246-290-72004  <<  246-290-72005 >>   246-290-72006

Report contents—Information on detected contaminants.

(1) This section specifies the requirements for information to be included in each report for contaminants subject to mandatory monitoring. It applies to:
(a) Contaminants subject to an MCL, action level, maximum residual disinfectant level or treatment technique (regulated contaminants);
(b) Detected unregulated contaminants for which monitoring is required under WAC 246-290-300(10) and 40 C.F.R. 140.40; and
(c) Disinfection byproducts for which monitoring is required by WAC 246-290-300(6) and 40 C.F.R. 141.142 or microbial contaminants for which monitoring is required by WAC 246-290-300(3) and 40 C.F.R. 141.143, except as provided under WAC 246-290-72006(1), and which are detected in the finished water.
(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 state monitoring and analytical requirements during the previous calendar year except that:
(a) Where a system is allowed to monitor for regulated contaminants less 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 five years need be included.
(b) Results of monitoring in compliance with 40 C.F.R. 141.142 and 40 C.F.R. 141.143 need only be included for five 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.
(4) For detected regulated contaminants listed in WAC 246-290-72012, the table(s) must contain:
(a) The MCL for that contaminant expressed as a number equal to or greater than 1.0 (as provided in WAC 246-290-72012);
(b) The MCLG for that contaminant expressed in the same units as the MCL;
(c) 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 WAC 246-290-72004;
(d) For contaminants subject to an MCL, except turbidity, total coliform, and E. coli, the highest contaminant level used to determine compliance with a National Primary Drinking Water Regulation and the range of results, as follows:
(i) When compliance with the MCL is determined annually or less frequently: The highest detected level at any sampling point and the range of results expressed in the same units as the MCL.
(ii) When compliance with the MCL is determined by calculating a running annual average of all samples taken at a sampling point: The highest average of any of the sampling points and the range of all sampling points expressed in the same units as the MCL. For the TTHM and HAA5 MCLs determined on the basis of the LRAA, systems must include the highest LRAA 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 location exceeds the TTHM or HAA5 MCL, the system must include the LRAA for all locations that exceed the MCL.
(iii) When compliance with the MCL is determined on a system-wide basis by calculating a running annual average of all samples at all sampling points: 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 WAC 246-290-300 (6)(b)(i)(F) 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.
(iv) Note to WAC 246-290-72005 (4)(d): When rounding of results to determine compliance with the MCL is allowed by the regulations, rounding should be done prior to multiplying the results by the factor listed in WAC 246-290-72012;
(e) For turbidity.
(i) When it is reported under chapter 246-290 WAC Part 6, Subpart C: The highest average monthly value.
(ii) When it is reported under the requirements of chapter 246-290 WAC Part 6, Subpart D: The highest monthly value. The report should include an explanation of the reasons for measuring turbidity.
(iii) When it is reported under chapter 246-290 WAC Part 6, Subpart B: The highest single measurement and the lowest monthly percentage of samples meeting the turbidity limits specified in chapter 246-290 WAC Part 6, Subpart B for the filtration technology being used. The report should include an explanation of the reasons for measuring turbidity;
(f) 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;
(g) For E. coli analytical results under WAC 246-290-300 (3)(e) through (g): The total number of positive samples; and
(h) The likely source(s) of detected contaminants to the best of the purveyor's knowledge. Specific information regarding contaminants may be available in sanitary surveys and source water assessments, and should be used when available to the purveyor. If the purveyor lacks specific information on the likely source, the report must include one or more of the typical sources for that contaminant listed in WAC 246-290-72012 which are 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 WAC 246-290-72012.
(7) For detected unregulated contaminants for which monitoring is required, 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.
[Statutory Authority: RCW 43.20.050 and 70.119A.080. WSR 17-01-062, § 246-290-72005, filed 12/14/16, effective 1/14/17. Statutory Authority: RCW 43.20.050. WSR 09-21-045, § 246-290-72005, filed 10/13/09, effective 1/4/10. Statutory Authority: RCW 70.119A.180 and 43.20.050. WSR 08-03-061, § 246-290-72005, filed 1/14/08, effective 2/14/08. Statutory Authority: RCW 43.20.050 (2) and (3) and 70.119A.080. WSR 03-08-037, § 246-290-72005, filed 3/27/03, effective 4/27/03. Statutory Authority: RCW 43.20.050. WSR 00-15-080, § 246-290-72005, filed 7/19/00, effective 8/19/00.]
Site Contents
Selected content listed in alphabetical order under each group