| (III) the public water system's sample siting plan
remains representative of water quality in the distribution system.
If a required repeat sample is used to meet both requirements and
found to be E. coli -positive, the
public water system will have achieved an E.
coli MCL as defined in subsection (b)(1)(A) - (D) of this section
and corrective action will be required for the groundwater source
where the sample was found to be E. coli -positive.
(iv) If the executive director does not require corrective
action under §290.116 of this title (relating to Groundwater
Corrective Actions and Treatment Techniques) for a fecal indicator
positive source water sample collected under this subparagraph that
is not invalidated under subsection (e) of this section, the public
water system shall collect five additional source water samples from
the same source within 24 hours of being notified of the fecal indicator
positive sample.
(v) If a public water system takes more than one repeat
sample at the monitoring location required for triggered source water
monitoring, the public water system may reduce the number of additional
source water samples required under clause (iv) of this subparagraph
by the number of repeat samples taken at that location that were not E. coli- positive.
(C) Consecutive and wholesale systems. Consecutive
groundwater systems receiving drinking water from a wholesaler must
notify the wholesale system(s) within 24 hours of being notified of
the positive coliform distribution sample. The wholesale groundwater
system(s) must comply with the following:
(i) A wholesale groundwater system that receives notice
of a distribution coliform sample positive from a consecutive system
it serves must collect a sample from each of its groundwater sources
within 24 hours of the notification and analyze each sample for the
presence of E. coli (or other approved
fecal indicator).
(ii) If any raw source sample is
E. coli (or other approved fecal indicator) positive, the wholesale
groundwater system must notify all consecutive systems served by that
groundwater source of the fecal indicator positive within 24 hours
of being notified. The wholesale system and all consecutive systems
served by that groundwater source must notify their water system customers
in accordance with subsection (h)(2) of this section and shall meet
the requirements of subparagraph (B)(iv) of this paragraph.
(iii) If any raw source sample is E. coli positive, the wholesale groundwater
system shall notify all consecutive systems served by that groundwater
source of the fecal indicator source water positive within 24 hours
of being notified and shall meet the requirements of subparagraph
(B)(iv) of this paragraph.
(D) Exceptions to the triggered source monitoring requirements.
A groundwater system is not required to comply with the triggered
source monitoring requirements if any of the following conditions
exist.
(i) The executive director determines and documents
in writing, that the distribution coliform-positive sample is caused
by a distribution system deficiency; or
(ii) The distribution coliform-positive sample is collected
at a location that meets the distribution coliform sample invalidation
criteria as specified in subsection (e)(1) of this section and the
replacement sample is negative for coliforms.
(E) Assessment source monitoring. The executive director
may require monthly source assessment raw monitoring without the presence
of a positive total coliform distribution sample if well conditions
exist that indicate the groundwater may be susceptible to fecal contamination.
The executive director may conduct a hydrogeological sensitivity assessment
to determine if the source is susceptible to fecal contamination.
If requested by the executive director, groundwater systems must provide
the executive director with any existing information that will enable
the executive director to perform a hydrogeological sensitivity assessment.
A groundwater system conducting assessment source monitoring may use
a triggered source sample collected under subparagraph (A) of this
paragraph to meet the assessment source monitoring requirement. A
groundwater system with a groundwater source sample collected under
this subparagraph or under subparagraph (A) of this paragraph that
is fecal indicator positive and that is not invalidated under subsection
(e)(2) of this section, including consecutive systems served by the
groundwater source, shall conduct public notification under §290.122(a)
of this title (relating to Public Notification). Additionally, an
assessment source monitoring sample may be used as a triggered source
monitoring sample if collected within 24 hours of notification of
the coliform-positive distribution sample. 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.
Cont'd... |
