materials, as appropriate, meet the following criteria.

1. (i) To qualify for a full waiver, or a lead waiver, the system must demonstrate that the 90th percentile lead level does not exceed 0.005 mg/L.
   1. (ii) To qualify for a full waiver, or a copper waiver, the system must demonstrate that the 90th percentile copper level does not exceed 0.65 mg/L.

(3) The Department shall notify the system of its waiver determination, in writing, setting forth the basis of its decision and any condition of the waiver. As a condition of the waiver, the Department may require the system to perform specific activities (e.g., limited monitoring, periodic outreach to customers to remind them to avoid installation of materials that might void the waiver) to avoid the risk of lead or copper concentration of concern in tap water. The system serving a population of ≤ 3,300 must continue monitoring for lead and copper at the tap as required by sections 8.7(d)(1)-(4), as appropriate, until it receives written notification from the Department that the waiver has been approved.

(4) Monitoring frequency for systems with waivers.

1. (i) A system with a full waiver must conduct tap water monitoring for lead and copper in accordance with section 8.7(d)(4)(iv) at the reduced number of sampling sites identified in section 8.7(c) at least once every nine years and provide the materials certification specified in section 8.7(g)(1) for both lead and copper to the Department along with the monitoring results.
   1. (ii) A system with a partial waiver must conduct tap water monitoring for the waived contaminant in accordance with section 8.7(d)(4)(iv) at the reduced number of sampling sites specified in section 8.7(c) at least once every nine years and provide the materials certification specified in section 8.7(g)(1) pertaining to the waived contaminant along with the monitoring results. Such a system also must continue to monitor for the non-waived contaminant in accordance with requirements of sections 8.7(d)(1)-(4), as appropriate.
      1. (iii) If a system with a full or partial waiver adds a new source of water or changes any water treatment, the system must notify the Department in writing in accordance with section 8.10(a)(3). The Department has the authority to require the system to add or modify waiver conditions (e.g., require re-certification that the system is free of lead-containing and/or copper-containing materials, require additional round(s) of monitoring), if it deems such modifications are necessary to address treatment or source water changes at the system.
         1. (iv) If a system with a full or partial waiver becomes aware that it is no longer free of lead-containing or copper-containing materials, as appropriate, (e.g., as a result of new construction or repairs), the system shall notify the Department in writing no later than 60 days after becoming aware of such a change.

(5) If the system continues to satisfy the requirements of section 8.7(g)(4), the waiver will be renewed automatically, unless any of the conditions listed in sections 8.7(g)(5)(i)-(iii) occurs. A system whose waiver has been revoked may re-apply for a waiver at such time as it again meets the appropriate materials and monitoring criteria of section 8.7(g)(1) and 8.7(g)(2).

1. (i) A system with a full waiver or a lead waiver no longer satisfies the materials criteria of section 8.7(g)(1)(i) or has a 90th percentile lead level greater than 0.005 mg/L.
   1. (ii) A system with a full waiver or a copper waiver no longer satisfies the materials criteria of section 8.7(g)(1)(ii) or has a 90th percentile copper level greater than 0.65 mg/L.
      1. (iii) The Department notifies the system, in writing, that the waiver has been revoked, setting forth the basis of its decision.

(6) A system whose full or partial waiver has been revoked by the Department is subject to the corrosion control treatment and lead and copper tap water monitoring requirements, as follows:

1. (i) If the system exceeds the lead and/or copper action level, the system must implement corrosion control treatment in accordance with the deadlines specified in section 8.2, and any other applicable requirements of Article 8.
   1. (ii) If the system meets both the lead and the copper action level, the system must monitor for lead and copper at the tap no less frequently than once every three years using the reduced number of sample sites specified in section 8.7(c).

8.8 Monitoring Requirements for Water Quality Parameters

All systems that exceed the lead or copper action level shall monitor water quality parameters in addition to lead and copper in accordance with section 8.8. The requirements of section 8.8 are summarized in the Table 8-4 - Summary of Monitoring Requirements for Water Quality Parameters.

(a) General requirements.

(1) Sample collection methods.

1. (i) Tap samples 8-2 shall be representative of water quality throughout the distribution system taking into account the number of individuals served, the different sources of water, the different treatment methods employed by the system, and seasonal variability. Tap sampling under section 8.8 is not required to be conducted at taps targeted for lead and copper sampling under section 8.7(a). 8-2 Systems may find it convenient to conduct tap sampling for water quality parameters at sites used for coliform sampling under Article 5, if coliform sampling sites are customers’ residences.
   1. (iii) Samples collected at the entry point(s) to the distribution system shall be from locations representative of each source after treatment. If a system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water is representative of all sources being used).

(2) Number of samples.

1. (i) Systems shall collect two tap samples for applicable water quality parameters during each monitoring period specified under sections 8.8(b) through (e) from the following number of sites.

Table 8-2 Number of Water Quality Parameter Samples for Lead and Copper System size (population Number of sites for served) water quality parameters Greater than ( > ) 25 100,000 10,001-100,000 10 3,301 to 10,000 3 501 to 3,300 2 101 to 500 1 Less than or equal to 1 ( ≤ ) 100

1. (ii) Except as provided in section 8.8(c)(3), systems shall collect two samples for each applicable water quality parameter at each entry point to the distribution system during each monitoring period specified in section 8.8(b). During each monitoring period specified in sections 8.8(c)-(e), systems shall collect one sample for each applicable water quality parameter at each entry point to the distribution system.

(b) All systems serving a population of greater than ( > ) 50,000 shall measure the applicable water quality parameters as specified below at taps and at each entry point to the distribution system during each six-month monitoring period specified in section 8.7(d)(1). All systems serving a population of less than or equal to (≤) 50,000 shall measure the applicable water quality parameters at the locations specified below during each six-month monitoring period specified in section 8.7(d)(1) during which the system exceeds the lead or copper action level.

(1) At taps:

1. (i) pH;
   1. (ii) Alkalinity;
      1. (iii) Orthophosphate, when an inhibitor containing a phosphate compound is used;
         1. (iv) Silica, when an inhibitor containing a silicate compound is used;
         2. (v) Calcium;
         3. (vi) Conductivity; and (vii) Water temperature.

(2) At each entry point to the distribution system: all of the applicable parameters listed in section 8.8(b)(1).

(c) Any system serving a population of greater than ( > ) 50,000 which installs optimal corrosion control treatment pursuant to section 8.2(d)(4) shall measure the water quality parameters at the locations and frequencies specified below during each six-month monitoring period specified in section 8.7(d)(2)(i). Any system serving a population of less than or equal to (≤) 50,000 which installs optimal corrosion control treatment shall conduct such monitoring during each six-month monitoring period specified in section 8.7(d)(2)(ii) in which the system exceeds the lead or copper action level.

(1) At taps, two samples for:

1. (i) pH;
   1. (ii) Alkalinity;
      1. (iii) Orthophosphate, when an inhibitor containing a phosphate compound is used;
         1. (iv) Silica, when an inhibitor containing a silicate compound is used;
         2. (v) Calcium, when calcium carbonate stabilization is used as part of corrosion control.

(2) Except as provided in section 8.8(c)(3), at each entry point to the distribution system, at least one sample no less frequently than every two weeks (biweekly) for:

1. (i) pH;
   1. (ii) When alkalinity is adjusted as part of optimal corrosion control, a reading of the dosage rate of the chemical used to adjust alkalinity, and the alkalinity concentration; and (iii) When a corrosion inhibitor is used as part of optimal corrosion control, a reading of the dosage rate of the inhibitor used, and the concentration of orthophosphate or silica (whichever is applicable).

(3) Any groundwater system can limit entry point sampling described in section 8.8(c)(2) to those entry points that are representative of water quality and treatment conditions throughout the system. If water from untreated groundwater sources mixes with water from treated groundwater sources, the system must monitor for water quality parameters both at representative entry points receiving treatment and representative entry points receiving no treatment. Prior to the start of any monitoring under section 8.8(c), the system shall provide to the Department written information identifying the selected entry points and documentation, including information on seasonal variability, sufficient to demonstrate that the sites are representative of water quality and treatment conditions throughout the system.

(d) After the Department specifies the values for applicable water quality control parameters reflecting optimal corrosion control treatment under section 8.3(f), all systems serving a population of greater than ( > ) 50,000 shall measure the applicable water quality parameters in accordance with section 8.8(c) and determine compliance with the requirements of section 8.3(g) every six months with the first six-month period to begin on the date the Department specifies the optimal values under section 8.3(f). Any system serving a population of less than or equal to (≤) 50,000 shall conduct such monitoring during each six-month period specified in section 8.8(d) in which the system exceeds the lead or copper action level. For any system serving a population of less than or equal to (≤) 50,000 that is subject to a reduced monitoring frequency pursuant to section 8.7(d)(4) at the time of the action level exceedance, the end of the applicable six-month period under section 8.8(d) shall coincide with the end of the applicable monitoring period under section 8.7(d)(4). Compliance with Department-designated optimal water quality parameter values shall be determined as specified under section 8.3(g).

(e) Reduced monitoring.

(1) Any water system that maintains the range of values for the water quality parameters reflecting optimal corrosion control treatment during each of two consecutive six-month monitoring periods under section 8.8(d) shall continue monitoring at the entry point(s) to the distribution system as specified in section 8.8(c)(2). Such system may collect two tap samples for applicable water quality parameters from the following reduced number of sites during each six-month monitoring period.

Table 8-3 Reduced Sampling Sites for Lead and Copper System Size (population Reduced number of sites served) for water quality parameters Greater than ( > ) 10 100,000 10,000 to 100,000 7 3,301 to 10,000 3 501 to 3,300 2 101 to 500 1 Less than or equal to 1 ( ≤ ) 100 (2) Maintaining water quality parameters.

1. (i) Any water system that maintains the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the Department under section 8.3(f) during three consecutive years of monitoring may reduce the frequency with which it collects the number of tap samples for applicable water quality parameters specified in this section 8.8(e)(1) from every six months to annually. Any water system that maintains the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the Department under section 8.3(f) during three consecutive years of annual monitoring under section 8.8(e)(2)(i) may reduce the frequency with which it collects the number of tap samples for applicable water quality parameters specified in section 8.8(e)(1) from annually to every three years.
   1. (ii) A water system may reduce the frequency with which it collects tap samples for applicable water quality parameters specified in section 8.8(e)(1) to every three years if it demonstrates during two consecutive monitoring periods that its tap water lead level at the 90th percentile is less than or equal to the PQL for lead specified in section 10.8.1(a)(1)(ii), that its tap water copper level at the 90th percentile is less than or equal to (≤) 0.65 mg/L for copper in section 8.1(a)(2), and that it also has maintained the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the Department under section 8.3(f).

(3) A water system that conducts sampling annually shall collect these samples evenly throughout the year so as to reflect seasonal variability.

(4) Any water system subject to the reduced monitoring frequency that fails to operate at or above the minimum value or within the range of values for the water quality parameters specified by the Department in section 8.3(f) for more than nine days in any six-month period specified in section 8.3(g) shall resume distribution system tap water sampling in accordance with the number and frequency requirements in section 8.8(d). Such a system may resume annual monitoring for water quality parameters at the tap at the reduced number of sites specified in section 8.8(e)(1) after it has completed two subsequent consecutive six-month rounds of monitoring that meet the criteria of section 8.8(e) and/or may resume triennial monitoring for water quality parameters at the tap at the reduced number of sites after it demonstrates through subsequent rounds of monitoring that it meets the criteria of either section 8.8(e)(2)(i) or 8.8(e)(2)(ii).

(f) The results of any monitoring conducted in addition to the minimum requirements of section 8.8 shall be considered by the system and the Department in making any determinations (i.e., determining concentrations of water quality parameters) under section 8.8 or section 8.3. Table 8-4 Summary of Monitoring Requirements for Water Quality Parameters 1

8.9 Monitoring Requirements for Lead and Copper in Source Water

(a) Sample location, collection methods, and number of samples.

(1) A water system that fails to meet the lead or copper action level on the basis of tap samples collected in accordance with section 8.7 shall collect lead and copper source water samples in accordance with the following requirements regarding sample location, number of samples, and collection methods:

1. (i) Groundwater systems shall take a minimum of one sample at every entry point to the distribution system that is representative of each well after treatment (hereafter called a sampling point). The system shall take one sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.
   1. (ii) Surface water systems 8-3 shall take a minimum of one sample at every entry point to the distribution system after any application of treatment or in the distribution system at a point that is representative of each source after treatment (hereafter called a sampling point). The system shall take each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.

8-3 For the purposes of Article 8, surface water systems include systems with a combination of surface and ground water sources.

1. (iii) If a system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water is representative of all sources being used).
   1. (iv) The Department may reduce the total number of samples that must be analyzed by allowing the use of compositing. Compositing of samples must be done by certified laboratory personnel. Composite samples from a maximum of five samples are allowed, provided that, if the lead concentration in the composite sample is greater than or equal to (≤) 0.001 mg/L or the copper concentration is greater than or equal to (≤) 0.160 mg/L, then either:
      1. (A) A follow-up sample shall be taken and analyzed within 14 days at each sampling point included in the composite; or (B) If duplicates of or sufficient quantities from the original samples from each sampling point used in the composite are available, the system may use these instead of re-sampling.

(2) Where the results of sampling indicate an exceedance of maximum permissible source water levels established under section 8.4(b)(4), the Department may require that one additional sample be collected as soon as possible after the initial sample was taken (but not to exceed two weeks) at the same sampling point. If a Department-required confirmation sample is taken for lead or copper, then the results of the initial and confirmation sample shall be averaged in determining compliance with the Department- specified maximum permissible levels. Any sample value below the detection limit shall be considered to be zero. Any value above the detection limit but below the PQL shall either be considered as the measured value or be considered one-half the PQL.

(b) Any system that exceeds the lead or copper action level at the tap shall collect one source water sample from each entry point to the distribution system within six months after the exceedance.

(c) Any system that installs source water treatment pursuant to section 8.4(a)(3) shall collect an additional source water sample from each entry point to the distribution system during two consecutive six-month monitoring periods by the deadline specified in section 8.4(a)(4).

(d) Monitoring frequency after Department specifies maximum permissible source water levels or determines that source water treatment is not needed.

(1) A system shall monitor at the frequency specified below in cases where the Department specifies maximum permissible source water levels under section 8.4(b)(4) or determines that the system is not required to install source water treatment under section 8.4(b)(2).

1. (i) A water system using only groundwater shall collect samples once during the three- year compliance period (as that term is defined in section 1.5.2(19) in effect when the applicable Department determination under section 8.9(d)(1) is made. Such systems shall collect samples once during each subsequent compliance period.
   1. (ii) A water system using surface water (or a combination of surface and groundwater) shall collect samples once during each year, the first annual monitoring period to begin on the date on which the applicable Department determination is made under section 8.9(d)(1).

(2) A system is not required to conduct source water sampling for lead and/or copper if the system meets the action level for the specific contaminant in tap water samples during the entire source water sampling period applicable to the system under section 8.9(d)(1)

1. (i) or 8.9(d)(1)(ii).

(e) Reduced monitoring frequency.

(1) A water system using only groundwater may reduce the monitoring frequency for lead and copper in source water to once during each nine-year compliance cycle, as defined in section 1.5.2(11), if the system meets one of the following criteria:

1. (i) The system demonstrates that finished drinking water entering the distribution system has been maintained below the maximum permissible lead and copper concentrations specified by the Department in section 8.4(b)(4) during at least three consecutive compliance periods under section 8.9(d)(1); or (ii) The Department has determined that source water treatment is not needed and the system demonstrates that, during at least three consecutive compliance periods in which sampling was conducted under section 8.9(d)(1), the concentration of lead in source water was less than or equal to 0.005 mg/L and the concentration of copper in source water was less than or equal to 0.65 mg/L.

(2) A water system using surface water (or a combination of surface water and groundwater) may reduce the monitoring frequency in section 8.9(d)(1) to once during each nine-year compliance cycle (as that term is defined in section 1.5.2(16)) if the system meets one of the following criteria:

1. (i) The system demonstrates that finished drinking water entering the distribution system has been maintained below the maximum permissible lead and copper concentrations specified by the Department in section 8.4(b)(4) for at least three consecutive years; or (ii) The Department has determined that source water treatment is not needed and the system demonstrates that, during at least three consecutive years, the concentration of lead in source water was less than or equal to (≤) 0.005 mg/L and the concentration of copper in source water was less than or equal to (≤)
   1. 0.65 mg/L.

(3) A water system that uses a new source of water is not eligible for reduced monitoring for lead and/or copper until concentrations in samples collected from the new source during three consecutive monitoring periods are below the maximum permissible lead and copper concentrations specified by the Department in section 8.4(a)(5).

8.10 Reporting Requirements

All water systems shall report all of the following information to the Department in accordance with section 8.10.

(a) Reporting requirements for tap water monitoring for lead and copper and for water quality parameter monitoring.

(1) Except as provided in section 8.10(a)(1)(viii), a water system shall report the information specified below for all tap water samples specified in section 8.7 and for all water quality parameter samples specified in section 8.8 within the first 10 days following the end of each applicable monitoring period specified in section 8.7 and section 8.8 (i.e., every six months, annually, every 3 years, or every 9 years):

1. (i) The results of all tap samples for lead and copper including the location of each site and the criteria under section 8.7(a) (3), (4), (5), (6), and/or (7) under which the site was selected for the system's sampling pool;
   1. (ii) Documentation for each tap water lead or copper sample for which the water system requests invalidation pursuant to section 8.7(f)(2);
      1. (iii) [Reserved] (iv) The 90th percentile lead and copper concentrations measured from among all lead and copper tap water samples collected during each monitoring period (calculated in accordance with section 8.1(a)(3)), unless the Department calculates the system's 90th percentile lead and copper levels under section 8.10(h);
         1. (v) With the exception of initial tap sampling conducted pursuant to section 8.7(d)(1), the system shall designate any site which was not sampled during previous monitoring periods, and include an explanation of why sampling sites have changed;
         2. (vi) The results of all tap samples for pH, and where applicable, alkalinity, calcium, conductivity, temperature, and orthophosphate or silica collected under section
         3. 8.8 (b)-(e);
         4. (vii) The results of all samples collected at the entry point(s) to the distribution system for applicable water quality parameters under section 8.8 (b)-(e);
         5. (viii) A water system shall report the results of all water quality parameter samples collected under sections 8.8(c)-(f) during each six-month monitoring period specified in section 8.8(d) within the first 10 days following the end of the monitoring period unless the Department has specified a more frequent reporting requirement.

(2) For a non-transient, non-community water system, or a community water system meeting the criteria of sections 8.6(c)(7)(i) and (ii), that does not have enough taps that can provide first-draw samples, the system must provide written documentation to the Department identifying standing times and locations for enough non-first-draw samples to make up its sampling pool under section 8.7(b)(5) by the start of the first applicable monitoring period under section 8.7(d).

(3) No later than 60 days after the addition of a new source or any change in water treatment a water system deemed to have optimized corrosion control under section 8.2(b)(3), a water system subject to reduced monitoring pursuant to section 8.7(d)(4), or a water system subject to a monitoring waiver pursuant to section 8.7(g), shall send written documentation to the Department describing the change.

(4) Any system serving a population of less than or equal to (≤) 3,300 applying for a monitoring waiver under section 8.7(g), or subject to a waiver granted pursuant to section 8.7(g)(3), shall provide the following information to the Department in writing by the specified deadline:

1. (i) By the start of the first applicable monitoring period under section 8.7(d), any system serving a population of less than or equal to (≤) 3,300 applying for a monitoring waiver shall provide the documentation required to demonstrate that it meets the waiver criteria of sections 8.7(g)(1) and 8.7(g)(2).
   1. (ii) No later than nine years after the monitoring previously conducted pursuant to section 8.7(g)(2) or section 8.7(g)(4)(i), each system serving a population of less than or equal to (≤) 3,300 desiring to maintain its monitoring waiver shall provide the information required by section 8.7(g)(4)(i) and (ii).
      1. (iii) No later than 60 days after it becomes aware that it is no longer free of lead- containing and/or copper-containing material, as appropriate, each system serving a population of less than or equal to (≤) 3,300 with a monitoring waiver shall provide written notification to the Department, setting forth the circumstances resulting in the lead-containing and/or copper-containing materials being introduced into the system and what corrective action, if any, the system plans to remove these materials.

(5) Each groundwater system that limits water quality parameter monitoring to a subset of entry points under section 8.8(c)(3) shall provide, by the commencement of such monitoring, written correspondence to the Department that identifies the selected entry points and includes information sufficient to demonstrate that the sites are representative of water quality and treatment conditions throughout the system.

(b) Source water monitoring reporting requirements.

(1) A water system shall report the sampling results for all source water samples collected in accordance with section 8.9 within the first 10 days following the end of each source water monitoring period (i.e., annually, per compliance period, per compliance cycle) specified in section 8.9.

(2) With the exception of the first round of source water sampling conducted pursuant to section 8.9(b), the system shall specify any site that was not sampled during previous monitoring periods, and include an explanation of why the sampling point has changed.

(c) By the applicable dates under section 8.2, systems shall report the following information:

(1) For systems demonstrating that they have already optimized corrosion control, information required in section 8.2(b) (2) or (3).

(2) For systems required to optimize corrosion control, their recommendation regarding optimal corrosion control treatment under section 8.3(a).

(3) For systems required to evaluate the effectiveness of corrosion control treatments under section 8.3(c), the information required by section 8.3(c).

(4) For systems required to install optimal corrosion control designated by the Department under section 8.3(d), a letter certifying that the system has completed installing that treatment.

(d) By the applicable dates in section 8.4, systems shall provide the following information to the Department:

(1) If required under section 8.4(b)(1), their recommendation regarding source water treatment;

(2) For systems required to install source water treatment under section 8.4(b)(2), a letter certifying that the system has completed installing the treatment designated by the Department within 24 months after the Department designated the treatment.

(e) Systems shall report the following information to the Department to demonstrate compliance with the requirements of section 8.5:

(1) Within 12 months after a system exceeds the lead action level in sampling referred to in section 8.5(a), the system shall demonstrate in writing to the Department that it has conducted a material evaluation, including the evaluation in section 8.7(a), to identify the initial number of lead service lines in its distribution system, and shall provide the Department with the system's schedule for replacing annually at least 7 percent of the initial number of lead service lines in its distribution system.

(2) Within 12 months after a system exceeds the lead action level in sampling referred to in section 8.5(a), and every 12 months thereafter, the system shall demonstrate to the Department in writing that the system has either:

1. (i) Replaced in the previous 12 months at least 7 percent of the initial lead service lines (or a greater number of lines specified by the Department under section 8.5(e)) in its distribution system, or (ii) Conducted sampling which demonstrates that the lead concentration in all service line samples from an individual line(s), taken pursuant to section 8.7(b)(3), is less than or equal to 0.015 mg/L. In such cases, the total number of lines replaced and/or which meet the criteria in section 8.5(c) shall equal at least 7 percent of the initial number of lead lines identified under section 8.10(a) (or the percentage specified by the Department under section 8.5(e)).

(3) The annual letter submitted to the Department under section 8.10(e)(2) shall contain the following information:

1. (i) The number of lead service lines scheduled to be replaced during the previous year of the system's replacement schedule;
   1. (ii) The number and location of each lead service line replaced during the previous year of the system's replacement schedule;
      1. (iii) If measured, the water lead concentration and location of each lead service line sampled, the sampling method, and the date of sampling.

(4) Any system which collects lead service line samples following partial lead service line replacement required by section 8.5 shall report the results to the Department within the first ten days of the month following the month in which the system receives the laboratory results, or as specified by the Department. Departments, at their discretion may eliminate this requirement to report these monitoring results. Systems shall also report any additional information as specified by the Department, and in a time and manner prescribed by the Department, to verify that all partial lead service line replacement activities have taken place.

(f) Public education program reporting requirements.

(1) Any water system that is subject to the public education requirements in section 8.6 shall, within ten days after the end of each period in which the system is required to perform public education tasks in accordance with section 8.6(c), send written documentation to the Department that contains:

1. (i) A demonstration that the system has delivered the public education materials that meet the content requirements in sections 8.6(a) and 8.6(b) and the delivery requirements in section 8.6(c); and (ii) A list of all the newspapers, radio stations, television stations, and facilities and organizations to which the system delivered public education materials during the period in which the system was required to perform public education tasks.

(2) Unless required by the Department, a system that previously has submitted the information required by section 8.10(f)(1)(ii) need not resubmit the information, as long as there have been no changes in the distribution list and the system certifies that the public education materials were distributed to the same list submitted previously.

(g) Any system which collects sampling data in addition to that required by Article 8 shall report the results to the Department within the first ten days following the end of the applicable monitoring period under sections 8.7, 8.8 and 8.9 during which the samples are collected.

(h) A water system is not required to report the 90th percentile lead and copper concentrations measured from among all lead and copper tap water samples collected during each monitoring period, as required by section 8.10(a)(1)(iv) if:

(1) The Department has previously notified the water system that it will calculate the water system's 90th percentile lead and copper concentrations, based on the lead and copper tap results submitted pursuant to section 8.10(h)(2)(i), and has specified a date before the end of the applicable monitoring period by which the system must provide the results of lead and copper tap water samples;

(2) The system has provided the following information to the Department by the date specified in section 8.10(h)(1):

1. (i) The results of all tap samples for lead and copper including the location of each site and the criteria under section 8.7(a)(3), (4), (5), (6), and/or (7) under which the site was selected for the system's sampling pool, pursuant to section 8.10(a)(1) (i); and (ii) An identification of sampling sites utilized during the current monitoring period that were not sampled during previous monitoring periods, and an explanation why sampling sites have changed; and

(3) The Department has provided the results of the 90th percentile lead and copper calculations, in writing, to the water system before the end of the monitoring period.

8.11 Recordkeeping Requirements

Any system subject to the requirements of Article 8 shall retain on its premises original records of all sampling data and analyses, reports, surveys, letters, evaluations, schedules, Department determinations, and any other information required by Article 8. Each water system shall retain the records required by Article 8 for no fewer than 12 years.

8.12 Prohibition on Use of Lead Pipes, Solder, and Flux

Article 9 Consumer Notification [Eff. 09/30/2007]

9.1 Consumer Confidence Reports

9.1.1 Introduction

(a) Section 9.1 establishes the minimum requirements for the content of annual reports that community water systems must deliver to their customers. These reports must contain information on the quality of the water delivered by the systems and characterize the risks (if any) from exposure to contaminants detected in the drinking water in an accurate and understandable manner.

(b) Notwithstanding the provisions of section 1.2, section 9.1 applies only to community water systems.

(c) For the purpose of this subpart, customers are defined as billing units or service connections to which water is delivered by a community water system.

(d) For the purpose of this subpart, detected means: at or above the levels prescribed by section 10.2.1 for inorganic contaminants, at or above the levels prescribed by section 6.2.5(a)(7) for the contaminants listed in section 2.1(a), at or above the levels prescribed by sections 10.3.2 and 10.3.3 for the contaminants listed in section 2.1(c), at or above the levels prescribed by section 10.7.2(b)(3)(iv) for the contaminants or contaminant groups listed in sections 2.4, 7.6, 7.7, and 7.8, and at or above the levels prescribed by section 10.4.1(c) for radioactive contaminants.

9.1.2 Important Dates

(a) Each existing community water system must deliver reports by July 1 every year. Each report must contain data, as prescribed in section 9.1.3(d)(3), collected during, or prior to, the previous calendar year.

(b) A new community water system must deliver its first report by July 1 of the year after its first full calendar year in operation and annually thereafter.

(c) A community water system that sells water to another community water system must deliver the applicable information required in section 9.1.3 to the buyer system:

(1) No later than April 1 annually or (2) On a date mutually agreed upon by the seller and the purchaser, and specifically included in a contract between the parties.

(d) The Certification of Delivery must be delivered to the division by July 1 of each year. The certification must contain information as prescribed in section 9.1.5(c).

9.1.3 Content of the Reports

(a) Each community water system must provide to its customers an annual report that contains the information specified in sections 9.1.3 and 9.1.4.

(b) Information on the source of the water delivered:

(1) Each report must identify the source(s) of the water delivered by the community water system by providing information on:

1. (i) The type of the water: e.g., surface water, groundwater; and (ii) The commonly used name (if any) and location of the body (or bodies) of water.

(2) If a source water assessment has been completed, the report must notify consumers of the availability of this information and the means to obtain it. In addition, systems are encouraged to highlight in the report significant sources of contamination in the source water area if they have readily available information. Where a system has received a source water assessment from the Department, the report must include a brief summary of the system's susceptibility to potential sources of contamination, using language provided by the Department or written by the operator.

(c) Definitions.

(1) Each report must include the following definitions:

1. (i) Maximum Contaminant Level Goal or MCLG: The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.
   1. (ii) Maximum Contaminant Level or MCL: The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology.

(2) A report for a community water system operating under a variance or an exemption issued under Article 4 - Variances and Exemptions must include the following definition: Variances and Exemptions: Department permission not to meet an MCL or a treatment technique under certain conditions.

(3) A report that contains data on contaminants that the Department regulates using any of the following terms must include the applicable definitions:

1. (i) Treatment Technique: A required process intended to reduce the level of a contaminant in drinking water.
   1. (ii) Action Level: The concentration of a contaminant, which if exceeded, triggers treatment or other requirements that a water system must follow.
      1. (iii) Maximum residual disinfectant level goal or MRDLG: The level of a drinking water disinfectant below which, there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.
         1. (iv) Maximum residual disinfectant level or MRDL: The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.

(d) Information on Detected Contaminants.

(1) This section 9.1.3(d) specifies the requirements for information to be included in each report for contaminants subject to mandatory monitoring (except Cryptosporidium). It applies to:

1. (i) Contaminants subject to a MCL, action level, maximum residual disinfectant level, or treatment technique (regulated contaminants).
   1. (ii) Unregulated contaminants for which monitoring is required by section 6.4; and

(2) The data relating to these contaminants must be displayed in one table or in several adjacent tables. Any additional monitoring results, which a community water system chooses to include in its report, must be displayed separately.

(3) The data must be derived from data collected to comply with EPA and Department monitoring and analytical requirements during the previous calendar year except that:

1. (i) Where a system is allowed to monitor for regulated contaminants less often than once a year, the table(s) must include the date and results of the most recent sampling and the report must include a brief statement indicating that the data presented in the report are from the most recent testing done in accordance with the regulations. No data older than 5 years need be included.
   1. (ii) Results of monitoring in compliance with the Information Collection Rule 9-1 (ICR)(40 CFR 141.142, July 1, 2000 and 40 CFR 141.143, July 1, 1996) need only be included for 5 years from the date of last sample or until any of the detected contaminants becomes regulated and subject to routine monitoring requirements, whichever comes first.

9-1 The Information Collection Rule was effective from August 14, 1996 until December 31, 2000.

(4) For detected regulated contaminants (listed in Table 9-1), the table(s) must contain:

1. (i) The MCL for that contaminant expressed as a number equal to or greater than 1.0 (as provided in Table 9-1);
   1. (ii) The MCLG for that contaminant expressed in the same units as the MCL;
      1. (iii) If there is no MCL for a detected contaminant, the table must indicate that there is a treatment technique, or specify the action level, applicable to that contaminant, and the report must include the definitions for treatment technique and/or action level, as appropriate, specified in section 9.1.3(c)(3);
         1. (iv) For contaminants subject to an MCL, except turbidity and total coliforms, the highest contaminant level used to determine compliance with a CPDWR and the range of detected levels, as follows:
         2. (A) When compliance with the MCL is determined annually or less frequently: The highest detected level at any sampling point and the range of detected levels expressed in the same units as the MCL.
         3. (B) When compliance with the MCL is determined by calculating a running annual average 9-2 of all samples taken at a monitoring location: the highest average of any of the monitoring locations and the range of all monitoring locations expressed in the same units as the MCL. For the MCLs for TTHM and HAA5 in section 2.4, systems must include the highest locational running annual average for TTHM and HAA5 and the range of individual sample results for all monitoring locations expressed in the same units as the MCL. If more than one (1) location exceeds the TTHM or HAA5 MCL, the system must include the locational running annual averages for all locations that exceed the MCL.

9-2 When the regulations allow rounding of results to determine compliance with the MCL, rounding should be done prior to multiplying the results by the factor listed in Table 9-1.

1. (C) When compliance with the MCL is determined on a system-wide basis by calculating a running annual average of all samples at all monitoring locations: the average and range of detection expressed in the same units as the MCL. The system is required to include individual sample results for the IDSE conducted under section 7.7 when determining the range of TTHM and HAA5 results to be reported in the annual Consumer Confidence Report for the calendar year that the IDSE samples were taken.
   1. (v) For turbidity. When it is reported pursuant to Article 7: The highest single measurement and the lowest monthly percentage of samples meeting the turbidity limits specified in Article 7 for the filtration technology being used. The report should include an explanation of the reasons for measuring turbidity;
      1. (vi) For lead and copper: the 90th percentile value of the most recent round of sampling and the number of sampling sites exceeding the action level;
         1. (vii) For total coliform:
         2. (A) The highest monthly number of positive samples for systems collecting fewer than 40 samples per month; or (B) The highest monthly percentage of positive samples for systems collecting at least 40 samples per month;
         3. (viii) For fecal coliform: The total number of positive samples; and (ix) The likely source(s) of detected contaminants to the best of the operator's knowledge. Specific information regarding contaminants may be available in sanitary surveys and source water assessments, and should be used when available to the operator. If the operator lacks specific information on the likely source, the report must include one or more of the typical sources for that contaminant listed in Table 9-1 that is most applicable to the system.

(5) If a community water system distributes water to its customers from multiple hydraulically independent distribution systems that are fed by different raw water sources, the table should contain a separate column for each service area and the report should identify each separate distribution system. Alternatively, systems could produce separate reports tailored to include data for each service area.

(6) The table(s) must clearly identify any data indicating violations of MCLs, MRDLs, or treatment techniques, and the report must contain a clear and readily understandable explanation of the violation including: the length of the violation, the potential adverse health effects, and actions taken by the system to address the violation. To describe the potential health effects, the system must use the relevant language of Table 9-1.

(7) For detected unregulated contaminants for which monitoring is required (except Cryptosporidium), the table(s) must contain the average and range at which the contaminant was detected. The report may include a brief explanation of the reasons for monitoring for unregulated contaminants.

(e) Information on Cryptosporidium, radon, and other contaminants:

(1) If the system has performed any monitoring for Cryptosporidium, including monitoring performed to satisfy the requirements of the Information Collection Rule 9-3 (ICR) (40 CFR 141.143, July 1, 1996), which indicates that Cryptosporidium may be present in the source water or the finished water, the report must include: 9-3 See Article 9.3(d)(3)(ii) for reporting requirements under the ICR.

1. (i) A summary of the results of the monitoring; and (ii) An explanation of the significance of the results.

(2) If the system has performed any monitoring for radon which indicates that radon may be present in the finished water, the report must include:

1. (i) The results of the monitoring; and (ii) An explanation of the significance of the results.

(3) If the system has performed additional monitoring which indicates the presence of other contaminants in the finished water, the Department strongly encourages systems to report any results, which may indicate a health concern. To determine if results may indicate a health concern, the Department recommends that systems find out if the EPA has proposed a National Primary Drinking Water Regulation or issued a health advisory for that contaminant by calling the Safe Drinking Water Hotline (800-426-4791). The Department considers detects above a proposed MCL or health advisory level to indicate possible health concerns. For such contaminants, the Department recommends that the report include:

1. (i) The results of the monitoring; and (ii) An explanation of the significance of the results noting the existence of a health advisory or a proposed regulation.

(f) In addition to the requirements of section 9.1.3(d)(6), the report must note any violation of the Colorado Primary Drinking Water Regulations that occurred during the year covered by the report of a requirement listed below, and include a clear and readily understandable explanation of the violation, any potential adverse health effects, and the steps the system has taken to correct the violation.

(1) Monitoring and reporting of compliance data;

(2) Filtration and disinfection prescribed by Article 7. For systems which have failed to install adequate filtration or disinfection equipment or processes, or have had a failure of such equipment or processes which constitutes a violation, the report must include the following language as part of the explanation of potential adverse health effects: “Inadequately treated water may contain disease-causing organisms. These organisms include bacteria, viruses, and parasites, which can cause symptoms such as nausea, cramps, diarrhea, and associated headaches.”

(3) For systems that fail to take one or more actions for lead and copper control prescribed by Article 8, the report must include the applicable language of Table 9-1 for lead, copper, or both;

(4) For systems that violate the requirements of section 6.2.2 for acrylamide and epichlorohydrin certification, the report must include the relevant language from Table 9-1;

(5) Recordkeeping of compliance data;

(6) Special monitoring requirements prescribed by section 6.4, Unregulated Contaminant Monitoring, and section 6.1.6(m), Special Monitoring for Sodium; and (7) Violation of the terms of a variance, an exemption, or an administrative or judicial order.

(g) If a system is operating under the terms of a variance or an exemption issued under Article 4, the report must contain:

(1) An explanation of the reasons for the variance or exemption;

(2) The date on which the variance or exemption was issued;

(3) A brief status report on the steps the system is taking to install treatment, find alternative sources of water, or otherwise comply with the terms and schedules of the variance or exemption; and (4) A notice of any opportunity for public input in the review, or renewal, of the variance or exemption.

(h) Systems required to comply with Article 13 Groundwater Rule.

(1) Any groundwater system that receives notice from the Department of a significant deficiency or notice from a laboratory of a fecal indicator-positive groundwater source sample that is not invalidated by the Department under section 13.3(d) must inform its customers of any significant deficiency that is uncorrected at the time of the next report or of any fecal indicator-positive groundwater source sample in the next report. The system must continue to inform the public annually until the Department determines that particular significant deficiency is corrected or the fecal contamination in the groundwater source is addressed under section 11.4 or 13.4(a). Each report must include the following elements.

1. (i) The nature of the particular significant deficiency or the source of the fecal contamination (if the source is known) and the date the significant deficiency was identified by the Department or the dates of the fecal indicator-positive groundwater source samples;
   1. (ii) If the fecal contamination in the groundwater source has been addressed under section 13.4(a) and the date of such action;
      1. (iii) For each significant deficiency or fecal contamination in the groundwater source that has not been addressed under section 11.4 or 13.4(a), the Department-approved plan and schedule for correction, including interim measures, progress to date, and any interim measures completed; and (iv) If the system receives notice of a fecal indicator-positive groundwater source sample that is not invalidated by the Department under section 13.3(d), the potential health effects using the health effects language of Table 9-1.

(2) If directed by the Department, a system with significant deficiencies that have been corrected before the next report is issued must inform its customers of the significant deficiency, how the deficiency was corrected, and the date of correction under section 9.1.3(h)(1).

(i) Additional Information (1) The report must contain a brief explanation regarding contaminants which may reasonably be expected to be found in drinking water including bottled water. This explanation may include the language of Sections 9.1.3(h)(1) (i) through (iii), or systems may use their own comparable language. The report also must include the language of section 9.1.3(h) (1)(iv).

1. (i) The sources of drinking water (both tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally occurring minerals and, in some cases, radioactive material, and can pick up substances resulting from the presence of animals or from human activity.
   1. (ii) Contaminants that may be present in source water include:
      1. (A) Microbial contaminants, such as viruses and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
         1. (B) Inorganic contaminants, such as salts and metals, which can be naturally- occurring or result from urban storm water runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming.
         2. (C) Pesticides and herbicides, which may come from a variety of sources such as agriculture, urban storm water runoff, and residential uses.
         3. (D) Organic chemical contaminants, including synthetic and volatile organic chemicals, which are by-products of industrial processes and petroleum production, and also may come from gas stations, urban storm water runoff, and septic systems.
         4. (E) Radioactive contaminants, which can be naturally occurring or be the result of oil and gas production and mining activities.
         5. (iii) In order to ensure that tap water is safe to drink, the Department prescribes regulations which limit the amount of certain contaminants in water provided by public water systems. The Food and Drug Administration regulations establish limits for contaminants in bottled water that must provide the same protection for public health.
         6. (iv) Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the Environmental Protection Agency's Safe Drinking Water Hotline (800-426-4791).

(2) The report must include the telephone number of the owner, operator, or designee of the community water system as a source of additional information concerning the report.

(3) In communities with a large proportion of non-English speaking residents, as determined by the Department, the report must contain information in the appropriate language(s) regarding the importance of the report or contain a telephone number or address where such residents may contact the system to obtain a translated copy of the report or assistance in the appropriate language.

(4) The report must include information (e.g., time and place of regularly scheduled board meetings) about opportunities for public participation in decisions that may affect the quality of the water.

(5) The systems may include such additional information, as they deem necessary for public education consistent with, and not detracting from, the purpose of the report.

9.1.4 Required Additional Health Information

(a) All reports must prominently display the following language: Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. EPA/CDC guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline (800-426-4791).

(b) Beginning in the report due by July 1, 2002, a system that detects arsenic above 0.005 mg/L and up to and including 0.010 mg/L:

(1) Must include in its report a short informational statement about arsenic, using language such as: While your drinking water meets the EPA's standard for arsenic, it does contain low levels of arsenic. The EPA's standard balances the current understanding of arsenic's possible health effects against the costs of removing arsenic from drinking water. The EPA continues to research the health effects of low levels of arsenic, which is a mineral known to cause cancer in humans at high concentrations and is linked to other health effects such as skin damage and circulatory problems.

(2) May write its own educational statement, but only in consultation with the Department.

(c) A system which detects nitrate at levels above 5 mg/L, but below the MCL:

(1) Must include a short informational statement about the impacts of nitrate on children using language such as: Nitrate in drinking water at levels above 10 ppm is a health risk for infants of less than six months of age. High nitrate levels in drinking water can cause blue baby syndrome. Nitrate levels may rise quickly for short periods of time because of rainfall or agricultural activity. If you are caring for an infant you should ask advice from your health care provider.

(2) May write its own educational statement, but only in consultation with the Department.

(d) Systems which detect lead above the action level in more than 5%, and up to and including 10%, of homes sampled:

(1) Must include a short informational statement about the special impact of lead on children using language such as: Infants and young children are typically more vulnerable to lead in drinking water than the general population. It is possible that lead levels at your home may be higher than at other homes in the community as a result of materials used in your home's plumbing. If you are concerned about elevated lead levels in your home's water, you may wish to have your water tested and flush your tap for 30 seconds to 2 minutes before using tap water. Additional information is available from the Safe Drinking Water Hotline (800-426-4791).

(2) May write its own educational statement, but only in consultation with the Department.

(e) Beginning in the report due by July 1, 2002 and ending January 22, 2006, a community water system that detects arsenic above 0.010 mg/L and up to and including 0.05 mg/L must include the arsenic health effects language prescribed by Table 9-1.

9.1.5 Report Delivery and Recordkeeping

(a) Except as provided in section 9.1.5(g), each community water system must mail or otherwise directly deliver one copy of the report to each customer.

(b) The system must make a good faith effort to reach consumers who do not get water bills, using means recommended by the Department. The Department expects that an adequate good faith effort will be tailored to the consumers who are served by the system but are not bill-paying customers, such as renters or workers. A good faith effort to reach consumers would include a mix of methods appropriate to the particular system such as: Posting the reports on the Internet; mailing to postal patrons in metropolitan areas; advertising the availability of the report in the news media; publication in a local newspaper; posting in public places such as cafeterias or lunch rooms of public buildings; delivery of multiple copies for distribution by single-billed customers such as apartment buildings or large private employers; or delivery to community organizations.

(c) No later than the date the system is required to distribute the report to its customers (April 1 for wholesale customers and July 1 for retail customers), each community water system must mail a copy of the report to the Department with a certification that the report has been distributed to customers, and that the information is correct and consistent with the compliance monitoring data previously submitted to the Department.

(d) No later than the date the system is required to distribute the report to its customers, each community water system must deliver the report to any other agency or clearinghouse identified by the Department.

(e) Each community water system must make its reports available to the public upon request.

(f) Each community water system serving 100,000 or more persons must post its current year's report to a publicly accessible site on the Internet.

(g) The requirement of section 9.1.5(a) for community water systems serving fewer than 10,000 persons may be waived if the system complies with all the requirements of 9.1.5(g)(1)(i)-(iii).

(1) Such systems must:

1. (i) Publish the reports in one or more local newspapers serving the area in which the system is located; and (ii) Inform the customers that the reports will not be mailed, either in the newspapers in which the reports are published or by other means approved by the Department; and (iii) Make the reports available to the public upon request.

(2) Systems serving 500 or fewer persons may forego the requirements of Sections 9.1.5(g)(1)(i) and (ii) if they provide notice at least once per year to their customers by mail, door-to- door delivery or by posting in an appropriate location that the report is available upon request.

(h) Any system subject to section 9.1 must retain copies of its Consumer Confidence Report for no less than 3 years.

Table 9-1 Table of Regulated Contaminants

9.2 Public Notification

9.2.1 Introduction

Public water systems must comply with the requirements in section 9.2 in accordance with section 1.4, unless otherwise noted.

(a) Each owner or operator of a public water system (community water systems, non-transient non- community water systems, and transient non-community water systems) must give notice for all violations of the Colorado Primary Drinking Water Regulations (CPDWR) and for other situations, as listed in Table 9-2. The term “CPDWR violations” is used in section 9.2 to include violations of the maximum contaminant level (MCL), maximum residual disinfection level (MRDL), treatment technique (TT), monitoring requirements, and testing procedures. Table 9-7 identifies the tier assignment for each specific violation or situation requiring a public notice. Table 9-2 Violation Categories and Other Situations Requiring a Public Notice (b) Public notice requirements are divided into three tiers, to take into account the seriousness of the violation or situation and any potential adverse health effects that may be involved. The tier to which it is assigned determines the public notice requirements for each violation or situation listed in Table 9-2. Table 9-3 provides the definition of each tier. Table 9-7 identifies the tier assignment for each specific violation or situation.

Table 9-3 Definition of Public Notice Tiers (1) Tier 1 public notice Required for CPDWR violations and situations with significant potential to have serious adverse effects on human health as a result of short-term exposure.

(2) Tier 2 public notice Required for all other CPDWR violations and situations with potential to have serious adverse effects on human health.

(3) Tier 3 public notice Required for all other CPDWR violations and situations not included in Tier 1 and Tier 2.

(c) Customer Notification.

(1) Each public water system must provide public notice to persons served by the water system, in accordance with this section 9.2. Public water systems that sell or otherwise provide drinking water to other public water systems (i.e., to consecutive systems) are required to give public notice to the owner or operator of the consecutive system; the consecutive system is responsible for providing public notice to the persons it serves.

(2) If a public water system has a violation in a portion of the distribution system that is physically or hydraulically isolated from other parts of the distribution system, the Department may allow the system to limit distribution of the public notice to only persons served by that portion of the system which is out of compliance. Permission by the Department for limiting distribution of the notice must be granted in writing.

(3) A copy of the notice must also be sent to the Department, in accordance with the requirements under section 1.6.4(d).

9.2.2 Tier 1 Public Notice Form, Manner, and Frequency of Notice

(a) Table 9-4 lists the violation categories and other situations requiring a Tier 1 public notice. Table 9-7 identifies the tier assignment for each specific violation or situation. Table 9-4 Violation Categories and Other Situations Requiring a Tier 1 Public Notice (1) Violation of the MCL for total coliforms when fecal coliform or E. coli are present in the water distribution system (as specified in Table 2-4(4)

1. (b)), or when the water system fails to test for fecal coliforms or E. coli when any repeat sample tests positive for coliform (as specified in section 5.1.2(a));

(2) Violation of the MCL for nitrate, nitrite, or total nitrate and nitrite, as listed in Table 2-3, or when the water system fails to take a confirmation sample within 24 hours of the system's receipt of the first sample showing an exceedance of the nitrate or nitrite MCL, as specified in section 6.1.3(b)

(3) Exceedance of the nitrate MCL by non-community water systems, where permitted to exceed the MCL by the Department under section 6.1.1(c) as required by 9.2.9.

(4) Violation of the MRDL for chlorine dioxide, as listed in Table 2-6(3)

1. when one or more samples taken in the distribution system the day following an exceedance of the MRDL at the entrance of the distribution system exceed the MRDL, or when the water system does not take the required samples in the distribution system, as specified in section 7.5.3(c)(2)(i)-(ii);

(5) [Reserved];

(6) Violation of the Surface Water Treatment Rule (SWTR – section 7.1), or Enhanced Surface Water Treatment Rule (ESWTR – section 7.2), or Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR – section 7.3) treatment technique requirement resulting from a single exceedance of the maximum allowable turbidity limit (as identified in Table 9- 7), where the Department determines after consultation that a Tier 1 notice is required or where consultation does not take place within 24 hours after the system learns of the violation;

(7) Occurrence of a waterborne disease outbreak, as defined in section 1.5.2(129), or other waterborne emergency (such as a failure or significant interruption in key water treatment processes, a natural disaster that disrupts the water supply or distribution system, or a chemical spill or unexpected loading of possible pathogens into the source water that significantly increases the potential for drinking water contamination);

(8) Detection of E. coli, enterococci, or coliphage in source water samples as specified in section 13.3(a) and section 13.3(b).

(9) Other violations or situations with significant potential to have serious adverse effects on human health as a result of short- term exposure, as determined by the Department either in Colorado Primary Drinking Water Regulations or on a case-by-case basis.

(b) For a Tier 1 public notice public water systems must:

(1) Provide a public notice as soon as practical but no later than 24 hours after the system learns of the violation;

(2) Initiate consultation with the Department as soon as practical, but no later than 24 hours after the public water system learns of the violation or situation, to determine additional public notice requirements; and (3) Comply with any additional public notification requirements (including any repeat notices or direction on the duration of the posted notices) that are established as a result of the consultation with the Department. Such requirements may include the timing, form, manner, frequency, and content of repeat notices (if any) and other actions designed to reach all persons served.

(c) Public water systems must provide the notice within 24 hours in a form and manner reasonably calculated to reach all persons served. The form and manner used by the public water system are to fit the specific situation, but must be designed to reach residential, transient, and non-transient users of the water system. In order to reach all persons served, water systems are to use one or more of the following forms of direct delivery:

(1) Appropriate broadcast media, including radio, television and a phone call to each customer using a reverse 911 system, where available;

(2) Hand delivery of the notice to persons served by the water system; or (3) Another direct delivery method approved in writing by the Department.

(d) In addition, the Department may require posting of the notice in conspicuous locations throughout the area served by the water system.

9.2.3 Tier 2 Public Notice Form, Manner, and Frequency of Notice

(a) Table 9-5 lists the violation categories and other situations requiring a Tier 2 public notice. Table 9-7 identifies the tier assignment for each specific violation or situation. Table 9-5 Violation Categories and Other Situations Requiring a Tier 2 Public Notice (1) All violations of the MCL, MRDL, and treatment technique requirements, except where a Tier 1 notice is required under section 9.2.2(a) or where the Department determines that a Tier 1 notice is required;

(2) Violations of the monitoring and testing procedure requirements, where the Department determines that a Tier 2 rather than a Tier 3 public notice is required, taking into account potential health impacts and persistence of the violation; and (3) Failure to comply with the terms and conditions of any variance or exemption in place.

(4) Failure to take corrective action or failure to maintain at least 4-log treatment of viruses before or at the first customer under sections

1. 11.4 or 13.4(a).

(b) Tier 2 public notice requirements.

(1) Public water systems must provide the public notice as soon as practical, but no later than 30 days after the system learns of the violation. If the public notice is posted, the notice must remain in place for as long as the violation or situation persists, but in no case for less than seven days, even if the violation or situation is resolved. The Department may, in appropriate circumstances, allow additional time for the initial notice of up to three months from the date the system learns of the violation. It is not appropriate for the Department to grant an extension to the 30-day deadline for any unresolved violation or to allow across-the-board extensions by rule or policy for other violations or situations requiring a Tier 2 public notice. Extensions granted by the Department must be in writing.

(2) The public water system must repeat the notice every three months as long as the violation or situation persists, unless the Department determines that appropriate circumstances warrant a different repeat notice frequency. In no circumstance may the repeat notice be given less frequently than once per year. Less frequent repeat notice for an MCL violation under Article 5 or a treatment technique violation under sections 7.1, 7.2 or 7.3, or across-the-board reductions in the repeat notice frequency for other ongoing violations requiring a Tier 2 repeat notice, is prohibited. Any determination allowing repeat notices to be given less frequently than once every three months must be in writing by the Department.

(3) For the turbidity violations specified in this section 9.2.3(b)(3), public water systems must consult with the Department as soon as practical but no later than 24 hours after the public water system learns of the violation, to determine whether a Tier 1 public notice under section 9.2.2(a) is required to protect public health. When consultation does not take place within the 24-hour period, the water system must distribute a Tier 1 notice of the violation within the next 24 hours (i.e., no later than 48 hours after the system learns of the violation), following the requirements under section 9.2.2(b) and (c). Consultation with the Department is required for a violation of an Article 7 treatment technique requirement resulting from a single exceedance of the maximum allowable turbidity limit.

(c) Public water systems must provide the initial public notice and any repeat notices in a form and manner that is reasonably calculated to reach persons served in the required time period. The form and manner of the public notice may vary based on the specific situation and type of water system, but it must at a minimum meet the following requirements:

(1) Unless directed otherwise by the Department in writing, community water systems must provide notice by:

1. (i) Mail or other direct delivery to each customer receiving a bill and to other service connections to which water is delivered by the public water system; and (ii) Any other method reasonably calculated to reach other persons, regularly served by the system, if they would not normally be reached by the notice required in section 9.2.3(c)(1)(i). Such persons may include those who do not pay water bills or do not have service connection addresses (e.g., house renters, apartment dwellers, university students, nursing home patients, prison inmates, etc.). Other methods may include: Publication in a local newspaper; delivery of multiple copies for distribution by customers that provide their drinking water to others (e.g., apartment building owners or large private employers); posting in public places served by the system or on the Internet; or delivery to community organizations.

(2) Unless directed otherwise by the Department in writing, non-community water systems must provide notice by:

1. (i) Posting the notice in conspicuous locations throughout the distribution system frequented by persons served by the system, or by mail or direct delivery to each customer and service connection (where known); and (ii) Any other method reasonably calculated to reach other persons served by the system if they would not normally be reached by the notice, required in section 9.2.3(c) (2)(i). Such persons may include those served who may not see a posted notice because the posted notice is not in a location they routinely pass by. Other methods may include: publication in a local newspaper or newsletter distributed to customers; use of E-mail to notify employees or students; or, delivery of multiple copies in central locations (e.g., community centers).

9.2.4 Tier 3 Public Notice Form, Manner, and Frequency of Notice

(a) Table 9-6 lists the violation categories and other situations requiring a Tier 3 public notice. Table 9-7 identifies the tier assignment for each specific violation or situation. Table 9-6 Violation Categories and Other Situations Requiring a Tier 3 Public Notice (1) Monitoring violations under the Colorado Primary Drinking Water Regulations, except where a Tier 1 notice is required under section 9.2.2(a) or where the Department determines that a Tier 2 notice is required;

(2) Failure to comply with a testing procedure established in the Colorado Primary Drinking Water Regulations, except where a Tier 1 notice is required under section 9.2.2(a)) or where the Department determines that a Tier 2 notice is required;

(3) Operation under a variance or exemption granted under Article 4;

(4) Availability of unregulated contaminant monitoring results, as required under section 9.2.7; and (5) Exceedance of the fluoride secondary maximum contaminant level (SMCL), as required under section 9.2.8.

(6) Failure to meet the monitoring requirements of section 13.3(a)-(f) or 13.4(b)(3).

(b) Tier 3 public notice requirements.

(1) Public water systems must provide the public notice not later than one year after the public water system learns of the violation or situation or begins operating under a variance or exemption. Following the initial notice, the public water system must repeat the notice annually for as long as the violation, variance, exemption, or other situation persists. If the public notice is posted, the notice must remain in place for as long as the violation, variance, exemption, or other situation persists, but in no case less than seven days (even if the violation or situation is resolved).

(2) Instead of individual Tier 3 public notices, a public water system may use an annual report detailing all violations and situations that occurred during the previous twelve months, as long as the timing requirements of section 9.2.4(b)(1) are met.

(c) Public water systems must provide the initial notice and any repeat notices in a form and manner that is reasonably calculated to reach persons served in the required time period. The form and manner of the public notice may vary based on the specific situation and type of water system, but it must at a minimum meet the following requirements:

(1) Unless directed otherwise by the Department in writing, community water systems must provide notice by:

1. (i) Mail or other direct delivery to each customer receiving a bill and to other service connections to which water is delivered by the public water system; and (ii) Any other method reasonably calculated to reach other persons regularly served by the system if they would not normally be reached by the notice required in section 9.2.4(c)(1)(i). Such persons may include those who do not pay water bills or do not have service connection addresses (e.g., house renters, apartment dwellers, university students, nursing home patients, prison inmates, etc.). Other methods may include: Publication in a local newspaper; delivery of multiple copies for distribution by customers that provide their drinking water to others (e.g., apartment building owners or large private employers); posting in public places or on the Internet; or delivery to community organizations.

(2) Unless directed otherwise by the Department in writing, non-community water systems must provide notice by:

1. (i) Posting the notice in conspicuous locations throughout the distribution system frequented by persons served by the system, or by mail or direct delivery to each customer and service connection (where known); and (ii) Any other method reasonably calculated to reach other persons served by the system if they would not normally be reached by the notice required in section 9.2.4(c)(2) (i). Such persons may include those who may not see a posted notice because the notice is not in a location they routinely pass by. Other methods may include: Publication in a local newspaper or newsletter distributed to customers; use of E- mail to notify employees or students; or, delivery of multiple copies in central locations (e.g., community centers).

(d) For community water systems, the Consumer Confidence Report (CCR) required under section 9.1 may be used as a vehicle for the initial Tier 3 public notice and all required repeat notices, as long as:

(1) The CCR is provided to persons served, no later than 12 months after the system learns of the violation or situation as required under section 9.2.4(b);

(2) The Tier 3 notice contained in the CCR follows the content requirements under section 9.2.5; and (3) The CCR is distributed following the delivery requirements under section 9.2.4(c).

9.2.5 Content of the Public Notice

(a) When a public water system violates a CPDWR or has a situation requiring public notification, each public notice must include the following elements:

(1) A description of the violation or situation, including the contaminant(s) of concern, and (as applicable) the contaminant level(s);

(2) When the violation or situation occurred;

(3) Any potential adverse health effects from the violation or situation, including the standard language under section 9.2.5(d)(1) or (d)(2), whichever is applicable;

(4) The population at risk, including sub-populations particularly vulnerable if exposed to the contaminant in their drinking water;

(5) Whether alternative water supplies should be used;

(6) What actions consumers should take, including when they should seek medical help, if known;

(7) What the system is doing to correct the violation or situation;

(8) When the water system expects to return to compliance or resolve the situation;

(9) The name, business address, and phone number of the water system owner, operator, or designee of the public water system as a source of additional information concerning the notice; and (10) A statement to encourage the notice recipient to distribute the public notice to other persons served, using the standard language under section 9.2.5(d)(3), where applicable.

(b) When a public water system is operating under a variance or exemption each public notice must include the following elements:

(1) If a public water system has been granted a variance or an exemption, the public notice must contain:

1. (i) An explanation of the reasons for the variance or exemption;
   1. (ii) The date on which the variance or exemption was issued;
      1. (iii) A brief status report on the steps the system is taking to install treatment, find alternative sources of water, or otherwise comply with the terms and schedules of the variance or exemption; and (iv) A notice of any opportunity for public input in the review of the variance or exemption.

(2) If a public water system violates the conditions of a variance or exemption, the public notice must contain the ten elements listed in section 9.2.5(a).

(c) Presentation of the public notice.

(1) Each public notice required by section 9.2:

1. (i) Must be displayed in a conspicuous way when printed or posted;
   1. (ii) Must not contain overly technical language or very small print;
      1. (iii) Must not be formatted in a way that defeats the purpose of the notice;
         1. (iv) Must not contain language that nullifies the purpose of the notice.

(2) Each public notice required by section 9.2 must comply with multilingual requirements, as follows:

1. (i) For public water systems serving a large proportion of non-English speaking consumers, as determined by the Department, the public notice must contain information in the appropriate language(s) regarding the importance of the notice or contain a telephone number or address where persons served may contact the water system to obtain a translated copy of the notice or to request assistance in the appropriate language.
   1. (ii) In cases where the Department has not determined what constitutes a large proportion of non-English speaking consumers, the public water system must include in the public notice the same information as in section 9.2.5(c)(2)(i), where appropriate to reach a large proportion of non-English speaking persons served by the water system.

(d) Public water systems are required to include the following standard language in their public notice:

(1) Public water systems must include in each public notice the health effects language specified in Table 9-8 corresponding to each MCL, MRDL, and treatment technique violation listed in Table 9-7, and for each violation of a condition of a variance or exemption.

(2) Public water systems must include the following language in their notice, including the language necessary to fill in the blanks, for all monitoring and testing procedure violations listed in Table 9-7:

(3) The statement: We are required to monitor your drinking water for specific contaminants on a regular basis. Results of regular monitoring are an indicator of whether or not your drinking water meets health standards. During [compliance period], we ” did not monitor or test” or ” did not complete all monitoring or testing” for [contaminant(s)], and therefore cannot be sure of the quality of your drinking water during that time.

(4) Public water systems must include in their notice the following language (where applicable): Please share this information with all the other people who drink this water, especially those who may not have received this notice directly (for example, people in apartments, nursing homes, schools, and businesses). You can do this by posting this notice in a public place or distributing copies by hand or mail.

9.2.6 Notice to New Billing Units or New Customers

(a) Community water systems must give a copy of the most recent public notice for any continuing violation, the existence of a variance or exemption, or other ongoing situations requiring a public notice to all new billing units or new customers prior to or at the time service begins.

(b) Non-community water systems must continuously post the public notice in conspicuous locations in order to inform new consumers of any continuing violation, variance or exemption, or other situation requiring a public notice for as long as the violation, variance, exemption, or other situation persists.

9.2.7 Special Notice of the Availability of Unregulated Contaminant Monitoring Results (a) The owner or operator of a community water system or non-transient, non-community water system required to monitor under section 6.4, must notify persons served by the system of the availability of the results of such sampling no later than 12 months after the monitoring results are known.

(b) The form and manner of the public notice must follow the requirements for a Tier 3 public notice prescribed in Sections 9.2.4(c), (d)(1), and (d)(3). The notice must also identify a person and provide the telephone number to contact for information on the monitoring results.

9.2.8 Special Notice for Exceedance of the SMCL for Fluoride

(a) Community water systems that exceed the fluoride secondary maximum contaminant level (SMCL) of 2.0 mg/L as specified in Table 3-1 (determined by the last single sample taken in accordance with section6.1.5), but do not exceed the maximum contaminant level (MCL) of 4.0 mg/L for fluoride (as specified in Table 2-3), must provide the public notice in section 9.2.8(c) to persons served. Public notice must be provided as soon as practical but no later than 12 months from the day the water system learns of the exceedance. A copy of the notice must also be sent to all new billing units and new customers at the time service begins and to the Department public health officer. The public water system must repeat the notice at least annually for as long as the SMCL is exceeded. If the public notice is posted, the notice must remain in place for as long as the SMCL is exceeded, but in no case less than seven days (even if the exceedance is eliminated). On a case-by-case basis, the Department may require an initial notice sooner than 12 months and repeat notices more frequently than annually.

(b) The form and manner of the public notice (including repeat notices) must follow the requirements for a Tier 3 public notice in section 9.2.4(c) and (d)(1) and (d)(3).

(c) The notice must contain the following mandatory language, including the language necessary to fill in the blanks:

This is an alert about your drinking water and a cosmetic dental problem that might affect children under nine years of age. At low levels, fluoride can help prevent cavities, but children drinking water containing more than 2 milligrams per liter (mg/L) of fluoride may develop cosmetic discoloration of their permanent teeth (dental fluorosis). The drinking water provided by your community water system [ name ] has a fluoride concentration of [ insert value ] mg/L. Dental fluorosis, in its moderate or severe forms, may result in a brown staining and/or pitting of the permanent teeth. This problem occurs only in developing teeth, before they erupt from the gums. Children under nine years of age should be provided with alternative sources of drinking water or water that has been treated to remove the fluoride to avoid the possibility of staining and pitting of their permanent teeth. You may also want to contact your dentist about proper use by young children of fluoride-containing products. Older children and adults may safely drink the water.

Drinking water containing more than 4 mg/L of fluoride (the Colorado Department of Public Health and Environment’s drinking water standard) can increase your risk of developing bone disease. Your drinking water does not contain more than 4 mg/L of fluoride, but we're required to notify you when we discover that the fluoride levels in your drinking water exceed 2 mg/L because of this cosmetic dental problem.

For more information, please call [name of water system contact] of [name of community water system] at [phone number]. Some home water treatment units are also available to remove fluoride from drinking water. To learn more about available home water treatment units, you may call NSF International at 1-877-8-NSF-HELP.''

9.2.9 Special Notice for Nitrate

A special notice is required for nitrate exceedances above the MCL by non-community water systems when granted permission by the Department under section 6.1.1(c).

(a) The owner or operator of a non-community water system granted permission by the Department under section 6.1.1(c) to exceed the nitrate MCL must provide notice to persons served according to the requirements for a Tier 1 notice under section 9.2.2(a) and (b).

(b) Non-community water systems granted permission by the Department to exceed the nitrate MCL under section 6.1(b)(2) must provide continuous posting of the fact that nitrate levels exceed 10 mg/L and the potential health effects of exposure, according to the requirements for Tier 1 notice delivery under section 9.2.2(c) and the content requirements under section 9.2.5.

9.2.10 Notice by the Department on Behalf of the Public Water System

(a) The Department may give the notice required by section 9.2 on behalf of the owner and operator of the public water system in accordance with the requirements of section 9.2.

(b) Notwithstanding section 9.2.10(a), the owner or operator of the public water system remains responsible for ensuring that the requirements of section 9.2 are met.

9.2.11 Special notice for repeated failure to conduct monitoring of the source water for Cryptosporidium and for failure to determine bin classification or mean Cryptosporidium level.

(a) When is the special notice for repeated failure to monitor to be given? The owner or operator of a community or non-community water system that is required to monitor source water under section 7.4.2 must notify persons served by the water system that monitoring has not been completed as specified no later than 30 days after the system has failed to collect any 3 months of monitoring as specified in section 7.4.2(c). The notice must be repeated as specified in section 9.2.3.

(b) When is the special notice for failure to determine bin classification or mean Cryptosporidium level to be given? The owner or operator of a community or non-community water system that is required to determine a bin classification under section 7.4.9 must notify persons served by the water system that the determination has not been made as required no later than 30 days after the system has failed report the determination as specified in section 7.4.9(e). The notice must be repeated as specified in section 9.2.3. The notice is not required if the system is complying with a Department-approved schedule to address the violation.

(c) What is the form and manner of the special notice? The form and manner of the public notice must follow the requirements for a Tier 2 public notice prescribed in section 9.2.3. The public notice must be presented as required in section 9.2.5.

(d) What mandatory language must be contained in the special notice? The notice must contain the following language, including the language necessary to fill in the blanks.

(1) The special notice for repeated failure to conduct monitoring must contain the following language:

1. We are required to monitor the source of your drinking water for Cryptosporidium. Results of the monitoring are to be used to determine whether water treatment at the (treatment plant name) is sufficient to adequately remove Cryptosporidium from your drinking water. We are required to complete this monitoring and make this determination by (required bin determination date). We “did not monitor or test” or “did not complete all monitoring or testing” on schedule and, therefore, we may not be able to determine by he required date what treatment modifications, if any, must be made to ensure adequate Cryptosporidium removal. Missing this deadline may, in turn, jeopardize our ability to have the required treatment modifications, if any, completed by the deadline required, (date).
   1. For more information, please call (name of water system contact) of (name of water system) at (phone number).

(2) The special notice for failure to determine bin classification must contain the following language:

1. We are required to monitor the source of your drinking water for Cryptosporidium in order to determine by (date) whether water treatment at the (treatment plant name) is sufficient to adequately remove Cryptosporidium from your drinking water. We have not made this determination by the required date. Our failure to do this may jeopardize our ability to have the required treatment modifications, if any, completed by the required deadline of (date). For more information, please call (name of water system contact) of (name of water system) at (phone number).

(3) Each special notice must also include a description of what the system is doing to correct the violation and when the system expects to return to compliance or resolve the situation.

9.2.12 Special notice for groundwater systems with a waiver request that the Department has determined satisfies the criteria of section 13.2(d)

(a) The groundwater system must notify persons served by the system in a manner prescribed by the Department no later than 30 days after the system has received notice of the Department’s determination.

(b) The groundwater system must present the notice in accordance with the requirements under section 9.2.5(c).

(c) The Department may require the groundwater system to provide notice to new billing units or new customers in accordance with the requirements under section 9.2.6. Table 9-7 Table of CPDWR Violations and Other Situations Requiring Public Notice 1 Table 9-8 Table of Standard Health Effects Language for Public Notification

9.2.13 List of Acronyms Used in Public Notification Regulation

CCR Consumer Confidence Report CPDWR Colorado Primary Drinking Water Regulation CWS Community Water System DBP Disinfection Byproduct ESWTR Enhanced Surface Water Treatment Rule GWR Groundwater Rule HPC Heterotrophic Plate Count IOC Inorganic Chemical LCR Lead and Copper Rule MCL Maximum Contaminant Level MCLG Maximum Contaminant Level Goal MRDL Maximum Residual Disinfectant Level MRDLG Maximum Residual Disinfectant Level Goal NCWS Non-Community Water System NTNCWS Non-transient, Non- Community Water System NTU Nephelometric Turbidity Unit PN Public Notification PWS Public Water System SDWA U.S. Safe Drinking Water Act SMCL Secondary Maximum Contaminant Level SOC Synthetic Organic Chemical SWTR Surface Water Treatment Rule TCR Total Coliform Rule TT Treatment Technique TNCWS Transient, Non- Community Water System VOC Volatile Organic Chemical Article 10 Analytical Requirements and Laboratory Certification

10.1 Bacteriological Analytical Requirements

10.1.1 Total Coliform Testing Requirements

(a) Public water systems must conduct total coliform analyses in accordance with one of the analytical methods in the following table.

Table 10-1 Total Coliform Analytical Methods

10.1.2 Fecal Coliform Testing Requirements

(a) Public water systems must conduct fecal coliform analysis in accordance with the following procedure. When the MTF Technique or Presence-Absence (PA) Coliform Test is used to test for total coliforms, shake the lactose-positive presumptive tube or P-A vigorously and transfer the growth with a sterile 3-mm loop or sterile applicator stick into brilliant green lactose bile broth and EC Medium to determine the presence of total and fecal coliforms, respectively. For EPA- approved analytical methods which use a membrane filter, transfer the total coliform-positive culture by one of the following methods: remove the membrane containing the total coliform colonies from the substrate with a sterile forceps and carefully curl and insert the membrane into a tube of EC Medium (the laboratory may first remove a small portion of selected colonies for verification), swab the entire membrane filter surface with a sterile cotton swab and transfer the inoculum to EC Medium (do not leave the cotton swab in the EC Medium), or inoculate individual total coliform-positive colonies into EC Medium. Gently shake the inoculated tubes of EC Medium to insure adequate mixing and incubate in a water bath at 44.5 ± 0.2 °C for 24 ± 2 hours. Gas production of any amount in the inner fermentation tube of the EC Medium indicates a positive fecal coliform test. The preparation of EC Medium is described in method 9221e (paragraph 1a) in the American Public Health Association’s “ Standard Methods For The Examination Of Water And Wastewater, ” 18th edition (1992), 19th edition (1995), and 20th edition (1998), The cited method in any one of these editions may be used. Public water systems need only determine the presence or absence of fecal coliforms; a determination of fecal coliform density is not required.

Table 10-2 Fecal Coliform Analytical Methods Organism Methodology 1 Methods 2 Fecal Coliform 9221 E Fecal Coliforms Procedure3 . Fecal Coliform Filter 9222 D Procedure The procedures shall be done in accordance with the documents listed below. These documents can be obtained from the Department’s Water Quality Control Division or the Laboratory Services Division. 1 Except where noted, all methods refer to the American Public Health Association’s “Standard Methods for the Examination of Water and Wastewater,” 18th edition (1992), 19th edition (1995), and 20th edition (1998). The cited method in any one of these editions may be used.

2 The time from sample collection to initiation of analysis may not exceed 8 hours. Systems must hold samples below 10 deg. C during transit.

3 A-1 Broth may be held up to three months in a tightly closed screw cap tube at 4 deg. C.

10.1.3 Escherichia coli Testing Requirements

(a) Public water systems must conduct analysis of Escherichia coli in accordance with one of the following analytical methods:

(1) EC Medium supplemented with 50 µg/ml of 4-methylumbelliferyl-beta-d-glucuronide (MUG) (final concentration), as described in Method 9222G in the American Public Health’s “ Standard Methods For The Examination Of Water And Wastewater ,” 19th edition (1995) and 20th edition (1998). Either edition may be used. Alternatively, the 18th edition

1. (1992) may be used if at least 10 mL of EC Medium as described in section 10.1.2(a) is supplemented with 50 µg/mL before autoclaving. The inner inverted fermentation tube may be omitted. If the 18th edition is used apply the procedure in section 10.1.2(a) for transferring a total coliform-positive culture to EC Medium supplemented with MUG, incubate the tube at 44.5 ± 0.2°C for 24 ± 2 hours, and then observe fluorescence with an ultraviolet light (366 nm) in the dark. If fluorescence is visible, E. coli are present; or

(2) Nutrient agar supplemented with 100 µg/mL 4-methylumbelliferyl-beta-d-glucuronide (MUG) (final concentration), as described in Method 9222G in the American Public Health’s “ Standard Methods For The Examination Of Water And Wastewater ,” 19th edition (1995) and 20th edition (1998). Either edition may be used for determining if a total coliform- positive samples, as determined by a membrane filter technique, contains E. coli . Alternatively, the 18th edition (1992) may be used if the membrane filter containing a total coliform-positive colony(ies) is transferred to nutrient agar, as described in Method 9221B(paragraph 3) of “Standard Methods for the Examination of Water and Wastewater” (18th edition), supplemented with 100 µg/mL (final concentration) of MUG. If the 18th edition is used, incubate the agar plate at 35 °C for 4 hours and then observe the colony(ies) under ultraviolet light (366 nm) in the dark for fluorescence. If fluorescence is visible, E. coli are present.

(3) Minimal Medium ONPG-MUG (MMO-MUG) test, as set forth in the article "National Field Evaluation Of A Defined Substrate Method For The Simultaneous Detection Of Total Coliforms And Escherichia coli From Drinking Water: Comparison With Presence- Absence Techniques" (Edberg et al.), Applied and Environmental Microbiology, Vol. 55,

1. pp. 1003-1008, April 1989. (Note: The Autoanalysis Colilert System is an MMO-MUG test). If the MMO-MUG test is total coliform-positive after a 24-hour incubation, test the medium for fluorescence with a 366-nm ultraviolet light (preferably with a 6-watt lamp) in the dark. If fluorescence is observed, the sample is E. coli -positive. If fluorescence is questionable (cannot be definitively read) after 24 hours incubation, incubate the culture for an additional four hours (but not to exceed 28 hours total), and again test the medium for fluorescence. The MMO-MUG Test with hepes buffer in lieu of phosphate buffer is the only approved formulation for the detection of E. coli.

(4) The Colisure Test, a description which is cited in footnote 9 to Table 10-1.

(5) The membrane filter method with MI agar adaptation, a description of which is cited in footnote 6 to Table 10-1.

(6) E*Colite ® Test, a description of which is cited in footnote 10 to Table 10-1.

(7) M-Coliblue24 ® Test, a description of which is cited in footnote 11 to Table 10-1.

(8) Readycult ® Coliforms 100 Presence/Absence test, a description of which is cited in footnote 13 to Table 10-1.

(9) Membrane Filter Technique using Chromocult Coliform Agar, a description of which is cited in footnote 14 to Table 10-1.

(10) Colitag®, a description of which is cited in footnote 15 to Table 10-1.

(b) As an option to section 10.1.3(a)(3), a system with a total coliform-positive, MUG-negative, MMO- MUG test may further analyze the culture for the presence of E. coli by transferring a 0.1 ml, 28- hour MMO-MUG culture to EC Medium + MUG with a pipet. The formulation and incubation conditions of EC Medium + MUG, and observation of the results are described in section 10.1.3(a)(1).

(c) E. coli in Source Water. Systems must use methods for enumeration of E. coli in source water approved in 40 CFR 136.3 (a).

(1) The time from sample collection to initiation of analysis may not exceed 30 hours.

(2) Systems must maintain samples between 0°C and 10°C during storage and transit to the laboratory.

10.1.4 Cryptosporidium Testing Requirements

(a) Cryptosporidium. Systems must analyze for Cryptosporidium using either Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA, 2005, United States Environmental Protection Agency, EPA-815-R-05-002 or Method 1622: Cryptosporidium in Water by Filtration/IMS/FA, 2005, United States Environmental Protection Agency, EPA-815-R-05-001.

(1) Systems must analyze at least a 10 L sample or a packed pellet volume of at least 2 mL as generated by the methods listed in paragraph (a) of this section. Systems unable to process a 10 L sample must analyze as much sample volume as can be filtered by two filters approved by EPA for the methods listed in paragraph (a) of this section, up to a packed pellet volume of at least 2 mL.

(2) Matrix spike (MS)

1. (A) Matrix spike (MS) samples, as required by the methods in paragraph (a)(1) of this section, must be spiked and filtered by a laboratory approved for Cryptosporidium analysis under Section 10.10.
   1. (B) If the volume of the MS sample is greater than 10 L, the system may filter all but 10 L of the MS sample in the field, and ship the filtered sample and the remaining 10 L of source water to the laboratory. In this case, the laboratory must spike the remaining 10 L of water and filter it through the filter used to collect the balance of the sample in the field.

(3) Flow cytometer-counted spiking suspensions must be used for MS samples and ongoing precision and recovery (OPR) samples.

10.1.5 Groundwater Source Testing Requirements

(a) A groundwater system subject to the source water monitoring requirements of section 13.3(a) must collect a standard sample volume of at least 100 mL for fecal indicator analysis regardless of the fecal indicator or analytical method used.

(b) A groundwater system must analyze all groundwater source samples collected under section 13.3(a) using one of the analytical methods listed in Table 10-3 for the presence of E. coli, enterococci, or coliphage.

Table 10-3 Analytical Methods for Source Water Monitoring 1 Methodology Method Citation Fecal indicator E. coli 3 2 Colilert 9223 B . 3 2 Colisure 9223 B . Membrane Filter Method 4 EPA Method 1604 with MI Agar . 5 .

1. m-ColiBlue24 Test . 6 .
   1. E*Colite Test . 7 2 EC-MUG 9221 F . 7 2 NA-MUG 9222 G . . .

Enterococci Multiple-Tube Technique 2 9230B . Membrane Filter 2 9230C Technique . Membrane Filter EPA Method 1600 8 Technique . 9 .

1. Enterolert . . .

Coliphage Two-Step Enrichment 10 EPA Method 1601 Presence-Absence Procedure . Single Agar Layer 11 EPA Method 1602 Procedure Analyses must be conducted in accordance with the documents listed below. 1 The time from sample collection to initiation of analysis may not exceed 30 hours. The groundwater system is encouraged but is not required to hold samples below 10°C during transit. 2 Methods are described in Standard Methods for the Examination of Water and Wastewater 20th edition (1998) and copies may be obtained from the American Public Health Association, 1015 Fifteenth Street, NW., Washington, DC 20005-2605. 3 Medium is available through IDEXX Laboratories, Inc., One IDEXX Drive, Westbrook, Maine 04092. 4 EPA Method 1604: Total Coliforms and Escherichia coli in Water by Membrane Filtration Using a Simultaneous Detection Technique (MI Medium); September 2002, EPA 821-R-02-024. Method is available at http://www.epa.gov/nerlcwww/1604sp02.pdf or from EPA's Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW., Washington, DC 20460. 5 A description of the m-ColiBlue24 Test, “Total Coliforms and E. coli Membrane Filtration Method with m-ColiBlue24® Broth,'' Method No. 10029 Revision 2, August 17, 1999, is available from Hach Company, 100 Dayton Ave., Ames, IA 50010 or from EPA's Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW., Washington, DC 20460. 6 A description of the E*Colite Test, “Charm E*Colite Presence/Absence Test for Detection and Identification of Coliform Bacteria and Escherichia coli in Drinking Water” , January 9, 1998, is available from Charm Sciences, Inc., 659 Andover St., Lawrence, MA 01843-1032 or from EPA's Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW., Washington, DC 20460. 7 EC-MUG (Method 9221F) or NA-MUG (Method 9222G) can be used for E. coli testing step as described in §141.21(f)(6)(i) or (ii) after use of Standard Methods 9221 B, 9221 D, 9222 B, or 9222 C. 8 EPA Method 1600: Enterococci in W ater by Membrane Filtration Using membrane-Enterococcus Indoxyl-β-D-Glucoside Agar (mEI) EPA 821-R-02-022 (September 2002) is an approved variation of Standard Method 9230C. The method is available at http://www.epa.gov/nerlcwww/1600sp02.pdf or from EPA’s Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW., Washington, DC 20560. The holding time and temperature for groundwater samples are specified in footnote 1 above, rather than as specified in Section 8 of EPA Method 1600.

9 Medium is available through IDEXX Laboratories, Inc., One IDEXX Drive, Westbrook, Maine 04092. Preparation and use of the medium is set forth in the article “Evaluation of Enterolert for Enumeration of Enterococci in Recreational Waters,'' by Budnick, G.E., Howard, R.T., and Mayo, D.R., 1996, Applied and Environmental Microbiology, 62:3881-3884. 10 EPA Method 1601: Male-specific (F+) and Somatic Coliphage in Water by Two-step Enrichment Procedure; April 2001, EPA 821- R-01-030. Method is available at http://www.epa.gov/nerlcwww/1601ap01.pdf or from EPA's Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW., Washington, DC 20460.

11 EPA Method 1602: Male-specific (F+) and Somatic Coliphage in Water by Single Agar Layer (SAL) Procedure; April 2001, EPA 821-R-01-029. Method is available at http://www.epa.gov/nerlcwww/1602ap01.pdf or from EPA's Water Resource Center (RC- 4100T), 1200 Pennsylvania Avenue, NW., Washington, DC 20460.

10.2 Inorganic Chemical Contaminants Analytical Requirements

10.2.1 Cited Detection Limits for Inorganic Chemical Contaminants

Cited detection limits for each analytical method and MCLs for each inorganic chemical contaminant are the following:

Table 10-4 Cited Detection Limits For Inorganic Chemical Contaminant Analytical Methods

10.2.2 Inorganic Chemical Contaminants Analysis

(a) Analysis for the following contaminants shall be conducted in accordance with the methods in the following table. Criteria for analyzing arsenic, barium, beryllium, cadmium, calcium, chromium, copper, lead, nickel, selenium, sodium, and thallium with digestion or directly without digestion, and other analytical test procedures are contained in “Technical Notes on Drinking Water Methods,” EPA-600/R-94-173, October 1994.

Table 10-5 Inorganic Chemical Contaminant Analytical Methods (b) Sample collection for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, nitrate, nitrite, selenium, and thallium under this section shall be conducted using the sample preservation, container, and maximum holding time procedures specified in the table below:

Table 10-6 Sample Collection Requirements for Inorganic Chemical Contaminants Contaminant 1 2 3 Preservative Container Time Antimony HNO 3 P or G 6 months Arsenic Conc HNO 3 to pH < 2. P or G 6 months Asbestos 4°C P or G 4 48 hours Barium HNO 3 P or G 6 months Beryllium HNO 3 P or G 6 months Cadmium HNO 3 P or G 6 months Chromium HNO 3 P or G 6 months Cyanide 4°C, NaOH P or G 14 days Fluoride None P or G 1 month Mercury HNO 3 P or G 28 days Nickel HNO 3 P or G 6 months Nitrate 4°C P or G 5 48 hours Nitrate-Nitrite 6 H 2 SO 4 P or G 28 days Nitrite 4°C P or G 48 hours Selenium HNO 3 P or G 6 months Thallium HNO 3 P or G 6 months 1 For cyanide determinations samples must be adjusted with sodium hydroxide to pH 12 at the time off collection. When chilling is indicated the sample must be shipped and stored at 4 °C or less. Acidification of nitrate or metals samples may be with a concentrated acid or a dilute (50% by volume) solution of the applicable concentrated acid. Acidification of samples for metals analysis is encouraged and allowed at the laboratory rather than at the time of sampling provided the shipping time and other instructions in section 8.3 of EPA Methods 200.7 or 200.8 or 200.9 are followed. 2 P = plastic, hard or soft; G = glass, hard or soft.

3 In all cases samples should be analyzed as soon after collection as possible. Follow additional (if any) information on preservation, containers or holding times that is specified in method. 4 Instructions for containers, preservation procedures and holding times as specified in EPA Method 100.2 must be adhered to for all compliance analyses including those conducted with EPA Method 100.1. 5 If the sample is chlorinated, the holding time for an unacidified sample kept at 4 °C is extended to 14 days. 6 Nitrate-Nitrite refers to a measurement of total nitrate.

10.3 Organic Chemical Analytical Requirements

Analyses for the organic chemical contaminants in this section shall be conducted using the following EPA methods or their equivalent as approved by EPA.

10.3.1 Organic Chemical Contaminants Analysis

(a) Analysis for organic chemical contaminants shall be conducted using the following methods, as further specified in Table 10-7.

EPA Method 508A and 515.1 are in “Methods for the Determination of Organic Compounds in Drinking Water,” EPA/600/4-88-039, December 1988, Revised, July 1991. EPA Methods 547, 550 and 550.1 are in “Methods for the Determination of Organic Compounds in Drinking Water -- Supplement I,” EPA/600-4-90-020, July 1990. EPA Methods 548.1, 549.1, 552.1 and 555 are in “Methods for the Determination of Organic Compounds in Drinking Water -- Supplement II,” EPA/600/R-92-129, August 1992. EPA Methods 502.2, 504.1, 505, 506, 507, 508, 508.1, 515.2, 524.2, 525.2, 531.1, 551.1 and 552.2 are in “Methods for the Determination of Organic Compounds in Drinking Water -- Supplement III,” EPA/600/R-95-131, August 1995.

EPA Method 1613 is titled "Tetra-through Octa-Chlorinated Dioxins and Furans by Isotope- Dilution HRGC/HRMS," EPA/821-B-94-005, October 1994.

Method 6651 shall be followed in accordance with the American Public Health Association’s “Standard Methods for the Examination of Water and Wastewater,” 18th edition (1992), 19th edition (1995), and 20th edition (1998). Any of these three editions may be used. Method 6610 shall be followed in accordance with the American Public Health Association’s “Standard Methods for the Examination of Water and Wastewater,” (18th Edition Supplement) (1994), 19th edition (1995), and 20th edition (1998). Any of these three editions may be used. Other required analytical test procedures germane to the conduct of these analyses are contained in “Technical Notes on Drinking Water Methods,” EPA/600/R-94-173, October 1994. EPA Methods 515.3 and 549.2 ASTM Method D 5317-93 is available in the Annual Book of ASTM Standards , (1999), Vol. 11.02, ASTM International, or in any edition published after 1993. EPA Method 515.4 is in "Determination of Chlorinated Acids in Drinking Water by Liquid-Liquid Microextraction, Derivatization and Fast Gas Chromatography with Electron Capture Detection," Revision 1.0, April 2000, EPA /815/B-00/001.

The Syngenta AG-625, "Atrazine in Drinking Water by Immunoassay", February 2001, is available from Syngenta Crop Protection, Inc.

EPA Method 531.2 is in "Measurement of N-methylcarbamoyloximes and N-methylcarbamates in Water by Direct Aqueous Injection HPLC with Postcolumn Derivatization," Revision 1.0, EPA 815/B/01/002, September 2001.

Table 10-7 Organic Chemical Contaminants Analytical Methods . Contaminant EPA METHOD Standard methods (1) Benzene 502.2, 524.2 .

(2) Carbon tetrachloride 502.2, 524.2, 551.1 .

(3) Chlorobenzene 502.2, 524.2 .

(4) 1,2-Dichlorobenzene 502.2, 524.2 .

(5) 1,4-Dichlorobenzene 502.2, 524.2 .

(6) 1,2-Dichloroethane 502.2, 524.2 .

(7) cis-Dichloroethylene 502.2, 524.2 .

(8) trans-Dichloroethylene 502.2, 524.2 .

(9) Dichloromethane 502.2, 524.2 .

(10) 1,2-Dichloropropane 502.2, 524.2 .

(11) Ethylbenzene 502.2, 524.2 .

(12) Styrene 502.2, 524.2 .

(13) Tetrachloroethylene 502.2, 524.2, 551.1 .

(14) 1,1,1-Trichloroethane 502.2, 524.2, 551.1 .

(15) Trichloroethylene 502.2, 524.2, 551.1 .

(16) Toluene 502.2, 524.2 .

(17) 1,2,4-Trichlorobenzene. 502.2, 524.2 .

(18) 1,1-Dichloroethylene 502.2, 524.2 .

(19) 1,1,2-Trichloroethane 502.2, 524.2, 551.1 .

(20) Vinyl chloride 502.2, 524.2 .

(21) Xylenes (total) 502.2, 524.2 .

(22) 2,3,7,8-TCDD (dioxin) 1613 .

(23) 3 515.1, 515.2, 515.3, .

1. 2,4-D (as acid, salts 515.4, 555 and esters)

(24) 3 515.1, 515.2, 515.3, .

1. 2,4,5-TP (Silvex)
   1. 515.4, 555

(25) 1 505, 507, 508.1, 525.2, .

1. Alachlor
   1. 551.1

(26) 1 505, 507, 508.1, 525.2, .

1. Atrazine
   1. 551.1

(27) Benzo(a)pyrene 525.2, 550, 550.1 .

(28) Carbofuran 531.1, 531.2 6610 (29) Chlordane 505, 508, 508.1, 525.2 .

(30) Dalapon 515.1, 515.3, 515.4, .

1. 552.1, 552.2

(31) Di(2-ethylhexyl)adipate 506, 525.2 .

(32) Di(2- 506, 525.2 .

1. ethylhexyl)phthalate.

(33) Dibromochloropropane 504.1, 551.1 .

1. (DBCP)

(34) 3 515.1, 515.2, 515.3, .

1. Dinoseb 515.4, 555

(35) Diquat 549.2 .

(36) Endothall 548.1 .

(37) Endrin 505, 508, 508.1, 525.2, .

1. 551.1

(38) Ethylene dibromide 504.1, 551.1 .

1. (EDB)

(39) Glyphosate 547 6651 (40) Heptachlor 505, 508, 508.1, 525.2, .

1. 551.1

(41) Heptachlor Epoxide 505, 508, 508.1, 525.2, .

1. 551.1

(42) Hexachlorobenzene 505, 508, 508.1, 525.2, .

1. 551.1

(43) Hexachlorocyclopentadie 505, 508, 508.1, 525.2, .

1. ne 551.1

(44) Lindane 505, 508, 508.1, 525.2, .

1. 551.1

(46) Methoxychlor 505, 508, 508.1, 525.2, .

1. 551.1

(46) Oxamyl 531.1, 531.2 6610 (47) 2 508A .

1. PCBs (as decachlorobiphenyl)

(48) 2 508, 508.1, 525.2, 505 .

1. PCBs (as Aroclors)

(49) Pentachlorophenol 515.1, 515.2, 515.3, .

1. 515.4, 525.2, 555

(50) 3 515.1, 515.2, 515.3, .

1. Picloram 515.4, 555

(51) 1 505, 507, 508.1, 525.2, .

1. Simazine
   1. 551.1

(52) Toxaphene 505, 508, 508.1, 525.2 .

(53) Total Trihalomethanes 502.2, 524.2, 551.1 .

1 Substitution of the detector specified in EPA Methods 505, 507, 508 or 508.1 for the purpose of achieving lower detection limits is allowed as follows. Either an electron capture or nitrogen phosphorous detector may be used provided all regulatory requirements and quality control criteria are met.

2 PCBs are qualitatively identified as Aroclors and measured for compliance purposes as decachlorobiphenyl. Users of EPA Method 505 may have more difficulty in achieving the required detection limits than users of EPA Methods 508.1, 525.2 or 508. 3 Accurate determination of the chlorinated esters requires hydrolysis of the sample as described in EPA Methods 515.1, 515.2, 515.3, 515.4 and 555 and ASTM Method D5317-93.

10.3.2 PCB Analysis

(a) Analysis for PCBs shall be conducted as follows using the methods in section 10.3.1(a):

(1) Each system which monitors for PCBs shall analyze each sample using either EPA Methods 508.1, 525.2, 508 or 505. Users of EPA Method 505 may have more difficulty in achieving the required Aroclor detection limits than users of EPA Methods 508.1, 525.2 or 508.

(2) If PCBs (as one of seven Aroclors) are detected (as designated in this paragraph) in any sample analyzed using EPA Methods 505, 508 or 525.2, the system shall reanalyze the sample using Method 508A to quantitate PCBs (as decachlorobiphenyl). Table 10-8 Cited Detection Limit for Aroclor Aroclor Cited Detection Limit (mg/L)

1016 0.00008 1221 0.02 1232 0.0005 1242 0.0003 1248 0.0001 1254 0.0001 1260 0.0002 (3) Compliance with the PCB MCL shall be determined based upon the quantitative results of analyses using EPA Method 508A.

10.3.3 Cited Detection for Organic Chemical Contaminants

(a) Detection as used in this section shall be defined as greater than or equal to the following concentrations for each chemical contaminant.

Table 10-9 Cited Detection Limits for Organic Chemical Contaminants Contaminant Cited Detection Limit (mg/L)

Alachlor 0.0002 Aldicarb 0.0005 Aldicarb sulfoxide 0.0005 Aldicarb sulfone 0.0008 Atrazine 0.0001 Benzo[a]pyrene 0.00002 Carbofuran 0.0009 Chlordane 0.0002 Dalapon 0.001 1,2-Dibromo-3- 0.00002 chloropropane (DBCP)

Di(2-ethylhexyl)adipate 0.0006 Di(2-ethylhexyl)phthalate 0.0006 Dinoseb 0.0002 Diquat 0.0004 2,4-D 0.0001 Endothall 0.009 Endrin 0.00001 Ethylene dibromide 0.00001 (EDB)

Glyphosate 0.006 Heptachlor 0.00004 Heptachlor epoxide 0.00002 Hexachlorobenzene 0.0001 Hexachlorocyclopentadie 0.0001 ne Lindane 0.00002 Methoxychlor 0.0001 Oxamyl 0.002 Picloram 0.0001 Polychlorinated biphenyls 0.0001 (PCBs) (as decachlorobiphenyl)

Pentachlorophenol 0.00004 Simazine 0.00007 Toxaphene 0.001 2,3,7,8-TCDD (Dioxin) 0.000000005 2,4,5-TP (Silvex) 0.0002

10.4 Radionuclide Analytical Requirements

10.4.1 Sampling and Analytical Requirements

(a) Analysis for the following Chemical contaminants shall be conducted to determine compliance with section 2.6 in accordance with the methods in the following table or their equivalent as determined by EPA in accordance with sections 10.9.1(a) and (b). Table 10-10 Sampling and Analytical Requirements for Radionuclides (b) When the identification and measurement of radionuclides other than those listed in section 2.6 is required, the following references are to be used, except in cases where alternative methods have been approved in accordance with sections 10.9.1(a) and (b).

(1) “Procedures for Radiochemical Analysis of Nuclear Reactor Aqueous Solutions,” H. L. Krieger and S. Gold, EPA-R4-73-014, USEPA, May 1973.

(2) “HASL Procedure Manual,” John H. Harley. HASL 300, ERDA Health and Safety Laboratory, New York, NY (1973).

10.4.2 Cited Detection Limits for Radionuclides

(a) For the purpose of monitoring radioactivity concentrations in drinking water, the required sensitivity of the radioanalysis is defined in terms of a detection limit. The detection limit shall be that concentration which can be counted with a precision of p lus or minus 100 percent at the 95 percent confidence level (1.96σ where σ is the standard deviation of the net counting rate of the sample).

(1) To determine compliance with section 2.6 the detection limit shall not exceed the concentrations in Table 10-11 to this section 10.4.2(a). Table 10-11 Cited Detection Limits for Gross Alpha Particle Activity, Radium 226, Radium 228, and Uranium . Contaminant Cited Detection limit (1) Gross alpha particle 3 pCi/L.

1. activity

(2) Radium 226 1 pCi/L.

(3) Radium 228 1 pCi/L.

(4) Uranium 1 µg/L (2) To determine compliance with section 6.5.1(d) the detection limits shall not exceed the concentrations listed in Table 10-12 to this section 10.4.2(a). Table 10-12 Cited Detection Limits for Man-Made Beta Particle and Photon Emitters . Radionuclide Cited Detection limit (1) Tritium 1,000 pCi/L (2) Strontium–89 10 pCi/L (3) Strontium–90 2 pCi/L (4) Iodine–131 1 pCi/L (5) Cesium–134 10 pCi/L (6) Gross beta 4 pCi/L.

(7) Other radionuclides 1/10 of the regulatory limit.

10.5 Turbidity and Disinfectant Analytical Requirements

10.5.1 Turbidity, Heterotrophic Plate Count (HPC) and Disinfectant Testing Requirements (a) Only the analytical method(s) specified in this section 10.5, or otherwise approved by EPA, may be used to demonstrate compliance with sections 7.1.1, 7.1.2 and 7.1.3. Measurements for pH, turbidity, temperature and residual disinfectant concentrations must be conducted by a operator that has been certified in accordance with Regulation 100, 5 C.C.R. 100-3-2. Measurement for HPC must be conducted by a laboratory certified by the Department to do such analysis. Until laboratory certification criteria are developed for the analysis of HPC, any laboratory certified for total coliforms analysis by the Department is deemed certified for fecal coliforms and HPC analysis. The following procedures shall be conducted in accordance with the publications listed in section 10.5. Copies of the Indigo Method as set forth in the article "Determination of Ozone in Water by the Indigo Method" (Bader and Hoigne), may be obtained from Ozone Science & Engineering, Pergamon Press Ltd.

(1) Public water systems must conduct analysis of pH and temperature in accordance with one of the methods listed in Table 10-5. Public water systems must conduct analysis of heterotrophic bacteria and turbidity in accordance with one of the following analytical methods and by using analytical test procedures contained in the U.S. Environmental Protection Agency’s “Technical Notes on Drinking Water Methods,” EPA-600/R-94-173, October 1994.

Table 10-13 Turbidity and HPC Analytical Methods (2) Public water systems must measure residual disinfectant concentrations with one of the analytical methods in the following table. Except for the method for ozone residuals, the disinfectant residual methods are contained in the the American Public Health Association’s “ Standard Methods for the Examination of Water and Wastewater, ” 18 th edition (1992), 19 th edition (1995), and 20 th edition (1998). The cited methods published in any of these three editions may be used. The ozone method, 4500-O3 B, is contained in both the 18 th and 19 th editions. Either edition may be used. If approved by the Department, residual disinfectant concentrations for free chlorine and combined chlorine also may be measured by using DPD colorimetric test kits. Free and total chlorine residuals may be measured continuously by adapting a specified chlorine residual method for use with a continuous monitoring instrument provided the chemistry, accuracy, and precision are consistent with the referenced method. Instruments used for continuous monitoring must be verified with a grab sample measurement at least every five days, or with a protocol approved by the Department. Table 10-14 Disinfectant Residual Analytical Methods

10.6 Calculating Contact Time (CT) Values

10.6.1 CT Calculations

(a) The total inactivation ratio is determined based on the CT99.9 values in Tables 10-14 through 10-21 of this section 10.6, as appropriate. The parameters necessary to determine the total inactivation ratio must be monitored as follows:

(1) The temperature of the disinfected water must be measured at least once per day at each residual disinfectant concentration sampling point.

(2) If the system uses chlorine, the pH of the disinfected water must be measured at least once per day at each chlorine residual disinfectant concentration sampling point.

(3) The disinfectant contact time(s) ("T") must be determined for each day during peak hourly flow.

1. (i) Disinfectant contact time in pipelines must be calculated based on "plug flow" by dividing the internal volume of the pipe by the maximum hourly flow rate through that pipe. Disinfectant contact time within mixing basins and storage reservoirs must be determined by tracer studies or an equivalent demonstration or by baffling factor estimates.

(4) The residual disinfectant concentration(s) ("C") of the water before or at the first customer must be measured each day during peak hourly flow.

Table 10-15 CT Values (CT ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free

1. 99.9

Chlorine at 0.5°C or Lower 1 Free Residual (mg/L) pH . .

. ≤ 6.0 6.5 7.0 ≤ 0.4 137 163 195

0.6 141 168 200

0.8 145 172 205

1.0 148 176 210

1.2 152 180 215

1.4 155 184 221

1.6 157 189 226

1.8 162 193 231

2.0 165 197 236

2.2 169 201 242

2.4 172 205 247

2.6 175 209 252

2.8 178 213 257

3.0 181 217 261

1 These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT value at the lower temperature and at the higher pH.

1. 99.9

Table 10-16 CT Values (CT ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free

1. 99.9

Chlorine at 5.0°C or Lower 1 Free Residual (mg/L) pH . .

. ≤ 6.0 6.5 7.0 ≤ 0.4 97 117 139

0.6 100 120 143

0.8 103 122 146

1.0 105 125 149

1.2 107 127 152

1.4 109 130 155

1.6 111 132 158

1.8 114 135 162

2.0 116 138 165

2.2 118 140 169

2.4 120 143 172

2.6 122 146 175

2.8 124 148 178

3.0 126 151 182

1 These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT value at the lower temperature and at the higher pH.

1. 99.9

Table 10-17 CT Values (CT ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free

1. 99.9

Chlorine at 10.0°C or Lower 1 Free Residual (mg/L) pH . .

. ≤ 6.0 6.5 7.0 ≤ 0.4 73 88 104

0.6 75 90 107

0.8 78 92 110

1.0 79 94 112

1.2 80 95 114

1.4 82 98 116

1.6 83 99 119

1.8 86 101 122

2.0 87 104 124

2.2 89 105 127

2.4 90 107 129

2.6 92 110 131

2.8 93 111 134

3.0 95 113 137

1 These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT value at the lower temperature and at the higher pH.

1. 99.9

Table 10-18 CT Values (CT ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free

1. 99.9

Chlorine at 15.0°C or Lower 1 Free Residual (mg/L) pH . .

. ≤ 6.0 6.5 7.0 ≤ 0.4 49 59 70

0.6 50 60 72

0.8 52 61 73

1.0 53 63 75

1.2 54 64 76

1.4 55 65 78

1.6 56 66 79

1.8 57 68 81

2.0 58 69 83

2.2 59 70 85

2.4 60 72 86

2.6 61 73 88

2.8 62 74 89

3.0 63 76 91

1 These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT value at the lower temperature and at the higher pH.

1. 99.9

Table 10-19 CT Values (CT ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free

1. 99.9

Chlorine at 20.0°C 1 Free Residual (mg/L) pH . .

. ≤ 6.0 6.5 7.0 ≤ 0.4 36 44 52

0.6 38 45 54

0.8 39 46 55

1.0 39 47 56

1.2 40 48 57

1.4 41 49 58

1.6 42 50 59

1.8 43 51 61

2.0 44 52 62

2.2 44 53 63

2.4 45 54 65

2.6 46 55 66

2.8 47 56 67

3.0 47 57 68

1 These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT value at the lower temperature and at the higher pH.

1. 99.9

Table 10-20 CT Values (CT ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free

1. 99.9

Chlorine at 25°C 1 and Higher Free Residual (mg/L) pH . .

. ≤ 6.0 6.5 7.0 ≤ 0.4 24 29 35

0.6 25 30 36

0.8 26 31 37

1.0 26 31 37

1.2 27 32 38

1.4 27 33 39

1.6 28 33 40

1.8 29 34 41

2.0 29 35 41

2.2 30 35 42

2.4 30 36 43

2.6 31 37 44

2.8 31 37 45

3.0 32 38 46

1 These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT value at the lower temperature and at the higher pH.

1. 99.9

Table 10-21 CT Values (CT ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Chlorine

1. 99.9

Dioxide and Ozone 1 . Temperature . .

1. ≤ 1 ° C 5 ° C 10 ° C Chlorine dioxide 63 26 23 Ozone 2.9 1.9 1.4 1 These CT values achieve greater than 99.99 percent inactivation of viruses. CT values between the indicated temperatures may be determined by linear interpolation. If no interpolation is used, use the CT value at the lower temperature for determining CT

99.9

values between indicated temperatures

99.9

Table 10-22 CT Values (CT ) for 99.9 Percent Inactivation of Giardia Lamblia Cysts By

1. 99.9

Chloramines 1 . Temperature . .

. ≤ 1 ° C 5 ° C 10 ° C Chloramines 3,800 2,200 1,850 1 These values are for pH values of 6 to 9. These CT values may be assumed to achieve greater than 99.99 percent inactivation of viruses only if chlorine is added and mixed in the water prior to the addition of ammonia. If this condition is not met, the system must demonstrate, based on on-site studies or other information, as approved by the State, that the system is achieving at least 99.99 percent inactivation of viruses. CT values between the indicated temperatures may be determined by linear interpolation. If no interpolation is used, use the CT value at the lower temperature for determining CT values between indicated temperatures.

1. 99.9 99.9

(b) The total inactivation ratio must be calculated as follows:

(1) If the system uses only one point of disinfectant application, the system may determine the total inactivation ratio based on either of the following two methods:

1. (i) One inactivation ratio (CTcalc/CT ) is determined before or at the first customer

99.9

1. during peak hourly flow and if the CTcalc/CT ≥ 1.0, the 99.9 percent Giardia
   1. 99.9
      1. lamblia inactivation requirement has been achieved; or (ii) Successive CTcalc/CT values, representing sequential inactivation ratios, are

99.9

1. determined between the point of disinfectant application and a point before or at the first customer during peak hourly flow. Under this alternative, the following method must be used to calculate the total inactivation ratio:
   1. (A) Determine (CTcalc/CT ) for each sequence

99.9

1. (B) Add the (CTcalc/CT ) values together ∑ (CTcalc/CT )
   1. 99.9 99.9
      1. (C) If ∑ (CTcalc/CT ) ≥ 1.0, the 99.9 percent Giardia lamblia inactivation

99.9

1. requirement has been achieved.

(2) If a public water system applies disinfectants at more than one point prior to the first customer, it must determine the CT of each disinfectant sequence before or at the first customer to determine the total percent inactivation or "total inactivation ratio." In determining the total inactivation ratio, the public water system must determine the residual disinfectant concentration of each disinfection sequence and corresponding contact time before any subsequent disinfection application point(s). "CT " is the CT

1. 99.9
   1. value required for 99.9 percent (3-log) inactivation of Giardia lamblia cysts. CT for
      1. 99.9
         1. a variety of disinfectants and conditions appear in section 10.6.1(Tables 1-8). (CTcalc/CT ) is the inactivation ratio. The sum of the inactivation ratios, or total

            99.9

            inactivation ratio, shown as the sum of ((CTcalc)/CT ), is calculated by adding together

            99.9

            the inactivation ratio for each disinfection sequence. A total inactivation ratio equal to or greater than 1.0 is assumed to provide a 3-log inactivation of Giardia lamblia cysts.

10.7 Disinfectants, Disinfection Byproducts and Disinfection Byproduct Precursor Analytical Requirements

10.7.1 General Analytical Requirements

(a) General (1) Systems shall use only the analytical methods specified in this section, or their equivalent to demonstrate compliance with the requirements of this section and with the requirements of sections 7.7 and 7.8. These methods are effective for compliance monitoring February 16, 1999, unless a different effective date is specified in this section or by the Department.

(2) The following documents are incorporated herein by reference: EPA Method 552.1 is in Methods for the Determination of Organic Compounds in Drinking Water-Supplement II, U.S. EPA, August 1992, EPA/600/R-92/129 EPA Methods 502.2, 524.2, 551.1, and 552.2 are in “Methods for the Determination of Organic Compounds in Drinking Water-Supplement III,” U.S. EPA, August 1995, EPA/600/R-95/131.

1. EPA Method 300.0 is in “Methods for the Determination of Inorganic Substances in Environmental Samples,” USEPA, August 1993, EPA/600/R-93/100. EPA Methods 300.1 and 321.8 are in “Methods for the Determination of Organic and Inorganic Compounds in Drinking Water,” Volume 1, USEPA, August 2000, EPA 815-R- 00-014.
   1. EPA Method 317.0, Revision 2.0, “Determination of Inorganic Oxyhalide Disinfection By- Products in Drinking Water Using Ion Chromatography with the Addition of a Postcolumn Reagent for Trace Bromate Analysis,” USEPA, July 2001, EPA 815-B-01-001. EPA Method 326.0, Revision 1.0, “Determination of Inorganic Oxyhalide Disinfection By- Products in Drinking Water Using Ion Chromatography Incorporating the Addition of a Suppressor Acidified Postcolumn Reagent for Trace Bromate Analysis,” USEPA, June 2002, EPA 815-R-03-007.
      1. EPA Method 327.0, Revision 1.1, “Determination of Chlorine Dioxide and Chlorite Ion in Drinking Water Using Lissamine Green B and Horseradish Peroxidase with Detection by Visible Spectrophotometry,” USEPA, May 2005, EPA 815-R-05-008. EPA Method 552.3, Revision 1.0, “Determination of Haloacetic Acids and Dalapon in Drinking Water by Liquid-liquid Microextraction, Derivatization, and Gas Chromatography with Electron Capture Detection,” USEPA, July 2003, EPA-815-B-03-002. EPA Method 415.3, Revision 1.1, “Determination of Total Organic Carbon and Specific UV Absorbance at 254 nm in Source Water and Drinking Water,” USEPA, February 2005, EPA/600/R-05/055.
         1. Standard Methods 4500-Cl D, 4500-Cl E, 4500-Cl F, 4500-Cl G, 4500-Cl H, 4500-Cl I, 4500-ClO2 D, 4500-ClO2 E, 6251 B, and 5910 B shall be followed in accordance with the American Public Health Association’s “Standard Methods for the Examination of Water and Wastewater,” 19th and 20th editions, 1995 and 1998 respectively. The cited methods published in either edition may be used.

            Standard Methods 5310 B, 5310 C, and 5310 D shall be followed in accordance with the Supplement to the 19th Edition of “Standard Methods for the Examination of Water and Wastewater,” or the Standard Methods for the Examination of Water and Wastewater, 20th Edition, American Public Health Association, 1996 and 1998, respectively. The cited methods published in either edition may be used. Copies may be obtained from the American Public Health Association, 1015 Fifteenth Street, NW, Washington, DC 20005. Standard Methods 4500-Cl D-00, 4500-Cl E-00, 4500-Cl F-00, 4500-Cl G-00, 4500-Cl H- 00, 4500-Cl I-00, 4500-ClO2 E-00, 6251 B-94, 5310 B-00, 5310 C-00, 5310 D-00 and 5910 B-00 are available at http://www.standardmethods.org or at EPA's Water Docket. The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only Online versions that are IBR-approved.

            ASTM Method D 1253-86 and D 1253-86 (Reapproved 1996) shall be followed in accordance with the Annual Book of ASTM Standards , Volume 11.01, American Society for Testing and Materials (1996), or any ASTM edition containing the IBR-approved version of the method may be used.

            ASTM Method D1253-03 shall be followed in accordance with the Annual Book of ASTM Standards , Volume 11.01, American Society for Testing and Materials International (2004), or any ASTM edition containing the IBR-approved version of the method may be used.

            ASTM Method D 6581-00 shall be followed in accordance with the Annual Book of ASTM Standards , Volume 11.01, American Society for Testing and Materials International (2001), or any ASTM edition containing the IBR-approved version of the method may be used.

10.7.2 Disinfection Byproduct Analytical Requirements

(a) Systems must measure disinfection byproducts by the methods (as modified by the footnotes) listed in Table 10-23:

Table 10-23 Approved Methods for Disinfection Byproduct Compliance Monitoring (b) Analysis under this section 10.7 for disinfection byproducts must be conducted by laboratories that have received certification by the EPA or the Department, except as specified under section 10.7.2(c) of this section. To receive certification to conduct analyses for the contaminants in sections 2.4, 7.6, 7.7 and 7.8, the laboratory must:

(1) Analyze Performance Evaluation (PE) samples that are acceptable to the Department at least once during each consecutive 12 month period by each method for which the laboratory desires certification.

(2) Beginning April 1, 2007, the laboratory must achieve quantitative results on the PE sample analyses that are within the following acceptance limits: Table 10-24 Acceptance Limits for Quantitative Results on PE Sample Analyses DBP Acceptance limits Comments (percent of true value)

TTHM . .

Chloroform ±20 Laboratory must meet all 4 individual THM acceptanc limits in order to successfully pass a PE sample for TTHM Bromodichloromethane ±20 .

Dibromochloromethane ±20 .

Bromoform ±20 .

. . .

HAA5 . .

Monochloroacetic Acid ±40 Laboratory must meet the acceptance limits for 4 out of 5 of the HAA5 compounds in order to successfully pass a PE sample for HAA5 Dichloroacetic Acid ±40 .

Trichloroacetic Acid ±40 .

Monobromoacetic Acid ±40 .

Dibromoacetic Acid ±40 .

. . .

Chlorite ±30 .

Bromate ±30 .

(3) Beginning April 1, 2007, report quantitative data for concentrations at least as low as the ones listed in the following table for all DBP samples analyzed for compliance with sections 2.4, 7.6, 7.7 and 7.8:

Table 10-25 Minimum Reporting Level for Quantitative Data for DBP Samples DBP Minimum reporting Comments level (mg/L)

1. 2 . .

TTHM Chloroform 0.0010 .

Bromodichloromethane 0.0010 .

Dibromochloromethane 0.0010 .

Bromoform 0.0010 .

. . .

1. 2 . .

HAA5 Monochloroacetic Acid 0.0020 .

Dichloroacetic Acid 0.0010 .

Trichloroacetic Acid 0.0010 .

Monobromoacetic Acid 0.0010 .

Dibromoacetic Acid 0.0010 .

. . .

Chlorite 0.020 Applicable to monitoring as prescribed in Section7.6.3(b)(2)(1)(B)

1. and (b)(2)(ii).

Bromate 0.0050 or 0.0010 Laboratories that use EPA Methods 317.0 Revision 2.0, 326.0 or 321.8 must meet a 0.0010 mg/L MRL for bromate.

1 The calibration curve must encompass the regulatory minimum reporting level (MRL) concentration. Data may be reported for concentrations lower than the regulatory MRL as long as the precision and accuracy criteria are met by analyzing an MRL check standard at the lowest reporting limit chosen by the laboratory. The laboratory must verify the accuracy of the calibration curve at the MRL concentration by analyzing an MRL check standard with a concentration less than or equal to 110% of the MRL with each batch of samples. The measured concentration for the MRL check standard must be ±50% of the expected value, if any field sample in the batch has a concentration less than 5 times the regulatory MRL. Method requirements to analyze higher concentration check standards and meet tighter acceptance criteria for them must be met in addition to the MRL check standard requirement. 2 When adding the individual trihalomethane or haloacetic acid concentrations to calculate the TTHM or HAA5 concentrations, respectively, a zero is used for any analytical result that is less than the MRL concentration for that DBP, unless otherwise specified by the Department.

(c) A party approved by the Department must measure daily chlorite samples at the entrance to the distribution system.

10.7.3 Disinfectant Residual Analytical Requirements

(a) Systems shall measure residual disinfectant concentrations for free chlorine, combined chlorine (chloramines), and chlorine dioxide by the methods listed in Table 10-26: Table 10-26 Approved Methods For Disinfectant Residual Compliance Monitoring (b) If approved by the Department, systems may also measure residual disinfectant concentrations for chlorine, chloramines, and chlorine dioxide by using DPD colorimetric test kits.

(c) A party approved by the Department must measure residual disinfectant concentration.

10.7.4 Additional Analytical Methods

Systems required to analyze parameters not included in Tables 10-22 and 10-23 must use the following methods. A party approved by the Department must measure these parameters.

(a) Alkalinity. All methods allowed in Table 10-5 for measuring alkalinity.

(b) Bromide. EPA Method 300.0 or EPA Method 300.1, 317.0 Revision 2.0, 326.0, or ASTM D 6581-00.

(c) Total Organic Carbon (TOC). The following analytical methods shall be used for measuring TOC. Standard Method 5310 B or 5310 B–00 (High-Temperature Combustion Method) or Standard Method 5310 C or 5310 C–00 (Persulfate-Ultraviolet or Heated-Persulfate Oxidation Method) or Standard Method 5310 D or 5310 D–00 (Wet-Oxidation Method) or EPA Method 415.3, Revision 1.1. Inorganic carbon must be removed from the samples prior to analysis. TOC samples may not be filtered prior to analysis. TOC samples must be acidified at the time of sample collection to achieve pH less than or equal to 2 with minimal addition of the acid specified in the method or by the instrument manufacturer. Acidified TOC samples must be analyzed within 28 days.

(d) Specific Ultraviolet Absorbance (SUVA). SUVA is equal to the UV absorption at 254nm (UV ) (measured in m -1 divided by the dissolved organic carbon (DOC) concentration (measured as mg/L). In order to determine SUVA, it is necessary to separately measure UV and DOC. When determining SUVA, systems must use the methods stipulated in section 10.7.4 (d)(1) to measure DOC and the method stipulated in section 10.7.4 (d)(2) to measure UV . SUVA must be determined on water prior to the addition of disinfectants/oxidants by the system. DOC and UV samples used to determine a SUVA value must be taken at the same time and at the same location.

(1) Dissolved Organic Carbon (DOC). The following analytical methods shall be sued for measuring DOC. Standard Method 5310 B or 5310 B–00 (High-Temperature Combustion Method) or Standard Method 5310 C or 5310 C–00 (Persulfate-Ultraviolet or Heated- Persulf ate Oxidation Method) or Standard Method 5310 D or 5310 D-00 (Wet-Oxidation Method) or EPA Method 415.3, Revision 1.1. DOC samples must be filtered through the

1. 0.45 µm pore-diameter filter as soon as practical after sampling, not to exceed 48 hours. After filtration, DOC samples must be acidified to achieve pH less than or equal to 2 with minimal addition of the acid specified in the method or by the instrument manufacturer. Acidified DOC samples must be analyzed within 28 days of sample collection. Inorganic carbon must be removed from the samples prior to analysis. Water passed through the filter prior to filtration of the sample must serve as the filtered blank. This filtered blank must be analyzed using procedures identical to those used for analysis of the samples and must meet the following criteria: DOC < 0.5 mg/L.

(2) Ultraviolet Absorption at 254 nm (UV ). The following analytical methods shall be used for measuring Ultraviolet Absorption. Standard Method 5910 B or 5910 B–00 (Ultraviolet Absorption Method) or EPA Method 415.3 Revision 1.1. UV absorption must be measured at 253.7 nm (may be rounded off to 254 nm). Prior to analysis, UV samples must be filtered through a 0.45 µm pore-diameter filter. The pH of UV samples may not be adjusted. Samples must be analyzed as soon as practical after sampling, not to exceed 48 hours.

(e) pH. Any of the methods in Table 10-5 shall be used for measuring pH.

(f) Magnesium. Any of the methods in Table 10-5(15) shall be used for measuring magnesium.

10.8 Lead and Copper Analytical Requirements

10.8.1 Lead and Copper Analysis

(a) Analyses for lead, copper, pH, conductivity, calcium, alkalinity, orthophosphate, silica, and temperature shall be conducted with the methods in Table 10-5.

(1) Analyses for alkalinity, calcium, conductivity, orthophosphate, pH, silica, and temperature may be performed by any person acceptable to the Department. Analyses under this section for lead and copper shall only be conducted by laboratories that have been certified by EPA or the Department. To obtain certification to conduct analyses for lead and copper, laboratories must:

1. (i) Analyze Performance Evaluation samples, which include lead and copper, provided by a third party, with approval by the Department, at least once a year by each method for which the laboratory desires certification; and (ii) Achieve quantitative acceptance limits as follows:
   1. (A) For Lead: ± 30 percent of the actual amount in the Performance Evaluation sample when the actual amount is greater than or equal to 0.005 mg/L. The Practical Quantitation Level, or PQL for lead is 0.005 mg/L.
      1. (B) For Copper: ± 10 percent of the actual amount in the Performance Evaluation sample when the actual amount is greater than or equal to
         1. 0.050 mg/L. The Practical Quantitation Level, or PQL for copper is
         2. 0.050 mg/L.
         3. (iii) Achieve the method detection limit for lead of 0.001 mg/L according to the procedures in Appendix B of 40 CFR Part 136, July 1, 2004. This need only be accomplished if the laboratory will be processing source water composite samples under section 8.9.
         4. (iv) Be currently certified by EPA or the Department to perform analyses to the specifications described in section 10.8.1 (a)(2).

(2) The Department has the authority to allow the use of previously collected monitoring data for purposes of monitoring, if the data were collected and analyzed in accordance with the requirements of this Article 10.

(3) All lead and copper levels measured between the PQL and MDL must be either reported as measured or they can be reported as one-half the PQL specified for lead and copper in section 10.8.1(a)(1)(ii). All levels below the lead and copper MDLs must be reported as zero.

(4) All copper levels measured between the PQL and the MDL must be either reported as measured or they can be reported as one-half the PQL (0.025 mg/L). All levels below the copper MDL must be reported as zero.

10.9 Alternate Analytical Techniques

10.9.1 Use of Other Analytical Methods

(a) With the written permission of the Department, concurred in by the EPA Administrator, an alternate analytical technique from those listed in this Article 10 may be employed.

(b) An alternate technique shall be accepted only if it is substantially equivalent to the prescribed test in both precision and accuracy as it relates to the determination of compliance with any MCL. The use of the alternate analytical technique shall not decrease the frequency of monitoring required by the Colorado Primary Drinking Water Regulation.

10.10 Certified Laboratories and Laboratory Certification

10.10.1 Certified Laboratories

(a) Unless otherwise stated in Article 10, when determining compliance with Articles 5 through 8 and 13, samples may be considered only if they have been analyzed by a laboratory certified by the Department except that measurements for alkalinity, calcium, conductivity, disinfectant residual, orthophosphate, pH, silica, temperature and turbidity may be performed by an operator that has been certified in accordance with Regulation 100, 5 C.C.R. 1003-2.

(b) The Department laboratory certification program will certify laboratories in accordance with EPA requirements and/or those listed in this section 10.10.

10.10.2 Laboratory Certification for Inorganic Chemical Contaminants

(a) Analysis under section 6.1 shall only be conducted by laboratories that have been certified by the Department. To receive certification to conduct analyses for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, nitrate, nitrite and selenium and thallium, the laboratory must:

(1) Analyze Performance Evaluation samples provided by a third party (with the approval of the Department) at least once a year.

(2) For each chemical contaminant that has been included in the PE sample and for each method for which the laboratory desires certification achieve quantitative results on the analyses that are within the following acceptance limits: Table 10-27 Acceptable Limits for Performance Evaluation Sample Analysis for Inorganic Chemical Contaminant Laboratory Certification Contaminant Acceptance limit Antimony ± 30 at > 0.006 mg/L Arsenic ± 30 at > 0.003 mg/L Asbestos 2 standard deviations based on study statistics Barium ± 15% at > 0.15 mg/L Beryllium ± 15% at > 0.001 mg/L Cadmium ± 20% at > 0.002 mg/L Chromium ± 15% at > 0.01 mg/L Cyanide ± 25% at > 0.1 mg/L Fluoride ± 10% at > 1 to 10 mg/L Mercury ± 30% at > 0.0005 mg/L Nickel ± 15% at > 0.01 mg/L Nitrate ± 10% at > 0.4 mg/L Nitrite ± 15% at > 0.4 mg/L Selenium ± 20% at > 0.01 mg/L Thallium ± 30% at > 0.002 mg/L

10.10.3 Laboratory Certification for Volatile Organic Compounds (VOCs)

(a) Analysis under section 6.2.5 shall only be conducted by laboratories that are certified by the Department according to the following conditions:

(1) To receive certification to conduct analyses for the chemical contaminants in Table 2-1 (2) through (21) the laboratory must:

1. (i) Analyze Performance Evaluation samples provided by a third party (with the approval of the Department) at least once a year by each method for which the laboratory desires certification.
   1. (ii) Achieve the quantitative acceptance limits under sections 10.10.3(a)(1)(iii) and (iv) for at least 80 percent of the regulated organic Chemical contaminants included in the Performance Evaluation sample.
      1. (iii) Achieve quantitative results on the analyses performed under section 10.10.3(a)(1)(i) that are within ± 20% of the actual amount of the substances in the Performance Evaluation sample when the actual amount is greater than or equal to 0.010 mg/L.
         1. (iv) Achieve quantitative results on the analyses performed under section 10.10.3(a)(1)(i) that are within ± 40 percent of the actual amount of the substances in the Performance Evaluation sample when the actual amount is less than 0.010 mg/L.
         2. (v) Achieve a method detection limit of 0.0005 mg/L, according to the procedures in appendix B of 40 CFR Part 136.

(2) To receive certification to conduct analyses for vinyl chloride, the laboratory must:

1. (i) Analyze Performance Evaluation samples provided by a third party (with the approval of the Department) at least once a year by each method for which the laboratory desires certification.
   1. (ii) Achieve quantitative results on the analyses performed under section 10.9.1 (a)(2)(i) that are within ± 40 percent of the actual amount of vinyl chloride in the Performance Evaluation sample.
      1. (iii) Achieve a method detection limit of 0.0005 mg/L, according to the procedures in appendix B of 40 CFR Part 136.
         1. (iv) Obtain certification for the Chemical contaminants listed in Table 2-1(2) through (21).

(b) Each certified laboratory must determine the method detection limit (MDL), as defined in appendix B to 40 CFR Part 136, at which it is capable of detecting VOCs. The acceptable MDL is 0.0005 mg/L. This concentration is the detection concentration for purposes of this section.

10.10.4 Laboratory Certification for Synthetic Organic Chemiclas (SOCs)

(a) Analysis for SOCs under section 6.2.6 shall only be conducted by laboratories that have received certification by the Department and have met the following conditions:

(1) To receive certification to conduct analyses for the chemical contaminants in Table 2-2 the laboratory must:

1. (i) Analyze Performance Evaluation samples provided by a third party (with the approval of the Department) at least once a year by each method for which the laboratory desires certification.
   1. (ii) For each chemical contaminant that has been included in the performance evaluation sample achieve quantitative results on the analyses that are within the following acceptance limits:

Table 10-28 Acceptable Limits for PE Sample Analysis for SOC Laboratory Certification Contaminant Acceptance limits (%- percent)

DBCP ±40 EDB ±40.

Alachlor ±45.

Atrazine ±45.

Benzo[a]pyrene 2 standard deviations.

Carbofuran ±45.

Chlordane ±45.

Dalapon 2 standard deviations.

Di(2-ethylhexyl)adipate 2 standard deviations.

Di(2-ethylhexyl)phthalate 2 standard deviations.

Dinoseb 2 standard deviations.

Diquat 2 standard deviations.

Endothall 2 standard deviations.

Endrin ±30.

Glyphosate 2 standard deviations.

Heptachlor ±45.

Heptachlor epoxide ±45.

Hexachlorobenzene 2 standard deviations.

Hexachlorocyclopentadie 2 standard deviations.

ne Lindane ±45.

Methoxychlor ±45.

Oxamyl 2 standard deviations.

PCBs (as 0-200.

Decachlorobiphenyl)

Picloram 2 standard deviations.

Simazine 2 standard deviations.

Toxaphene ±45.

Aldicarb 2 standard deviations.

Aldicarb sulfoxide 2 standard deviations.

Aldicarb sulfone 2 standard deviations.

Pentachlorophenol ±50.

2,3,7,8-TCDD (Dioxin) 2 standard deviations.

2,4-D ±50.

2,4,5-TP (Silvex) ±50.

10.10.5 Laboratory Certification for Cryptosporidium and E. coli

(a) Cryptosporidium. Systems must have Cryptosporidium samples analyzed by a laboratory that is approved under EPA's Laboratory Quality Assurance Evaluation Program for Analysis of Cryptosporidium in Water or a laboratory that has been certified for Cryptosporidium analysis by an equivalent Department laboratory certification program.

(b) E. coli. Any laboratory certified by the EPA, the National Environmental Laboratory Accreditation Conference or the Department for total coliform or fecal coliform analysis under section 10.10.1 is approved for E. coli analysis under this section when the laboratory uses the same technique for E. coli that the laboratory uses for Turbidity. Measurements of turbidity must be made by a party approved by the Department.

10.11 Laboratory Compositing

10.11.1 Compositing of Samples by the Laboratory

(a) Compositing of samples must be done in the laboratory and analyzed within 14 days of sample collection.

(b) Compositing samples prior to GC analysis.

(1) Add 5 mL or equal larger amounts of each sample (up to 5 samples are allowed) to a 25 mL glass syringe. Special precautions must be made to maintain zero headspace in the syringe.

(2) The samples must be cooled at 4°C during this step to minimize volatilization losses.

(3) Mix well and draw out a 5 mL aliquot for analysis.

(4) Follow sample introduction, purging, and desorption steps described in the method.

(5) If less than five samples are used for compositing, a proportionately small syringe may be used.

(c) Compositing samples prior to GC/MS analysis.

(1) Inject 5 mL or equal larger amounts of each aqueous sample (up to 5 samples are allowed) into a 25 mL purging device using the sample introduction technique described in the method.

(2) The total volume of the sample in the purging device must be 25 mL.

(3) Purge and desorb as described in the method.

Article 11 Sanitary Surveys and Composite Correction Program

11.1 Sanitary Surveys

(a) Public water systems must provide the Department, at the Department's request, any existing information that will enable the Department to conduct a sanitary survey.

(b) A sanitary survey includes but is not limited to, an onsite review of the water source(s) (identifying sources of contamination by using results of source water assessments or other relevant information where available), facilities, equipment, operation, maintenance, and monitoring compliance of a public water system to evaluate the adequacy of the system, its sources and operations and the distribution of safe drinking water.

(c) Sanitary surveys must be performed by the Department or by a third party approved by the Department in accordance with section 1.7. The public water system is responsible for ensuring the survey takes place. In the event that a sanitary survey has not been performed within the time-period specified in section 11.2, the system must notify the Department and schedule the survey prior to the end of the time period.

11.2 Sanitary Survey Frequency

A sanitary survey must be completed for all public water systems at a frequency as follows: Prior to December 1, 2009, public water systems must comply with sections 11.2(a) through 11.2(c). Beginning on December 1, 2009, public water systems must comply with sections 11.2(d) through 11.2(e).

(a) A sanitary survey must be completed for all community and non-community groundwater systems every five years; except for non-community water systems using only disinfected and protected groundwater as determined by the Department, in which case a sanitary survey must be completed at least every 10 years.

(b) A sanitary survey must be completed for all community systems using surface water or groundwater under the direct influence of surface water every three years. For systems determined by the Department to have outstanding performance based on prior sanitary surveys, the frequency of conducting subsequent sanitary surveys may be extended to no less frequently than every five years.

(c) A sanitary survey must be completed for all non-community systems using surface water or groundwater under the direct influence of surface water every five years.

(d) A sanitary survey must be completed no less frequently than every three years for community water systems, except as provided in 11.2(e), and every five years for non-community water systems.

(e) For community systems that provide at least 4-log treatment of viruses before or at the first customer for all sources and have an outstanding performance record, as determined by the Department and documented in previous sanitary surveys, and have no history of total coliform MCL or monitoring violations since the last sanitary survey, the frequency of conducting subsequent surveys may be extended to no less frequently than every five years.

11.3 Sanitary Survey Components

A sanitary survey is composed of, but not limited to, eight components:

(1) Source(s), (2) Treatment, (3) Distribution system, (4) Finished water storage, (5) Pumps, pump facilities, and controls, (6) Monitoring, reporting, and data verification, (7) System management and operation, and (8) Operator compliance with all requirements of the Colorado Primary Drinking Water Regulations , Certified Operator Requirements of Regulation 100 and any other mandated requirements.

11.4 Response to Significant Deficiencies or Violations of Colorado Primary Drinking Water Regulations in a Sanitary Survey Written Notice Prior to December 1, 2009, public water systems must comply with section 11.4(e). Beginning on December 1, 2009, public water systems must comply with sections 11.4(a) though 11.4(d).

(a) If the Department, or authorized party, detects significant deficiencies or violations of the Colorado Primary Drinking Water Regulations, then the Department, or authorized party, must issue written notice to the public water systems within 30 days of completing site visit activities. If the Department, or authorized party fails to issue the notice within this timeframe, the public water system must still meet all the requirements of the remainder of section 11.4.

(b) A public water system must consult with the Department regarding appropriate corrective action and a schedule for implementing corrective action within 30 days of receiving written notice from the Department, or authorized party, of significant deficiencies or violations, as defined in sections 1.5.2(119) and (146). This consultation may take the form of a telephone conversation, electronic mail, meeting, or other mechanism agreed to by the Department. Groundwater systems with significant deficiencies must implement one or more of the following corrective actions:

(1) Correct all significant deficiencies (2) Provide an alternate source of water;

(3) Eliminate the source of contamination; or (4) Provide treatment that reliably achieves at least 4-log treatment of viruses before or at the first customer for the groundwater source.

(c) Within 45 days of receiving notice of significant deficiencies or violations, the system must submit a written response to the Department indicating the corrective actions the system will take to address the significant deficiencies or violations, and include a proposed schedule for completing those actions. The Department will review this response. If approved, this response shall constitute a Department approved corrective action plan as referenced below in section 11.4(d) (2).

(d) Within 120 days (or earlier if directed by the department) of receiving notification from the Department of a significant deficiency or violations, a public water system must either:

(1) Have completed corrective action in accordance with applicable Department plan review processes including section 1.11 or other Department direction, if any, including Department specified interim measures; or (2) Be in compliance with a Department approved corrective action plan and schedule subject to the conditions specified in sections 11.4(d)(2)(i) and (d)(2)(ii).

1. (i) Any subsequent modifications to a Department approved corrective action plan and schedule must also be approved by the Department.
   1. (ii) If the Department specifies interim measures for protection of the public health pending Department approval of the corrective action plan and schedule or pending the completion of the corrective action plan, the system must comply with these interim measures as well as with any schedule specified by the Department.

(e) A public water system must respond in writing to significant deficiencies and violations, as defined in sections 1.5.2(119) and (146), outlined in the sanitary survey report no later than 45 days after receipt of the report. The system must submit a response to the Department indicating the actions the system will take to address the significant deficiencies and violations noted in the survey and include a proposed schedule for completing those corrective actions and achieving compliance.

11.5 Composite Correction Program

A composite correction program consists of two elements, a Comprehensive Performance Evaluation (CPE) and Comprehensive Technical Assistance (CTA).

(a) Comprehensive Performance Evaluation (1) The CPE, as defined in section 1.5.2(20), must be performed by the Department or by a third party approved by the Department.

(2) A CPE must be completed following individual filter turbidity exceedances as outlined in Article 7.

(3) Anytime a CPE is required to be conducted, the public water system is responsible for ensuring the evaluation takes place within the specified time frames outlined in Article 7.

(4) For purposes of compliance, the CPE must consist of the following:

1. (i) Assessment of plant performance;
   1. (ii) Evaluation of major unit processes;
      1. (iii) Identification and prioritization of performance limiting factors;
         1. (iv) Assessment of the applicability of Comprehensive Technical Assistance (CTA); and (v) Preparation of a CPE report.

(b) Comprehensive Technical Assistance (CTA)

(1) The CTA, as defined in section 1.5.2(21), must be completed by the public water system following the CPE if the CPE results indicate the potential for improved performance by the public water system.

(2) During the CTA phase, the public water system must identify and systematically address plant-specific factors as outlined in the CPE and include them in a report to the Department within 90 days of the completion of the CPE. Article 12 Hazardous Cross-Connection [Eff. 09/30/2007]

12.1 Control of Hazardous Cross-Connections

(a) A public water system or a consecutive distribution system of a public water system shall have no uncontrolled cross-connections to a pipe, fixture, or supply, any of which contain water not meeting all applicable provisions of the Colorado Primary Drinking Water Regulations.

(b) A supplier of water shall protect the public water system from contamination in the following manner:

(1) Identify potentially uncontrolled hazardous service cross connections.

(2) Require system users to install and maintain containment devices on any uncontrolled hazardous service cross connections, provided the Department has determined that the device is consistent with the degree of hazard posed by the uncontrolled cross connection.

(3) Installation of containment devices shall be approved by the public water system upon installation.

(4) All containment devices shall be tested and maintained as necessary on installation and at least annually thereafter, by a Certified Cross-Connection Control Technician.

(c) Public water systems shall retain maintenance records of all containment devices. Section 1.6.3 requires these records to be available for inspection by Department personnel. All maintenance records shall be kept for three years.

(d) A public water system shall notify the Department of any cross-connection, as defined in section 1.5.2(29), within 10 calendar days of its discovery. The cross-connection shall be corrected within 10 days of being ordered in writing by the Department to correct the problem. Failure to do so may result in an enforcement order.

(e) Violations shall be subject to the provisions and penalties prescribed by sections 25.1.114 and 25.1.114.1, Colorado Revised Statutes, and to such other actions as provided by law.

12.2 Cross-Connection Control Technician Certification

(a) A Certified Cross-Connection Control Technician must possess a valid certification from the American Society of Sanitary Engineering (ASSE), the American Backflow Prevention Association (ABPA), or the Association of Boards of Certification (ABC). The process for certification must include successful completion of an examination administered by one of the approved organizations. Certifications that are not renewed on or before their expiration date shall not be valid after such date.

(b) Cross-Connection Control Technicians certified prior to January 1, 2003 under the program administered by the Colorado Water and Wastewater Collection Systems Certification Council, Inc. shall be considered compliant with the certification requirements of this provision through the scheduled expiration date of their certification except as noted below. Individuals whose certification would otherwise expire between January 1, 2003, and December 31, 2004, will have until December 31, 2004, to obtain certification from one of the organizations approved in 12.1(a) or the certification will lapse as of January 1, 2005.

(c) The Department shall, no less often than once every two years, conduct an evaluation of the certification process of each organization referenced in section 12.2(a) and report the results to the Water Quality Control Commission. The Department shall ensure that the certification processes, including the examination requirement, are adequate to protect public water systems as referenced in section 12.1(b). If the Department concludes, based upon the available facts, that an organization’s certification process no longer meets the standards necessary for the purposes of this article, it may request that the Water Quality Control Commission, after notice and comment rulemaking, revoke the organization’s standing under Article 12. Article 13 Groundwater Rule

13.1 General requirements and applicability.

(a) Scope. The requirements of Article 13 constitute Colorado Primary Drinking Water Regulations.

(b) Applicability . The Groundwater Rule applies to all public water systems that use groundwater except that it does not apply to public water systems that combine all of their groundwater with surface water or with groundwater under the direct influence of surface water prior to treatment under Article 7. For the purposes of Article 13, “groundwater system” is defined as any public water system meeting this applicability statement, including consecutive systems receiving finished groundwater.

(c) General requirements.

(1) Sanitary survey information requirements for all groundwater systems as described in section 11.1(a).

(2) Microbial source water monitoring requirements for groundwater systems that do not treat all of their groundwater to at least 99.99 percent (4-log) treatment of viruses before or at the first customer as described in section 13.3.

(3) Treatment technique requirements, described in section 13.4, that apply to groundwater systems that have fecally contaminated source waters, as determined by source water monitoring conducted under section 13.3. A groundwater system with fecally contaminated source water must implement one or more of the following corrective actions: correct all significant deficiencies; provide an alternate source of water; eliminate the source of contamination; or provide treatment that reliably achieves at least 4-log treatment of viruses before or at the first customer.

(4) Groundwater systems that provide at least 4-log treatment of viruses before or at the first customer are required to conduct compliance monitoring to demonstrate treatment effectiveness, as described in section 13.4(b).

(5) If requested by the Department, groundwater systems must provide the Department with any existing information that will enable the Department to perform a hydrogeologic sensitivity assessment.

(d) Compliance date . Groundwater systems must comply, unless otherwise noted, with the requirements of Article 13 beginning December 1, 2009.

13.2 Disinfection of Groundwater

(a) In addition to complying with the requirements under section 7.6, public water systems that use groundwater must comply with section 13.2.

(b) A public water system that uses only groundwater sources which have been determined to not be under the direct influence of surface water shall be disinfected by means or methods which are approved by the Department and are affective in the killing or removal of pathogenic organisms. Disinfection may include physical as well as chemical treatment. When chlorination methods are employed, a sufficient amount of chlorine shall be added to the water to destroy any pathogenic organisms potentially present and to maintain a detectable residual in at least 95 percent of the samples taken at the extremities of the distribution system from which water may be withdrawn.

(c) The following requirements pertain to residual disinfectant concentrations of finished water within the distribution system:

(1) The residual disinfectant concentration in the distribution system, measured as total chlorine, combined chlorine, free chlorine or chlorine dioxide, cannot be undetectable in more than 5 percent of the samples taken each month, for any two consecutive months that the system serves water to the public.

(2) The residual disinfectant concentration must be measured at least at the same points in the distribution system and at the same time as total coliforms are sampled.

(d) The Department may waive the requirement for disinfection upon written application by a supplier. Waivers may be granted when competent evidence is submitted by the supplier to establish that the water being supplied to the public is from a protected groundwater source, determined safe and free from contamination. An application for a waiver shall include information regarding the source, distribution and quality of the system’s water.

(e) If the Department initially determines that a waiver request satisfies the criteria of section 13.2(d):

(1) The public water system shall provide publication of a special notice regarding the waiver pursuant to section 9.2.12.

(2) A person adversely affected or aggrieved by the waiver may request a hearing. Such requests shall be filed in writing with the Department within 60 days after publication of notice. Such hearing shall be conducted in accordance with procedures established by Article 4 of Title 24, Colorado Revised Statutes. The applicant shall be named as a party to such hearing. If no request for hearing is made, the waiver shall take effect 60 days from publication of notice. If a request for a hearing is made the waiver shall remain in effect prior to any determination made at the hearing.

(f) If the Department denies the request for waiver, the applicant may request a hearing to contest the denial. Such request shall be in writing and shall be filed with the Department within 60 days after service of the Department’s statement of denial. Such hearing shall be conducted in accordance with procedures established by Article 4 of Title 24, Colorado Revised Statutes.

(g) Samples from public water systems for which waivers have been granted shall be submitted for analyses upon request of the Department. If at any time it appears that the water being furnished is not in compliance with applicable contaminant levels or for any reason is not safe to drink, the Department may summarily withdraw the waiver, whereupon disinfection shall be required. The affected supplier may request a hearing to contest the withdrawal of the waiver. Request for such a hearing shall be filed in writing within 60 days after service of the Department’s withdrawal. Such hearing shall be conducted pursuant to the procedures established by Article 4 of Title 24, Colorado Revised Statutes.

13.3 Groundwater source microbial monitoring and analytical methods.

(a) Triggered source water monitoring (1) General requirements. A groundwater system must conduct triggered source water monitoring if both the conditions identified in sections 13.3(a)(1)(i) and (a)(1)(ii) exist.

1. (i) The system does not provide at least 4-log treatment of viruses before or at the first customer for each groundwater source; and (ii) The system is notified that a sample collected under section 5.1.1 is total coliform- positive and the sample is not invalidated under section 5.3.

(2) Sampling requirements. A groundwater system must collect, within 24 hours of notification of the total coliform-positive sample, at least one groundwater source sample from each groundwater source in use at the time the total coliform-positive sample was collected under section 5.1.1, except as provided in section 13.3(a)(2)(ii).

1. (i) The Department may extend the 24-hour time limit on a case-by-case basis if the system cannot collect the groundwater source water sample within 24 hours due to circumstances beyond its control. In the case of an extension, the Department must specify how much time the system has to collect the sample.
   1. (ii) If approved by the Department, systems with more than one groundwater source may meet the requirements of section 13.3(a)(2) by sampling a representative groundwater source or sources. If directed by the Department, systems must submit for Department approval a triggered source water monitoring plan that identifies one or more groundwater sources that are representative of each monitoring site in the system's sample siting plan under section 5.1.1 and that the system intends to use for representative sampling under section 13.3(a)(2).
      1. (iii) A groundwater system serving 1,000 people or fewer may use a repeat sample collected from a groundwater source to meet both the requirements of section 5.1.2 and to satisfy the monitoring requirements of section 13.3 (a)(2) for that groundwater source only if the Department approves the use of E. coli as a fecal indicator for source water monitoring under this section 13.3(a). If the repeat sample collected from the groundwater source is E.coli positive, the system must comply with section 13.3(a)(3).

(3) Additional requirements. If the Department does not require corrective action under section 13.4(a) for a fecal indicator-positive source water sample collected under section 13.3(a)

1. (2) that is not invalidated under section 13.3(d), the system must collect five additional source water samples from the same source within 24 hours of being notified of the fecal indicator-positive sample.

(4) Consecutive and wholesale systems

1. (i) In addition to the other requirements of section 13.3(a), a consecutive groundwater system that has a total coliform-positive sample collected under section 5.1.1 must notify the wholesale system(s) within 24 hours of being notified of the total coliform-positive sample.
   1. (ii) In addition to the other requirements of section 13.3(a), a wholesale groundwater system must comply with sections 13.3 (a)(4)(ii)(A) and (a)(4)(ii)(B).
      1. (A) A wholesale groundwater system that receives notice from a consecutive system it serves that a sample collected under section 5.1.1 is total coliform-positive must, within 24 hours of being notified, collect a sample from its groundwater source(s) under section 13.3(a)(2) of this section and analyze it for a fecal indicator under section 13.3(c).
         1. (B) If the sample collected under section 13.3 (a)(4)(ii)(A) is fecal indicator- positive, the wholesale groundwater system must notify all consecutive systems served by that groundwater source of the fecal indicator source water positive within 24 hours of being notified of the groundwater source sample monitoring result and must meet the requirements of section 13.3(a)(3).

(5) Exceptions to the triggered source water monitoring requirements. A groundwater system is not required to comply with the source water monitoring requirements of section 13.3(a) if either of the following conditions exists:

1. (i) The Department determines, and documents in writing, that the total coliform-positive sample collected under section 5.1.1 is caused by a distribution system deficiency; or (ii) The total coliform-positive sample collected under section 5.1.1 is collected at a location that meets Department criteria for distribution system conditions that will cause total coliform-positive samples.

(b) Assessment source water monitoring. If directed by the Department, groundwater systems must conduct assessment source water monitoring that meets Department determined requirements for such monitoring. A groundwater system conducting assessment source water monitoring may use a triggered source water sample collected under section 13.3(a)(2) to meet the requirements of section 13.3(b). Department-determined assessment source water monitoring requirements may include:

(1) Collection of a total of twelve (12) groundwater source samples that represent each month the system provides groundwater to the public, (2) Collection of samples from each well unless the system obtains written Department approval to conduct monitoring at one or more wells within the groundwater system that are representative of multiple wells used by that system and that draw water from the same hydrogeologic setting, (3) Collection of a standard sample volume of at least 100 mL for fecal indicator analysis regardless of the fecal indicator or analytical method used, (4) Analysis of all groundwater source samples using one of the analytical methods listed in Table 10-3 for the presence of E. coli, enterococci, or coliphage, (5) Collection of groundwater source samples at a location prior to any treatment of the groundwater source unless the Department approves a sampling location after treatment, and (6) Collection of groundwater source samples at the well itself unless the system's configuration does not allow for sampling at the well itself and the Department approves an alternate sampling location that is representative of the water quality of that well.

(c) Analytical methods. A groundwater system must analyze all groundwater source samples collected under section 13.3(a) using one of the analytical methods listed in Table 10-3 for the presence of E. coli, enterococci, or coliphage.

(d) Invalidation of a fecal indicator-positive groundwater source sample.

(1) A groundwater system may obtain Department invalidation of a fecal indicator-positive groundwater source sample collected under section 13.3(a) only under the conditions specified in sections 13.3(d)(1)(i) and (ii).

1. (i) The system provides the Department with written notice from the laboratory that improper sample analysis occurred; or (ii) The Department determines and documents in writing that there is substantial evidence that a fecal indicator-positive groundwater source sample is not related to source water quality.

(2) If the Department invalidates a fecal indicator-positive groundwater source sample, the groundwater system must collect another source water sample under section 13.3(a) within 24 hours of being notified by the Department of its invalidation decision and have it analyzed for the same fecal indicator using the analytical methods in Table 10-3. The Department may extend the 24-hour time limit on a case-by-case basis if the system cannot collect the source water sample within 24 hours due to circumstances beyond its control. In the case of an extension, the Department must specify how much time the system has to collect the sample.

(e) Sampling location.

(1) Any groundwater source sample required under section 13.3(a) must be collected at a location prior to any treatment of the groundwater source unless the Department approves a sampling location after treatment.

(2) If the system's configuration does not allow for sampling at the well itself, the system may collect a sample at a Department-approved location to meet the requirements of section 13.3(a) if the sample is representative of the water quality of that well. The Department has authority to require that sampling equipment be installed at the well itself.

(f) New sources. If directed by the Department, a groundwater system that places a new groundwater source into service after November 30, 2009, must conduct assessment source water monitoring under section 13.3(b). If directed by the Department, the system must begin monitoring before the groundwater source is used to provide water to the public.

(g) Public notification. A groundwater system with a groundwater source sample collected under sections 13.3 (a) or (b) that is fecal indicator-positive and that is not invalidated under section 13.3(d), including consecutive systems served by the groundwater source, must conduct public notification under section 9.2.2.

13.4 Treatment technique requirements for groundwater systems.

(a) Groundwater systems with a fecal indicator positive source water sample collected under section 13.3(a)(3) must comply with the requirements of this section. Groundwater systems with a fecal indicator positive source water sample collected under 13.3(a)(2), 13.3(a)(4), or 13.3(b) must comply with the requirements of this section if directed by the Department.

(1) Groundwater systems meet the conditions of sections 13.4(a) must implement one or more of the following corrective actions:

1. (i) Correct all significant deficiencies;
   1. (ii) Provide an alternate source of water;
      1. (iii) Eliminate the source of contamination; or (iv) Provide treatment that reliably achieves at least 4-log treatment of viruses before or at the first customer for the groundwater source.

(2) Unless the Department directs the groundwater system to implement a specific corrective action, the groundwater system must consult with the Department regarding the appropriate corrective action within 30 days of receiving written notice from a laboratory or direction from the Department. This consultation may take the form of a telephone conversation, electronic mail, meeting, or other mechanism agreed to by the Department.

(3) Within 45 days of receiving this notice or direction, the system must submit a written response to the Department indicating the actions the system will take to address fecal indicator positive groundwater source sample(s), and include a proposed schedule for completing those actions. The Department will review this notice. If approved, this notice shall constitute a Department approved corrective action plan as referenced below in section 13.4(a)(4)(ii).

(4) Within 120 days (or earlier if directed by the Department) of receiving written notice from a laboratory or direction from the Department the groundwater system must either:

1. (i) Have completed corrective action in accordance with applicable Department plan review processes or other Department guidance or direction, if any, including Department-specified interim measures; or (ii) Be in compliance with a Department-approved corrective action plan and schedule subject to the conditions specified in sections 13.4(a)(4)(ii)(A) and 13.4(a)(4)(ii) (B).
   1. (A) Any subsequent modifications to a Department-approved corrective action plan and schedule must also be approved by the Department.
      1. (B) If the Department specifies interim measures for protection of the public health pending Department approval of the corrective action plan and schedule or pending completion of the corrective action plan, the system must comply with these interim measures as well as with any schedule specified by the Department.

(b) Compliance monitoring (1) Existing groundwater sources. A groundwater system that is not required to meet the source water monitoring requirements of Article 13 for any groundwater source because it provides at least 4-log treatment of viruses before or at the first customer for any groundwater source before December 1, 2009, must notify the Department in writing that it provides at least 4-log treatment of viruses before or at the first customer for the specified groundwater source and begin compliance monitoring in accordance with section 13.4(b)(3) by December 1, 2009. Notification to the Department must include engineering, operational, or other information that the Department requests to evaluate the submission.

(2) New groundwater sources. A groundwater system that places a groundwater source in service after November 30, 2009, that is not required to meet the source water monitoring requirements of Article 13 because the system provides at least 4-log treatment of viruses before or at the first customer for the groundwater source must comply with the requirements of sections 13.4 (b)(2)(i), (b)(2)(ii) and (b)(2)(iii).

1. (i) The system must notify the Department in writing that it provides at least 4-log treatment of viruses before or at the first customer for the groundwater source. Notification to the Department must include engineering, operational, or other information that the Department requests to evaluate the submission.
   1. (ii) The system must conduct compliance monitoring as required under section 13.4(b)(3) within 30 days of placing the source in service.

(3) Monitoring requirements . A groundwater system subject to the requirements of sections 13.4(a), (b)(1) or (b)(2) must monitor the effectiveness and reliability of treatment for that groundwater source before or at the first customer as follows:

1. (i) Chemical disinfection (A) Groundwater systems serving greater than 3,300 people. A groundwater system that serves greater than 3,300 people must continuously monitor the residual disinfectant concentration using analytical methods specified in section 10.5(a)(2) at a location approved by the Department and must record the lowest residual disinfectant concentration each day that water from the groundwater source is served to the public. The groundwater system must maintain the Department-determined residual disinfectant concentration every day the groundwater system serves water from the groundwater source to the public. If there is a failure in the continuous monitoring equipment, the groundwater system must conduct grab sampling every four hours until the continuous monitoring equipment is returned to service. The system must resume continuous residual disinfectant monitoring within fourteen (14) days.
   1. (B) Groundwater systems serving 3,300 or fewer people. A groundwater system that serves 3,300 or fewer people must monitor the residual disinfectant concentration using analytical methods specified in section 10.5(a)(2) at a location approved by the Department and record the residual disinfection concentration each day that water from the groundwater source is served to the public. The groundwater system must maintain the Department-determined residual disinfectant concentration every day the groundwater system serves water from the groundwater source to the public. The groundwater system must take a daily grab sample during the hour of peak flow or at another time specified by the Department. If any daily grab sample measurement falls below the Department-determined residual disinfectant concentration, the groundwater system must take follow-up samples every four hours until the residual disinfectant concentration is restored to the Department- determined level. Alternatively, a groundwater system that serves 3,300 or fewer people may monitor continuously and meet the requirements of section 13.4(b)(3)(i)(A).
      1. (ii) Membrane filtration. A groundwater system that uses membrane filtration to meet the requirements Article 13 must monitor the membrane filtration process in accordance with all Department-specified monitoring requirements and must operate the membrane filtration in accordance with all Department-specified compliance requirements. A groundwater system that uses membrane filtration is in compliance with the requirement to achieve at least 4-log removal of viruses when:
         1. (A) The membrane has an absolute molecular weight cut-off (MWCO), or an alternate parameter that describes the exclusion characteristics of the membrane, that can reliably achieve at least 4-log removal of viruses;
         2. (B) The membrane process is operated in accordance with Department-specified compliance requirements; and (C) The integrity of the membrane is intact.
         3. (iii) Alternative treatment. A groundwater system that uses a Department-approved alternative treatment to meet the requirements of Article 13 by providing at least 4-log treatment of viruses before or at the first customer must:
         4. (A) Monitor the alternative treatment in accordance with all Department-specified monitoring requirements; and (B) Operate the alternative treatment in accordance with all compliance requirements that the Department determines to be necessary to achieve at least 4-log treatment of viruses.

(c) Discontinuing compliance monitoring or treatment. A groundwater system may discontinue compliance monitoring if the system notifies the Department and the Department determines and documents in writing that compliance monitoring is no longer necessary for that groundwater source. A system that discontinues compliance monitoring is subject to the source water monitoring and analytical methods requirements of sections 13.3 and 10.1.5. A system discontinuing compliance monitoring is still subject to the requirements for disinfection of groundwater in sections 13.2(b) and 13.2(c), unless the system has obtained a disinfection waiver under sections 13.2(d) and 13.2(e).

Articles 14-19 Reserved Article 20 Statement of Statutory Authority and Basis and Purpose (July 9, 2007 Rulemaking, Effective September 30, 2007) [Eff. 09/30/2007] Adoption of Section 7.4 - Enhanced Treatment for Cryptosporidium, Section 7.7 - Initial Distribution System Evaluations (IDSE) and Section 7.8 - Additional Requirements for Disinfection Byproducts Compliance with Amendments to Articles 1, 2, 7, 9, 10 and 12(c) of the Colorado Primary Drinking Water Regulations.

The provisions of the Colorado Revised Statutes (CRS), §25-1.5-202, provides specific statutory authority for adoption of these regulatory amendments. The Commission also adopted, in compliance with §24-4-103(4), CRS, the following statement of basis and purpose. Basis and Purpose All suppliers of drinking water in Colorado are subject to regulations adopted by the U.S. Environmental Protection Agency (EPA) under the Safe Drinking Water Act, (42 U.S.C. 300f et seq.) as well as by the Colorado Primary Drinking Water Regulations under the direction of the Water Quality Control Division (Division). Colorado has been granted primary enforcement responsibility (primacy) for the public water system supervision program under the federal Safe Drinking Water Act; however, in order to maintain primacy, states must promulgate regulations that are no less stringent than those adopted by the federal government. By retaining primacy, the Division is able to protect the public health by ensuring that public water systems provide safe drinking water to Colorado citizens and visitors and remains eligible both for program grants of $1.3 million and for federal revolving funds to assist water systems construct facility improvements of $13 million per year.

The Commission amends Articles 1, 2, 7, 9, 10, and 12(c) of the Colorado Primary Drinking Water Regulations to include:

- The provisions of the federal regulations as published in the Federal Register, Volume 71, Number 2, January 4, 2006, pages 388 through 493, National Primary Drinking Water Regulations: Stage 2 Disinfectants and Disinfection Byproducts Rule incorporated as sections 7.7 and 7.8. - The provisions of the federal regulations as published in the Federal Register, Volume 71, Number 3, January 5, 2006, pages 654 through 786, National Primary Drinking Water Regulations: Long Term 2 Enhanced Surface Water Rule incorporated as section 7.4. - Changes referencing the Commission throughout the regulation instead of the Board of Health in accordance with §25-8-202(1)(n), C.R.S.

- Numerous minor changes removing obsolete references and definitions that are not used within the regulation, and correction of spelling and typographical errors, including a number of non- substantive amendments to Article 10 in an effort to provide clarity (such as spelling out abbreviations), and to provide consistency in the citing of materials incorporated by reference (i.e. EPA and other nationally-recognized test methods). Many of the references to these test methods contained unnecessary information about the places where copies could be obtained. The Commission also updated the numbering of footnotes throughout the regulation for consistency. Sections 7.7 and 7.8 amend the existing regulatory requirements for disinfection byproducts for all public water systems in Colorado that add a disinfectant to the water in any part of the drinking water treatment process. Section 7.4 amends existing treatment requirements for all public water systems in Colorado that use surface water or ground water under the direct influence of surface water as drinking water sources.

These amendments and additions provide for increased public health protection against the potential risks for cancer and adverse reproductive and developmental health effects associated with disinfection byproducts and they provide further public health protection against Cryptosporidium and other microbial pathogens in drinking water.

The provisions of sections 7.7 and 7.8, Stage 2 Disinfectants and Disinfection Byproducts Rule, are summarized as follows:

- Adds record keeping requirements for turbidity and monitoring plans. - Establishes maximum contaminant level goals for chloroform, monochloroacetic acid and trichloroacetic acid.

- Finalizes maximum contaminant levels for disinfection byproducts. - Changes compliance from system-wide running annual average to locational running annual average at each monitoring location.

- Revises the requirements for reduced monitoring for bromate. - Specifies the best available technologies for control of disinfection byproducts in drinking water. - Revises the public notification requirements for total trihalomethanes and haloacetic acids. - Approves additional analytical methods for the determination of disinfectants and disinfection byproducts in drinking water.

The Stage 2 Disinfectants and Disinfection Byproducts Rule is designed to further minimize the formation of disinfection byproducts in the finished water in an effort to reduce the associated long-term cancer risks and reproductive and developmental health effects associated with disinfection byproducts while ensuring continued protection from microbiological contaminants that may pose an acute health threat. The Commission is simultaneously amending the Colorado Primary Drinking Water Regulations to include the provisions of the National Primary Drinking Water Regulations: Long Term 2 Enhanced Surface Water Treatment Rule to ensure that drinking water is microbiologically safe while considering the limits set for disinfection byproducts.

The provisions of section 7.4, Long Term 2 Enhanced Surface Water Rule, are summarized as follows: - Requires public water systems using surface water or ground water under the direct influence of surface water to monitor their source water to determine an average Cryptosporidium level. - Specifies criteria for sampling frequency and schedule, sampling location, use of previously collected data, providing treatment instead of monitoring, sampling by systems that use surface water for only part of the year, and monitoring of new plants and sources. - Establishes requirements for reporting monitoring results, using approved analytical methods, and using certified laboratories for all analysis.

- Supplements current regulations by establishing risk-targeted treatment technique requirements to control Cryptosporidium in public water systems using surface water or ground water under the direct influence of surface water. (Existing regulations remain in effect.) - Based on the results of the source water Cryptosporidium monitoring, systems will be classified in one of four (4) treatment categories or “bins.” The bin classification determines the degree of additional Cryptosporidium treatment, if any, the system must provide. - Adds the Microbial Toolbox options that systems must use if required to meet the additional Cryptosporidium treatment required based on bin classification. - Adds recordkeeping requirements specific to the changes. - Adds requirements for a “Special notice for repeated failure to conduct monitoring of the source water for Cryptosporidium and for failure to determine bin classification or mean Cryptosporidium level” to the Public Notification requirements.

- Specifies the Public Notification tier level of notice for violations related to these amendments. Implementing the Long Term 2 Enhanced Surface Water Rule will substantially lower rates of endemic crytosporidiosis, the illness caused by Cryptosporidium, which can be severe and sometimes fatal in sensitive subpopulations (e.g., infants, people with weakened immune systems). In addition, the treatment technique requirements will increase protection against other microbial pathogens like Giardia lamblia.

In addition to the inclusion of sections 7.4, 7.7 and 7.8, the Colorado Primary Drinking Water Regulations are amended as follows:

Article 1 1. Sections 1.1, 1.3, and 1.4 are amended to replace references to the State Board of Health with the Water Quality Control Commission.

2. Section 1.3 is amended to remove references to Colorado State Board of Health regulations from 1950 and 1954. These references are obsolete and no longer applicable.

3. Section 1.5.2 is amended to correct the definition of initial compliance period, to change the definition of consecutive systems, integrated systems, deletes the definition of supply systems, and adds the definitions of dual sample set, emergency source/connection, GAC 20, Initial Distribution System Evaluation (IDSE), finished water, locational running annual average (LRAA), Water Quality Control Commission, and wholesale systems. The definitions for consecutive systems, integrated systems and supply systems were Colorado specific and conflicted with or were redundant to the EPA definitions of consecutive systems and wholesale systems added as part of the Stage 2 Disinfection Byproducts Rule.

4. Section 1.5.2 is amended to include definitions for Bag filters, Bank filtration, Cartridge filters, Flowing stream, Lake/reservoir, Membrane filtration, Membrane module, Plant intake, Presedimentation, Recycle, Two-stage lime softening, and Uncovered finished water storage facility added by the Long Term 2 Enhanced Surface Water Rule.

5. Section 1.5.2 is amended to adjust numbering of definitions because of additions and removal of definitions that are no longer used in the regulation.

6. Section 1.6.3 is amended to add the record keeping requirements specified by the Stage 2 Disinfection Byproducts Rule and the Long Term 2 Enhanced Surface Water Rule.

7. Sections 1.8, 1.9 and 1.10 are amended to reflect the changes in definition for consecutive systems and wholesale systems.

8. Section 1.14 is amended to include the Laboratory Services Division as a place where materials incorporated by reference could be examined.

Article 2 Section 2.4 is amended to include the new maximum contaminant level goals (MCLG) for chloroform, monochloroacetic acid and trichloroacetic acid.

Article 7 1. Section 7.3.7 was moved to section 1.6.3 for consistency.

2. Section 7.4 and 7.5 are renumbered to 7.5 and 7.6 respectively because of the addition of the requirements for Long Term 2 Enhanced Surface Water Rule as section 7.4.

3. Section 7.6.3(b)(1)(iv) has been amended to add the following language: “Systems on a reduced monitoring schedule may remain on that reduced schedule as long as the average of all samples taken in the year (for systems which must monitor quarterly) or the result of the sample (for systems which must monitor no more frequently than annually) is no more than 0.060 mg/L and 0.045 mg/L for TTHMs and HAA5, respectively.”

This language was inadvertently omitted in the Federal Register when Stage 1 Disinfectants, Disinfection Byproducts Rule was printed. The Stage 2 Disinfection Byproducts Rule includes the reinstatement of this language to the Stage 1 DDBP Rule.

4. Section 7.6.3(b)(3)(ii) has been amended to change the requirements for reduced monitoring for bromate.

Article 9 1. Section 9.1.3(d)(iv) is amended to clarify reporting of results for the Stage 2 Disinfection Byproducts Rule in the community water system’s annual Consumer Confidence Report.

2. Tables 9-7 and 9-8 with endnotes is amended to update the health effects language for public notifications and tier requirements for violations of the Stage 2 Disinfection Byproducts Rule.

3. Section 9.2.11 is amended to add the special notice requirements for repeated failure to conduct monitoring of the source water for Cryptosporidium and for failure to determine bin classification or mean Cryptosporidium level and to identify the public notification tier levels for violations of the Long Term 2 Enhanced Surface Water Rule.

Article 10 Article 10 is amended to include additional approved analytical methods for drinking water analyses for disinfection byproducts and disinfection byproduct precursors. Article 12 Section 12.2(c) is amended to replace references to the State Board of Health with the Water Quality Control Commission.

Aspects of the Long Term 2 Enhanced Surface Water Rule that were not included in the Colorado Primary Drinking Water Regulations 1. Long Term 2 Enhanced Surface Water Rule, Section 40 CFR 141.712, and other CFR sections which allow systems to use unfiltered surface water were not incorporated in the regulation. Historically, the regulations promulgated by the Colorado State Board of Health have required all public water systems that use surface water or ground water under the direct influence of surface water to provide filtration.

2. Language from the Long Term 2 Enhanced Surface Water Rule, Section 40 CFR 141.714 that allows for the use of uncovered finished water storage facilities was not incorporated in the regulation. Historically, the regulations promulgated by the Colorado State Board of Health have required all public water systems to use only covered finished water storage facilities. There are currently no known uncovered finished water storage facilities in use and existing regulatory language prohibits the new construction of such a facility.

3. The federal rule includes requirements for systems to respond to significant deficiencies identified in sanitary surveys performed by EPA. Sanitary surveys of public water systems in Colorado are conducted by the Department and requirements for the system to respond in writing to significant deficiencies are already included in Article 11 of the Colorado Primary Drinking Water Regulations. Language from the federal rule that makes reference to sanitary surveys performed by EPA was not incorporated in the regulation.

1. Parties to Rulemaking Hearing

1. City of Boulder Article 21 STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE: July 14, 2008 Rulemaking Hearing; Effective Date September 30, 2008 Adoption of Article 13 – Groundwater Rule , with Amendments to Articles 1, 5, 7, 9, 10 and 11 of the Colorado Primary Drinking Water Regulations .

The Colorado Revised Statutes (CRS), §25-1.5-202, provide specific authority for adoption of these regulatory amendments. The Commission also adopted, in compliance with §24-4-103(4), CRS, the following statement of basis and purpose.

BASIS AND PURPOSE All suppliers of drinking water in Colorado are subject to regulations adopted by the U.S. Environmental Protection Agency (EPA) under the Safe Drinking Water Act, (42 U.S.C. 300f et seq.) as well as by the Colorado Primary Drinking Water Regulations under the direction of the Water Quality Control Division (Division). Colorado has been granted primary enforcement responsibility (primacy) for the public water system supervision program under the federal Safe Drinking Water Act. However, in order to maintain primacy, states must also promulgate new regulations that are no less stringent than those adopted by the federal government. By retaining primacy, the Division is able to protect the public health by ensuring that public water systems provide safe drinking water to Colorado citizens and visitors and remains eligible for program grants of $1.3 million and for federal revolving funds to assist public water systems construct facility improvements of $13 million per year. The Commission adds Article 13, and amends Articles 1, 5, 7, 9, 10 and 11 of the Colorado Primary Drinking Water Regulations to include:

- The provisions of the federal regulations as published in the Federal Register, Volume 71, Number 216, November 8, 2006, pages 65574 through 65660, National Primary Drinking Water Regulations : Ground Water Rule incorporated as Article 13. - Additional definitions and record keeping and reporting requirements. - Moving Article 7 concerning Disinfection for Groundwater to Article 13. - Additions to Consumer Notification requirements.

- Additions to Analytical Requirements and Laboratory Certification. - Changes to Article 11 concerning requirements to correct significant deficiencies and violations detected during sanitary surveys to better align with new requirements in the Groundwater Rule . The changes in this section that will become effective after December 1, 2009 will ensure uniformity of requirements regardless of water system type or source.

- Numerous minor changes removing obsolete references and definitions that are not used within the regulation, and correction of spelling and typographical errors. Article 13 amends and adds regulatory requirements for all public water systems in Colorado that use groundwater sources.

These amendments and additions provide for increased public health protection against microbial pathogens in public water systems that use groundwater sources. The provisions of Articles 11 and 13 are summarized as follows: - Increased frequency of sanitary surveys at groundwater systems to check for significant deficiencies in eight key operational areas.

- Specific requirements for public water systems to correct significant deficiencies in a timely fashion.

- A flexible program for identifying higher risk systems through existing Total Coliform Rule monitoring and State determinations.

- Groundwater source monitoring to detect fecal contamination at targeted groundwater systems that do not provide 4-log treatment of viruses.

- Treatment technique requirements to address fecal contamination in groundwater. - Compliance monitoring to ensure that 4-log treatment (99.99 percent removal/inactivation) of viruses is maintained where it is used to comply with this rule. The Groundwater Rule establishes a risk-targeted approach to identify groundwater systems that are susceptible to fecal contamination. The occurrence of fecal indicators in a drinking water supply is an indication of the potential presence of microbial pathogens that may pose a threat to public health. This rule requires groundwater systems with sources that are confirmed to contain indicators of fecal contamination to take corrective action to reduce potential cases of illnesses and deaths due to exposure to microbial pathogens.

In addition to the inclusion of Article 13, the Colorado Primary Drinking Water Regulations are amended as follows:

Article 1 1. Section 1.5.2 is amended to include definitions for 4-Log Treatment of Viruses, Assessment Source Water Monitoring, Compliance Monitoring, Groundwater System (GWS), Hydrogeologic Sensitivity Assessment (HAS), Inactivation, Triggered Source Water Monitoring, and Triggered Source Water Monitoring Plan added by the Groundwater Rule .

2. Section 1.5.2(119) is amended to include additional language for clarification.

3. Section 1.5.2 is amended to adjust numbering of definitions because of the added definitions.

4. Section 1.6.3 is amended to add the record keeping requirements specified by the Groundwater Rule .

5. Section 1.6.4 is amended to add the reporting requirements specified by the Groundwater Rule . Article 5 1. Section 5.1.2 (e) and (h) were amended to remove language that was not consistent with federal drinking water requirements.

Article 7 1. Section 7.9 Disinfection for Groundwater was moved to section 13.2 for consistency. Article 9 1. Section 9.1.3(h) is amended to include reporting requirements for the Groundwater Rule in the community water system’s annual Consumer Confidence Report.

2. Section 9.1.3 is amended to adjust numbering because of additions.

3. Table 9-1 Table of Regulated Contaminants is amended to add Fecal Indicators.

4. Table 9-4 Violation Categories and Other Situations Requiring a Tier 1 Public Notice is amended to include requirements of the Groundwater Rule .

5. Table 9-5 Violation Categories and Other Situations Requiring a Tier 2 Public Notice is amended to include requirements of the Groundwater Rule .

6. Table 9-6 Violation Categories and Other Situations Requiring a Tier 3 Public Notice is amended to include requirements of the Groundwater Rule .

7. Table 9-7 is amended to update language for public notification concerning waiver of disinfection.

8. Tables 9-7 and 9-8 with endnotes is amended to update the health effects language for public notifications and tier requirements for violations of the Groundwater Rule .

9. Special notice requirements for groundwater systems with a waiver of disinfection is added as section 9.2.12.

10. Section 9.2.12 List of Acronyms Used in Public Notification Regulation, is renumbered as Section 9.2.13 to adjust numbering because of previous addition and is amended to add the acronym GWR for the Groundwater Rule.

Article 10 1. Section 10.1.5 is added to include additional approved analytical methods for fecal indicators analyses in drinking water sources.

2. Article 10 is amended to adjust numbering because of additions. Article 11 1. Section 11.2 is amended to increase the frequency of sanitary surveys at groundwater systems in accordance with the Groundwater Rule .

2. Section 11.3 is amended to adjust numbering.

3. Section 11.4 is amended to align with requirements concerning significant deficiencies in 13.4 of the Groundwater Rule .

_____________________________________________________ Editor’s Notes History Articles 1, 2, 7, 9, 19, 12 – 20 Eff. 09/302007. Article 7 Eff. 11/01/2007. Articles 1, 5, 6, 7, 8, 9, 10, 11, 12, 13, 21 Eff. 09/30/2008. Section 7.9 Repealed Eff. 09/30/2008.