PURPOSE: This rule establishes the monitoring requirements which are applicable to lead and copper in drinking water.

1. (1) Sample Site Location. A water system shall use the information on lead, copper and galvanized steel that it is required to collect under this section when conducting a materials evaluation. When an evaluation of the information collected pursuant to this section is insufficient to locate the requisite number of lead and copper sampling sites that meet the targeting criteria in subsection (1)(A) of this rule, the water system shall review the sources of information listed in this rule in order to identify a sufficient number of sampling sites. In addition, the system shall seek to collect that information where possible in the course of its normal operations (for example, checking service line materials when reading water meters or performing maintenance activities); all plumbing codes, permits and records in the files of the building department(s) which indicate the plumbing materials that are installed within publiclyand privately-owned structures connected to the distribution system; 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 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.

   1. (A) By the applicable date for commencement of monitoring under subsection (4)(A) of this rule, each water system shall complete a materials evaluation of its distribution system in order to identify a pool of targeted sampling sites that meets the requirements of this section and which is sufficiently large to ensure that the water system can collect the number of lead and copper tap samples required in section (3) of this rule. 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.

      1. (B) Community water supply systems

shall identify whether the following construction materials are present in their distribution system:

1. 1. Lead from piping, solder caulking,

interior lining of distribution mains, alloys and home plumbing;

1. 2. Copper from piping and alloys, ser-

vice lines and home plumbing;

1. 3. Ferrous piping materials, such as cast

iron and steel;

1. 4. Asbestos cement pipe;
2. 5. Vinyl-lined asbestos cement pipe; and
3. 6. Coal tar-lined pipes and tanks.
4. (C) The sampling sites selected for a community water system’s sampling pool (tier 1 sampling sites) shall consist of single-family structures that contain copper pipes with lead solder installed after 1982, or contain lead pipes, or are served by a lead service line, or a combination of these. When multiple-family residences comprise at least twenty percent (20%) of the structures served by a water system, the system may include these types of structures in its sampling pool.
5. (D) 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 contain copper pipes with lead solder installed after 1982, or contain lead pipes, or are served by a lead service line, or a combination of these.
6. (E) 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.
7. (F) The sampling sites selected for a nontransient noncommunity water system (tier 1 sampling sites) shall consist of buildings that contain copper pipes with lead solder installed after 1982, or contain lead pipes, or are served by a lead service line, or a combination of these.
8. (G) A nontransient noncommunity water system with insufficient tier 1 sites that meet the targeting criteria in subsection (1)(F) of this rule shall complete its sampling pool with sampling sites that contain copper pipes with lead solder installed before 1983.
9. (H) Any water system whose sampling pool does not consist exclusively of tier 1 sites shall demonstrate in a letter submitted to the department under 10 CSR 60-7.020(1)(B) why a review of the information listed in subsection (1)(B) of this rule was inadequate to locate a sufficient number of tier 1 sites. Any community water system which includes tier 3 sampling sites in its sampling pool shall demonstrate in a letter why it was unable to locate a sufficient number of tier 1 and tier 2 sampling sites.
10. (I) Any water system whose distribution system contains lead service lines shall draw fifty percent (50%) of the samples it collects during each monitoring period from sites that contain lead pipes or copper pipes with lead solder and fifty percent (50%) of those 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 demonstrate in a letter submitted to the department under 10 CSR 60-7.020(1)(D) why the system was unable to locate a sufficient number of these sites. This water system shall collect first-draw samples from all of the sites identified as being served by these lines.

1. (2) Sample Collection Methods.

   1. (A) All tap samples for lead and copper collected in accordance with this rule, with the exception of lead service line samples collected under 10 CSR 60-15.050(3), shall be first-draw samples.

   2. (B) Each first-draw tap sample for lead and copper shall be one liter (1 l) in volume and have stood motionless in the plumbing system of each sampling site for at least six (6) hours. First-draw samples from residential housing shall be collected from the coldwater kitchen tap or bathroom sink tap. Firstdraw samples from a nonresidential building 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

      (930/96) Rebecca McDowell Cook

specified in this section. To avoid problems of residents handling nitric acid, acidification of first-draw samples may be done in the laboratory up to fourteen (14) days after the sample is collected. If the sample is not acidified immediately after collection, then the sample must stand in the original container for at least twenty-eight (28) hours after acidification. If a system allows residents to perform sampling, the system may not challenge, based on alleged errors in sample collection, the accuracy of sampling results.

1. (C) Each service line sample shall be one

1. (1) liter in volume and have stood motionless in the lead service line for at least six (6) hours. Lead service line samples shall be collected in one (1) of the following three (3) ways:

   1. 1. 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. 2. Tapping directly into the lead service

line; or

1. 3. If the sampling site is a building con-

structed as a single-family residence, allowing the water to run until there is a significant change in temperature which would be indicative of water that has been standing in the lead service line.

1. (D) A water system shall collect each firstdraw 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.

1. (3) Water systems shall collect at least one (1) sample during each monitoring period specified in section (4) from the number of sites listed in the first column following (standard monitoring). A system conducting reduced monitoring under subsection (4)(D) may collect one (1) sample from the number of sites specified in the second column during each monitoring period specified in subsection (4)(D).

   System Size # of sites # of sites (# People (Standard (Reduced Served) Monitoring) Monitoring) >100,000 100 50 10,001–100,000 60 30 3301–10,000 40 20 501– 3300 20 10 101–500 10 5 5 5 @100

2. (4) Timing of Monitoring.

   1. (A) Initial Tap Sampling. The first six (6)- month monitoring period for small (serving less than or equal to three thousand three hundred (3300) persons), medium-size (serving three thousand three hundred one to fifty thousand (3301–50,000) persons) and large (serving more than fifty thousand (>50,000) persons) systems shall begin on the following dates:

      First Six (6)-Month Monitoring Period

   System Size Begins On

(# People Served) >50,000 January 1, 1992 3301–50,000 July 1, 1992 July 1, 1993 @3300

1. 1. All large systems shall monitor during

two (2) consecutive six (6)-month periods.

1. 2. All small and medium-size systems

shall monitor during each six (6)-month monitoring period until the system—

1. A. Exceeds the lead or copper action

level and is therefore required to implement the corrosion control treatment requirements under 10 CSR 60-15.020, in which case the system shall continue monitoring in accordance with subsection (4)(B) of this rule; or

1. B. Meets the lead and copper action

levels during two (2) consecutive six (6)- month monitoring periods, in which case the system may reduce monitoring in accordance with subsection (4)(D) of this rule.

1. (B) Monitoring After Installation of Corrosion Control and Source Water Treatment.

   1. 1. Any large system which installs opti-

mal corrosion control treatment pursuant to 10 CSR 60-15.020(1)(A)4. shall monitor during two (2) consecutive six (6)-month monitoring periods by the date specified in 10 CSR 60-15.020(1)(A)5.

1. 2. Any small or medium-size system

which installs optimal corrosion control treatment pursuant to 10 CSR 60-15.020(2)(A)5. shall monitor during two (2) consecutive six (6)-month monitoring periods by the date specified in 10 CSR 60-15.020(2)(A)6.

1. 3. Any system which installs source

water treatment pursuant to 10 CSR 60- 15.040(1)(C) shall monitor during two (2) consecutive six (6)-month monitoring periods by the date specified in 10 CSR 60- 15.040(1)(D).

1. (C) After the department specifies the values for water quality control parameters under 10 CSR 60-15.030(6), the system shall monitor during each subsequent six (6)- month monitoring period, with the first mon- 10 CSR 60-15

itoring period to begin on the date the department specifies the optimal values under 10 CSR 60-15.030(6).

1. (D) Reduced Monitoring.

   1. 1. A small or medium-size water system

that meets the lead and copper action levels during each of two (2) consecutive six (6)- month monitoring periods may reduce the number of samples in accordance with section (3) of this rule and reduce the frequency of sampling to once per year.

1. 2. Any water system that maintains the range of values for the water quality control parameters reflecting optimal corrosion control treatment specified by the state under 10 CSR 60-15.030(6) during each of two (2) consecutive six (6)-month monitoring periods may request that the department allow the system to reduce the frequency of monitoring to once per year and to reduce the number of lead and copper samples in accordance with section (3) of this rule. The department shall review the information submitted by the water system and shall make its decision in writing, setting forth the basis for its determination. 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. 3. A small or medium-size water system

that meets the lead and copper action levels during three (3) consecutive years of monitoring may reduce the frequency of monitoring for lead and copper from annually to once every three (3) 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 10 CSR 60-15.030(6) during three (3) consecutive years of monitoring may request that the department allow the system to reduce the frequency of monitoring from annually to once every three (3) years. The department shall review the information submitted by the water system and shall make its decision in writing, setting forth the basis for its determination. 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. 4. A water system that reduces the num-

ber and frequency of sampling shall collect these samples from sites included in the pool of targeted sampling sites identified in section (1) of this rule. Systems sampling annually or less frequently shall conduct the lead and copper tap sampling during the months of June, July, August or September.

1. 5. A small or medium-size water system

subject to reduced monitoring that exceeds the lead or copper action level shall resume sampling in accordance with subsection (4)(C) of this rule and collect the number of samples specified for standard monitoring under section (3) of this rule. This system also shall conduct water quality parameter monitoring in accordance with 10 CSR 60- 15.080(2),(3) or (4) (as appropriate) during the monitoring period in which it exceeded the action level. Any water system subject to reduced monitoring frequency that fails to operate within the range of values for the water quality control parameters specified by the department under 10 CSR 60-15.030(6) shall resume tap water sampling in accordance with subsection (4)(C) of this rule and collect the number of samples specified for standard monitoring under section (3) of this rule.

1. (5) The results of any monitoring conducted, in addition to the minimum requirements of this section, shall be considered by the system and the department in making any determinations (that is, calculating the ninetieth percentile lead or copper level) under this rule.

AUTHORITY: section 640.100, RSMo (1994).* Original rule filed Aug. 4, 1992, effective May 6, 1993. Amended: Filed Feb. 1, 1996, effective Oct. 30, 1996. *Original authority 1939, amended 1978, 1981, 1982, 1988, 1989, 1992, 1993, 1995.