WAC 246-290-72230

This section takes effect on January 1, 2027.

(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, federal action level, SAL, TT, or MRDL (regulated contaminants); and

(b) Detected contaminants without an MCL, federal action level, SAL, TT, or MRDL for which monitoring is required.

(2) The data relating to these contaminants must be presented in the reports in a manner that is clear and understandable for consumers. For example, the data may 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)(a) Except under (b) of this subsection, the data must be derived from data collected to comply with EPA and state monitoring and analytical requirements during the previous calendar year, or the most recent calendar year before the previous calendar year.

(b) When a system is allowed to monitor for regulated contaminants less than once a year, the contaminant data section 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.

(c) No data older than five years need be included.

(4) For each detected regulated contaminant listed in WAC 246-290-72400, the contaminant data section(s) must contain:

(a) The MCL or SAL for that contaminant expressed as a number equal to or greater than 1.0 (as provided in WAC 246-290-72400);

(b) The MCLG for that contaminant expressed in the same units as the MCL;

(c) If there is no MCL or SAL for a detected contaminant, the contaminant data section(s) 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, action level, or both, as appropriate, specified in WAC 246-290-72220;

(d) Except for turbidity and E. coli, the contaminant data section(s) for contaminants with an MCL or SAL must contain the highest contaminant level used to determine compliance with a SAL or a National Primary Drinking Water Regulation and the range of results, as follows:

(i) When compliance with the MCL or SAL is determined annually or less frequently: The highest detected level at any sampling location and the range of results expressed in the same units as the MCL or SAL.

(ii) When compliance with the MCL or SAL is determined by calculating a running annual average of all samples taken at a sampling location: The highest average of any of the sampling locations and the range of individual sample results for all sampling locations expressed in the same units as the MCL or SAL. 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 rounding of results to determine compliance with the MCL or SAL is allowed by the regulations, rounding should be done prior to multiplying the results by the factor listed in WAC 246-290-72400;

(e) For turbidity:

(i) When it is reported under WAC 246-290-670 through 246-290-678: The highest average monthly value.

(ii) When it is reported under the requirements of WAC 246-290-686 through 246-290-696: The highest monthly value. The report should include an explanation of the reasons for measuring turbidity.

(iii) When it is reported under WAC 246-290-650 through 246-290-668: The highest single measurement and the lowest monthly percentage of samples meeting the turbidity limits specified in WAC 246-290-650 through 246-290-668 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 246-290-72400 that 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 contaminant data section(s) should differentiate contaminant data for each service area and the report should identify each separate distribution system. For example, if displayed in a table, it should contain a separate column for each service area. Alternatively, systems could produce separate reports tailored to include data for each service area.

(6)(a) The detected contaminant data section(s) must clearly identify any data indicating violations of MCLs, MRDLs, or treatment techniques.

(b) The report must contain a clear and readily understandable explanation of each violation including:

(i) The length of the violation;

(ii) The potential adverse health effects using the relevant language of WAC 246-290-72400; and

(iii) Actions taken by the system to address the violation.

(7) Detected contaminants without an MCL, SAL, federal action level, TT, or MRDL for which monitoring is required, the reports must present the average and range at which the contaminant was detected. The report must include a brief explanation of the reasons for monitoring for unregulated contaminants such as:

(a) Unregulated contaminant monitoring helps EPA to determine where certain contaminants occur and whether EPA should consider regulating those contaminants in the future.

(b) An alternative educational statement approved by the department.

(8) For systems that exceeded the lead action level in 40 C.F.R. 141.80(c) as adopted under WAC 246-290-025:

(a) The detected contaminant data section must clearly identify the exceedance if any corrective action has been required by EPA or the department during the monitoring period covered by the report.

(b) The report must include:

(i) A clear and readily understandable explanation of the exceedance;

(ii) The steps consumers can take to reduce their exposure to lead in drinking water; and

(iii) A description of any corrective actions the system has or will take to address the exceedance.