Current through Register Vol. 24-18, September 15, 2024
(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 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 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.
(4)
For detected regulated contaminants listed in WAC
246-290-72012, the table(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 246-290-72012);
(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 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 with a SAL, or
contaminants with an established MCL, except turbidity, and
E.
coli, 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 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 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 or SAL 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) Detected contaminants without an MCL,
SAL, federal action level, TT or MRDL for which monitoring is required, the
table 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. 09-21-045, § 246-290-72005,
filed 10/13/09, effective 1/4/10. Statutory Authority:
RCW
70.119A.180 and
43.20.050. 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. 03-08-037, §
246-290-72005, filed 3/27/03, effective 4/27/03. Statutory Authority:
RCW
43.20.050. 00-15-080, § 246-290-72005,
filed 7/19/00, effective 8/19/00.
