| Assessment source monitoring
requirements may include:
(i) Source monitoring, collected in a manner described
in §290.119(b)(10) of this title, for a period of 12 months that
represents each month that the system provides groundwater to the
public from the raw groundwater source or such time period as specified
by the executive director.
(ii) Collection of samples from each well unless the
system has an approved triggered source monitoring plan under subparagraph
(B)(ii) of this paragraph.
(5) Culture analysis. If any routine or repeat sample
is total coliform-positive, that total coliform-positive medium will
be analyzed to determine if E. coli are
present. If E. coli are present, the
public water system shall notify the executive director by the end
of the day in accordance with subsection (h) of this section.
(6) Sample Siting Plan requirements. All public water
systems shall develop and complete a written Sample Siting Plan as
described in this paragraph that identifies routine and repeat microbial
sampling sites and a sample collection schedule as required by this
subsection that are representative of water throughout the distribution
system. The Sample Siting Plan shall include all groundwater sources
and any associated sampling points necessary to meet the requirements
of this subsection. The Sample Siting Plan shall be included as a
part of the public water system's monitoring plan as described in §290.121
of this title. Sample Siting Plans shall be completed in a format
specified by the executive director and are subject to review and
revision by the executive director.
(A) All public water systems shall collect routine
and repeat samples according to a written Sample Siting Plan. All
routine and repeat sample site locations, any required SOP, and any
sampling point locations necessary to meet the requirements of this
subsection shall be reflected in the written Sample Siting Plan. For
community and noncommunity public water systems serving 1,000 or fewer
people using only groundwater, the executive director shall evaluate
during every sanitary survey (on-site inspection) the water system
factors (including but not limited to pertinent water quality, compliance
history, distribution system, all the components of a sanitary survey
and its findings) to ensure the timeframe during the month, locations,
and number of microbial compliance monitoring sample sites are adequate
for producing and distributing safe drinking water.
(B) All public water systems shall include any required
SOP for any proposed repeat sampling sites as described in paragraph
(3)(C) of this subsection in the Sample Siting Plan. As required by
the executive director, the executive director may review, revise,
and approve any repeat sampling proposed by public water systems under
paragraph (3)(C) of this subsection.
(C) The Sample Siting Plan shall include a distribution
system map or series of maps which identifies distribution system
valves and mains as described in §290.46(n)(2) of this title.
The distribution system map shall also include the location of all
routine microbial sample sites, water main sizes, entry point source
locations, water storage facilities, and any pressure plane boundaries.
(D) All public water systems shall update their written
Sample Siting Plan and map as necessary, or as requested by the executive
director, to identify the most current microbial routine and repeat
sampling sites and a sample collection schedule that are representative
of water throughout the public water system's distribution system.
(E) All public water systems shall maintain a copy
of their updated Sample Siting Plan and map on-site at the public
water system for inspection purposes and at the request of the executive
director, provide a copy of their Sample Siting Plan and/or map to
the executive director for review and/or revision purposes.
(e) Analytical and invalidation requirements for microbial
contaminants. Analytical procedures shall be performed in accordance
with §290.119 of this title. Testing for microbial contaminants
shall be performed at a laboratory certified by the executive director.
The public water system must use a certified laboratory certified
for each method and associated contaminant(s) for compliance analyses
in accordance with §290.119 of this title.
(1) Distribution coliform sample invalidation. The
executive director may invalidate a distribution total coliform-positive
sample if one of the following conditions is met.
(A) The executive director may invalidate a sample
if the laboratory provides written notice that improper sample analysis
caused the total coliform-positive result.
(B) The executive director may invalidate a sample
if the results of repeat samples collected, as required by this section,
determine that the total coliform-positive sample resulted from a
domestic or other non-distribution system plumbing problem. The executive
director cannot invalidate a sample on the basis of repeat sample
results unless all repeat sample(s) collected at the same tap as the
original total coliform-positive sample are also total coliform-positive,
and all repeat samples collected within five service connections of
the original tap are total coliform-negative. Under those circumstances,
the system may request that the executive director invalidate the
sample. The system must provide copies of the routine positive and
all repeat samples. The executive director may not invalidate a total
coliform-positive sample solely on the grounds that all repeat samples
are total coliform-negative or if the system has only one service
connection.
(C) The executive director may invalidate a sample
if there are substantial grounds to believe that the total coliform-positive
result is due to a circumstance or condition which does not reflect
water quality in the distribution system. In this case, the system
must still collect all repeat samples required by this section, and
use them to determine compliance with the E.
coli MCL as described in subsection (g) of this section and
whether a coliform treatment technique trigger has been exceeded as
described in subsection (c) of this section. The system must provide
written documentation which must state the specific cause of the total
coliform-positive sample, and the action the system has taken, or
will take, to correct this problem. The system must obtain the written
and signed approval from the executive director before the sample
can be invalidated under this condition. The executive director may
not invalidate a total coliform-positive sample solely on the grounds
that all repeat samples are total coliform-negative.
(D) The executive director may invalidate a sample
if the laboratory provides written notice that the sample was unsuitable
for analysis and the laboratory invalidated the sample based on the
requirements of 40 CFR §141.853(c)(2). When the sample is invalidated
under this condition, the system must collect another sample from
the same location as the original sample within 24 hours of being
notified, and have it analyzed for the presence of total coliforms.
The system must continue to re-sample within 24 hours and have the
samples analyzed until it obtains a valid result. The executive director
may waive the 24-hour time limit on a case-by-case basis. Alternatively,
the executive director may implement criteria for waiving the 24-hour
sampling time limit to use in lieu of case-by-case extension.
(E) If a sample is invalidated by the laboratory, the
public water system must collect another sample from the same location
as the original sample within 24 hours of being notified, or as soon
as possible if the laboratory is closed, and have it analyzed for
the presence of total coliform. The system must continue to resample
within 24 hours and have the samples analyzed until it obtains a valid
result.
(2) A groundwater system may obtain invalidation of
a fecal indicator positive groundwater source sample if the conditions
of subparagraphs (A) and (B) of this paragraph apply. If the executive
director invalidates a fecal indicator positive groundwater source
sample, the system must collect another source sample as specified
in subsection (d)(4) of this section within 24 hours of being notified
of the invalidation.
(A) Notice from the laboratory must document that improper
sample analysis occurred. If a laboratory invalidates a sample, the
system must collect another sample from the same location as the original
sample within 24 hours of being notified of the invalidated sample,
and have it analyzed for the presence of E.
coli (or other approved fecal indicator). The public water
system must continue to re-sample within 24 hours and have the samples
analyzed until it obtains a valid result. If approved by the executive
director, the 24-hour time limit may be extended.
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