Current through February, 2024
(a) General
Requirements
(1) The requirements of this
section constitute national primary drinking water regulations. The regulations
in this section establish or extend treatment technique requirements in lieu of
maximum contaminant levels for Cryptosporidium. These requirements are in
addition to requirements for filtration and disinfection in sections
11-20-46
and
11-20-46.1.
(2) Applicability. The
requirements of this section apply to all subpart H systems, which are public
water systems supplied by a surface water source and public water systems
supplied by a ground water source under the direct influence of surface water.
(A) Wholesale systems, as defined in section
11-20-2,
must comply with the requirements of this section based on the population of
the largest system in the combined distribution system.
(B) The requirements of this section for
filtered systems apply to systems required by National Primary Drinking Water
Regulations to provide filtration treatment, whether or not the system is
currently operating a filtration system.
(C) The requirements of this section for
unfiltered systems apply only to unfiltered systems that timely met and
continue to meet the filtration avoidance criteria in sections
11-20-46
and
11-20-46.1,
as applicable.
(3)
Requirements. Systems subject to this section must comply with the following
requirements:
(A) Systems must conduct an
initial and a second round of source water monitoring for each plant that
treats a surface water or GWUDI source. This monitoring may include sampling
for Cryptosporidium, E. coli, and turbidity as described in subsections (b)
through (g), to determine what level, if any, of additional Cryptosporidium
treatment they must provide.
(B)
Systems that plan to make a significant change to their disinfection practice
must develop disinfection profiles and calculate disinfection benchmarks, as
described in subsections (i) through (j).
(C) Filtered systems must determine their
Cryptosporidium treatment bin classification as described in subsection (k) and
provide additional treatment for Cryptosporidium, if required, as described in
subsection (l). All unfiltered systems must provide treatment for
Cryptosporidium as described in subsection (m). Filtered and unfiltered systems
must implement Cryptosporidium treatment according to the schedule in
subsection (n).
(D) Systems with
uncovered finished water storage facilities must comply with the requirements
to cover the facility or treat the discharge from the facility as described in
subsection (o).
(E) Systems
required to provide additional treatment for Cryptosporidium must implement
microbial toolbox options that are designed and operated as described in
sections (p) through (u).
(F)
Systems must comply with the applicable recordkeeping and reporting
requirements described in subsection (v) through (w).
(G) Systems must address significant
deficiencies identified in sanitary surveys performed by EPA as described in
subsection (x).
(b)
Source water monitoring.
(1)
Initial round of source water monitoring. Systems must conduct the following
monitoring on the schedule in paragraph (3) unless they meet the monitoring
exemption criteria in paragraph (4).
(A)
Filtered systems serving at least 10,000 people must sample their source water
for Cryptosporidium, E. coli, and turbidity at least monthly for 24
months.
(B) Unfiltered systems
serving at least 10,000 people must sample their source water for
Cryptosporidium at least monthly for 24 months.
(C) Filtered systems serving fewer than
10,000 people must sample their source water for E. coli at least once every
two weeks for 12 months. A filtered system serving fewer than 10,000 people may
avoid E. coli monitoring if the system notifies the State that it will monitor
for Cryptosporidium as described in subparagraph (D). The system must notify
the State no later than 3 months prior to the date the system is otherwise
required to start E. coli monitoring under paragraph (3).
(D) Filtered systems serving fewer than
10,000 people must sample their source water for Cryptosporidium at least twice
per month for 12 months or at least monthly for 24 months if they meet one of
the following, based on monitoring conducted under subparagraph (C) :
(i) For systems using lake/reservoir sources,
the annual mean E. coli concentration is greater than 10 E. coli/100 mL.
(ii) For systems using flowing
stream sources, the annual mean E. coli concentration is greater than 50 E.
coli/100 mL.
(iii) The system does
not conduct E. coli monitoring as described in subparagraph (C).
(iv) Systems using ground water under the
direct influence of surface water (GWUDI) must comply with the requirements of
this subparagraph based on the E. coli level that applies to the nearest
surface water body. If no surface water body is nearby, the system must comply
based on the requirements that apply to systems using lake/reservoir
sources.
(E) For
filtered systems serving fewer than 10,000 people, the State may approve
monitoring for an indicator other than E. coli under subparagraph (C). The
State also may approve an alternative to the E. coli concentration in
subparagraphs (D)(i),(ii) and (iv) to trigger Cryptosporidium monitoring. This
approval by the State must be provided to the system in writing and must
include the basis for the State's determination that the alternative indicator
and/or trigger level will provide a more accurate identification of whether a
system will exceed the Bin 1 Cryptosporidium level in subsection (k).
(F) Unfiltered systems serving
fewer than 10,000 people must sample their source water for Cryptosporidium at
least twice per month for 12 months or at least monthly for 24
months.
(G) Systems may sample more
frequently than required under this section if the sampling frequency is evenly
spaced throughout the monitoring period.
(2) Second round of source water monitoring.
Systems must conduct a second round of source water monitoring that meets the
requirements for monitoring parameters, frequency, and duration described in
paragraph (1), unless they meet the monitoring exemption criteria in paragraph
(4). Systems must conduct this monitoring on the schedule in paragraph
(3).
(3) Monitoring schedule.
Systems must begin the monitoring required in paragraphs (1) and (2) no later
than the month beginning with the date listed in this table:
Source Water Monitoring Starting Dates Table
Systems that serve ...
|
Must begin the first round of source water monitoring
no later than the month beginning ...
|
And must begin the second round of source water
monitoring no later than the month beginning...
|
At least 100,000 people.
|
October 1, 2006
|
April 1, 2015
|
From 50,000 to 99,999 people.
|
April 1, 2007
|
October 1, 2015
|
From 10,000 to 49,999 people.
|
April 1, 2008
|
October 1, 2016
|
Fewer than 10,000 and monitor for E.
coli1.
|
October 1, 2008
|
October 1, 2017
|
Fewer than 10,000 and monitor for
Cryptosporidium2
|
April 1, 2010
|
April 1, 2019
|
1Applies only to filtered
systems.
2Applies to filtered systems that
meet the conditions of paragraph (1)(D) and unfiltered systems.
(4) Monitoring avoidance.
(A) Filtered systems are not required to
conduct source water monitoring under this section if the system will provide a
total of at least 5.5-log of treatment for Cryptosporidium, equivalent to
meeting the treatment requirements of Bin 4 in subsection (l).
(B) Unfiltered systems are not required to
conduct source water monitoring under this section if the system will provide a
total of at least 3-log Cryptosporidium inactivation, equivalent to meeting the
treatment requirements for unfiltered systems with a mean Cryptosporidium
concentration of greater than 0.01 oocysts/L in subsection (m).
(C) If a system chooses to provide the level
of treatment in subparagraphs (A) or (B), as applicable, rather than start
source water monitoring, the system must notify the State in writing no later
than the date the system is otherwise required to submit a sampling schedule
for monitoring under subsection (c). Alternatively, a system may choose to stop
sampling at any point after it has initiated monitoring if it notifies the
State in writing that it will provide this level of treatment. Systems must
install and operate technologies to provide this level of treatment by the
applicable treatment compliance date in subsection (n).
(5) Plants operating only part of the year.
Systems with subpart H plants that operate for only part of the year must
conduct source water monitoring in accordance with this section, but with the
following modifications:
(A) Systems must
sample their source water only during the months that the plant operates unless
the State specifies another monitoring period based on plant operating
practices.
(B) Systems with plants
that operate less than six months per year and that monitor for Cryptosporidium
must collect at least six Cryptosporidium samples per year during each of two
years of monitoring. Samples must be evenly spaced throughout the period the
plant operates.
(6) New
sources.
(A) A system that begins using a new
source of surface water or GWUDI after the system is required to begin
monitoring under paragraph (3) must monitor the new source on a schedule the
State approves. Source water monitoring must meet the requirements of this
section. The system must also meet the bin classification and Cryptosporidium
treatment requirements of subsections (k), (l), and (m), as applicable, for the
new source on a schedule the State approves.
(B) The requirements of this paragraph apply
to subpart H systems that begin operation after the monitoring start date
applicable to the system's size under paragraph (3).
(C) The system must begin a second round of
source water monitoring no later than 6 years following initial bin
classification under subsection (k) or determination of the mean
Cryptosporidium level under subsection (m), as applicable.
(7) Failure to collect any source water
sample required under this section in accordance with the sampling schedule,
sampling location, analytical method, approved laboratory, and reporting
requirements of subsections (c) through (g) is a monitoring
violation.
(8) Grandfathering
monitoring data. Systems may use (grandfather) monitoring data collected prior
to the applicable monitoring start date in paragraph (3) to meet the initial
source water monitoring requirements in paragraph (1). Grandfathered data may
substitute for an equivalent number of months at the end of the monitoring
period. All data submitted under this paragraph must meet the requirements in
subsection (h).
(c)
Sampling schedules.
(1) Systems required to
conduct source water monitoring under subsection (b) must submit a sampling
schedule that specifies the calendar dates when the system will collect each
required sample.
(A) Systems must submit
sampling schedules no later than 3 months prior to the applicable date listed
in subsection (b)(3) for each round of required monitoring.
(B) Systems serving at least 10,000 people
must submit their sampling schedule for the initial round of source water
monitoring under subsection (b)(1) to EPA electronically at
https://intranet.epa.gov/lt2/. If a system is unable to submit the sampling
schedule electronically, the system may use an alternative approach for
submitting the sampling schedule that EPA approves.
(C) Systems serving fewer than 10,000 people
must submit their sampling schedules for the initial round of source water
monitoring subsection (b)(1) to the State.
(D) Systems must submit sampling schedules
for the second round of source water monitoring subsection (b)(2) to the
State.
(E) If EPA or the State does
not respond to a system regarding its sampling schedule, the system must sample
at the reported schedule.
(2)
Systems must collect samples within two days before or two days
after the dates indicated in their sampling schedule (i.e., within a five-day
period around the schedule date) unless one of the conditions of subparagraph
(A) or (B) applies.
(A) If an extreme
condition or situation exists that may pose danger to the sample collector, or
that cannot be avoided and causes the system to be unable to sample in the
scheduled five-day period, the system must sample as close to the scheduled
date as is feasible unless the State approves an alternative sampling date. The
system must submit an explanation for the delayed sampling date to the State
concurrent with the shipment of the sample to the laboratory.
(B) If a system is unable to report a valid
analytical result for a scheduled sampling date due to equipment failure, loss
of or damage to the sample, failure to comply with the analytical method
requirements, including the quality control requirements in subsection (e), or
the failure of an approved laboratory to analyze the sample, then the system
must collect a replacement sample. The system must collect the replacement
sample not later than 21 days after receiving information that an analytical
result cannot be reported for the scheduled date unless the system demonstrates
that collecting a replacement sample within this time frame is not feasible or
the State approves an alternative resampling date. The system must submit an
explanation for the delayed sampling date to the State concurrent with the
shipment of the sample to the laboratory.
(3) Systems that fail to meet the criteria of
paragraph (2) for any source water sample required under subsection (b) must
revise their sampling schedules to add dates for collecting all missed samples.
Systems must submit the revised schedule to the State for approval prior to
when the system begins collecting the missed samples.
(d) Sampling locations.
(1) Systems required to conduct source water
monitoring under subsection (b) must collect samples for each plant that treats
a surface water or GWUDI source. Where multiple plants draw water from the same
influent, such as the same pipe or intake, the State may approve one set of
monitoring results to be used to satisfy the requirements of subsection (b) for
all plants.
(2) Systems must
collect source water samples prior to chemical treatment, such as coagulants,
oxidants and disinfectants, unless the system meets the condition of this
paragraph. The State may approve a system to collect a source water sample
after chemical treatment. To grant this approval, the State must determine that
collecting a sample prior to chemical treatment is not feasible for the system
and that the chemical treatment is unlikely to have a significant adverse
effect on the analysis of the sample.
(3)
Systems that recycle filter backwash water must collect source
water samples prior to the point of filter backwash water addition.
(4) Bank filtration. Systems that receive
Cryptosporidium treatment credit for bank filtration under section
11-20-46.1(c)(2),
as applicable, must collect source water samples in the surface water prior to
bank filtration. Systems that use bank filtration as pretreatment to a
filtration plant must collect source water samples from the well (i.e., after
bank filtration). Use of bank filtration during monitoring must be consistent
with routine operational practice. Systems collecting samples after a bank
filtration process may not receive treatment credit for the bank filtration
under subsection (r)(3).
(5)
Multiple sources. Systems with plants that use multiple water sources,
including multiple surface water sources and blended surface water and ground
water sources, must collect samples as specified in subparagraph (A) or (B).
The use of multiple sources during monitoring must be consistent with routine
operational practice.
(A) If a sampling tap
is available where the sources are combined prior to treatment, systems must
collect samples from the tap.
(B)
If a sampling tap where the sources are combined prior to treatment is not
available, systems must collect samples at each source near the intake on the
same day and must follow either clauses (i) or (ii) for sample analysis.
(i) Systems may composite samples from each
source into one sample prior to analysis. The volume of sample from each source
must be weighted according to the proportion of the source in the total plant
flow at the time the sample is collected.
(ii) Systems may analyze samples from each
source separately and calculate a weighted average of the analysis results for
each sampling date. The weighted average must be calculated by multiplying the
analysis result for each source by the fraction the source contributed to total
plant flow at the time the sample was collected and then summing these values.
(6)
Additional Requirements. Systems must submit a description of their sampling
location(s) to the State at the same time as the sampling schedule required
under subsection (c). This description must address the position of the
sampling location in relation to the system's water source(s) and treatment
processes, including pretreatment, points of chemical treatment, and filter
backwash recycle. If the State does not respond to a system regarding sampling
location(s), the system must sample at the reported
location(s).
(e)
Analytical methods.
(1) Cryptosporidium.
Systems must analyze for Cryptosporidium using Method 1623: Cryptosporidium and
Giardia in Water by Filtration/IMS/FA, 2005, United States Environmental
Protection Agency, EPABB815-RBB05BB002 or Method 1622: Cryptosporidium in Water
by Filtration/IMS/FA, 2005, United States Environmental Protection Agency,
EPABB815BBRBB05BB001, which are incorporated by reference or alternative
methods listed in Appendix A to Title 40 Code of Federal Regulations, Part 141,
Subpart C. The Director of the Federal Register approves this incorporation by
reference in accordance with
5
U.S.C. 552(a) and 1 C.F.R.
part 51. You may obtain a copy of these methods online from
http://www.epa.gov/safewater/disinfection/lt2 or from the United States
Environmental Protection Agency, Office of Ground Water and Drinking Water,
1201 Constitution Ave., NW, Washington, DC 20460 (Telephone: 800BB426BB4791).
You may inspect a copy at the Water Docket in the EPA Docket Center, 1301
Constitution Ave., NW, Washington, DC, (Telephone: 202BB566BB2426) or at the
National Archives and Records Administration (NARA). For information on the
availability of this material at NARA, call 202BB741BB6030, or go to:
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
(A) Systems must analyze at least a 10 L
sample or a packed pellet volume of at least 2 mL as generated by the methods
listed in this paragraph. Systems unable to process a 10 L sample must analyze
as much sample volume as can be filtered by two filters approved by EPA for the
methods listed in this paragraph, up to a packed pellet volume of at least 2
mL.
(B) Matrix spike (MS) samples,
as required by the methods in this paragraph, must be spiked and filtered by a
laboratory approved for Cryptosporidium analysis under subsection (f). If the
volume of the MS sample is greater than 10 L, the system may filter all but 10
L of the MS sample in the field, and ship the filtered sample and the remaining
10 L of source water to the laboratory. In this case, the laboratory must spike
the remaining 10 L of water and filter it through the filter used to collect
the balance of the sample in the field.
(C)
Flow cytometer-counted spiking suspensions must be used for MS
samples and ongoing precision and recovery (OPR) samples.
(2) E. coli. Systems must use methods for
enumeration of E. coli in source water approved in
40 C.F.R.
136.3(a).
(A) The time from sample collection to
initiation of analysis may not exceed 30 hours unless the system meets the
condition of subparagraph (B).
(B)
The State may approve on a case-by-case basis the holding of an
E. coli sample for up to 48 hours between sample collection and initiation of
analysis if the State determines that analyzing an E. coli sample within 30
hours is not feasible. E. coli samples held between 30 to 48 hours must be
analyzed by the Colilert reagent version of Standard Method 9223B as listed in
40 C.F.R.
136.3(a) of this title or
alternative methods listed in Appendix A to Title 40 Code of Federal
Regulations, Part 141, Subpart C.
(C) Systems must maintain samples between
0°C and 10°C during storage and transit to the laboratory.
(3) Turbidity. Systems must use
methods for turbidity measurement approved in
40 C.F.R.
141.74(a)(1).
(f) Approved laboratories.
(1) Cryptosporidium. Systems must have
Cryptosporidium samples analyzed by a laboratory that is approved under EPA's
Laboratory Quality Assurance Evaluation Program for Analysis of Cryptosporidium
in Water or a laboratory that has been certified for Cryptosporidium analysis
by an equivalent State laboratory certification program.
(2) E. coli. Any laboratory certified by the
EPA, the National Environmental Laboratory Accreditation Conference or the
State for total coliform or fecal coliform analysis under
40 C.F.R.
141.74 is approved for E. coli analysis under
this section when the laboratory uses the same technique for E. coli that the
laboratory uses for
40 C.F.R.
141.74.
(3)
Turbidity. Measurements of turbidity must be made by a party
approved by the State.
(g)
Reporting source water monitoring results.
(1) Systems must report results from the
source water monitoring required under subsection (b) no later than 10 days
after the end of the first month following the month when the sample is
collected.
(2) All systems serving
at least 10,000 people must report the results from the initial source water
monitoring required under subsection (b)(1) to EPA electronically at
https://intranet.epa.gov/lt2/. If a system is unable to report monitoring
results electronically, the system may use an alternative approach for
reporting monitoring results that EPA approves.
(3) Systems serving fewer than 10,000 people
must report results from the initial source water monitoring required under
subsection (b)(1) to the State.
(4)
All systems must report results from the second round of source water
monitoring required under subsection (b)(2) to the State.
(5) Systems must report the applicable
information in subparagraphs (A) and (B) for the source water monitoring
required under subsection (b).
(A) Systems
must report the following data elements for each Cryptosporidium analysis:
Data element.
PWS ID.
Facility ID.
Sample collection date.
Sample type (field or matrix spike).
Sample volume filtered(L), to nearest 1/4 L.
Was 100% of filtered volume examined.
Number of oocysts counted.
(i)
For matrix spike samples, systems must also report the sample
volume spiked and estimated number of oocysts spiked. These data are not
required for field samples.
(ii)
For samples in which less than 10 L is filtered or less than 100% of the sample
volume is examined, systems must also report the number of filters used and the
packed pellet volume.
(iii) For
samples in which less than 100% of sample volume is examined, systems must also
report the volume of resuspended concentrate and volume of this resuspension
processed through immunomagnetic separation.
(B) Systems must report the following data
elements for each E. coli analysis:
Data element.
PWS ID.
Facility ID.
Sample collection date.
Analytical method number.
Method type.
Source type (flowing stream, lake/reservoir, GWUDI).
E. coli/100 mL.
Turbidity. \1\
\1\ Systems serving fewer than 10,000 people that are not
required to monitor for turbidity under subsection (b) are not required to
report turbidity with their E. coli results.
(h) Grandfathering previously
collected data.
(1) Systems may comply with
the initial source water monitoring requirements of subsection (b)(1) by
grandfathering sample results collected before the system is required to begin
monitoring (i.e., previously collected data). To be grandfathered, the sample
results and analysis must meet the criteria in this section and the State must
approve. A filtered system may grandfather Cryptosporidium samples to meet the
requirements of subsection (b)(1) when the system does not have corresponding
E. coli and turbidity samples. A system that grandfathers Cryptosporidium
samples without E. coli and turbidity samples is not required to collect E.
coli and turbidity samples when the system completes the requirements for
Cryptosporidium monitoring under subsection (b)(1).
(2) E. coli sample analysis. The analysis of
E. coli samples must meet the analytical method and approved laboratory
requirements of subsection (e) through (f).
(3)
Cryptosporidium sample analysis. The analysis of Cryptosporidium
samples must meet the criteria in this paragraph.
(A)
Laboratories analyzed Cryptosporidium samples using one of the
analytical methods in clauses (i) through (vi), which are incorporated by
reference. The Director of the Federal Register approves this incorporation by
reference in accordance with
5
U.S.C. 552(a) and 1 C.F.R.
part 51. You may obtain a copy of these methods online from the United States
Environmental Protection Agency, Office of Ground Water and Drinking Water,
1201 Constitution Ave, NW, Washington, DC 20460 (Telephone: 800BB426BB4791).
You may inspect a copy at the Water Docket in the EPA Docket Center, 1301
Constitution Ave., NW, Washington, DC, (Telephone: 202BB566BB2426) or at the
National Archives and Records Administration (NARA). For information on the
availability of this material at NARA, call 202BB741BB6030, or go to:
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
(i) Method 1623: Cryptosporidium and Giardia
in Water by Filtration/IMS/FA, 2005, United States Environmental Protection
Agency, EPABB815BBRBB05BB002.
(ii)
Method 1622: Cryptosporidium in Water by Filtration/IMS/FA, 2005,
United States Environmental Protection Agency, EPABB815BBRBB05BB001.
(iii) Method 1623: Cryptosporidium and
Giardia in Water by Filtration/IMS/FA, 2001, United States Environmental
Protection Agency, EPABB821BBRBB01BB025.
(iv)
Method 1622: Cryptosporidium in Water by Filtration/IMS/FA, 2001,
United States Environmental Protection Agency, EPABB821BB-RBB01BB026.
(v) Method 1623: Cryptosporidium
and Giardia in Water by Filtration/IMS/FA, 1999, United States Environmental
Protection Agency, EPABB821BBRBB99BB006.
(vi)
Method 1622: Cryptosporidium in Water by Filtration/IMS/FA, 1999,
United States Environmental Protection Agency, EPABB821BBRBB99BB001.
(B) For each Cryptosporidium
sample, the laboratory analyzed at least 10 L of sample or at least 2 mL of
packed pellet or as much volume as could be filtered by 2 filters that EPA
approved for the methods listed in subparagraph (A).
(4) Sampling location. The sampling location
must meet the conditions in subsection (d).
(5)
Sampling frequency. Cryptosporidium samples were collected no
less frequently than each calendar month on a regular schedule, beginning no
earlier than January 1999. Sample collection intervals may vary for the
conditions specified in subsections (c)(2)(A) and (B) if the system provides
documentation of the condition when reporting monitoring results.
(A) The State may approve grandfathering of
previously collected data where there are time gaps in the sampling frequency
if the system conducts additional monitoring the State specifies to ensure that
the data used to comply with the initial source water monitoring requirements
of subsection (b)(1) are seasonally representative and unbiased.
(B) Systems may grandfather previously
collected data where the sampling frequency within each month varied. If the
Cryptosporidium sampling frequency varied, systems must follow the monthly
averaging procedure in subsections (k)(2)(E) or (m)(1)(C), as applicable, when
calculating the bin classification for filtered systems or the mean
Cryptosporidium concentration for unfiltered systems.
(6) Reporting monitoring results for
grandfathering. Systems that request to grandfather previously collected
monitoring results must report the following information by the applicable
dates listed in this paragraph. Systems serving at least 10,000 people must
report this information to EPA unless the State approves reporting to the State
rather than EPA. Systems serving fewer than 10,000 people must report this
information to the State.
(A) Systems must
report that they intend to submit previously collected monitoring results for
grandfathering. This report must specify the number of previously collected
results the system will submit, the dates of the first and last sample, and
whether a system will conduct additional source water monitoring to meet the
requirements of subsection (b)(1). Systems must report this information no
later than the date the sampling schedule under subsection (c) is
required.
(B) Systems must report
previously collected monitoring results for grandfathering, along with the
associated documentation listed in clauses (i) through (iv), no later than two
months after the applicable date listed in subsection (b)(3).
(i) For each sample result, systems must
report the applicable data elements in subsection (g).
(ii) Systems must certify that the reported
monitoring results include all results the system generated during the time
period beginning with the first reported result and ending with the final
reported result. This applies to samples that were collected from the sampling
location specified for source water monitoring under this section, not spiked,
and analyzed using the laboratory's routine process for the analytical methods
listed in this section.
(iii)
Systems must certify that the samples were representative of a plant's source
water(s) and the source water(s) have not changed. Systems must report a
description of the sampling location(s), which must address the position of the
sampling location in relation to the system's water source(s) and treatment
processes, including points of chemical addition and filter backwash
recycle.
(iv) For Cryptosporidium
samples, the laboratory or laboratories that analyzed the samples must provide
a letter certifying that the quality control criteria specified in the methods
listed in paragraph (3)(A) were met for each sample batch associated with the
reported results. Alternatively, the laboratory may provide bench sheets and
sample examination report forms for each field, matrix spike, IPR, OPR, and
method blank sample associated with the reported results.
(7) If the State
determines that a previously collected data set submitted for grandfathering
was generated during source water conditions that were not normal for the
system, such as a drought, the State may disapprove the data. Alternatively,
the State may approve the previously collected data if the system reports
additional source water monitoring data, as determined by the State, to ensure
that the data set used under subsection (k) or subsection (m) represents
average source water conditions for the system.
(8) If a system submits previously collected
data that fully meet the number of samples required for initial source water
monitoring under subsection (b)(1) and some of the data are rejected due to not
meeting the requirements of this section, systems must conduct additional
monitoring to replace rejected data on a schedule the State approves. Systems
are not required to begin this additional monitoring until two months after
notification that data have been rejected and additional monitoring is
necessary.
(i)
Requirements when making a significant change in disinfection practice.
(1) Following the completion of initial
source water monitoring under subsection (b)(1), a system that plans to make a
significant change to its disinfection practice, as defined in paragraph (2),
must develop disinfection profiles and calculate disinfection benchmarks for
Giardia lamblia and viruses as described in subsection (j). Prior to changing
the disinfection practice, the system must notify the State and must include in
this notice the information in subparagraphs (A) through (C).
(A) A completed disinfection profile and
disinfection benchmark for Giardia lamblia and viruses as described in
subsection (j).
(B) A description
of the proposed change in disinfection practice.
(C) An analysis of how the proposed change
will affect the current level of disinfection.
(2) Significant changes to disinfection
practice are defined as follows:
(A) Changes
to the point of disinfection;
(B)
Changes to the disinfectant(s) used in the treatment plant;
(C) Changes to the disinfection process;
or
(D) Any other modification
identified by the State as a significant change to disinfection practice.
(j)
Developing the disinfection profile and benchmark.
(1)
Systems required to develop disinfection profiles under
subsection (i) must follow the requirements of this section. Systems must
monitor at least weekly for a period of 12 consecutive months to determine the
total log inactivation for Giardia lamblia and viruses. If systems monitor more
frequently, the monitoring frequency must be evenly spaced. Systems that
operate for fewer than 12 months per year must monitor weekly during the period
of operation. Systems must determine log inactivation for Giardia lamblia
through the entire plant, based on CT99.9 values in Tables 1.1 through 1.6, 2.1
and 3.1 of
40 C.F.R.
141.74(b) as applicable.
Systems must determine log inactivation for viruses through the entire
treatment plant based on a protocol approved by the State.
(2) Systems with a single point of
disinfectant application prior to the entrance to the distribution system must
conduct the monitoring in subparagraphs (A) through (D). Systems with more than
one point of disinfectant application must conduct the monitoring in
subparagraphs (A) through (D) for each disinfection segment. Systems must
monitor the parameters necessary to determine the total inactivation ratio,
using analytical methods in
40 C.F.R.
141.74(a).
(A) For systems using a disinfectant other
than UV, the temperature of the disinfected water must be measured at each
residual disinfectant concentration sampling point during peak hourly flow or
at an alternative location approved by the State.
(B) For systems using chlorine, the pH of the
disinfected water must be measured at each chlorine residual disinfectant
concentration sampling point during peak hourly flow or at an alternative
location approved by the State.
(C)
The disinfectant contact time(s)(t) must be determined during
peak hourly flow.
(D) The residual
disinfectant concentration(s)(C) of the water before or at the first customer
and prior to each additional point of disinfectant application must be measured
during peak hourly flow.
(3)
In lieu of conducting new monitoring under paragraph (2), systems
may elect to meet the requirements of subparagraphs (A) or (B).
(A) Systems that have at least one year of
existing data that are substantially equivalent to data collected under the
provisions of paragraph (b) may use these data to develop disinfection profiles
as specified in this section if the system has neither made a significant
change to its treatment practice nor changed sources since the data were
collected. Systems may develop disinfection profiles using up to three years of
existing data.
(B) Systems may use
disinfection profile(s) developed under section
11-20-46.1(b)
in lieu of developing a new profile if the system has neither made a
significant change to its treatment practice nor changed sources since the
profile was developed. Systems that have not developed a virus profile under
section
11-20-46.1(b)
must develop a virus profile using the same monitoring data on which the
Giardia lamblia profile is based.
(4)
Systems must calculate the total inactivation ratio for Giardia
lamblia as specified in subparagraphs (A) through (C).
(A)
Systems using only one point of disinfectant application may
determine the total inactivation ratio for the disinfection segment based on
either of the methods in clauses (i) or (ii).
(i)
Determine one inactivation ratio
(CTcalc/CT99.9) before or at the first customer during
peak hourly flow.
(ii) Determine
successive CTcalc/CT99.9 values, representing sequential
inactivation ratios, between the point of disinfectant application and a point
before or at the first customer during peak hourly flow. The system must
calculate the total inactivation ratio by determining
(CTcalc/CT99.9) for each sequence and then adding the
(CTcalc/CT99.9) values together to determine ([SIGMA]S
(CTcalc/CT99.9)).
(B) Systems using more than one point of
disinfectant application before the first customer must determine the CT value
of each disinfection segment immediately prior to the next point of
disinfectant application, or for the final segment, before or at the first
customer, during peak hourly flow. The (CTcalc/CT99.9)
value of each segment and ([SIGMA]S (CTcalc/CT99.9) )
must be calculated using the method in subsection (d)(1)(ii).
(C) The system must determine the total logs
of inactivation by multiplying the value calculated in subparagraphs (A) or (B)
by 3.0.
(D) Systems must calculate
the log of inactivation for viruses using a protocol approved by the
State.
(5) Systems must
use the procedures specified in subparagraphs (A) and (B) to calculate a
disinfection benchmark.
(A) For each year of
profiling data collected and calculated under paragraphs (1) through (4),
systems must determine the lowest mean monthly level of both Giardia lamblia
and virus inactivation. Systems must determine the mean Giardia lamblia and
virus inactivation for each calendar month for each year of profiling data by
dividing the sum of daily or weekly Giardia lamblia and virus log inactivation
by the number of values calculated for that month.
(B) The disinfection benchmark is the lowest
monthly mean value (for systems with one year of profiling data) or the mean of
the lowest monthly mean values (for systems with more than one year of
profiling data) of Giardia lamblia and virus log inactivation in each year of
profiling data.
(k) Bin classification for filtered systems.
(1) Following completion of the initial round
of source water monitoring required under subsection (b)(1), filtered systems
must calculate an initial Cryptosporidium bin concentration for each plant for
which monitoring was required. Calculation of the bin concentration must use
the Cryptosporidium results reported under subsection (b)(1) and must follow
the procedures in paragraphs (2)(A) through (E).
(2) Compliance Calculations
(A) For systems that collect a total of at
least 48 samples, the bin concentration is equal to the arithmetic mean of all
sample concentrations.
(B) For
systems that collect a total of at least 24 samples, but not more than 47
samples, the bin concentration is equal to the highest arithmetic mean of all
sample concentrations in any 12 consecutive months during which Cryptosporidium
samples were collected.
(C) For
systems that serve fewer than 10,000 people and monitor for Cryptosporidium for
only one year (i.e., collect 24 samples in 12 months), the bin concentration is
equal to the arithmetic mean of all sample concentrations.
(D) For systems with plants operating only
part of the year that monitor fewer than 12 months per year under subsection
(b)(5), the bin concentration is equal to the highest arithmetic mean of all
sample concentrations during any year of Cryptosporidium monitoring.
(E) If the monthly Cryptosporidium sampling
frequency varies, systems must first calculate a monthly average for each month
of monitoring. Systems must then use these monthly average concentrations,
rather than individual sample concentrations, in the applicable calculation for
bin classification in paragraphs (2)(A) through (D).
(3) Filtered systems must determine their
initial bin classification from the following table and using the
Cryptosporidium bin concentration calculated under paragraphs (1) and (2):
For systems that are...
|
With a Cryptosporidium concentration
of...1
|
The bin classification is...
|
...required to monitor for Cryptosporidium under
subsection (b).
|
Cryptosporidium <0.075 oocysts/L
|
Bin 1
|
0.075 oocysts/L < Cryptosporidium <1.0
oocysts/L
|
Bin 2
|
1.0 oocysts/L < Cryptosporidium <3.0
oocysts/L
|
Bin 3
|
Cryptosporidium >=3.0 oocysts/L
|
Bin 4
|
...serving fewer than 10,000 and NOT required to
monitor for Cryptosporidium under subparagraph (b)(1)(D).
|
N/A
|
Bin 1
|
1Based on calculations in
paragraphs (1) or (4), as applicable.
|
(4)
Following completion of the second round of source water monitoring required
under subsection (b)(2), filtered systems must recalculate their
Cryptosporidium bin concentration using the Cryptosporidium results reported
under paragraph (b)(2) and following the procedures in paragraphs (2)(A)
through (D). Systems must then redetermine their bin classification using this
bin concentration and the table in paragraph (3).
(5) Filtered systems must report their
initial bin classification under paragraph (3) to the State for approval no
later than 6 months after the system is required to complete initial source
water monitoring based on the schedule in subsection (b)(3). Systems must
report their bin classification under paragraph (4) to the State for approval
no later than 6 months after the system is required to complete the second
round of source water monitoring based on the schedule in subsection (b)(3).
The bin classification report to the State must include a summary of source
water monitoring data and the calculation procedure used to determine bin
classification.
(6) Failure to
comply with the conditions of paragraph (5) is a violation of the treatment
technique requirement.
(l)
Filtered system additional Cryptosporidium treatment
requirements.
(1) Filtered systems must
provide the level of additional treatment for Cryptosporidium specified in this
paragraph based on their bin classification as determined under subsection (k)
and according to the schedule in subsection (n).
If the system bin classification is...
|
And the system uses the following filtration
treatment in full compliance with sections
11-20-46
and
11-20-46.1
(as applicable), then the additional Cryptosporidium treatment requirements are
. . .
|
Conventional filtration treatment (including
softening)
|
Direct filtration
|
Slow sand or diatomaceous earth filtration
|
Alternative filtration technologies
|
Bin 1
|
No additional treatment
|
No additional treatment
|
No additional treatment
|
No additional treatment
|
Bin 2
|
1-log treatment
|
1.5-log treatment
|
1-log treatment
|
See footnote 1
|
Bin 3
|
2-log treatment
|
2.5-log treatment
|
2-log treatment
|
See footnote 2
|
Bin 4
|
2.5 log treatment
|
3-log treatment
|
2.5 log treatment
|
See footnote 3
|
1As determined by the State such
that the total Cryptosporidium removal and inactivation is at least
4.0-log.
2As determined by the State such
that the total Cryptosporidium removal and inactivation is at least
5.0-log.
3As determined by the State such
that the total Cryptosporidium removal and inactivation is at least
5.5-log.
(2) Filtered
systems must use one or more of the treatment and management options listed in
subsection (p), termed the microbial toolbox, to comply with the additional
Cryptosporidium treatment required in paragraph (1). Systems classified in Bin
3 and Bin 4 must achieve at least 1-log of the additional Cryptosporidium
treatment required under paragraph (1) using either one or a combination of the
following: bag filters, bank filtration, cartridge filters, chlorine dioxide,
membranes, ozone, or UV, as described in subsections (q) through (u).
(3) Failure by a system in any month to
achieve treatment credit by meeting criteria in subsections (q) through (u) for
microbial toolbox options that is at least equal to the level of treatment
required in paragraph (1) is a violation of the treatment technique
requirement.
(4) If the State
determines during a sanitary survey or an equivalent source water assessment
that after a system completed the monitoring conducted under subsections (b)(1)
or (2), significant changes occurred in the system's watershed that could lead
to increased contamination of the source water by Cryptosporidium, the system
must take actions specified by the State to address the contamination. These
actions may include additional source water monitoring and/or implementing
microbial toolbox options listed in subsection (p).
(m) Unfiltered system Cryptosporidium
treatment requirements.
(1) Determination of
mean Cryptosporidium level.
(A) Following
completion of the initial source water monitoring required under subsection
(b)(1), unfiltered systems must calculate the arithmetic mean of all
Cryptosporidium sample concentrations reported under subsection (b)(1). Systems
must report this value to the State for approval no later than 6 months after
the month the system is required to complete initial source water monitoring
based on the schedule in subsection (b)(3).
(B)
Following completion of the second round of source water
monitoring required under subsection (b)(2), unfiltered systems must calculate
the arithmetic mean of all Cryptosporidium sample concentrations reported under
subsection (b)(2). Systems must report this value to the State for approval no
later than 6 months after the month the system is required to complete the
second round of source water monitoring based on the schedule in subsection
(b)(3).
(C) If the monthly
Cryptosporidium sampling frequency varies, systems must first calculate a
monthly average for each month of monitoring. Systems must then use these
monthly average concentrations, rather than individual sample concentrations,
in the calculation of the mean Cryptosporidium level in subparagraphs (A) and
(B).
(D) The report to the State
of the mean Cryptosporidium levels calculated under subparagraphs (A) and (B)
must include a summary of the source water monitoring data used for the
calculation.
(E) Failure to comply
with the conditions of paragraph (1) is a violation of the treatment technique
requirement.
(2)
Cryptosporidium inactivation requirements. Unfiltered systems must provide the
level of inactivation for Cryptosporidium specified in this paragraph, based on
their mean Cryptosporidium levels as determined under paragraph (1) and
according to the schedule in subsection (n).
(A)
Unfiltered systems with a mean Cryptosporidium level of 0.01
oocysts/L or less must provide at least 2-log Cryptosporidium
inactivation.
(B) Unfiltered
systems with a mean Cryptosporidium level of greater than 0.01 oocysts/L must
provide at least 3-log Cryptosporidium inactivation.
(3) Inactivation treatment technology
requirements. Unfiltered systems must use chlorine dioxide, ozone, or UV as
described in subsection (u) to meet the Cryptosporidium inactivation
requirements of this section.
(A) Systems that
use chlorine dioxide or ozone and fail to achieve the Cryptosporidium
inactivation required in paragraph (2) on more than one day in the calendar
month are in violation of the treatment technique requirement.
(B) Systems that use UV light and fail to
achieve the Cryptosporidium inactivation required in paragraph (2) by meeting
the criteria in clause (u)(4)(C)(ii) are in violation of the treatment
technique requirement.
(4)
Use of two disinfectants. Unfiltered systems must meet the
combined Cryptosporidium inactivation requirements of this section and Giardia
lamblia and virus inactivation requirements of
40
C.F.R. 141.72(a) using a
minimum of two disinfectants, and each of two disinfectants must separately
achieve the total inactivation required for either Cryptosporidium, Giardia
lamblia, or viruses.
(n)
Schedule for compliance with Cryptosporidium treatment requirements.
(1) Following initial bin classification
under subsection (k)(3), filtered systems must provide the level of treatment
for Cryptosporidium required under subsection (l) according to the schedule in
paragraph (3).
(2) Following
initial determination of the mean Cryptosporidium level under subsection
(m)(1)(A), unfiltered systems must provide the level of treatment for
Cryptosporidium required under subsection (m) according to the schedule in
paragraph (3).
(3) Cryptosporidium
treatment compliance dates.
Cryptosporidium Treatment Compliance Dates Table
Systems that serve...
|
Must comply with Cryptosporidium treatment
requirements no later than...1
|
At least 100,000 people
|
April 1, 2012
|
From 50,000 to 99,999 people
|
October 1, 2012
|
From 10,000 to 49,999 people
|
October 1, 2013
|
Fewer than 10,000 people
|
October 1, 2014
|
1States may allow up to an
additional two years for complying with the treatment requirement for systems
making capital improvements.
(4)
If the bin classification for a filtered system changes following
the second round of source water monitoring, as determined under subsection
(k)(4), the system must provide the level of treatment for Cryptosporidium
required under subsection (l) on a schedule the State approves.
(5) If the mean Cryptosporidium level for an
unfiltered system changes following the second round of monitoring, as
determined under subsection (m)(1)(B), and if the system must provide a
different level of Cryptosporidium treatment under subsection (m) due to this
change, the system must meet this treatment requirement on a schedule the State
approves.
(o)
Requirements for uncovered finished water storage facilities.
(1) Systems using uncovered finished water
storage facilities must comply with the conditions of this section.
(2) Systems must notify the State of the use
of each uncovered finished water storage facility no later than April 1,
2008.
(3) Systems must meet the
conditions of subparagraph (A) or (B) for each uncovered finished water storage
facility or be in compliance with a State-approved schedule to meet these
conditions no later than April 1, 2009.
(A)
Systems must cover any uncovered finished water storage facility.
(B) Systems must treat the discharge from the
uncovered finished water storage facility to the distribution system to achieve
inactivation and/or removal of at least 4-log virus, 3-log Giardia lamblia, and
2-log Cryptosporidium using a protocol approved by the State.
(4) Failure to comply with the
requirements of this section is a violation of the treatment technique
requirement.
(p)
Microbial toolbox options for meeting Cryptosporidium treatment requirements.
(1) Systems receive the treatment credits
listed in the table in paragraph (2) by meeting the conditions for microbial
toolbox options described in subsections (q) through (u). Systems apply these
treatment credits to meet the treatment requirements in subsections (l) or (m),
as applicable. Unfiltered systems are eligible for treatment credits for the
microbial toolbox options described in subsection (u) only.
(2) The following table summarizes options in
the microbial toolbox:
Microbial Toolbox Summary Table: Options, Treatment Credits
and Criteria
Toolbox Option
|
Cryptosporidium treatment credit with design and
implementation criteria
|
Source Protection and Management Toolbox
Options
|
Watershed control program
|
0.5-log credit for State-approved program comprising
required elements, annual program status report to State, and regular watershed
survey. Unfiltered systems are not eligible for credit. Specific criteria are
in subsection (q)(1).
|
Alternative source/intake management
|
No prescribed credit. Systems may conduct
simultaneous monitoring for treatment bin classification at alternative intake
locations or under alternative intake management strategies. Specific criteria
are in subsection (q)(2).
|
Pre Filtration Toolbox Options
|
Presedimentation basin with coagulation
|
0.5-log credit during any month that presedimentation
basins achieve a monthly mean reduction of 0.5-log or Cryptosporidium treatment
credit with design and implementation criteria greater in turbidity or
alternative State-approved performance criteria. To be eligible, basins must be
operated continuously with coagulant addition and all plant flow must pass
through basins. Specific criteria are in subsection (r)(1).
|
Two-stage lime softening
|
0.5-log credit for two-stage softening where chemical
addition and hardness precipitation occur in both stages. All plant flow must
pass through both stages. Single-stage softening is credited as equivalent to
conventional treatment. Specific criteria are in subsection (r)(2).
|
Bank filtration
|
0.5-log credit for 25-foot setback; 1.0-log credit
for 50-foot setback; aquifer must be unconsolidated sand containing at least 10
percent fines; average turbidity in wells must be less than 1 NTU. Systems
using wells followed by filtration when conducting source water monitoring must
sample the well to determine bin classification and are not eligible for
additional credit. Specific criteria are in subsection (r)(3).
|
Treatment Performance Toolbox Options
|
Combined filter performance
|
0.5-log credit for combined filter effluent turbidity
less than or equal to 0.15 NTU in at least 95 percent of measurements each
month. Specific criteria are in subsection (s)(1).
|
Individual filter performance
|
0.5-log credit (in addition to 0.5-log combined
filter performance credit) if individual filter effluent turbidity is less than
or equal to 0.15 NTU in at least 95 percent of samples each month in each
filter and is never greater than 0.3 NTU in two consecutive measurements in any
filter. Specific criteria are in subsection (s)(2).
|
Demonstration of performance
|
Credit awarded to unit process or treatment train
based on a demonstration to the State with a State-approved protocol. Specific
criteria are in subsection (s)(3).
|
Additional Filtration Toolbox Options
|
Bag or cartridge filters (individual filters)
|
Up to 2-log credit based on the removal efficiency
demonstrated during challenge testing with a 1.0-log factor of safety. Specific
criteria are in
|
Bag or cartridge filters (in series)
|
Up to 2.5-log credit based on the removal efficiency
demonstrated during challenge testing with a 0.5-log factor of safety. Specific
criteria are in subsection (t)(1).
|
Membrane filtration
|
Log credit equivalent to removal efficiency
demonstrated in challenge test for device if supported by direct integrity
testing. Specific criteria are in subsection (t)(2).
|
Second stage filtration
|
0.5-log credit for second separate granular media
filtration stage if treatment train includes coagulation prior to first filter.
Specific criteria are in subsection (t)(3).
|
Slow sand filters
|
2.5-log credit as a secondary filtration step;
3.0-log credit as a primary filtration process. No prior chlorination for
either option. Specific criteria are in subsection (t)(4).
|
Inactivation Toolbox Options
|
Chlorine dioxide
|
Log credit based on measured CT in relation to CT
table. Specific criteria in subsection (u)(2).
|
Ozone
|
Log credit based on measured CT in relation to CT
table. Specific criteria in subsection (u)(2).
|
UV
|
Log credit based on validated UV dose in relation to
UV dose table; reactor validation testing required to establish UV dose and
associated operating conditions. Specific criteria in subsection (u)(4).
|
(q)
Source toolbox components.
(1)
Watershed control program. Systems receive 0.5-log Cryptosporidium treatment
credit for implementing a watershed control program that meets the requirements
of this section.
(A) Systems that intend to
apply for the watershed control program credit must notify the State of this
intent no later than two years prior to the treatment compliance date
applicable to the system in subsection (n).
(B)
Systems must submit to the State a proposed watershed control
plan no later than one year before the applicable treatment compliance date in
subsection (n). The State must approve the watershed control plan for the
system to receive watershed control program treatment credit. The watershed
control plan must include the elements in clauses (i) through (iv).
(i) Identification of an "area of influence"
outside of which the likelihood of Cryptosporidium or fecal contamination
affecting the treatment plant intake is not significant. This is the area to be
evaluated in future watershed surveys under paragraph (1)(E)(ii).
(ii) Identification of both potential and
actual sources of Cryptosporidium contamination and an assessment of the
relative impact of these sources on the system's source water
quality.
(iii) An analysis of the
effectiveness and feasibility of control measures that could reduce
Cryptosporidium loading from sources of contamination to the system's source
water.
(iv) A statement of goals
and specific actions the system will undertake to reduce source water
Cryptosporidium levels. The plan must explain how the actions are expected to
contribute to specific goals, identify watershed partners and their roles,
identify resource requirements and commitments, and include a schedule for plan
implementation with deadlines for completing specific actions identified in the
plan.
(C) Systems with
existing watershed control programs (i.e., programs in place on January 5,
2006) are eligible to seek this credit. Their watershed control plans must meet
the criteria in paragraph (1)(B) and must specify ongoing and future actions
that will reduce source water Cryptosporidium levels.
(D) If the State does not respond to a system
regarding approval of a watershed control plan submitted under this section and
the system meets the other requirements of this section, the watershed control
program will be considered approved and 0.5 log Cryptosporidium treatment
credit will be awarded unless and until the State subsequently withdraws such
approval.
(E) Systems must
complete the actions in clauses (i) through (iii) to maintain the 0.5-log
credit.
(i) Submit an annual watershed
control program status report to the State. The annual watershed control
program status report must describe the system's implementation of the approved
plan and assess the adequacy of the plan to meet its goals. It must explain how
the system is addressing any shortcomings in plan implementation, including
those previously identified by the State or as the result of the watershed
survey conducted under clause (ii). It must also describe any significant
changes that have occurred in the watershed since the last watershed sanitary
survey. If a system determines during implementation that making a significant
change to its approved watershed control program is necessary, the system must
notify the State prior to making any such changes. If any change is likely to
reduce the level of source water protection, the system must also list in its
notification the actions the system will take to mitigate this effect.
(ii) Undergo a watershed sanitary
survey every three years for community water systems and every five years for
noncommunity water systems and submit the survey report to the State. The
survey must be conducted according to State guidelines and by persons the State
approves. The watershed sanitary survey must meet the following criteria:
encompass the region identified in the State-approved watershed control plan as
the area of influence; assess the implementation of actions to reduce source
water Cryptosporidium levels; and identify any significant new sources of
Cryptosporidium. If the State determines that significant changes may have
occurred in the watershed since the previous watershed sanitary survey, systems
must undergo another watershed sanitary survey by a date the State requires,
which may be earlier than the regular date in this clause.
(iii) The system must make the
watershedcontrol plan, annual status reports, and watershed sanitary survey
reports available to the public upon request. These documents must be in a
plain language style and include criteria by which to evaluate the success of
the program in achieving plan goals. The State may approve systems to withhold
from the public portions of the annual status report, watershed control plan,
and watershed sanitary survey based on water supply security
considerations.
(F) If
the State determines that a system is not carrying out the approved watershed
control plan, the State may withdraw the watershed control program treatment
credit.
(2) Alternative
source.
(A) A system may conduct source water
monitoring that reflects a different intake location (either in the same source
or for an alternate source) or a different procedure for the timing or level of
withdrawal from the source (alternative source monitoring). If the State
approves, a system may determine its bin classification under subsection (k)
based on the alternative source monitoring results.
(B) If systems conduct alternative source
monitoring under subparagraph (A), systems must also monitor their current
plant intake concurrently as described in subsection (b).
(C) Alternative source monitoring under
subparagraph (A) must meet the requirements for source monitoring to determine
bin classification, as described in subsections (b) through (g). Systems must
report the alternative source monitoring results to the State, along with
supporting information documenting the operating conditions under which the
samples were collected.
(D) If a
system determines its bin classification under subsection (k) using alternative
source monitoring results that reflect a different intake location or a
different procedure for managing the timing or level of withdrawal from the
source, the system must relocate the intake or permanently adopt the withdrawal
procedure, as applicable, no later than the applicable treatment compliance
date in subsection (n).
(r)
Pre-filtration treatment toolbox components.
(1) Presedimentation. Systems receive 0.5-log
Cryptosporidium treatment credit for a presedimentation basin during any month
the process meets the criteria in this paragraph.
(A) The presedimentation basin must be in
continuous operation and must treat the entire plant flow taken from a surface
water or GWUDI source.
(B) The
system must continuously add a coagulant to the presedimentation
basin.
(C) The presedimentation
basin must achieve the performance criteria in clauses (i) or (ii).
(i) Demonstrates at least 0.5-log mean
reduction of influent turbidity. This reduction must be determined using daily
turbidity measurements in the presedimentation process influent and effluent
and must be calculated as follows: log10 (monthly mean
of daily influent turbidity) - log10 (monthly mean of
daily effluent turbidity).
(ii)
Complies with State-approved performance criteria that demonstrate at least
0.5-log mean removal of micron-sized particulate material through the
presedimentation process.
(2) Two-stage lime softening. Systems receive
an additional 0.5-log Cryptosporidium treatment credit for a two-stage lime
softening plant if chemical addition and hardness precipitation occur in two
separate and sequential softening stages prior to filtration. Both softening
stages must treat the entire plant flow taken from a surface water or GWUDI
source.
(3) Bank filtration.
Systems receive Cryptosporidium treatment credit for bank filtration that
serves as pretreatment to a filtration plant by meeting the criteria in this
paragraph. Systems using bank filtration when they begin source water
monitoring under subsection (b)(1) must collect samples as described in
subsection(d)(4) and are not eligible for this credit.
(A)
Wells with a ground water flow path of at least 25 feet receive
0.5-log treatment credit; wells with a ground water flow path of at least 50
feet receive 1.0-log treatment credit. The ground water flow path must be
determined as specified in subparagraph (D).
(B)
Only wells in granular aquifers are eligible for treatment
credit. Granular aquifers are those comprised of sand, clay, silt, rock
fragments, pebbles or larger particles, and minor cement. A system must
characterize the aquifer at the well site to determine aquifer properties.
Systems must extract a core from the aquifer and demonstrate that in at least
90 percent of the core length, grains less than 1.0 mm in diameter constitute
at least 10 percent of the core material.
(C)
Only horizontal and vertical wells are eligible for treatment
credit.
(D) For vertical wells, the
ground water flow path is the measured distance from the edge of the surface
water body under high flow conditions (determined by the 100-year floodplain
elevation boundary or by the floodway, as defined in Federal Emergency
Management Agency flood hazard maps) to the well screen. For horizontal wells,
the ground water flow path is the measured distance from the bed of the river
under normal flow conditions to the closest horizontal well lateral
screen.
(E) Systems must monitor
each wellhead for turbidity at least once every four hours while the bank
filtration process is in operation. If monthly average turbidity levels, based
on daily maximum values in the well, exceed 1 NTU, the system must report this
result to the State and conduct an assessment within 30 days to determine the
cause of the high turbidity levels in the well. If the State determines that
microbial removal has been compromised, the State may revoke treatment credit
until the system implements corrective actions approved by the State to
remediate the problem.
(F) Springs
and infiltration galleries are not eligible for treatment credit under this
section, but are eligible for credit under subsection (s)(3).
(G) Bank filtration demonstration of
performance. The State may approve Cryptosporidium treatment credit for bank
filtration based on a demonstration of performance study that meets the
criteria in this subparagraph. This treatment credit may be greater than
1.0-log and may be awarded to bank filtration that does not meet the criteria
in subparagraphs (A) through (E).
(i) The
study must follow a state-approved protocol and must involve the collection of
data on the removal of Cryptosporidium or a surrogate for Cryptosporidium and
related hydrogeologic and water quality parameters during the full range of
operating conditions.
(ii) The
study must include sampling both from the production well(s) and from
monitoring wells that are screened and located along the shortest flow path
between the surface water source and the production well(s).
(s)
Treatment performance toolbox components.
(1)
Combined filter performance. Systems using conventional filtration treatment or
direct filtration treatment receive an additional 0.5-log Cryptosporidium
treatment credit during any month the system meets the criteria in this
paragraph. Combined filter effluent (CFE) turbidity must be less than or equal
to 0.15 NTU in at least 95 percent of the measurements. Turbidity must be
measured as described in sections
11-20-46(d)(1)
and (2).
(2) Individual filter
performance. Systems using conventional filtration treatment or direct
filtration treatment receive 0.5-log Cryptosporidium treatment credit, which
can be in addition to the 0.5-log credit under paragraph (1), during any month
the system meets the criteria in this paragraph. Compliance with these criteria
must be based on individual filter turbidity monitoring as described in section
11-20-46.1(d),
as applicable.
(A) The filtered water
turbidity for each individual filter must be less than or equal to 0.15 NTU in
at least 95 percent of the measurements recorded each month.
(B) No individual filter may have a measured
turbidity greater than 0.3 NTU in two consecutive measurements taken 15 minutes
apart.
(C) Any system that has
received treatment credit for individual filter performance and fails to meet
the requirements of subparagraph (A) or (B) during any month does not receive a
treatment technique violation under paragraph (l)(3) if the State determines
the following:
(i) The failure was due to
unusual and short-term circumstances that could not reasonably be prevented
through optimizing treatment plant design, operation, and maintenance.
(ii) The system has experienced no
more than two such failures in any calendar year.
(3) Demonstration of performance.
The State may approve Cryptosporidium treatment credit for drinking water
treatment processes based on a demonstration of performance study that meets
the criteria in this paragraph. This treatment credit may be greater than or
less than the prescribed treatment credits in subsection (l) or subsections (r)
through (u) and may be awarded to treatment processes that do not meet the
criteria for the prescribed credits.
(A)
Systems cannot receive the prescribed treatment credit for any toolbox box
option in subsections (r) through (u) if that toolbox option is included in a
demonstration of performance study for which treatment credit is awarded under
this paragraph.
(B) The
demonstration of performance study must follow a state-approved protocol and
must demonstrate the level of Cryptosporidium reduction the treatment process
will achieve under the full range of expected operating conditions for the
system.
(C) Approval by the State
must be in writing and may include monitoring and treatment performance
criteria that the system must demonstrate and report on an ongoing basis to
remain eligible for the treatment credit. The State may designate such criteria
where necessary to verify that the conditions under which the demonstration of
performance credit was approved are maintained during routine operation.
(t) Additional
filtration toolbox components.
(1) Bag and
cartridge filters. Systems receive Cryptosporidium treatment credit of up to
2.0-log for individual bag or cartridge filters and up to 2.5-log for bag or
cartridge filters operated in series by meeting the criteria in subparagraphs
(A) through (J). To be eligible for this credit, systems must report the
results of challenge testing that meets the requirements of subparagraphs (B)
through (I) to the State. The filters must treat the entire plant flow taken
from a subpart H source.
(A) The
Cryptosporidium treatment credit awarded to bag or cartridge filters must be
based on the removal efficiency demonstrated during challenge testing that is
conducted according to the criteria in subparagraphs (B) through (I). A factor
of safety equal to 1-log for individual bag or cartridge filters and 0.5-log
for bag or cartridge filters in series must be applied to challenge testing
results to determine removal credit. Systems may use results from challenge
testing conducted prior to January 5, 2006 if the prior testing was consistent
with the criteria specified in subparagraphs (B) through (I).
(B) Challenge testing must be performed on
full-scale bag or cartridge filters, and the associated filter housing or
pressure vessel, that are identical in material and construction to the filters
and housings the system will use for removal of Cryptosporidium. Bag or
cartridge filters must be challenge tested in the same configuration that the
system will use, either as individual filters or as a series configuration of
filters.
(C) Challenge testing must
be conducted using Cryptosporidium or a surrogate that is removed no more
efficiently than Cryptosporidium. The microorganism or surrogate used during
challenge testing is referred to as the challenge particulate. The
concentration of the challenge particulate must be determined using a method
capable of discreetly quantifying the specific microorganism or surrogate used
in the test; gross measurements such as turbidity may not be used.
(D) The maximum feed water concentration that
can be used during a challenge test must be based on the detection limit of the
challenge particulate in the filtrate (i.e., filtrate detection limit) and must
be calculated using the following equation:
Maximum Feed Concentration = 1 x 10
4 x (Filtrate Detection Limit)
(E) Challenge testing must be conducted at
the maximum design flow rate for the filter as specified by the
manufacturer.
(F) Each filter
evaluated must be tested for a duration sufficient to reach 100 percent of the
terminal pressure drop, which establishes the maximum pressure drop under which
the filter may be used to comply with the requirements of this
section.
(G) Removal efficiency of
a filter must be determined from the results of the challenge test and
expressed in terms of log removal values using the following equation:
LRV = LOG10 (Cf) -
LOG10 (Cp)
Where:
LRV = log removal value demonstrated during challenge
testing; Cf = the feed concentration measured during the
challenge test; and Cp = the filtrate concentration
measured during the challenge test. In applying this equation, the same units
must be used for the feed and filtrate concentrations. If the challenge
particulate is not detected in the filtrate, then the term
Cp must be set equal to the detection limit.
(H) Each filter tested must be
challenged with the challenge particulate during three periods over the
filtration cycle: within two hours of start-up of a new filter; when the
pressure drop is between 45 and 55 percent of the terminal pressure drop; and
at the end of the cycle after the pressure drop has reached 100 percent of the
terminal pressure drop. An LRV must be calculated for each of these challenge
periods for each filter tested. The LRV for the filter
(LRVfilter) must be assigned the value of the minimum
LRV observed during the three challenge periods for that filter.
(I) If fewer than 20 filters are tested, the
overall removal efficiency for the filter product line must be set equal to the
lowest LRVfilter among the filters tested. If 20 or more
filters are tested, the overall removal efficiency for the filter product line
must be set equal to the 10th percentile of the set of
LRVfilter values for the various filters tested. The
percentile is defined by (i/(n+1) ) where i is the rank of n individual data
points ordered lowest to highest. If necessary, the 10th percentile may be
calculated using linear interpolation.
(J) If a previously tested filter is modified
in a manner that could change the removal efficiency of the filter product
line, challenge testing to demonstrate the removal efficiency of the modified
filter must be conducted and submitted to the State.
(2) Membrane filtration.
(A) Systems receive Cryptosporidium treatment
credit for membrane filtration that meets the criteria of this paragraph.
Membrane cartridge filters that meet the definition of membrane filtration in
subsection
11-20-2
are eligible for this credit. The level of treatment credit a system receives
is equal to the lower of the values determined under clauses (i) and (ii).
(i) The removal efficiency demonstrated
during challenge testing conducted under the conditions in subparagraph
(B).
(ii) The maximum removal
efficiency that can be verified through direct integrity testing used with the
membrane filtration process under the conditions in subparagraph (C).
(B) Challenge Testing. The
membrane used by the system must undergo challenge testing to evaluate removal
efficiency, and the system must report the results of challenge testing to the
State. Challenge testing must be conducted according to the criteria in clauses
(i) through (vii). Systems may use data from challenge testing conducted prior
to January 5, 2006 if the prior testing was consistent with the criteria in
clauses (i) through (vii).
(i) Challenge
testing must be conducted on either a full-scale membrane module, identical in
material and construction to the membrane modules used in the system's
treatment facility, or a smaller-scale membrane module, identical in material
and similar in construction to the full-scale module. A module is defined as
the smallest component of a membrane unit in which a specific membrane surface
area is housed in a device with a filtrate outlet structure.
(ii) Challenge testing must be conducted
using Cryptosporidium oocysts or a surrogate that is removed no more
efficiently than Cryptosporidium oocysts. The organism or surrogate used during
challenge testing is referred to as the challenge particulate. The
concentration of the challenge particulate, in both the feed and filtrate
water, must be determined using a method capable of discretely quantifying the
specific challenge particulate used in the test; gross measurements such as
turbidity may not be used.
(iii)
The maximum feed water concentration that can be used during a challenge test
is based on the detection limit of the challenge particulate in the filtrate
and must be determined according to the following equation:
Maximum Feed Concentration = 3.16 x 10 6
x (Filtrate Detection Limit)
(iv) Challenge testing must be conducted
under representative hydraulic conditions at the maximum design flux and
maximum design process recovery specified by the manufacturer for the membrane
module. Flux is defined as the throughput of a pressure driven membrane process
expressed as flow per unit of membrane area. Recovery is defined as the
volumetric percent of feed water that is converted to filtrate over the course
of an operating cycle uninterrupted by events such as chemical cleaning or a
solids removal process (i.e., backwashing).
(v) Removal efficiency of a membrane module
must be calculated from the challenge test results and expressed as a log
removal value according to the following equation:
LRV = LOG10
(Cf) - LOG10
(Cp)
Where:
LRV = log removal value demonstrated during the challenge
test; Cf = the feed concentration measured during the
challenge test; and Cp = the filtrate concentration
measured during the challenge test. Equivalent units must be used for the feed
and filtrate concentrations. If the challenge particulate is not detected in
the filtrate, the term Cp is set equal to the detection
limit for the purpose of calculating the LRV. An LRV must be calculated for
each membrane module evaluated during the challenge test.
(vi) The removal efficiency of a membrane
filtration process demonstrated during challenge testing must be expressed as a
log removal value (LRVC-Test). If fewer than 20 modules are tested, then
LRVC-Test is equal to the lowest of the representative LRVs among the modules
tested. If 20 or more modules are tested, then LRVC-Test is equal to the 10th
percentile of the representative LRVs among the modules tested. The percentile
is defined by (i/(n+1) ) where i is the rank of n individual data points
ordered lowest to highest. If necessary, the 10th percentile may be calculated
using linear interpolation.
(vii)
The challenge test must establish a quality control release value (QCRV) for a
non-destructive performance test that demonstrates the Cryptosporidium removal
capability of the membrane filtration module. This performance test must be
applied to each production membrane module used by the system that was not
directly challenge tested in order to verify Cryptosporidium removal
capability. Production modules that do not meet the established QCRV are not
eligible for the treatment credit demonstrated during the challenge
test.
(viii) If a previously tested
membrane is modified in a manner that could change the removal efficiency of
the membrane or the applicability of the nondestructive performance test and
associated QCRV, additional challenge testing to demonstrate the removal
efficiency of, and determine a new QCRV for, the modified membrane must be
conducted and submitted to the State.
(C) Direct integrity testing. Systems must
conduct direct integrity testing in a manner that demonstrates a removal
efficiency equal to or greater than the removal credit awarded to the membrane
filtration process and meets the requirements described in clauses (i) through
(vi). A direct integrity test is defined as a physical test applied to a
membrane unit in order to identify and isolate integrity breaches (i.e., one or
more leaks that could result in contamination of the filtrate).
(i) The direct integrity test must be
independently applied to each membrane unit in service. A membrane unit is
defined as a group of membrane modules that share common valving that allows
the unit to be isolated from the rest of the system for the purpose of
integrity testing or other maintenance.
(ii)
The direct integrity method must have a resolution of 3
micrometers or less, where resolution is defined as the size of the smallest
integrity breach that contributes to a response from the direct integrity test.
(iii) The direct integrity test
must have a sensitivity sufficient to verify the log treatment credit awarded
to the membrane filtration process by the State, where sensitivity is defined
as the maximum log removal value that can be reliably verified by a direct
integrity test. Sensitivity must be determined using the approach in this
clause as applicable to the type of direct integrity test the system uses. For
direct integrity tests that use an applied pressure or vacuum, the direct
integrity test sensitivity must be calculated according to the following
equation:
LRVDIT = LOG10
(Qp /(VCF xx Qbreach) )
Where:
LRVDIT = the sensitivity of the direct
integrity test; Qp = total design filtrate flow from the
membrane unit; Qbreach = flow of water from an integrity
breach associated with the smallest integrity test response that can be
reliably measured, and VCF = volumetric concentration factor. The volumetric
concentration factor is the ratio of the suspended solids concentration on the
high pressure side of the membrane relative to that in the feed water.
For direct integrity tests that use a particulate or
molecular marker, the direct integrity test sensitivity must be calculated
according to the following equation:
LRVDIT =
LOG10(Cf) -
LOG10(Cp)
Where:
LRVDIT = the sensitivity of the direct
integrity test; Cf = the typical feed concentration of
the marker used in the test; and Cp = the filtrate
concentration of the marker from an integral membrane unit.
(iv) Systems must establish a control limit
within the sensitivity limits of the direct integrity test that is indicative
of an integral membrane unit capable of meeting the removal credit awarded by
the State.
(v) If the result of a
direct integrity test exceeds the control limit established under clause (iv),
the system must remove the membrane unit from service. Systems must conduct a
direct integrity test to verify any repairs, and may return the membrane unit
to service only if the direct integrity test is within the established control
limit.
(vi) Systems must conduct
direct integrity testing on each membrane unit at a frequency of not less than
once each day that the membrane unit is in operation. The State may approve
less frequent testing, based on demonstrated process reliability, the use of
multiple barriers effective for Cryptosporidium, or reliable process
safeguards.
(D) Indirect
integrity monitoring. Systems must conduct continuous indirect integrity
monitoring on each membrane unit according to the criteria in clauses (i)
through (v). Indirect integrity monitoring is defined as monitoring some aspect
of filtrate water quality that is indicative of the removal of particulate
matter. A system that implements continuous direct integrity testing of
membrane units in accordance with the criteria in paragraphs (2)(C)(i) through
(v) is not subject to the requirements for continuous indirect integrity
monitoring. Systems must submit a monthly report to the State summarizing all
continuous indirect integrity monitoring results triggering direct integrity
testing and the corrective action that was taken in each case.
(i) Unless the State approves an alternative
parameter, continuous indirect integrity monitoring must include continuous
filtrate turbidity monitoring.
(ii)
Continuous monitoring must be conducted at a frequency of no less
than once every 15 minutes.
(iii)
Continuous monitoring must be separately conducted on each membrane unit.
(iv) If indirect integrity
monitoring includes turbidity and if the filtrate turbidity readings are above
0.15 NTU for a period greater than 15 minutes (i.e., two consecutive 15-minute
readings above 0.15 NTU), direct integrity testing must immediately be
performed on the associated membrane unit as specified in paragraphs (2)(C)(i)
through (v).
(v) If indirect
integrity monitoring includes a state-approved alternative parameter and if the
alternative parameter exceeds a state-approved control limit for a period
greater than 15 minutes, direct integrity testing must immediately be performed
on the associated membrane units as specified in paragraphs (2)(C)(i) through
(v).
(3)
Second stage filtration. Systems receive 0.5-log Cryptosporidium treatment
credit for a separate second stage of filtration that consists of sand, dual
media, GAC, or other fine grain media following granular media filtration if
the State approves. To be eligible for this credit, the first stage of
filtration must be preceded by a coagulation step and both filtration stages
must treat the entire plant flow taken from a surface water or GWUDI source. A
cap, such as GAC, on a single stage of filtration is not eligible for this
credit. The State must approve the treatment credit based on an assessment of
the design characteristics of the filtration process.
(4) Slow sand filtration (as secondary
filter). Systems are eligible to receive 2.5-log Cryptosporidium treatment
credit for a slow sand filtration process that follows a separate stage of
filtration if both filtration stages treat entire plant flow taken from a
surface water or GWUDI source and no disinfectant residual is present in the
influent water to the slow sand filtration process. The State must approve the
treatment credit based on an assessment of the design characteristics of the
filtration process. This paragraph does not apply to treatment credit awarded
to slow sand filtration used as a primary filtration
process.
(u) Inactivation
toolbox components.
(1) Calculation of CT
values.
(A) CT is the product of the
disinfectant contact time (T, in minutes) and disinfectant concentration (C, in
milligrams per liter). Systems with treatment credit for chlorine dioxide or
ozone under paragraph (2) or (3) must calculate CT at least once each day, with
both C and T measured during peak hourly flow as specified in
40 C.F.R.
141.74(a) through (b).
(B) Systems with several
disinfection segments in sequence may calculate CT for each segment, where a
disinfection segment is defined as a treatment unit process with a measurable
disinfectant residual level and a liquid volume. Under this approach, systems
must add the Cryptosporidium CT values in each segment to determine the total
CT for the treatment plant.
(2) CT values for chlorine dioxide and ozone.
(A) Systems receive the Cryptosporidium
treatment credit listed in the table referenced at
40 C.F.R.
141.720(b)(1) by meeting the
corresponding chlorine dioxide CT value for the applicable water temperature,
as described in paragraph (1).
(B)
Systems receive the Cryptosporidium treatment credit listed in the table
referenced at
40 C.F.R.
141.720(b)(2) by meeting the
corresponding ozone CT values for the applicable water temperature, as
described in paragraph (1).
(3)
Site-specific study. The State may approve alternative chlorine
dioxide or ozone CT values to those listed in paragraph (2) on a site-specific
basis. The State must base this approval on a site-specific study a system
conducts that follows a state-approved protocol.
(4) Ultraviolet light. Systems receive
Cryptosporidium, Giardia lamblia, and virus treatment credits for ultraviolet
(UV) light reactors by achieving the corresponding UV dose values shown in
subparagraph (A). Systems must validate and monitor UV reactors as described in
subparagraphs (B) and (C) to demonstrate that they are achieving a particular
UV dose value for treatment credit.
(A) UV
dose table. The treatment credits listed in the table referenced at
40 C.F.R.
141.720(d)(1) are for UV
light at a wavelength of 254 nm as produced by a low pressure mercury vapor
lamp. To receive treatment credit for other lamp types, systems must
demonstrate an equivalent germicidal dose through reactor validation testing,
as described in subparagraph (B). The UV dose values in this table are
applicable only to post-filter applications of UV in filtered systems and to
unfiltered systems.
(B) Reactor
validation testing. Systems must use UV reactors that have undergone validation
testing to determine the operating conditions under which the reactor delivers
the UV dose required in subparagraph (A)(i.e., validated operating conditions).
These operating conditions must include flow rate, UV intensity as measured by
a UV sensor, and UV lamp status.
(i) When
determining validated operating conditions, systems must account for the
following factors: UV absorbance of the water; lamp fouling and aging;
measurement uncertainty of on-line sensors; UV dose distributions arising from
the velocity profiles through the reactor; failure of UV lamps or other
critical system components; and inlet and outlet piping or channel
configurations of the UV reactor.
(ii) Validation testing must include the
following: Full scale testing of a reactor that conforms uniformly to the UV
reactors used by the system and inactivation of a test microorganism whose dose
response characteristics have been quantified with a low pressure mercury vapor
lamp.
(iii) The State may approve an
alternative approach to validation testing.
(C) Reactor monitoring.
(i) Systems must monitor their UV reactors to
determine if the reactors are operating within validated conditions, as
determined under subparagraph (B). This monitoring must include UV intensity as
measured by a UV sensor, flow rate, lamp status, and other parameters the State
designates based on UV reactor operation. Systems must verify the calibration
of UV sensors and must recalibrate sensors in accordance with a protocol the
State approves.
(ii) To receive
treatment credit for UV light, systems must treat at least 95 percent of the
water delivered to the public during each month by UV reactors operating within
validated conditions for the required UV dose, as described in subparagraphs
(A) and (B). Systems must demonstrate compliance with this condition by the
monitoring required under subparagraph (C)(i).
(v) Reporting requirements.
(1) Systems must report sampling schedules
under subsection (c) and source water monitoring results under subsection (g)
unless they notify the State that they will not conduct source water monitoring
due to meeting the criteria of subsection (b)(4).
(2) Systems must report the use of uncovered
finished water storage facilities to the State as described in subsection
(o).
(3) Filtered systems must
report their Cryptosporidium bin classification as described in subsection
(k).
(4) Unfiltered systems must
report their mean source water Cryptosporidium level as described in subsection
(m).
(5) Systems must report
disinfection profiles and benchmarks to the State as described in subsection
(i) through (j) prior to making a significant change in disinfection practice.
(6) Systems must report to the
State in accordance with the table referenced at
40 C.F.R.
141.721(f) for any microbial
toolbox options used to comply with treatment requirements under subsection (l)
or (m). Alternatively, the State may approve a system to certify operation
within required parameters for treatment credit rather than reporting monthly
operational data for toolbox options.
(w) Recordkeeping requirements.
(1) Systems must keep results from the
initial round of source water monitoring under subsection (b)(1) and the second
round of source water monitoring under subsection (b)(2) until 3 years after
bin classification under subsection (k) for filtered systems or determination
of the mean Cryptosporidium level under subsection (k) for unfiltered systems
for the particular round of monitoring.
(2)
Systems must keep any notification to the State that they will
not conduct source water monitoring due to meeting the criteria of subsection
(b)(4) for 3 years.
(3) Systems
must keep the results of treatment monitoring associated with microbial toolbox
options under subsection (q) through (u) and with uncovered finished water
reservoirs under subsection (o), as applicable, for 3 years.
(x) Requirements to respond to
significant deficiencies identified in sanitary surveys performed by EPA.
(1) A sanitary survey is an onsite review of
the water source (identifying sources of contamination by using results of
source water assessments where available), facilities, equipment, operation,
maintenance, and monitoring compliance of a PWS to evaluate the adequacy of the
PWS, its sources and operations, and the distribution of safe drinking
water.
(2) For the purposes of this
section, a significant deficiency includes a defect in design, operation, or
maintenance, or a failure or malfunction of the sources, treatment, storage, or
distribution system that EPA determines to be causing, or has the potential for
causing the introduction of contamination into the water delivered to
consumers.
(3) For sanitary
surveys performed by EPA, systems must respond in writing to significant
deficiencies identified in sanitary survey reports no later than 45 days after
receipt of the report, indicating how and on what schedule the system will
address significant deficiencies noted in the survey.
(4) Systems must correct significant
deficiencies identified in sanitary survey reports according to the schedule
approved by EPA, or if there is no approved schedule, according to the schedule
reported under paragraph (3) if such deficiencies are within the control of the
system.