Current through Register Vol. 48, No. 9, September 27, 2024
(1) Corrosion
Control Treatment
This section sets forth when a system must complete the
corrosion control treatment steps for systems in paragraph (4) or (5) of this
section to optimize or re-optimize corrosion control treatment based on size,
whether the system has corrosion control treatment, and whether it has exceeded
the lead trigger and/or action level and/or the copper action level.
(a) Large water system (serving greater than
50,000 people).
(i) Large water systems with
corrosion control treatment that exceed either the lead trigger level or copper
action level shall complete the corrosion control treatment steps specified in
paragraph (4) of this section.
(ii)
Large water systems without corrosion control treatment with
90th percentile results as calculated in accordance
with R.61-58.11.B(3)(d)
that exceed either the lead practical quantitation level of 0.005 mg/L or the
copper action level shall complete the corrosion control treatment steps
specified in paragraph (5) of this section.
(iii) Large water systems with corrosion
control treatment with 90th percentile results as
calculated in accordance with R.61-58.11.B(3)(d)
that exceed the lead practical quantitation level but do not exceed the lead
trigger level or the copper action level may be required by the Department to
complete the corrosion control treatment steps in paragraph (4) of this
section.
(b) Medium-size
water systems (serving greater than 10,000 and 50,000 people or less).
(i) Medium-size water systems with corrosion
control treatment that exceed either the lead trigger level or copper action
level shall complete the corrosion control treatment steps specified in
paragraph (4) of this section.
(ii)
Medium-size water systems without corrosion control treatment that exceed
either the lead or copper action level shall complete the corrosion control
treatment steps specified in paragraph (5) of this section.
(iii) Medium-size water systems without
corrosion control treatment that exceed the lead trigger level but do not
exceed the lead or copper action levels shall complete the treatment
recommendation step specified in paragraph (5)(a) of this section (Step 1). The
water system shall complete the remaining steps in paragraph (5) of this
section if it subsequently exceeds either the lead or copper action
level.
(c) Small water
systems (serving 10,000 people or less) and non-transient, non-community water
systems.
(i) Small and non-transient,
non-community water systems with corrosion control treatment that exceed the
lead trigger level or the lead action level but do not exceed the copper action
level, shall complete the corrosion control treatment steps specified in
paragraph (4) of this section, if corrosion control treatment is approved by
the Department as a compliance option under R.61-58.11.O.
(ii) Small and non-transient, non-community
water systems with corrosion control treatment that exceed the copper action
level shall complete the corrosion control treatment steps specified in
paragraph (4) of this section.
(iii) Small and non-transient, non-community
water systems without corrosion control treatment that exceed the lead action
level shall complete the corrosion control treatment steps specified in
paragraph (5) of this section if corrosion control treatment is approved by the
Department as a compliance option under R.61-58.11.O.
(iv) Small and non-transient, non-community
water systems without corrosion control treatment that exceed the copper action
level shall complete the corrosion control treatment steps specified in
paragraph (5) of this section.
(2) Systems Deemed to have Optimized
Corrosion Control.
A system is deemed to have optimal corrosion control treatment
(OCCT) or re-optimized OCCT if the system satisfies one of the criteria
specified in paragraphs (2)(a) through (c) of this section. Any such system
deemed to have OCCT under this paragraph and which has corrosion control
treatment in place shall continue to operate and maintain that treatment and
meet any additional requirements that the Department determines to be
appropriate to ensure optimal corrosion control treatment is maintained.
(a) A small or medium-size water system
without corrosion control treatment is deemed to have optimal corrosion control
if the water system does not exceed the lead action level and copper action
level during two (2) consecutive six (6)-month tap sampling monitoring periods
and thereafter remains at or below the lead trigger level and copper action
level in all tap sampling periods conducted in accordance with
R.61-58.11.H.
(b) A small or
medium-size water system with corrosion control treatment is deemed to have
optimal corrosion control treatment if the water system does not exceed the
lead trigger level and copper action level during two (2) consecutive six
(6)-month monitoring periods conducted in accordance with R.61-58.11.H and thereafter remains
at or below the lead trigger level and copper action level in all tap sampling
periods conducted in accordance with R.61-58.11.H. Small or medium-size
systems with corrosion control treatment that exceed the lead trigger level but
do not exceed the lead and copper action levels during two (2) consecutive six
(6)-month monitoring periods and thereafter remains at or below the lead and
copper action levels in all tap sampling periods conducted in accordance with
R.61-58.11.H are deemed to have re-optimized optimal corrosion control
treatment if the system meets the requirements of this section. Where the
Department has set optimal water quality parameters (OWQPs) under paragraph (4)
or (5) of this section a system will not be eligible to be deemed to have
optimized or re-optimized OCCT pursuant to paragraph (2) of this
section
(c) Any water system is
deemed to have optimized or re-optimized corrosion control if it submits
results of tap water monitoring in accordance with R.61-58.11.H demonstrating
that the 90th percentile tap water lead level is
less than or equal to the lead practical quantitation level of 0.005 mg/L and
does not exceed the copper action level for two (2) consecutive six (6)-month
tap sampling monitoring periods, and does not have optimal water quality
parameters that were set by the Department under paragraph (4) or (5) of this
section. Any such system with 90th percentile tap
sample results that thereafter exceeds the lead practical quantitation level or
copper action level during any tap sampling period shall not be eligible to be
deemed to have optimized OCCT in accordance with this paragraph (2)(c) without
first completing the treatment steps specified in paragraph (4) or (5) of this
section
(i) [Reserved]
(ii) Any water system deemed to have
optimized corrosion control in accordance with this paragraph (2)(c) shall
continue monitoring for lead and copper at the tap no less frequently than once
every three (3) calendar years using the reduced number of sites specified in
R. 61-58.11.H(3) and
collecting the samples at times and locations specified in R.
61-58.11.H(4)(d)(v).
(iii) [Reserved]
(iv) [Reserved]
(v) [Reserved]
(3) Corrosion Control Steps
Completion for Small and Medium-Size Water Systems Without Corrosion Control
Treatment.
Any small or medium-sized system without corrosion control
treatment required to complete the corrosion control steps in paragraph (5) of
this section due to its exceedance of the lead or copper action level that does
not exceed either the lead or copper action levels during each of two (2)
consecutive six (6)-month tap sample monitoring periods pursuant to
R.61-58.11.H prior to the start of Step 3 in paragraph (5)(c) of this section
or Step 5 in paragraph (5)(e) of this section may cease completing the steps
and is not required to complete Step 3 or Step 5, respectively, except that
medium-sized systems with lead service lines and small systems with lead
service lines that choose the corrosion control option pursuant to R.
61-58.11.O must complete a
corrosion control treatment study under paragraph (5)(c)(i) of this section.
Any system that initiates Step 5 must complete all remaining steps in
paragraphs (5)(f) through (h) of this section and is not permitted to cease the
steps. Any system that ceases the steps either prior to Step 3 or Step 5 and
thereafter exceeds either the lead or copper action level shall not be
permitted to cease the steps a second time and shall complete the applicable
treatment steps beginning with the first treatment step which was not
previously completed in its entirety. The Department may require a water system
to repeat treatment steps previously completed by the water system when the
Department determines that this is necessary to implement the treatment
requirements of this section. The Department must notify the system in writing
of such a determination and explain the basis for its decision.
(4) Treatment Steps and Deadlines
for Water Systems Re-optimizing Corrosion Control Treatment.
Except as provided in paragraph (2) of this section or
R.61-58.11.O, water systems with
corrosion control treatment shall complete the following corrosion control
treatment steps (described in the referenced portions of R.61-58.11.D, R.61-58.11.H, and R.61-58.11.I by the indicated time
periods.
(a) Step 1:
(i) A water system other than those covered
in paragraph (4)(a)(ii) of this section shall recommend re-optimized optimal
corrosion control treatment (R.61-58.11.D(3))
within six (6) months after the end of the tap sampling period during which it
exceeds either the lead trigger level or copper action level. The Department
may approve modifications of the existing corrosion control treatment without a
study for systems that exceed the lead trigger level, but do not exceed the
lead or copper action level. The Department shall specify re-optimized
corrosion control treatment within six (6) months of receiving the treatment
recommendation. The system shall complete modifications to corrosion control
treatment to have re-optimized corrosion control treatment installed within six
(6) months of the Department specifying re-optimized corrosion control
treatment.
(ii) A water system with
lead service lines that exceeds the lead action level must harvest lead pipes
from the distribution system and construct flowthrough pipe loops and operate
the loops with finished water within one (1) year after the end of the tap
sampling period during which it exceeds the lead action level. These water
systems must proceed to Step 3 in paragraph (4)(c) of this section and conduct
the corrosion control studies for re-optimization under paragraph (4)(c)(i) of
this section using the pipe loops.
(b) Step 2:
(i) Large water systems shall conduct the
corrosion control studies for re-optimization under paragraph (4)(c) of this
section (Step 3) unless the system is at or below the lead action level and the
Department has approved the modification of the existing corrosion control
treatment made under paragraph (4)(c)(i) of this section (Step 1).
(ii) Within twelve (12) months after the end
of the tap sampling period during which a small or medium-size water system
with corrosion control treatment exceeds the lead trigger level or copper
action level, the Department may require the water system to perform corrosion
control studies for re-optimization (R.61-58.11.D(3)(b)
or (c)). If the Department does not require the system to perform such studies,
the Department must specify re-optimized corrosion control treatment
(R.61-58.11.D(4)(b))
within the timeframes specified in paragraphs (4)(b)(ii)(A) and (B) of this
section. The Department must provide its determination to the system in
writing.
(A) For medium-size water systems,
within twelve (12) months after the end of the tap sampling period during which
such water system exceeds the lead trigger level or copper action
level.
(B) For small water systems,
within eighteen (18) months after the end of the tap sampling period during
which such water system exceeds the lead trigger level or copper action
level.
(c)
Step 3:
(i) Any water system with lead
service lines that exceeded the lead action level shall complete the corrosion
control treatment studies for re-optimization within thirty (30) months after
the end of the tap sampling period during which it exceeds the lead action
level.
(ii) If the water system is
required to perform corrosion control studies under paragraph (4)(b) of this
section (Step 2), the water system shall complete the studies (R.61-58.11.D(3)(b))
within eighteen (18) months after the Department requires that such studies be
conducted.
(d) Step 4:
(i) The Department shall designate
re-optimized corrosion control treatment (R.61-58.11.D(4)(c))
within six (6) months after completion of paragraph (4)(c)(i) of this section
(Step 3).
(ii) If the water system
has performed corrosion control studies under paragraph (4)(b) of this section
(Step 2), the Department shall designate re-optimized corrosion control
treatment (R.61-58.11.D(4)(b)
or (d)) within six (6) months after completion of paragraph (4)(c)(ii) of this
section (Step 3).
(e)
Step 5:
(i) Large water systems shall
complete modifications to corrosion control treatment to have reoptimized
corrosion control treatment installed within twelve (12) months after
completion of paragraph (4)(d)(i) of this section (Step 4).
(ii) Small or medium-size water systems shall
install re-optimized corrosion control treatment (R.61-58.11.D(5)(a))
within twelve (12) months after completion of paragraph (4)(d)(ii) of this
section (Step 4).
(f)
Step 6: Water systems must complete follow-up sampling (R.61-58.11.H(4)(b) and
R.61-58.11.I(3)) within twelve (12)
months after completion of paragraph (4)(e)(i) or (ii) of this section (Step
5).
(g) Step 7: The Department must
review the water system's installation of treatment and designate optimal water
quality control parameters (R.61-58.11.D(6)(a))
within six (6) months of completion of paragraph (4)(f) of this section (Step
6).
(h) Step 8: The water system
must operate in compliance with the Department-designated optimal water quality
control parameters (R.61-58.11.D(7))
and continue to conduct tap sampling (R.61-58.11.H(4)(c)) and water
quality parameter monitoring under R.61-58.11.I(4).
(5) Treatment Steps and Deadlines
for Systems Without Corrosion Control Treatment.
Except as provided in paragraph (2) of this section or
R.61-58.11.O, water systems without
corrosion control treatment must complete the following corrosion control
treatment steps (described in the referenced portions of R.61-58.11.D, R.61-58.11.H, and R.61-58.11.I) by
the indicated time periods.
(a) Step
1:
(i) A water system other than those
covered in paragraph (5)(a)(ii) or (iii) of this section must recommend optimal
corrosion control treatment (R.61-58.11.D(1)(a), (b), (c), or
(d)) within six (6) months after the end of
the tap sampling period during which it exceeds either the lead trigger level
or copper action level.
(ii) A
water system with lead service lines that exceeds the lead action level must
harvest lead pipes from the distribution system and construct flowthrough pipe
loops and operate the loops with finished water within one (1) year after the
end of the tap sampling period during which it exceeds the lead action level.
These water systems must proceed to Step 3 in paragraph (5)(c) of this section
and conduct the corrosion control studies for optimization under paragraph
(5)(c)(i) of this section using the pipe loops.
(iii) Large water systems under paragraph
(1)(a)(ii) of this section must conduct the corrosion control studies for
optimization under paragraph (5)(c) of this section (Step 3).
(b) Step 2: Within twelve (12)
months after the end of the tap sampling period during which a system exceeds
the lead or copper action level, if not otherwise required by this rule, the
Department may require the water system to perform corrosion control studies
(R. 61-58.11.D(2)
below). The Department must notify the system in writing of this requirement.
If the Department does not require the system to perform such studies, the
Department must specify optimal corrosion control treatment
(R.61-58.11.D(4))
within the timeframes established in paragraphs (5)(b)(i) and (ii) of this
section. The Department must provide its determination to the system in
writing.
(i) For medium-size systems,
within eighteen (18) months after the end of the tap sampling monitoring period
during which such water system exceeds the lead trigger level or copper action
level.
(ii) For small systems,
within twenty-four (24) months after the end of the tap sampling monitoring
period during which such water system exceeds the lead trigger level or copper
action level.
(c) Step
3:
(i) Large water systems with or without
lead service lines and medium or small systems with lead service lines that
exceed the lead action level shall complete the corrosion control treatment
studies for optimization within thirty (30) months after the end of the tap
sampling period during which it exceeds the lead action level.
(ii) If the Department requires a water
system to perform corrosion control studies under paragraph (5)(b) of this
section (Step 2), the water system must complete the studies R.61-58.11.D(3)(a)
within eighteen (18) months after the Department notifies the system in writing
that such studies must be conducted.
(d) Step 4:
(i) The Department shall designate
re-optimized corrosion control treatment (R.61-58.11.D(4)(c))
within six (6) months after completion of paragraph (4)(c)(i) of this section
(Step 3).
(ii) If the water system
has performed corrosion control studies under paragraph (5)(b) of this section
(Step 2), the Department must designate optimal corrosion control treatment
(R.61-58.11.D(4)(a))
within six (6) months after completion of paragraph (5)(c) of this section
(Step 3).
(e) Step 5:
The water system must install optimal corrosion control treatment
(R.61-58.11.D(5)(a))
within twenty-four (24) months after the Department designates optimal
corrosion control treatment under paragraph (5)(b) or (d) of this section (Step
2 or Step 4).
(f) Step 6: The water
system shall complete follow-up sampling (R.61-58.11.H(4)(b) and
R.61-58.11.I(3) below) within twelve (12) months after completion of paragraph
(5)(e) of this section (Step 5).
(g) Step 7: The Department must review the
system's installation of treatment and designate optimal water quality control
parameters (R.61-58.11.D(6)
below) within six (6) months of completion of paragraph (5)(f) of this section
(Step 6).
(h) Step 8: The water
system must operate in compliance with the Department-designated optimal water
quality control parameters (R.61-58.11.D(7)
below) and continue to conduct tap sampling (R.61-58.11.H(4)(c) and water quality
parameter monitoring under R.61-58.11.I(4)).
(6) Treatment Steps and Deadlines
for Small Community Water Systems and Non-Transient Non-Community Water Systems
Electing Corrosion Control Treatment (CCT) as a Compliance Option Under
R.51-58.11.O, or as Required by the
Department.
Water systems selecting the corrosion control small system
compliance flexibility option must complete the following steps by the
indicated time periods.
(a) Step 1: A
water system recommends corrosion control treatment as a small system
compliance flexibility option under R.61-58.11.O(1)(b) within six (6)
months after the end of the tap sampling period during which it exceeds either
the lead trigger level or the lead action level.
(b) Step 2: The Department approves in
writing the recommendation of corrosion control treatment as a small system
compliance flexibility option or designates an alternative option in accordance
with R.61-58.11.O(1) within six (6)
months of the recommendation by the water system in paragraph (6)(a) of this
section (Step 1). Water systems required by the Department to optimize or
re-optimize corrosion control treatment must follow the schedules in paragraph
(4) or (5) of this section, beginning with Step 3 in paragraph (4)(c) or (5)(c)
of this section unless the Department specifies optimal corrosion control
treatment pursuant to either paragraph (4)(b)(ii) or (5)(b)(ii) of this
section, as applicable.
