Current through Register Vol. 24-18, September 15, 2024
(1) General.
(a) When an MCL or MRDL violation or SAL
exceedance occurs, the purveyor shall take follow-up action as described in
this section.
(b) When a primary
standard violation occurs the purveyor shall:
(i) Notify the department under WAC
246-290-480;
(ii) Notify the consumers served by the
system and the owner or operator of any consecutive system served in accordance
with
40 C.F.R.
141.201 through 208, and Part 7, Sub-part A
of this chapter;
(iii) Investigate
the cause of the contamination, within the purveyor's control; and
(iv) Take action as directed by the
department.
(c) When a
secondary standard violation occurs, the purveyor shall notify the department
and take action as directed by the department.
(d) When a SAL exceedance under WAC
246-290-315 occurs, the purveyor
shall:
(i) Notify the department in accordance
with WAC 246-290-480;
(ii) Notify water system users and the owner
or operator of any consecutive system served water in exceedance of the SAL in
accordance with WAC
246-290-71006;
(iii) Continue monitoring in accordance with
subsection (8) or (9) of this section, as applicable;
(iv) Investigate the cause of the
contamination within the purveyor's control; and
(v) Take action as directed by the
department.
(e) The
department may require additional sampling for confirmation of
results.
(2)
Bacteriological. Coliform treatment technique triggers and assessment
requirements for protection against potential fecal contamination.
(a) Treatment technique triggers. Systems
shall conduct assessments in accordance with (b) of this subsection after
exceeding treatment technique triggers as follows:
(i) Level 1 treatment technique triggers.
(A) For systems taking forty or more routine
samples per month, the system exceeds 5.0 percent total coliform-positive
samples for the month.
(B) For
systems taking fewer than forty routine samples per month, the system has two
or more total coliform-positive samples in the same month.
(C) The system fails to take every required
repeat sample after any single total coliform-positive routine
sample.
(ii) Level 2
treatment technique triggers.
(A) An
E. coli MCL violation, as specified in WAC
246-290-310(2)(b).
(B) A second level 1 treatment technique
trigger as defined in (a)(i) of this subsection within a rolling twelvemonth
period, unless the department has determined a likely reason that the samples
that caused the first level 1 treatment technique trigger were total
coliform-positive and has established that the system has corrected the
problem.
(b)
Requirements for assessments.
(i) Systems
shall conduct level 1 and 2 assessments to identify the possible presence of
sanitary defects and defects in distribution system coliform monitoring
practices. Level 1 assessments must be conducted by the system operator or
purveyor. Level 2 assessments must be conducted by the department or a party
approved by the department which may include the system operator.
(ii) When conducting assessments, systems
shall direct the assessor to evaluate minimum elements that include:
(A) Review and identification of atypical
events that could affect distributed water quality or indicate that distributed
water quality was impaired;
(B)
Changes in distribution operation and maintenance that could affect distributed
water quality, including water storage;
(C) Source and treatment considerations that
bear on distributed water quality, where appropriate. For example, whether or
not a groundwater system is disinfected;
(D) Existing water quality monitoring
data;
(E) Inadequacies in sample
sites, sampling protocol, and sample processing; and
(F) The system shall conduct the assessment
consistent with any department directives that tailor specific assessment
elements with respect to the size and type of the system and the size, type,
and characteristics of the distribution system.
(iii) Level 1 assessments. A system shall
conduct a level 1 assessment consistent with the requirements in subsection
(2)(b) of this section if the system exceeds one of the treatment technique
triggers in (a)(i) of this subsection.
(A)
The system shall complete a level 1 assessment as soon as practical after any
treatment technique trigger is met in (a)(i) of this subsection. The completed
assessment must describe sanitary defects detected, corrective actions
completed, and a proposed timetable for any corrective actions not already
completed. The assessment may also note that no sanitary defects were
identified. The system shall submit the completed level 1 assessment to the
department within thirty days after the system learns that it has exceeded a
treatment technique trigger.
(B)
Upon completion and submission of the level 1 assessment by the system, the
department shall determine if the system has identified a likely cause for the
level 1 treatment technique trigger and has corrected the problem. If the
system has not corrected the problem, the department shall determine if the
proposed timetable for corrective action is sufficient.
(C) If after reviewing the completed level 1
assessment, the department determines the assessment is not sufficient,
including any proposed timetable for any corrective actions not already
completed, the department may require the system to submit a revised assessment
to the department within thirty days from the date of department
notification.
(iv) Level
2 assessments. A system shall conduct a level 2 assessment consistent with
requirements in subsection (2)(b) of this section if the system exceeds one of
the treatment technique triggers in (a)(ii) of this subsection. The system
shall comply with any expedited actions or additional actions required by the
department in the case of an
E. coli MCL violation.
(A) A level 2 assessment must be conducted as
soon as practical after any treatment technique trigger in (a)(ii) of this
subsection and shall be conducted by either a water distribution manager 2, 3,
or 4 certified in accordance with chapter 246-292 WAC, a licensed professional
engineer that meets the requirements of WAC
246-290-040(1),
a local health jurisdiction, or the department. The system shall submit a
completed level 2 assessment to the department within thirty days after the
system learns that it has exceeded a treatment technique trigger. The completed
assessment must describe sanitary defects detected, corrective actions
completed, and a proposed timetable for any corrective actions not already
completed in accordance with (d) of this subsection. The assessment may also
note that no sanitary defects were identified.
(B) Upon completion and submission of the
level 2 assessment by the system, the department shall determine if the system
has identified a likely cause for the level 2 treatment technique trigger and
has corrected the problem. If the system has not corrected the problem, the
department shall determine if the proposed timetable for corrective action is
sufficient.
(C) If after reviewing
the submitted level 2 assessment, the department determines the assessment is
not sufficient, including any proposed timetable for any corrective actions not
already completed in accordance with (d) of this subsection, the department may
require the system to submit a revised assessment within thirty days from the
date of department notification.
(c) To achieve compliance with the MCL for
E. coli under WAC
246-290-310(2)(b),
the following are identified as the best technology, treatment techniques, or
other means available:
(i) Protection of wells
from fecal contamination by appropriate placement and construction;
(ii) Maintenance of a disinfectant residual
throughout the distribution system;
(iii) Proper maintenance of the distribution
system including appropriate pipe replacement and repair procedures, main
flushing programs, proper operation and maintenance of storage tanks and
reservoirs, cross-connection control, and continual maintenance of positive
water pressure in all parts of the distribution system;
(iv) Filtration, disinfection, or both, of
surface water, using the proper strength of oxidants such as chlorine, chlorine
dioxide, or ozone; and
(v) For
systems using groundwater, compliance with a wellhead protection program
developed and implemented under WAC
246-290-135(3).
(d) Corrective action. Systems shall correct
sanitary defects found through either a level 1 or level 2 assessment conducted
under (b) of this subsection. For corrections not completed by the time of
submission of the assessment to the department, the system shall complete the
corrective actions in compliance with a timetable approved by the department in
consultation with the system under (e) of this subsection. The system shall
notify the department when each scheduled corrective action is
completed.
(e) Consultation. At any
time during the assessment or corrective action phase, the water system may
request a consultation with the department to determine the appropriate actions
to be taken. The system may consult with the department on all relevant
information that may impact the system's ability to comply with the
requirements of subsection (2) of this section, including the method of
accomplishment, an appropriate time frame, and other relevant information.
(f) A treatment technique
violation occurs when a system exceeds a treatment technique trigger specified
in subsection (2)(a) of this section and then fails to conduct the required
assessment or complete corrective actions within the time frame specified in
subsection (2)(b) and (d) of this section.
(3) Inorganic chemical and physical follow-up
monitoring shall be conducted in accordance with the following:
(a) For nonnitrate/nitrite primary inorganic
chemicals,
40 C.F.R.
141.23(a)(4),
141.23(b)(8),
141.23(c)(7),
141.23(c)(9),
141.23(f)(1),
141.23(g),
141.23(m)
and
141.23(n);
(b) For nitrate,
40 C.F.R.
141.23(a)(4),
141.23(d)(2),
141.23(d)(3),
141.23(f)(2),
141.23(g),
141.23(m),
141.23(n),
and
141.23(o);
(c) For nitrite,
40 C.F.R.
141.23(a)(4),
141.23(e)(3),
141.23(f)(2),
and
141.23(g);
or
(d) The purveyor of any public
water system providing service that has secondary inorganic MCL exceedances
shall take follow-up action as required by the department. Follow-up action
shall be commensurate with the degree of consumer acceptance of the water
quality and their willingness to bear the costs of meeting the secondary
standard. For new community water systems and new nontransient noncommunity
water systems without active consumers, treatment for secondary contaminant MCL
exceedances will be required.
(4) Lead and copper follow-up monitoring
shall be conducted in accordance with
40
C.F.R. 141.85(c),
141.86(d)(2),
141.86(d)(3),
141.87(c),
141.87(d)
and
141.88(b)
through
141.88(d).
(5) Turbidity.
Purveyors monitoring turbidity in accordance with Part 6 of
this chapter shall provide follow-up under WAC
246-290-634.
(6) Organic chemicals. Follow-up monitoring
shall be conducted in accordance with the following:
(a) For VOCs,
40 C.F.R.
141.24(f)(11) through
141.24(f)(15),
and
141.24(f)(22);
or
(b) For SOCs,
40 C.F.R.
141.24(h)(7) through
141.24(h)(11),
and
141.24(h)(20).
(7) Radionuclide follow-up monitoring shall
be conducted under
40
C.F.R. 141.26(a)(2)(iv),
141.26(a)(3)(ii)
through (v),
141.26(a)(4),
141.26(b)(6),
and
141.26(c)(5).
(8) Organic contaminants with a SAL.
(a) All increased monitoring for organic
contaminants will be for the test panel on which the contaminant is listed in
WAC 246-390-075.
(b) The purveyor shall monitor quarterly as
shown in Table 10 of this section. The number of samples required in the three
quarters after the first detection will be determined based on the highest
detection in the year of monitoring. For public water systems required to
sample for PFAS under the federal Unregulated Contaminant Monitoring Rule 5
(UCMR5), if a detection is reported below the minimum detection limit per UCMR5
and is greater than twenty percent of a SAL, then one additional quarter of
follow-up monitoring is required. The samples must be taken:
(i) Beginning in the calendar quarter
following the first confirmed detection per WAC
246-290-315(4)(b);
and
(ii) At each sampling point
from which the result was equal to or greater than the SDRL under chapter
246-390 WAC.
TABLE 10
MONITORING REQUIREMENTS FOLLOWING THE FIRST DETECTION OF AN
ORGANIC CONTAMINANT WITH A SAL
|
If the highest detection in the first year is:
|
Total number of additional consecutive quarters.
|
|
[LESS THAN EQUAL TO] 20% of the SAL. |
1 |
|
[GREATER THAN] 20% but < 80% of the SAL.
|
2 |
|
[GREATER THAN EQUAL TO] 80% of the SAL.
|
3 |
(c) Ongoing monitoring is specified in Table
11 of this section, or as directed by the department. Ongoing monitoring is
based upon the results of samples collected in the most recent year of
monitoring, or the most recent result for samples collected less frequently
than annually.
TABLE 11
ONGOING MONITORING REQUIREMENTS FOR SOURCES WITH ORGANIC
CONTAMINANTS WITH A SAL
|
If highest detection being considered is:
|
Monitoring frequency: |
|
[LESS THAN EQUAL TO] 20% of the SAL. |
Every 3 years |
|
[GREATER THAN] 20% but < 80% of the SAL.
|
Annually |
|
[GREATER THAN EQUAL TO] 80% of the SAL.
|
1. Quarterly, if contaminant is Tier 1, or Tier 2
and bioaccumulative per Table 17 in WAC
246-290-71006.
2. Annually if the contaminant is Tier 2 and not
bioaccumulative per Table 17 in WAC
246-290-71006. |
(d)
When the monitoring frequency is less often than quarterly, the purveyor shall
collect samples during the quarter assigned by the department.
(e) The department may reduce the annual
monitoring frequency to one sample every three years after three consecutive
years of results that demonstrate the levels are less than eighty percent of
the SAL.
(f) The department may
increase the monitoring frequency from once every year or once every three
years to once every quarter if results of reduced monitoring are equal to or
greater than eighty percent of the SAL.
(9) Inorganic contaminants with a SAL.
(a) The purveyor shall collect quarterly
samples at each sampling point beginning in the quarter following a detection
greater than the SAL under Table 9 of this section. Increased monitoring for
inorganic contaminants will be for a specific contaminant which is detected
above the SAL.
(b) The department
may reduce the quarterly monitoring frequency when results are reliably and
consistently below the SAL. When the monitoring frequency is less often than
quarterly, the purveyor shall collect samples during the quarter assigned by
the department.
(10) If a
contaminant has no MCL, MRDL, TT, or SAL, the department may use an EPA
health advisory level to determine subsequent monitoring per
this section.
(11) The department
shall determine the purveyor's follow-up action when a contaminant not included
in this chapter is detected.
Statutory Authority:
RCW
43.20.050(2) and
70.119A.080. 11-17-062, §
246-290-320, filed 8/15/11, effective 10/1/11. Statutory Authority:
RCW
43.20.050 and
70.119A.080. 10-20-068, §
246-290-320, filed 9/29/10, effective 11/1/10. Statutory Authority:
RCW
70.119A.180 and
43.20.050. 08-03-061, §
246-290-320, filed 1/14/08, effective 2/14/08. Statutory Authority:
RCW
43.20.050 and
70.119A.080. 04-04-056, §
246-290-320, filed 1/30/04, effective 3/1/04. Statutory Authority:
RCW
43.20.050(2) and (3) and
70.119A.080. 03-08-037, §
246-290-320, filed 3/27/03, effective 4/27/03. Statutory Authority: RCW
43.02.050 [43.20.050]. 99-07-021, § 246-290-320, filed 3/9/99, effective
4/9/99. Statutory Authority:
RCW
43.20.050. 94-14-001, § 246-290-320,
filed 6/22/94, effective 7/23/94; 93-08-011 (Order 352B), § 246-290-320,
filed 3/25/93, effective 4/25/93; 92-04-070 (Order 241B), § 246-290-320,
filed 2/4/92, effective 3/6/92. Statutory Authority: Chapter 43.20 RCW.
91-07-031 (Order 150B), § 246-290-320, filed 3/15/91, effective 4/15/91.
Statutory Authority:
RCW
43.20.050. 91-02-051 (Order 124B), recodified
as § 246-290-320, filed 12/27/90, effective 1/31/91. Statutory Authority:
P.L. 99-339. 89-21-020 (Order 336), § 248-54-185, filed 10/10/89,
effective 11/10/89. Statutory Authority: RCW 34.04.045. 88-05-057 (Order 307),
§ 248-54-185, filed 2/17/88. Statutory Authority:
RCW
43.20.050. 83-19-002 (Order 266), §
248-54-185, filed 9/8/83.
