Washington Administrative Code
Title 246 - Health, Department of
WATER SYSTEMS
Chapter 246-290 - Group A public water supplies
Part 4 - WATER QUALITY
Section 246-290-300 - Monitoring requirements
Universal Citation: WA Admin Code 246-290-300
Current through Register Vol. 24-18, September 15, 2024
(1) General.
(a) The monitoring requirements
specified in this section are minimums. The department may require additional
monitoring when:
(i) Contamination is present
or suspected in the water system;
(ii) A groundwater source is determined to be
a potential GWI;
(iii) The degree
of source protection is not satisfactory;
(iv) Additional monitoring is needed to
verify source vulnerability for a requested monitoring waiver;
(v) Under other circumstances as identified
in a department order; or
(vi)
Additional monitoring is needed to evaluate continuing effectiveness of a
treatment process where problems with the treatment process may
exist.
(b) Special
purpose samples collected by the purveyor do not count toward fulfillment of
the monitoring requirements of this chapter unless the quality of data and
method of sampling and analysis are acceptable to the department.
(c) The purveyor shall ensure samples
required by this chapter are collected, transported, and submitted for analysis
according to EPA-approved methods. The analyses must be performed by a
laboratory accredited by the state using EPA-approved methods or other
department-approved methods. Qualified water utility, accredited laboratory,
health department personnel, and other parties approved by the department may
conduct measurements for pH, temperature, residual disinfectant concentration,
alkalinity, bromide, chlorite, TOC, SUVA, turbidity, calcium, conductivity,
orthophosphate, and silica as required by this chapter, provided, these
measurements are made according to EPA approved methods.
(d) Compliance samples required by this
chapter must be taken at locations listed in Table 4 of this section.
(e) Purveyors failing to comply with a
monitoring requirement shall notify:
(i) The
department under WAC
246-290-480; and
(ii) The owner or operator of any consecutive
system served and the appropriate water system users under
40 C.F.R.
141.201 and Part 7, Subpart A of this
chapter.
(2) Selling and receiving water.
(a) Source
monitoring. Purveyors, with the exception of those that "wheel" water to their
consumers (i.e., sell water that has passed through another purchasing
purveyor's distribution system), shall conduct source monitoring under this
chapter for the sources under their control. The level of monitoring must
satisfy the monitoring requirements associated with the total population served
by the source.
(b) Distribution
system monitoring. The purveyor of a system that receives and distributes water
shall perform distribution-related monitoring requirements. Monitoring must
include, but not be limited to, the following:
(i) Collect coliform samples under subsection
(3) of this section;
(ii) Collect
disinfection byproduct samples as required by subsection (6) of this
section;
(iii) Perform the
distribution system residual disinfectant concentration monitoring under
subsection (6) of this section, and as required under WAC
246-290-451,
246-290-664, or
246-290-694. Systems with fewer
than one hundred connections shall measure residual disinfectant concentration
at the same time and location that a routine or repeat coliform sample is
collected, unless the department determines that more frequent monitoring is
necessary to protect public health;
(iv) Perform lead and copper monitoring
required under
40
C.F.R. 141.86,
141.87,
and
141.88;
(v) Perform the distribution system
monitoring under
40 C.F.R.
141.23(b) for asbestos if
applicable;
(vi) Other monitoring
as required by the department.
(c) Reduced monitoring for regional programs.
The receiving purveyor may receive reductions in the coliform, lead and copper,
disinfection byproduct (including TTHMs and HAA5) and distribution system
disinfectant residual concentration monitoring requirements, provided the
receiving system:
(i) Purchases water from a
purveyor that has a department-approved regional monitoring program;
(ii) Has a written agreement with the
supplying system or regional water supplier that is acceptable to the
department, and which identifies the responsibilities of both the supplying and
receiving system(s) with regards to monitoring, reporting and maintenance of
the distribution system; and
(iii)
Has at least one compliance monitoring location for disinfection byproducts, if
applicable.
(d) Periodic
review of regional programs. The department may periodically review the
sampling records of public water systems participating in a department-approved
monitoring program to determine if continued reduced monitoring is appropriate.
If the department determines a change in the monitoring requirements of the
receiving system is appropriate:
(i) The
department shall notify the purveyor of the change in monitoring requirements;
and
(ii) The purveyor shall conduct
monitoring as directed by the department.
(3) Bacteriological.
(a) The purveyor shall be responsible for
collection and submittal of coliform samples from representative points
throughout the distribution system. Samples must be collected after the first
service and at regular time intervals each month the system provides water to
consumers. Samples must be collected that represent normal system operating
conditions.
(i) Systems providing disinfection
treatment shall measure the residual disinfectant concentration within the
distribution system at the same time and location of routine and repeat
samples.
(ii) Systems providing
disinfection treatment shall assure that disinfectant residual concentrations
are measured and recorded on all coliform sample report forms submitted for
compliance purposes.
(b)
Coliform monitoring plan.
(i) Systems shall
develop a written coliform monitoring plan that identifies sampling sites and a
sample collection schedule that are representative of water throughout the
distribution system. The plan is subject to department review and approval.
Systems shall collect total coliform samples according to the plan. Monitoring
may take place at a customer's premises, dedicated sampling station, or other
designated compliance sampling location. Routine and repeat sample sites and
any sampling points necessary to meet the requirements of Part 6 of this
chapter and WAC
246-290-300(3)(h)
must be identified in the plan.
(ii) Systems shall collect samples at regular
time intervals throughout the month, except for systems that use groundwater
and serve four thousand nine hundred or fewer people may collect all required
samples on a single day if the samples are taken from different
sites.
(iii) Systems shall take at
least the minimum number of required samples even if the system has had an
E. coli MCL violation or has exceeded the coliform treatment
technique triggers in WAC
246-290-320(2).
(iv) Systems may conduct more compliance
monitoring than is required under subsection (3)(b) of this section to
investigate potential problems in the distribution system and use monitoring as
a tool to assist in identifying problems. Systems may take more than the
minimum number of required routine samples and must include the results in
calculating whether or not the coliform treatment technique triggers in WAC
246-290-320(2)
have been exceeded only if the samples are taken in accordance with the plan
and are representative of water throughout the distribution system.
(v) Systems shall identify repeat monitoring
locations in the plan. Unless the provisions of subsection (3)(b)(i) through
(iv) of this section are met, the system shall collect at least one repeat
sample from the sample tap where the original total coliformpositive sample was
taken, and at least one repeat sample at a tap within five service connections
upstream and at least one repeat sample at a tap within five service
connections downstream of the original sample site. If a total coliformpositive
sample is at the end of the distribution system, or one service connection away
from the end of the distribution system, the system shall still take all
required repeat samples. The department may allow an alternative sampling
location in lieu of the requirement to collect at least one repeat sample
upstream or downstream of the original sampling site. Systems may propose
repeat monitoring locations to the department that the system believes to be
representative of a pathway for contamination of the distribution system. A
system may elect to specify either alternative fixed locations or criteria for
selecting repeat sampling sites on a situational basis in a standard operating
procedure (SOP) in its plan. The system shall design its SOP to focus the
repeat samples at locations that best verify and determine the extent of
potential contamination of the distribution system area based on specific
situations. The department may modify the SOP or require alternative monitoring
locations as needed.
(vi) The
purveyor shall:
(A) Keep the coliform
monitoring plan on file with the system and make it available to the department
for inspection upon request;
(B)
Revise or expand the plan at any time the plan no longer ensures representative
monitoring of the system, or as directed by the department; and
(C) Submit the plan to the department for
review and approval when requested and as part of the water system plan
required under WAC
246-290-100.
(c) Special purpose coliform samples. Special
purpose coliform samples, such as those taken to determine whether disinfection
practices are sufficient following pipe placement, replacement, or repair, must
not be used to determine whether or not the coliform treatment technique
trigger has been exceeded. Repeat samples taken in accordance with subsection
(3) of this section are not considered special purpose coliform samples, and
must be used to determine whether or not the coliform treatment technique
trigger has been exceeded.
(d)
Invalidation of total coliform samples. A total coliform-positive sample
invalidated under subsection (3) of this section does not count toward meeting
the minimum monitoring requirements of this section.
(i) The department may invalidate a total
coliform-positive sample if one or more of the following conditions are met:
(A) The laboratory establishes that improper
sample analysis caused the total coliform-positive result;
(B) The department, on the basis of the
results of repeat samples collected as required under subsection (3) of this
section, determines that the total coliform-positive samples resulted from a
domestic or other nondistribution system plumbing problem. The department may
not invalidate a sample on the basis of repeat sample results unless all repeat
samples collected at the same tap as the original total coliform-positive
sample are also total coliform-positive, and all repeat samples collected at a
location other than the original tap are total coliform-negative. For example,
the department may not invalidate a total coliform-positive sample on the basis
of repeat samples if all the repeat samples are total coliform-negative, or if
the system has only one service connection; or
(C) The department has substantial grounds to
believe that a total coliform-positive result is due to a circumstance or
condition that does not reflect water quality in the distribution system. In
this case, the system shall still collect all repeat samples required under
subsection (3) of this section, and use the samples to determine whether a
coliform treatment technique trigger under WAC
246-290-320(2)
has been exceeded.
(ii)
Unless total coliforms are detected, a laboratory shall invalidate a total
coliform sample if the sample produces a turbid culture in the absence of gas
production using an analytical method where gas formation is examined such as
the multiple-tube fermentation technique, produces a turbid culture in the
absence of an acid reaction in the presence-absence coliform test, or exhibits
confluent growth or produces colonies TNTC with an analytical method using a
membrane filter such as a membrane filter technique. If a laboratory
invalidates a sample because of such interference, the system shall collect
another sample from the same location as the original sample within twenty-four
hours of notification of the interference problem, and have it analyzed for the
presence of total coliforms. The system shall continue to re sample within
twenty-four hours and have the samples analyzed until it obtains a valid
result. The department may waive the twenty-four hour time limit on a
case-by-case basis.
(e)
Monitoring frequency. The number of required routine coliform samples is based
on total population served.
(i) Purveyors of
community systems shall collect and submit for analysis no less than the number
of routine samples listed in Table 2 of this section during each calendar month
of operation;
(ii) Unless directed
otherwise by the department, purveyors of noncommunity systems shall collect
and submit for analysis no less than the number of samples required in Table 2
of this section. Each month's population must be based on the average daily
population and must include all residents and nonresidents served during that
month. During months when the average daily population served is less than
twenty-five, routine sample collection is not required when:
(A) Using only protected groundwater
sources;
(B) The system has a clean
compliance history for a minimum of twelve months;
(C) The system has no sanitary defects or
significant deficiencies;
(D) The
system has detected no total coliform-positive routine or repeat samples in the
previous month; and
(E) The system
has collected and submitted for analysis one routine sample during one of the
previous two months.
(iii) Purveyors of NTNC and TNC systems are
not required to collect routine samples in months when the population served is
zero.
(iv) Purveyors of systems
serving both a resident and a nonresident population shall base their minimum
sampling requirement on the total of monthly populations served, both resident
and nonresident as determined by the department, but no less than the minimum
required in Table 2 of this section.
(v) Seasonal systems.
(A) In accordance with WAC
246-290-480(2)(f)(ii),
seasonal systems shall certify that a department-approved start-up procedure,
which may include a requirement for start-up sampling, was completed prior to
serving water to the public.
(B)
Seasonal systems shall monitor every month that it is in operation unless it
meets the criteria in subsection (3)(e)(ii) of this section.
(C) The department may exempt a seasonal
system from some or all of the requirements in subsection (3)(e)(v)(A) of this
section if the entire distribution system remains pressurized during the entire
period that the system is not operating, except that systems that monitor less
frequently than monthly shall still monitor during the vulnerable period
designated by the department.
Table 2
Total Coliform Monitoring Frequency
|
Population served |
Minimum number of samples per month |
|
1 to 1,000* |
1 |
|
1,001 to 2,500 |
2 |
|
2,501 to 3,300 |
3 |
|
3,301 to 4,100 |
4 |
|
4,101 to 4,900 |
5 |
|
4,901 to 5,800 |
6 |
|
5,801 to 6,700 |
7 |
|
6,701 to 7,600 |
8 |
|
7,601 to 8,500 |
9 |
|
8,501 to 12,900 |
10 |
|
12,901 to 17,200 |
15 |
|
17,201 to 21,500 |
20 |
|
21,501 to 25,000 |
25 |
|
25,001 to 33,000 |
30 |
|
33,001 to 41,000 |
40 |
|
41,001 to 50,000 |
50 |
|
50,001 to 59,000 |
60 |
|
59,001 to 70,000 |
70 |
|
70,001 to 83,000 |
80 |
|
83,001 to 96,000 |
90 |
|
96,001 to 130,000 |
100 |
|
130,001 to 220,000 |
120 |
|
220,001 to 320,000 |
150 |
|
320,001 to 450,000 |
180 |
|
450,001 to 600,000 |
210 |
|
600,001 to 780,000 |
240 |
|
780,001 to 970,000 |
270 |
|
970,001 to 1,230,000 |
300 |
|
1,230,001 to 1,520,000 |
330 |
|
1,520,001 to 1,850,000 |
360 |
|
1,850,001 to 2,270,000 |
390 |
|
2,270,001 to 3,020,000 |
420 |
|
3,020,001 to 3,960,000 |
450 |
|
3,960,001 or more |
480 |
*Noncommunity systems using only protected groundwater sources and serving less than twenty-five individuals, may collect and submit for analysis, one sample every three months per WAC 246-290-300(3)(e)(ii).
(f) Repeat monitoring.
(i) If a routine sample taken under
subsection (3) of this section is total coliform-positive, the system shall
collect a set of repeat samples within twenty-four hours of being notified of
the positive result. Additional treatment, such as batch or shock chlorination
must not be started prior to the collection of repeat samples unless the
department gives prior authorization. The purveyor shall contact the department
to determine the best interim approach in this situation. The system shall
collect no fewer than three repeat samples for each total coliform-positive
sample found. The department may extend the twenty-four hour limit on a
case-by-case basis if the system has a logistical problem in collecting the
repeat samples within twenty-four hours that is beyond its control. Following
the collection of repeat samples, and before the analytical results are known,
the system may provide interim precautionary treatment or other means to
protect public health.
(ii) The
system shall collect all repeat samples on the same day, except the department
may allow a system with a single connection to collect the required set of
repeat samples over a three-day period or to collect a larger volume of repeat
samples in one or more sample containers of any size, as long as the total
volume collected is at least 300 mL.
(iii) The system shall collect an additional
set of repeat samples in the manner specified in subsection (3)(f)(i) through
(iii) of this section if one or more repeat samples in the current set of
repeat samples is total coliform-positive. The system shall collect the
additional set of repeat samples within twenty-four hours of being notified of
the positive result, unless the department extends the time limit as provided
in subsection (3)(f)(i) of this section. The system shall continue to collect
additional sets of repeat samples until either total coliforms are not detected
in one complete set of repeat samples or the system determines that a coliform
treatment technique trigger specified in WAC
246-290-320(2)(a)
has been exceeded as a result of a repeat
sample being total coliform-positive and notifies the department. If a
treatment technique trigger identified in WAC
246-290-320(2)(a)
is exceeded as a result of a routine sample
being total coliform-positive, the system is required to conduct only one round
of repeat monitoring for each total coliform-positive routine sample.
(iv) After a system collects a routine sample
and before it gets the results of the analysis of that sample, if it collects
subsequent routine samples from within five adjacent service connections of the
initial sample, and the initial sample, after analysis, is found to contain
total coliforms, then the system may count the subsequent samples as a repeat
sample instead of as a routine sample.
(v) Results of all routine and repeat samples
taken under subsection (3)(e) and (f) of this section not invalidated by the
department under subsection (3)(d) of this section must be used to determine
whether a coliform treatment technique trigger specified in WAC
246-290-320(2)(a)
has been exceeded.
(g)
E. coli testing.
(i) If any routine or repeat sample is total
coliform-positive, the system shall analyze that total coliform-positive
culture medium to determine if E. coli are present. If
E. coli are present, the system shall notify the department by
the end of the day when the system is notified of the test result.
(ii) The department may allow a system, on a
case-by-case basis, to forgo E. coli testing on a total
coliform-positive sample if the system assumes that the total coliform-positive
sample is E. coli-positive. Accordingly, the system shall
notify the department as specified in WAC
246-290-320(1)(a).
(h) Triggered source water
monitoring.
(i) All groundwater systems with
their own groundwater sources must conduct triggered source water monitoring
unless the following conditions exist:
(A) The
system has submitted a project report and received department approval that it
provides at least 4-log treatment of viruses using inactivation, removal, or a
department-approved combination of 4-log virus inactivation and removal before
or at the first customer for each groundwater source; and
(B) The system is conducting compliance
monitoring under WAC
246-290-453(2).
(ii) Any groundwater source sample required
under this subsection (3) must be collected at the source prior to any
treatment unless otherwise approved by the department.
(iii) Any groundwater source sample collected
under this subsection (3) must be at least 100 mL in size and must be analyzed
for E. coli using one of the analytical methods under
40
C.F.R. 141.402(c).
(iv) Groundwater systems shall collect at
least one sample from each groundwater source in use at the time a routine
sample collected under subsection (3) of this section is total
coliform-positive and not invalidated under subsection (3)(d) of this section.
These source samples must be collected within twenty-four hours of notification
of the total coliform-positive sample. The following exceptions apply:
(A) The twenty-four hour time limit may be
extended if granted by the department and will be determined on a case-by-case
basis. If an extension is granted, the system shall sample by the deadline set
by the department.
(B) Systems with
more than one groundwater source may meet the requirements of subsection
(3)(h)(iv) of this section by sampling a representative groundwater source or
sources. The system shall have a department-approved triggered source water
monitoring plan that identifies one or more groundwater sources that are
representative of each monitoring site in the system's coliform monitoring plan
under subsection (3)(b) of this section. The plan must be approved by the
department before representative sampling will be allowed.
(v) Groundwater systems with an E.
coli positive source water sample that is not invalidated under
subsection (3)(h)(vii) of this section, shall:
(A) Notify the department by the end of the
day when the system is notified of the test result.
(B) Provide Tier 1 public notice as required
under Part 7, Subpart A of this chapter and special notification under WAC
246-290-71005(4) and
(5);
(C) If directed by the department, take
corrective action as required under WAC
246-290-453(1);
and
(D) Systems that are not
directed by the department to take corrective action shall collect five
additional samples from the same source within twenty-four hours of being
notified of the E. coli positive source water sample. If any
of the five additional samples are E. coli positive, the
system shall take corrective action under WAC
246-290-453(1).
(vi) Any consecutive groundwater
system that has a total coliform-positive routine sample collected under this
subsection and not invalidated under subsection (3)(d) of this section shall
notify each wholesale system it receives water from within twenty-four hours of
being notified of the total coliform-positive sample and comply with subsection
(3)(h) of this section.
(A) A wholesale
groundwater system that receives notice from a consecutive system under
subsection (3)(h)(vi) of this section shall conduct triggered source water
monitoring under subsection (3)(h) of this section unless the department
determines and documents in writing that the total coliform-positive sample
collected was caused by a distribution system deficiency in the consecutive
system.
(B) If the wholesale
groundwater system source sample is E. coli positive, the
wholesale system shall notify all consecutive systems served by that
groundwater source within twenty-four hours of being notified of the results
and shall meet the requirements of subsection (3)(h)(v) of this section.
(C) Any consecutive groundwater
system receiving water from a source with an E. coli positive
sample shall notify water system users as required under subsection
(3)(h)(v)(B) of this section.
(vii) An E. coli positive
groundwater source sample may be invalidated only if one of the following
conditions apply:
(A) The system provides the
department with written notice from the laboratory that improper sample
analysis occurred; or
(B) The
department determines and documents in writing that there is substantial
evidence that the E. coli positive groundwater sample is not
related to source water quality.
(viii) If the department invalidates an
E. coli positive groundwater source sample, the system shall
collect another source water sample within twenty-four hours of being notified
by the department of its invalidation decision and have the sample analyzed
using the same analytical method. The department may extend the twenty-four
hour time limit as allowed under subsection (3)(h)(iv)(A) of this
section.
(ix) Groundwater systems
that fail to meet any of the monitoring requirements of subsection (3)(h) of
this section shall conduct Tier 2 public notification under Part 7, Subpart A
of this chapter.
(i)
Assessment source water monitoring. If directed by the department, a
groundwater system shall conduct assessment source water monitoring which may
include, but is not limited to, the collection of at least one representative
groundwater source sample each month the source provides groundwater to the
public, for a minimum of twelve months.
(i)
Sampling must be conducted as follows:
(A)
Source samples must be collected at a location prior to any treatment. If the
water system's configuration does not allow sampling at the source itself, the
department may approve an alternative source sampling location representative
of the source water quality.
(B)
Source samples must be at least 100 mL in size and must be analyzed for
E. coli using one of the analytical methods under
40
C.F.R.
141.402(c).
(ii) A groundwater system may use a triggered
source water sample collected under subsection (3)(h) of this section to meet
the requirements for assessment source water monitoring.
(iii) A groundwater system with an E.
coli positive assessment source water sample that is not invalidated
under subsection (3)(h)(vii) of this section, and consecutive systems receiving
water from this source shall:
(A) Provide
Tier 1 public notice under Part 7, Subpart A of this chapter and special
notification under WAC
246-290-71005(4) and
(5); and
(B) Take corrective action as required under
WAC 246-290-453(1).
(iv) A groundwater system that fails to
conduct assessment source water monitoring as directed by the department shall
provide Tier 2 public notice under Part 7, Subpart A of this chapter.
(4) Inorganic chemical and physical.
(a) A complete
inorganic chemical and physical analysis must consist of the primary and
secondary chemical and physical contaminants.
(i) Primary chemical and physical
contaminants are antimony, arsenic, asbestos, barium, beryllium, cadmium,
chromium, cyanide, fluoride, mercury, nickel, nitrate (as N), nitrite (as N),
selenium, sodium, thallium, and for unfiltered surface water, turbidity.
(Except that the MCL for arsenic under WAC 246-290-310 does not apply to TNC
systems.)
(ii) Secondary chemical
and physical contaminants are chloride, color, hardness, iron, manganese,
specific conductivity, silver, sulfate, total dissolved solids, and zinc. Total
dissolved solids are required only when specific conductivity exceeds seven
hundred micromhos/centimeter.
(b) Purveyors shall monitor for all primary
and secondary chemical and physical contaminants identified in WAC
246-290-310, Table 5 and Table 6.
Samples must be collected in accordance with the monitoring requirements
referenced in
40 C.F.R.
141.23 introductory text, 141.23(a) through
141.23(j), and
40
C.F.R. 143.4, except for composite samples
for systems serving less than three thousand three hundred one persons. For
these systems, compositing among different systems may be allowed if the
systems are owned or operated by a department-approved satellite management
agency.
(c) Samples required by
this subsection must be taken at designated locations under
40 C.F.R.
141.23(a) through
141.23(j),
and 40 C.F.R. 143.4, and Table 4 of this section.
(i) Wellfield samples are allowed from
department designated wellfields; and
(ii) Under
40 C.F.R.
141.23(a)(3), alternate
sampling locations may be used if approved by the department. The process for
determining these alternate sites is described in department guidance.
Purveyors of community and NTNC systems may ask the department to approve an
alternate sampling location for multiple sources within a single system that
are blended prior to entry to the distribution system. Alternate sampling plans
must address the following:
(A) Source
vulnerability;
(B) Individual
source characteristics;
(C)
Previous water quality information;
(D) Status of monitoring waiver applications;
and
(E) Other information deemed
necessary by the department.
(d) Composite samples:
(i) Under
40 C.F.R.
141.23(a)(4), purveyors may
ask the certified laboratory to composite samples representing as many as five
individual samples from within one system. Sampling procedures and protocols
are outlined in department guidance; and
(ii) For systems serving a population of less
than three thousand three hundred one, the department may approve composite
sampling between systems when those systems are part of an approved satellite
management agency.
(e)
When the purveyor provides treatment for one or more inorganic chemical or
physical contaminants, the department may require the purveyor to sample before
and after treatment. The department shall notify the purveyor if and when this
additional source sampling is required.
(f) Inorganic monitoring plans.
(i) Purveyors of community and NTNC systems
shall prepare an inorganic chemical monitoring plan and base routine monitoring
on the plan.
(ii) The purveyor
shall:
(A) Keep the monitoring plan on file
with the system and make it available to the department for inspection upon
request;
(B) Revise or expand the
plan at any time the plan no longer reflects the monitoring requirements,
procedures or sampling locations, or as directed by the department;
and
(C) Submit the plan to the
department for review and approval when requested and as part of the water
system plan required under WAC
246-290-100.
(g) Monitoring waivers.
(i) Purveyors may request in writing, a
monitoring waiver from the department for any nonnitrate/nitrite inorganic
chemical and physical monitoring requirements identified in this
chapter.
(ii) Purveyors requesting
a monitoring waiver shall comply with applicable subsections of
40 C.F.R.
141.23(b)(3), and
141.23(c)(3).
(iii) Purveyors shall update and resubmit
requests for waiver renewals as applicable during each compliance cycle or
period or more frequently as directed by the department.
(iv) Failure to provide complete and accurate
information in the waiver application may be grounds for denial of the
monitoring waiver.
(h)
The department may require the purveyor to repeat sample for confirmation of
results.
(i) Purveyors with
emergency and seasonal sources shall monitor those sources when they are in
use.
(5) Lead and copper. Monitoring for lead and copper shall be conducted in accordance with 40 C.F.R. 141.86(a) -(f), 141.87, and 141.88. All systems that have fewer than five drinking water taps used for human consumption shall collect at least one sample from each tap and then collect additional samples from those taps on different days during the monitoring period to meet the required number of samples as described in 40 C.F.R. 141.86(c).
(6) Disinfection byproducts (DBP), disinfectant residuals, and disinfection byproduct precursors (DBPP). Purveyors of community and NTNC systems providing water treated with chemical disinfectants and TNC systems using chlorine dioxide shall monitor as follows:
(a) General requirements.
(i) Systems shall collect samples during
normal operating conditions.
(ii)
All monitoring shall be conducted in accordance with the analytical
requirements in
40 C.F.R.
141.131.
(iii) Systems required to monitor under this
subsection shall prepare and implement a monitoring plan in accordance with
40 C.F.R.
141.132(f) or 40 C.F.R.
141.622, as applicable.
(A) Community and
NTNC surface water and GWI systems that deliver water that has been treated
with a disinfectant other than ultraviolet light and serve more than three
thousand three hundred people shall submit a monitoring plan to the
department.
(B) The department may
require submittal of a monitoring plan from systems not specified in subsection
(6)(a)(iii)(A) of this section, and may require revision of any monitoring
plan.
(C) Failure to monitor for
TTHM, HAA5, or bromate will be treated as a violation for the entire period
covered by the annual average where compliance is based on a locational running
annual average or running annual average of monthly or quarterly samples or
averages, as applicable.
(D)
Failure to monitor for chlorine and chloramine residuals will be treated as a
violation for the entire period covered by the annual average where compliance
is based on a running annual average of monthly or quarterly samples or
averages and the systems' failure to monitor makes it impossible to determine
compliance with the MRDLs.
(b) Disinfection byproducts - Community and
NTNC systems only.
(i) TTHMs and HAA5.
(A) Systems shall monitor for TTHM and HAA5
in accordance with
40 C.F.R.
141.620,
141.621, and
141.622.
(B) With department approval, systems may
reduce monitoring in accordance with
40 C.F.R.
141.623.
(C) Systems on department-approved reduced
monitoring schedules may be required to return to routine monitoring, or
initiate increased monitoring in accordance with
40 C.F.R.
141.625 or 40 C.F.R. 141.627, as
applicable.
(D) Systems must meet
requirements of
40
C.F.R. 141.628 and 40 C.F.R. 141.625(c) to
return to routine monitoring.
(E)
Systems must calculate operational evaluation levels each calendar quarter and
take action, as needed, in accordance with
40 C.F.R.
141.626.
(F) NTNC systems serving ten thousand or more
people and community systems must comply with the provisions of 40 C.F.R.
Subpart U - Initial Distribution System Evaluation under:
|
40 C.F.R. 141.600 |
General requirements. |
|
40 C.F.R. 141.601 |
Standard monitoring. |
|
40 C.F.R. 141.602 |
System specific studies. |
|
40 C.F.R. 141.603 |
40/30 certification. |
|
40 C.F.R. 141.604 |
Very small system waivers. |
|
40 C.F.R. 141.605 |
Subpart V compliance monitoring location recommendations. |
(ii) Chlorite - Only systems that use
chlorine dioxide.
(A) Systems using chlorine
dioxide shall conduct daily and monthly monitoring in accordance with 40 C.F.R.
141. 132 (b)(2)(i) and additional chlorite monitoring in accordance with
40 C.F.R.
141.132(b)(2)(ii).
(B) With department approval, monthly
monitoring may be reduced in accordance with
40 C.F.R.
141.132(b)(2)(iii) (B).
Daily monitoring at entry to distribution required by
40 C.F.R.
141.132(b)(2)(i)(A) may not
be reduced.
(iii)
Bromate - Only systems that use ozone.
(A)
Systems using ozone for disinfection or oxidation must conduct bromate
monitoring in accordance with
40 C.F.R.
141.132(b)(3)(i).
(B) With department approval, monthly bromate
monitoring may be reduced to once per quarter in accordance with
40 C.F.R.
141.132(b)(3)(ii)(B).
(c) Disinfectant
residuals.
(i) Chlorine and chloramines.
Systems that deliver water continuously treated with chlorine or chloramines,
including consecutive systems, shall monitor and record the residual
disinfectant level in the distribution system under WAC
246-290-300(2)(b),
246-290-451,
246-290-664(6),
or 246-290-694(8).
(ii) Chlorine dioxide. Community, NTNC, or
TNC systems that use chlorine dioxide shall monitor in accordance with
40 C.F.R.
141.132(c)(2) and record
results.
(d) Disinfection
byproducts precursors. Community and NTNC surface water or GWI systems that use
conventional filtration with sedimentation as defined in WAC
246-290-660(3)
shall monitor under
40 C.F.R.
141.132(d), and meet the
requirements of
40
C.F.R. 141.135.
(7) Organic chemicals.
(a) Purveyors of community and NTNC water
systems shall comply with monitoring requirements under
40 C.F.R.
141.24(f)(1) - (f)(15),
141.24(f)(18)
- (19),
141.24(f)(21),
141.24(h)(1)
- (11), and
141.24(h)(14)
- (17).
(b) Sampling locations shall be as defined in
40 C.F.R.
141.24(f) and
141.24(h).
(i) Wellfield samples are allowed from
department designated wellfields; and
(ii) Under
40 C.F.R.
141.24(f)(3) and
141.24(h)(3),
alternate sampling locations may be allowed if approved by the department.
These alternate locations are described in department guidance. Purveyors may
ask the department to approve an alternate sampling location for multiple
sources within a single system that are blended prior to entry to the
distribution system. The alternate sampling location shall consider the
following:
(A) Source vulnerability;
(B) An updated organic monitoring plan
showing location of all sources with current and proposed sampling
locations;
(C) Individual source
characteristics;
(D) Previous water
quality information;
(E) Status of
monitoring waiver applications; and
(F) Other information deemed necessary by the
department.
(c)
Composite samples:
(i) Purveyors may ask the
certified lab to composite samples representing as many as five individual
samples from within one system. Sampling procedures and protocols are outlined
in department guidance;
(ii) For
systems serving a population of less than three thousand three hundred one, the
department may approve composite sampling between systems when those systems
are part of an approved satellite management agency.
(d) The department may require the purveyor
to sample both before and after treatment for one or more organic contaminants.
The department shall notify the purveyor if and when this additional source
sampling is required.
(e) Organic
chemical monitoring plans.
(i) Purveyors of
community and NTNC systems shall prepare an organic chemical monitoring plan
and base routine monitoring on the plan.
(ii) The purveyor shall:
(A) Keep the monitoring plan on file with the
system and make it available to the department for inspection upon
request;
(B) Revise or expand the
plan at any time the plan no longer reflects the monitoring requirements,
procedures or sampling locations, or as directed by the department;
and
(C) Submit the plan to the
department for review and approval when requested and as part of the water
system plan required under WAC
246-290-100.
(f) Monitoring waivers.
(i) Purveyors may request in writing, a
monitoring waiver from the department for any organic monitoring
requirement;
(ii) Purveyors
requesting a monitoring waiver shall comply with
40 C.F.R.
141.24(f)(7),
141.24(f)(10),
141.24(h)(6),
and
141.24(h)(7);
(iii) Purveyors shall update and resubmit
requests for waiver renewals as directed by the department; and
(iv) Failure to provide complete and accurate
information in the waiver application shall be grounds for denial of the
monitoring waiver.
(g)
Purveyors with emergency and seasonal sources shall monitor those sources under
the applicable requirements of this section when they are actively providing
water to consumers.
(8) Radionuclides.
Monitoring for radionuclides shall be conducted under
40
C.F.R. 141.26.
(9)
Cryptosporidium and
E. coli source monitoring. Purveyors with surface water or GWI
sources shall monitor the sources in accordance with
40 C.F.R.
141.701 and 702.
(10) Contaminants with a SAL under WAC
246-290-315, Table 9.
(a) Purveyors shall
monitor for contaminants with a SAL in accordance with Tables 3 and 4 of this
section. Source sample locations and blended samples are allowed as consistent
with other federally regulated organic contaminants referenced in subsection
(7)(b) of this section.
TABLE 3
SAL MONITORING
|
Contaminant or Group of Contaminants |
Applicable Water System Classification |
Initial Sampling |
Routine Sampling Frequency |
Sampling Location |
|
Organic Contaminants |
||||
|
Per- and polyfluoroalkyl substances (PFAS) |
Community and NTNC, and if applicable, TNC |
One sample on or before December 31, 2025 |
Once every three years |
Per the locations described in WAC 246-290-300(7)(b) and Table 4 of this section |
(b)
Purveyors shall monitor for PFAS contaminants using an approved method in WAC
246-390-075(17)(a)
and all method specific contaminants as
listed on Table 7 in WAC
246-390-075.
(i) Purveyors, on a schedule determined by
the department, but no later than December 31, 2025, shall complete initial
sampling for PFAS from a sample location representing each source as listed in
Table 4 of this section.
(ii)
Initial PFAS sampling prioritization and scheduling is based on the following
criteria:
(A) Susceptibility of the source
water to contamination by surface activities due to physical attributes of the
source;
(B) Vulnerability of the
source water to PFAS contamination; and
(C) Population served.
(iii) Purveyors of TNC systems determined by
the department to be at risk of PFAS contamination due to proximity of the
system's water supply to known PFAS contamination shall collect a sample for
analysis as directed by the department and, if detected, comply with the
follow-up requirements under WAC
246-290-320(8).
(c) Analytical results for contaminants or
groups of contaminants listed in Table 3 of this section reported prior to
January 1, 2023, that meet the SDRL and requirements established in chapter
246-390 WAC with the effective date of January 1, 2022, or later may be used to
comply with the initial PFAS monitoring requirement in this chapter.
(d) For sources that become active after
January 1, 2022, purveyors shall perform the required monitoring as part of the
source approval process under WAC
246-290-130.
(e) The department may require a confirmation
sample. If a confirmation sample is required by the department, the result will
be averaged with the first sampling result and the average is used as the final
result. The department has the discretion to delete results of obvious sampling
errors from this calculation.
(f)
After completing initial sampling as described in Table 3 of this section, each
source must be monitored as follows:
(i) For
sources with organic results less than the SDRL, purveyors shall begin routine
monitoring as described in Table 3 of this section, unless a monitoring waiver
is granted by the department under (h) of this subsection.
(ii) For sources with organic detections
equal to or greater than the SDRL, purveyors shall conduct follow-up monitoring
under WAC
246-290-320(8).
(iii) For sources with inorganic detections
below the SAL, purveyors shall monitor as identified in subsection (4) of this
section.
(iv) For sources with
inorganic detections above the SAL, purveyors shall conduct follow-up
monitoring under WAC
246-290-320(9).
(g) For public water systems required to
sample for PFAS under EPA's fifth Unregulated Contaminant Monitoring Rule
(UCMR5), if the minimum reporting limits are less than fifty percent of any
SAL, the department shall accept data that has been accepted by EPA under UCMR5
for the purposes of meeting initial monitoring requirements under WAC
246-290-300. Public water systems
required to sample for PFAS shall submit all results to the department to be
considered in compliance with the initial monitoring requirements.
(i) If the minimum reporting limit for a
result is greater than twenty percent of any SAL, but the result is reported as
a nondetect, then follow-up monitoring per WAC
246-290-320 will not be
required.
(ii) If a detection is
reported below the minimum detection limit and is greater than twenty percent
of a SAL, then one additional quarter of follow-up monitoring will be required
per WAC 246-290-320(8)(b).
(h) Monitoring waivers for contaminants with
a SAL.
(i) The department may grant a waiver
for SAL monitoring requirements identified in this chapter.
(ii) As a condition of the waiver, the
department may require a purveyor take a minimum of one sample per source while
the waiver is effective.
(11) Other contaminants. On the basis of
public health concerns, the department may require a purveyor to monitor for
additional contaminants.
TABLE 4
MONITORING LOCATION
|
Sample Type |
Sample Location |
|
Asbestos |
One sample from distribution system or if required by department, from the source. |
|
Bacteriological |
From representative points throughout distribution system. |
|
Cryptosporidium and E. coli (Source Water) - WAC 246-290-630(16) |
Under 40 C.F.R. 141.703. |
|
Complete Inorganic Chemical & Physical |
From a point representative of the source, after treatment, and prior to entry to the distribution system. |
|
Lead/Copper |
From the distribution system at targeted sample tap locations. |
|
Nitrate/Nitrite |
From a point representative of the source, after treatment, and prior to entry to the distribution system. |
|
Disinfection Byproducts - TTHMs and HAA5 - WAC 246-290-300(6) |
Under 40 C.F.R. 141.132(b)(1) (Subpart L of the C.F.R.). |
|
Disinfection Byproducts - TTHMs and HAA5 - WAC 246-290-300(6) |
Under 40 C.F.R. 141.600 - 629 (IDSE and LRAA in Subparts U and V of the C.F.R.). |
|
Disinfection Byproducts - Chlorite (Systems adding chlorine dioxide) |
Under 40 C.F.R. 141.132(b)(2). |
|
Disinfection Byproducts - Bromate (Systems adding ozone) |
Under 40 C.F.R. 141.132(b)(3). |
|
Disinfectant Residuals - Chlorine and Chloramines |
Under 40 C.F.R. 141.132(c)(1). |
|
Disinfectant Residuals - Chlorine dioxide |
Under 40 C.F.R. 141.132(c)(2). |
|
Disinfection Precursors - Total Organic Carbon (TOC) |
Under 40 C.F.R. 141.132(d). |
|
Disinfection Precursors - Bromide (Systems using ozone) |
From the source before treatment. |
|
Radionuclides |
From a point representative of the source, after treatment and prior to entry to distribution system. |
|
Organic Chemicals (VOCs, SOCs, & PFAS) |
From a point representative of the source, after treatment and prior to entry to distribution system. |
Other contaminants without As directed by the department. an MCL, MRDL, TT or SAL
Statutory Authority: RCW 43.20.050(2) and 70.119A.080. 11-17-062, § 246-290-300, filed 8/15/11, effective 10/1/11. Statutory Authority: RCW 43.20.050 and 70.119A.080. 10-20-068, § 246-290-300, filed 9/29/10, effective 11/1/10. Statutory Authority: RCW 43.20.050. 09-21-045, § 246-290-300, filed 10/13/09, effective 1/4/10. Statutory Authority: RCW 70.119A.180 and 43.20.050. 08-03-061, § 246-290-300, filed 1/14/08, effective 2/14/08. Statutory Authority: RCW 43.20.050 and 70.119A.080. 04-04-056, § 246-290-300, filed 1/30/04, effective 3/1/04. Statutory Authority: RCW 43.20.050(2) and (3) and 70.119A.080. 03-08-037, § 246-290-300, filed 3/27/03, effective 4/27/03. Statutory Authority: RCW 43.02.050 [43.20.050]. 99-07-021, § 246-290-300, filed 3/9/99, effective 4/9/99. Statutory Authority: RCW 43.20.050. 94-14-001, § 246-290-300, filed 6/22/94, effective 7/23/94; 93-08-011 (Order 352B), § 246-290-300, filed 3/25/93, effective 4/25/93; 92-04-070 (Order 241B), § 246-290-300, filed 2/4/92, effective 3/6/92. Statutory Authority: Chapter 43.20 RCW. 91-07-031 (Order 150B), § 246-290-300, filed 3/15/91, effective 4/15/91. Statutory Authority: RCW 43.20.050. 91-02-051 (Order 124B), recodified as § 246-290-300, filed 12/27/90, effective 1/31/91. Statutory Authority: P.L. 99-339. 89-21-020 (Order 336), § 248-54-165, filed 10/10/89, effective 11/10/89. Statutory Authority: RCW 34.04.045. 88-05-057 (Order 307), § 248-54-165, filed 2/17/88. Statutory Authority: RCW 43.20.050. 83-19-002 (Order 266), § 248-54-165, filed 9/8/83.
Disclaimer: These regulations may not be the most recent version. Washington may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
This site is protected by reCAPTCHA and the Google
Privacy Policy and
Terms of Service apply.
