1. (a) Monitoring and analysis of the synthetic organic chemical (SOC) contaminants listed in §290.103(3)(A) of this title (relating to Standards of Chemical Quality) for the purposes of determining compliance with the maximum contaminant level shall be conducted as follows.

   1. (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 subsequent sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.
   2. (2) Surface 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 subsequent sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.
   3. (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. (4) Synthetic organic chemical (SOC) monitoring frequency.

      1. (A) Each community and non-transient non-community water system shall take four consecutive quarterly samples for each contaminant listed in §290.103(3)(A) of this title during each compliance period beginning with the initial compliance period.
      2. (B) Systems serving more than 3,300 persons which do not detect a contaminant in the initial compliance period may reduce the sampling frequency to a minimum of two consecutive quarterly samples in one year during each repeat compliance period.
      3. (C) Systems serving less than or equal to 3,300 persons which do not detect a contaminant in the initial compliance period may reduce the sampling frequency to a minimum of one sample during each repeat compliance period.

   5. (5) The commission may grant a waiver from the requirement of paragraph (4) of this subsection after evaluating the following factors: knowledge of previous use (including transport, storage, or disposal) of the contaminant within the watershed or zone of influence of the water source(s). If a determination by the commission reveals no previous use of the contaminant within the watershed or zone of influence, a waiver may be granted. If previous use of the 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;
      2. (B) the proximity of the system to a potential point or non-point source of contamination. Point sources include spills and leaks of chemicals at or near a water treatment facility or at drinking water sources, 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 insects, weeds, or pests on agricultural areas, forest lands, home and garden property, or other land application uses;
      3. (C) the environmental persistence and transport of the pesticide herbicide or contaminant;
      4. (D) how well the water source is protected against contamination due to such factors as depth of the well, type of soil, and the integrity of well construction. Surface water systems must consider watershed vulnerability and protection;
      5. (E) elevated nitrate levels at the water supply source; and
      6. (F) use of PCBs in equipment used in the production, storage, or distribution of water (i.e., PCBs used in pumps, transformers, etc.).
   6. (6) The commission will consider the waiver for each compliance period.

   7. (7) If an organic SOC contaminant listed in §290.103(3)(A) of this title (relating to Standards of Chemical Quality) is detected, as defined in 40 CFR 141.24(h)(18), in any sample, then:

      1. (A) The system must monitor quarterly at each sampling point at which a detection occurs.
      2. (B) The commission may decrease the quarterly monitoring requirement specified in subparagraph (A) of this paragraph provided it has determined that the system is reliably and consistently below the MCL. In no case shall the commission make this determination unless a groundwater system takes a minimum of two consecutive quarterly samples and a surface water system takes a minimum of four consecutive quarterly samples.
      3. (C) After the commission determines that a system is reliably and consistently below the MCL, it may allow the system to monitor annually. Systems which monitor annually must monitor during the quarter that previously yielded the highest analytical result.
      4. (D) Systems which have three consecutive annual samples with no detection of a contaminant be granted a waiver as specified in paragraph (6) of this subsection.
      5. (E) If monitoring results in detection of one or more of certain related contaminants (aldicarb, aldicarb sulfone, aldicarb sulfoxide and heptachlor, heptachlor epoxide), then subsequent monitoring shall analyze for all related contaminants.
   8. (8) Systems which violate the MCLs of §290.103(3)(A) of this title as determined by paragraph (11) of this subsection must monitor quarterly. After a minimum of four quarterly samples show the system is in compliance and the commission determines the system is reliably and consistently below the MCL, as specified in paragraph (11) of this subsection, the system shall monitor at the frequency specified in paragraph (7)(C) of this subsection.
   9. (9) The commission may require a confirmation sample for positive or negative results. If a confirmation sample is required by the commission, the result must be averaged with the first sampling result and the average used for the compliance determination as specified by paragraph (15) of this subsection. The commission has discretion to delete results of obvious sampling errors from this calculation.

   10. (10) The commission may reduce the total number of samples required from a system for analysis by allowing the use of compositing. Composite samples from a maximum of five sampling points are allowed. Compositing of samples must be done in the laboratory and analyzed within 14 days of sample collection.

       1. (A) If, in the composite sample, a detection of one or more SOC contaminants listed in §290.103(3)(A) of this title occurs, then a follow-up sample must be taken from each sampling point included in the composite and analyzed within 14 days of collection.
       2. (B) If duplicates of the original sample taken from each sampling point used in the composite are available, the commission may use these duplicates instead of resampling. The duplicate must be analyzed within 14 days of collection and the results reported to the commission.
       3. (C) Compositing may only be permitted at sampling points within a single system.

   11. (11) Compliance with the MCLs of §290.103(3)(A) of this title shall be determined based on the analytical results obtained at each sampling point.

       1. (A) For systems which are conducting monitoring at a frequency greater than annual, compliance is determined by a running annual average of all samples taken at each sampling point. If the annual average of any sampling point is greater than the MCL, then the system is out of compliance. If the initial sample or a subsequent sample would cause the annual average to be exceeded, then the system is out of compliance immediately. Any samples below the detection limit shall be calculated as zero for purposes of determining the annual average.
       2. (B) If monitoring is conducted annually, or less frequently, the system is out of compliance if the level of a contaminant at any sampling point is greater than the MCL. If a confirmation sample is required by the commission, the determination of compliance will be based on the average of the two samples.
       3. (C) If a public water system has a distribution system separable from other parts of the distribution system with no interconnections, the commission may allow the system to give public notice to only that portion of the system which is out of compliance.
   12. (12) If monitoring data collected after January 1, 1990, are generally consistent with the requirements of subsection (a) of this section, then the commission may allow systems to use that data to satisfy the monitoring requirement for the initial compliance period.
   13. (13) The commission 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, etc.).
   14. (14) The commission has the authority to determine compliance or initiate enforcement action based upon analytical results and other information compiled by their sanctioned representatives and agencies.
   15. (15) Each public water system shall monitor at the time designated by the commission within each compliance period.

2. (b) Beginning with the initial compliance period: sampling and analysis of the VOC contaminants listed in §290.103(3)(B) of this title (relating to Standards of Chemical Quality), for the purpose of determining compliance with the MCLs shall be conducted as follows.

   1. (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 subsequent sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.
   2. (2) Surface water systems (and combined surface/groundwater 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 subsequent sample must be taken at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.
   3. (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. (4) Each community and non-transient, non-community water system shall take four consecutive quarterly samples for each contaminant listed in §290.103(3)(B) of this title during each compliance period, beginning with the initial compliance period.
   5. (5) If the initial monitoring for VOC contaminants listed in §290.103(3)(B) of this title as allowed in paragraph (16) of this subsection has been completed by December 31, 1992, and the system did not detect any contaminant listed in §290.103(3)(B) of this title then each ground and surface water system shall take one sample annually beginning with the initial compliance period.
   6. (6) After a minimum of three years of annual sampling, the commission may allow groundwater systems with no previous detection of any contaminant listed for VOCs in §290.103(3)(B) of this title to take one sample during each compliance period.
   7. (7) Each community and non-transient groundwater system which does not detect a contaminant listed in §290.103(3)(B) of this title may be granted a waiver from the requirements of paragraphs (5) and (6) of this subsection after completing the initial monitoring. (For the purposes of this section, detection is defined as greater than or equal to 0.0005 mg/liter.) A waiver shall be effective for no more than six years (two compliance periods).

   8. (8) The commission may grant a waiver after evaluating the following factor(s): the knowledge of previous use (including transport, storage, or disposal) of the contaminant within the watershed or zone of influence of the water sources. If a determination by the commission reveals no previous use of the contaminant within the watershed or zone of influence, a waiver may be granted. If previous use of the 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;
      2. (B) the proximity of the system to a potential point or non-point source of contamination. Point sources include spills and leaks of chemicals at or near a water treatment facility or at drinking water sources manufacturing, distribution, or storage facilities, or from hazardous and municipal waste landfills and other waste handling or treatment facilities;
      3. (C) the environmental persistence and transport of the contaminants;
      4. (D) the number of persons served by the public water system and the proximity of a smaller system to a larger system;
      5. (E) how well the water source is protected against contamination (i.e., is it a surface or groundwater system). Groundwater systems must consider factors such as depth of the well, the type of soil, and well construction. Surface water systems must consider watershed protection.
   9. (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 paragraph (8) of this subsection. Based on this updated vulnerability assessment the commission must reconfirm that the system is not vulnerable. If the commission does not make this reconfirmation within three years of the initial determination, then the waiver is invalid and the system is required to sample annually as specified in paragraph (5) of this subsection.
   10. (10) Each community and non-transient surface water system which does not detect a contaminant listed for VOCs in §290.103(3)(B) of this title may be considered by the commission for a waiver from the requirements of paragraph (5) of this subsection after completing the initial monitoring. Systems meeting this criteria must be determined by the commission to be non-vulnerable based on a vulnerability assessment during each compliance period. Each system receiving a waiver shall sample at the frequency specified by the commission (if any).

   11. (11) If a VOC contaminant listed in §290.103(3)(B) of this title (relating to Standards of Chemical Quality) is detected at a level exceeding 0.0005 mg/liter in any sample, then:

       1. (A) the system must monitor quarterly at each sampling point which resulted in a detection;
       2. (B) the commission may decrease the quarterly monitoring requirement specified in subparagraph (A) of this paragraph provided it has determined that the system is reliably and consistently below the maximum contaminant level. In no case shall the commission 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;
       3. (C) if the commission determines that the system is reliably and consistently below the MCL, the commission may allow the system to monitor annually. Systems which monitor annually must monitor during the quarter which previously yielded the highest analytical result;
       4. (D) systems which have three consecutive annual samples with no detection of a contaminant may be granted a waiver as specified in paragraph (7) of this subsection;
       5. (E) 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 was detected. If the result of the first analysis does not detect vinyl chloride, the commission may reduce the quarterly monitoring frequency for vinyl chloride to one sample during each compliance period. Surface water systems are required to monitor for vinyl chloride as specified by the commission.
   12. (12) Systems which violate the VOC MCLs of §290.103(3)(B) of this title, as determined by paragraph (15) of this subsection, must monitor quarterly. After a minimum of four consecutive quarterly samples which show the system is in compliance as specified in paragraph (15) of this subsection and the commission determines that the system is reliably and consistently below the maximum contaminant level, the system may monitor at the frequency and time specified in paragraph (11)(C) of this subsection.
   13. (13) The commission may require a confirmation sample for positive or negative results. If a confirmation sample is required by the commission, the result must be averaged with the first sampling result and the average is used for the compliance determination as specified by paragraph (15) of this subsection. The commission has discretion to delete results of obvious sampling errors from this calculation.

   14. (14) The commission 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. Compositing of samples must be done in the laboratory and analyzed within 14 days of sample collection.

       1. (A) If the VOC concentration in the composite sample is greater than or equal to 0.0005 mg/liter for any contaminant listed in §290.103(3)(B) of this title, then a follow-up sample must be taken and analyzed within 14 days from each sampling point included in the composite.
       2. (B) If duplicates of the original sample taken from each sampling point used in the composite are available, the system may use these instead of resampling. The duplicate must be analyzed and the results reported to the commission within 14 days of collection.
       3. (C) Compositing may only be permitted by the commission at sampling points within a single system.
       4. (D) Procedures for compositing VOC samples are as stated in 40 CFR §141.24(f)(14)(iv).

   15. (15) Compliance with §290.103(3)(B) of this title shall be determined based on the analytical results obtained at each sampling point.

       1. (A) For systems which are conducting monitoring at a frequency greater than annual, compliance is determined by a running annual average of all samples taken at each sampling point. If the annual average of any sampling point is greater than the MCL, then the system is out of compliance. If the initial sample or a subsequent sample would cause the annual average to be exceeded, then the system is out of compliance immediately.
       2. (B) If monitoring is conducted annually, or less frequently, the system is out of compliance if the level of a contaminant at any sampling point is greater than the MCL. If a confirmation sample is required by the commission, the determination of compliance will be based on the average of the two samples.
       3. (C) If a public water system has a distribution system separable from other parts of the distribution system with no interconnections, the commission may allow the system to give public notice to only that area served by that portion of the system which is out of compliance.
   16. (16) The commission may allow the use of monitoring data collected after January 1, 1988 for purposes of initial monitoring compliance. If the data are generally consistent with the other requirements in this section, the commission may use these data (i.e., a single sample rather than four quarterly samples) to satisfy the initial monitoring requirement of paragraph (4) of this subsection. Systems which use these samples and do not detect any contaminant listed in §290.103(3)(B) of this title shall begin monitoring annually in accordance with paragraph (5) of this subsection beginning January 1, 1993.
   17. (17) The commission may increase required monitoring where necessary to detect variations within the system.
   18. (18) Each public water system shall monitor at the time designated by the commission within each compliance period.
   19. (19) Analysis of unregulated contaminants shall be as specified in 40 CFR §141.40. The commission adopts by reference Federal Regulations referred to in this subsection. Copies are available for review in the Water Utilities Division, Texas Natural Resource Conservation Commission, P.O. Box 13087, Austin, Texas 78711-3087.
3. (c) Acrylamide and epichlorohydrin treatment techniques. Each public water system must certify annually to the commission (using third party or manufacturer's certification) that when acrylamide or epichlorohydrin are used in drinking water systems, the combination (or product) of dose and monomer level does not exceed 0.05% dosed at 1 ppm (or equivalent) for acrylamide and 0.01% dosed at 20 ppm (or equivalent) for epichlorohydrin.

Source Note:The provisions of this §290.109 adopted to be effective April 15, 1994, 19 TexReg 2282; amended to be effective December 7, 1994, 19 TexReg 9368.