(B) The executive director shall designate optimal
corrosion control treatment. The executive director shall either approve
the corrosion control treatment option recommended by the system,
or designate alternative corrosion control treatment(s) from among
those listed in paragraph (1)(B)(i) of this subsection. When designating
optimal treatment the executive director shall consider the effects
that additional corrosion control treatment will have on water quality
parameters and on other water quality treatment processes. If the
executive director requests additional information, the water system
shall provide the information.
(C) Upon its own initiative or in response to a request
by a water system or other interested party, the executive director
may modify the determination of the optimal corrosion control treatment.
A request for modification by a system or other interested party shall
be in writing, explain why the modification is appropriate, and provide
supporting documentation. The executive director may modify the determination
when the change is necessary to ensure that the system continues to
optimize corrosion control treatment. A revised determination shall
be made in writing, set forth the new treatment requirements, explain
the basis for the decision, and provide an implementation schedule
for completing the treatment modifications.
(D) The executive director shall notify the system
of the decision on optimal corrosion control treatment in writing
and will provide the basis for this determination. The executive director
will review the study and designate optimal corrosion control treatment
and water quality parameters.
(i) For systems serving more than 50,000 customers,
optimal corrosion control treatment and OWQPs shall be designated
within six months of submittal.
(ii) For systems serving 3,300 to 50,000 customers,
optimal corrosion control treatment and OWQPs shall be designated
within 18 months of submittal.
(iii) For systems serving fewer than 3,300, optimal
corrosion control treatment and OWQPs shall be designated within 24
months of submittal.
(4) Installation of optimal corrosion control treatment.
A system shall perform corrosion control activities identified in
their approved corrosion control study. A system shall install optimal
corrosion control treatment within 24 months after the executive director
designates optimal corrosion control treatment and notifies the water
system. All applicable water systems shall operate optimal corrosion
control treatment in a manner that minimizes lead and copper concentrations
at users' taps while ensuring that the treatment does not cause the
system to violate any other drinking water standard.
(5) Operation of corrosion control treatment. All systems
optimizing corrosion control shall continue to operate and maintain
optimal corrosion control treatment, including operating within approved
OWQP ranges and complying with all other requirements of this section.
(A) The executive director shall evaluate the results
of all lead and copper tap samples and WQP samples submitted by the
water system to determine whether the corrosion control treatment
was properly installed and if the system is properly operating the
designated optimal corrosion control treatment.
(B) The system shall operate in such a manner as to
meet any requirements that the executive director determines appropriate
to ensure optimal corrosion control treatment is maintained.
(6) Small system activities cessation. A system serving
50,000 or fewer people that is required to perform corrosion control
activities because of an action level exceedance may cease the corrosion
control activities if it conducts two consecutive six-month lead and
copper monitoring rounds and meets the lead and copper action levels
based on the 90th percentile in both rounds.
(g) Treatment of source water lead and copper. Systems
may be required to perform treatment to remove lead or copper from
source water. Any system exceeding the lead or copper action level
shall implement all applicable source water treatment requirements
specified by the executive director under this subsection. The executive
director will determine whether such treatment is required.
(1) Determination of need for source water treatment.
Any system which exceeds the lead or copper action level shall recommend
in writing to the executive director the installation and operation
of ion exchange, reverse osmosis, lime softening or coagulation/filtration.
The executive director shall evaluate all entry point water sample
results, along with the corrosion control study, to determine if source
water treatment is necessary. If source water treatment is required
by the executive director, the system must install the treatment in
accordance with the scheduling requirements specified in this subsection.
(A) The system shall submit the results for all source
water samples to aid in the executive director's evaluation of whether
source water treatment is necessary.
(B) The executive director may approve the treatment
recommended by the system or may require installation and operation
of another source water treatment from among the following: ion exchange,
reverse osmosis, lime softening or coagulation/filtration.
(C) If the executive director requests additional information
to aid in its review, the water system shall provide the information
by the date specified by the executive director in the request.
(D) A system may recommend that no treatment be installed
based upon a demonstration that source water treatment is not necessary
to minimize lead and copper levels at users' taps.
(E) The executive director shall notify the system
in writing of the determination and will provide the basis for the
decision.
(2) Schedule for installation of treatment of source
water lead and copper. If source water treatment is required, the
system must install the treatment in accordance with the scheduling
requirements specified in this subsection.
(A) A system exceeding the lead or copper action level
shall recommend treatment to the executive director no later than
180 days after the end of the monitoring period during which the lead
or copper action level was exceeded.
(B) The executive director shall make a determination
regarding source water treatment within six months after the system
submits the treatment recommendation and supporting data under subparagraph
(A) of this paragraph.
(C) The system shall properly install and operate the
source water treatment approved by the executive director within 24
months after the executive director's determination under subparagraph
(B) of this paragraph.
(D) The system shall complete follow-up tap sampling
under subsection (c) of this section and entry point monitoring under
subsection (d) of this section within 36 months after the executive
director's determination of source water treatment under subparagraph
(B) of this paragraph.
(3) Operation of source water lead and copper treatment.
If source water treatment is required, the system shall properly operate
the treatment in compliance with the specified MPLs for lead and copper
and continue entry point monitoring under subsection (d) of this section.
(A) A water system shall operate the source water treatment
in a manner that maintains lead and copper levels below the MPLs designated
by the executive director at each entry point.
(B) The executive director may review the system's
data and determine whether the system has properly installed and operated
the source water treatment.
(4) Modification of source water treatment decisions.
Upon its own initiative or in response to a request by a water system
or other interested party, the executive director may modify the determination
of the source water treatment under paragraph (1) of this subsection,
or MPLs for lead and copper at entry points under subsection (b)(6)
of this section. A request for modification by a system or other interested
party shall be in writing, explain why the modification is appropriate,
and provide supporting documentation. The executive director may modify
the determination when the change is necessary to ensure that the
system continues to minimize lead and copper concentrations in water
entering the distribution system. A revised determination shall be
made in writing, set forth the new treatment requirements, explain
the basis for the executive director's decision, and provide an implementation
schedule for completing the treatment modifications.
(h) Analytical methods, sample collection, and sample
invalidation. All methods used for analysis under this section shall
be consistent with 40 CFR Part 141, Subpart I, concerning Lead and
Copper.
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