Code of Massachusetts Regulations
310 CMR - DEPARTMENT OF ENVIRONMENTAL PROTECTION
Title 310 CMR 22.00 - Drinking Water
Section 22.20D - Interim Enhanced Surface Water Treatment Rule
Universal Citation: 310 CMR 22.00 MA Code of Regs 22.20D
Current through Register 1531, September 27, 2024
(1) General Requirements.
(a)310 CMR 22.20D
establishes requirements for filtration and disinfection that are in addition
to criteria established under
310 CMR
22.20A. The requirements of 310 CMR 22.20D
apply to all public water supplies serving at least 10,000 people, beginning
January 1, 2002 unless otherwise specified. 310 CMR 22.20D establishes or
extends treatment technique requirements in lieu of maximum contaminant levels
for the following contaminants:
1.
Giardia lamblia;
2. Viruses;
3. Heterotrophic plate count
bacteria;
4.
Legionella;
5.
Cryptosporidium; and
6. Turbidity.
(b) Each supplier of water serving at least
10,000 people using a surface water source, or ground water source under the
direct influence of surface water shall provide treatment of its source water
that complies with the treatment technique requirements set forth in 310 CMR
22.20D in addition to the requirements identified in
310 CMR
22.20A. The treatment technique requirements
set out in 310 CMR 22.20D consist of installing and properly operating water
treatment processes which reliably achieve:
1. At least 99% (2-log) removal of
Cryptosporidium between a point where water is not subject to
recontamination by surface water runoff and a point downstream before or at the
first customer for filtered systems, or Cryptosporidium
control under the watershed control plan for unfiltered
systems.
2. Compliance with the
profiling and benchmark requirements under the provisions of 310 CMR
22.20D(3).
(c) A public
water system subject to the requirements of 310 CMR 22.20D is deemed to be in
compliance with the requirements of 310 CMR 22.20D(1)(a) and (b) if:
1. It meets the requirements for avoiding
filtration in
310 CMR 22.20A(2)
and 22.20D(2) and the disinfection
requirements in
310 CMR 22.20A(3)
and 22.20D(3); or,
2. It meets the applicable filtration
requirements in either
310 CMR 22.20A(4)
or 22.20D(4) and the disinfection
requirements in
310 CMR 22.20A(3)
and 22.20D(3).
(d) A supplier of water is not permitted to
construct uncovered finished water storage facilities.
(e) A supplier of water that uses a surface
water source or ground water source under the direct influence of surface water
that did not conduct disinfection profiling under 310 CMR 22.20D(3)(b) because
they served fewer than 10,000 persons when such monitoring was required, but
serve more than 10,000 persons prior to January 14, 2005 must comply with 310
CMR 22.20D(1), (2) and (4) through (6). These systems must also consult with
the Department to establish a disinfection benchmark. A supplier of water that
decides to make a significant change to its disinfection practice, as described
in 310 CMR 22.20D(3)(c)1.a. through e. must consult with the Department prior
to making such change.
(2) Criteria for Avoiding Filtration. 310 CMR 22.20D(2) establishes criteria for avoiding filtration for a supplier of water that uses a surface water source or a ground water source under the influence of surface water to serve a population of at least 10,000 people in addition to the requirements of 310 CMR 22.20A(2). Each supplier of water shall meet all of the following conditions:
(a)
Site-specific
Conditions. In addition to site-specific conditions in
310 CMR
22.20A(2)(b), a supplier of
water shall maintain the watershed control program under
310 CMR
22.20A(2)(b)5. to minimize
the potential for contamination by Cryptosporidium oocysts in
the source water. The watershed control program shall, for
Cryptosporidium:
1. Identify
watershed characteristics and activities which may have an adverse effect on
source water quality; and,
2.
Monitor the occurrence of activities that may have an adverse effect on source
water quality.
(b)
During the onsite inspection conducted under the provisions of
310 CMR
22.20A(2)(b)(3), the
Department will determine whether the watershed control program established
under
310 CMR
22.20A(2)(b)5. is adequate
to limit potential contamination by Cryptosporidium
oocysts.
(3) Disinfection Profiling and Benchmarking. 310 CMR 22.20D(3) establishes criteria that the Department will use to determine public water systems that are required to profile. A supplier of water subject to the requirements of 310 CMR 22.20D(3) had to determine its TTHM annual average using the procedure in 310 CMR 22.20D(3)(a) and its HAA5 annual average using the procedure of 310 CMR 22.20D(3)(b). The annual average is the arithmetic average of the quarterly averages of four consecutive quarters of monitoring.
(a)
Determination of Systems
Required to Profile.
1. The TTHM
annual average is the annual average determined during the same period as was
used for the HAA5 annual average:
a. A
supplier of water who collected data under the provisions of the "Information
Collection Rule" (ICR) was required to use the results of the samples collected
during the last four quarters of required monitoring under the "disinfection
byproduct and related monitoring" of the ICR.
b. A supplier of water who used
"grandfathered'' HAA5 occurrence data that met the provisions of 310 CMR
22.20D(3)(a)2.b. shall use TTHM data collected at the same time under the
provisions of
310
CMR 22.07E.
c. A supplier of water who used HAA5
occurrence data that met the provisions of 310 CMR 22.20D(3)(a)2.c.(i) was
required to use TTHM data collected at the same time under the provisions of
310 CMR 22.07(2) and
22.07E.
2. The HAA5 annual average is the
annual average during the same period as was used for the TTHM annual average
with the following provisions:
a. A supplier
of water who collected data under the Information Collection Rule shall have
used the results of the samples collected during the last four quarters of
required monitoring under the ICR.
b. A supplier of water who collected four
quarters of HAA5 occurrence data that met the routine monitoring sample number
and location requirements for TTHMs in
310
CMR 22.07E(1), (2) and the
handling and analytical method requirements of the ICR may use that data to
determine whether the requirements of 310 CMR 22.20D(3) apply.
c. A supplier of water who did not collect
four quarters of HAA5 occurrence data that met the provisions of either 310 CMR
22.20D(3)(a)2.a. and b. by March 31, 1999 must either:
(i) have conducted monitoring for HAA5 that
met the routine monitoring sample number and location requirements for TTHM in
310 CMR 22.07(2) and
22.07E
and the handling and analytical method requirements of
310
CMR 22.07E to determine the HAA5 annual
average and whether the requirements of
310
CMR 22.07C(3) apply, which
monitoring shall have been completed so that the applicability determination
could be made no later than March 31, 2000; or,
(ii) comply with all other provisions of 310
CMR 22.20D(3)(b)2. as if the HAA5 monitoring had been conducted and the results
required compliance with 310 CMR 22.20D(3)(b).
3. The supplier of water may request the
Department approve a more representative annual data set than the data set
determined in 310 CMR 22.20D(3)(a)1. or 2. for the purpose of determining
applicability of the requirements of 310 CMR 22.20D(3). A representative data
set was to be determined based on the following:
a. Whether the method of collection was in
accordance with 310 CMR 22.07(2),
22.07E
and 22.20D(3);
b. Whether the
annual set presented is representative of the plant's current and/or long-term
disinfection practices.
4. The Department may require that a system
use a more representative annual data set than the data set determined under
310 CMR 22.20D(3)(a)1. or 2. for the purpose of determining applicability of
the requirements of 310 CMR 22.20D.
5. The supplier of water must have submitted
data to the Department on the schedule as shown below:
a. A supplier of water who collected TTHM and
HAA5 data under the provisions of Information Collection Rule (ICR), as was
required by 310 CMR 22.20D(3)(a)1.a. and 2.a., must have submitted the results
of the samples collected during the last 12 months of required monitoring under
the ICR not later than December 31, 1999.
b. A supplier of water who collected four
consecutive quarters of data that met the routine monitoring sample number and
location for TTHM in
310
CMR 22.07A and
310
CMR 22.07E for handling and analytical method
requirements, as was allowed by 310 CMR 22.20D(3)(a)1.b. and 2.b., must have
submitted that data to the Department not later than April 16, 1999. Until the
Department has approved the data, the system shall conduct monitoring for HAA5
using the monitoring requirements specified under 310 CMR 22.20D(3)(a)
2.c.
c. A supplier of water who
conducted monitoring for HAA5 using the monitoring requirements specified by
310 CMR 22.20D(3)(a)1.c. and 2.c.(i), must have submitted TTHM and HAA5 data
not later than March 31, 2000.
d. A
supplier of water who elected to comply with all other provisions of 310 CMR
22.20D(3) as if the HAA5 monitoring had been conducted and the results required
compliance with 310 CMR 22.20D(3)(a), as was allowed under 310 CMR
22.20D(3)(a)2.c.(i), must have notified the Department in writing of their
election not later than March 31, 2000.
e. If the supplier of water elected to
request that the Department approve a more representative annual data set than
the data set determined under 310 CMR 22.20D(3)(a)2.a., the system must have
submitted this request in writing not later than March 31, 2000.
6. Any supplier of water having
either a TTHM annual average greater than or equal to 0.064 mg/L or an HAA5
annual average greater than or equal to 0.048 mg/L during the period identified
in 310 CMR 22.20D(3)(a)1. and 2. shall comply with 310 CMR
22.20D(3)(b).
7. An owner or
operator of a consecutive systems was not required to develop a disinfection
profile; however, they are required to meet the requirements of
310
CMR 22.07E.
(b)
Disinfection
Profiling.
1. A supplier of
water who meets the criteria in 310 CMR 22.20D(3)(a)6. shall develop a
disinfection profile of their disinfection practice for a period of up to three
years.
2. A supplier of water shall
monitor daily for a period of 12 consecutive calendar months to determine the
total logs of inactivation for each day of operation, based on the
CT99.9 values in
310 CMR
22.20A(5)(b): Tables
1.1 through 1.6, 2.1, and
3.1 and 310 CMR 22.20D(3): Tables C1 through
C13, as appropriate, through the entire treatment plant. The
supplier of water shall have begun this monitoring not later than April 1,
2000. As a minimum, the supplier of water using a single point of disinfectant
application prior to entrance to the distribution system shall conduct
monitoring in accordance with 310 CMR 22.20D(3)(b)2.a. through d. A supplier of
water using a system with more than one point of disinfectant application shall
conduct the monitoring in accordance with 310 CMR 22.20D(3)(b)2.a. through d.
for each disinfection segment. The supplier of water shall monitor the
parameters necessary to determine the total inactivation ratio, using
analytical methods in
310 CMR
22.20A(5), as follows:
a. The temperature of the disinfected water
shall be measured once daily at each residual disinfectant concentration
sampling point during peak hourly flow.
b. If the system uses chlorine, the pH of the
disinfected water shall be measured once daily at each chlorine residual
disinfectant concentration sampling point during peak hourly flow.
c. The disinfectant contact time(s) ("T")
shall be determined for each day 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 disinfection shall be measured daily during peak hourly
flow.
3. In lieu
of the monitoring conducted under the provisions of 310 CMR
22.20D(3)(b)2. to develop the disinfection profile, the supplier of water may
have elected to meet the requirements of paragraph 310 CMR 22.20D(3)(b)3.a. In
addition to the monitoring conducted under the of 310 CMR 22.20D(3)(b)2. to
develop the disinfection profile, the system may elect to meet the requirements
of 310 CMR 22.20D(3)(b)3.b.
a. A supplier of
water who has three years of existing operational data could have submitted
that data, a profile generated using that data, and a request that the
Department approve the use of that data in lieu of monitoring
under the provisions of 310 CMR 22.20D(3)(b)2. not later than March 31, 2000.
This data shall be representative of Giardia lamblia
inactivation through the entire treatment plant and not just of
certain treatment segments. Until the Department approves this request, the
supplier of water is required to conduct monitoring under the provisions of 310
CMR 22.20D(3)(b)2.
b. In addition
to the disinfection profile generated under 310 CMR 22.20D(3)(b)2., a supplier
of water who has existing operational data may use that data to develop a
disinfection profile for additional years. The supplier of water may use these
additional yearly disinfection profiles to develop a benchmark under the
provisions of 310 CMR 22.20D(3)(c). The Department will determine whether these
operational data are substantially equivalent to data collected under the
provisions of 310 CMR 22.20D(3)(b)2. These data shall be representative of
inactivation through the entire treatment plant, and not just of certain
treatment segments.
4.
The supplier of water shall calculate the total inactivation ratio as follows:
a. If the supplier of water uses only one
point of disinfectant application, the supplier of water may determine the
total inactivation ratio for the disinfection segment based on either of the
methods below:
(i) Determine one inactivation
ratio CTcalc/CT99.9 before or at the first customer
during peak hourly flow; or,
(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. Under this
alternative, the supplier of water shall calculate the total inactivation ratio
by determining CTcalc/CT99.9 for each sequence and then
add the CTcalc/CT 99.9 values together:
b. If
the supplier of water uses more than one point of disinfectant application
before the first customer, the supplier of water shall 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 supplier of water shall calculate the
CTcalc/CT99.9 value of each segment and
S(CTcalc/CT99.9) using the method in 310 CMR
22.20D(3)(b)4.a.
c. The supplier of
water shall determine the total logs of inactivation (z) by multiplying the
value calculated in 310 CMR 22.20D(b)4.a. or b. by 3.0 as shown below:
5. Each supplier of water who uses either
chloramines or ozone for primary disinfection shall also calculate the logs of
inactivation for Viruses using a method approved by the Department.
6. A supplier of water who uses mixed
oxidants shall calculate the overall "CT" by finding the summation of the
individual "CTs" of each disinfectant within the mix.
7. Each supplier of water shall retain the
disinfection profile data in graphic form, as a spreadsheet, or in some other
format acceptable to the Department for review as part of sanitary surveys
conducted by the Department.
(c)
Disinfection
Benchmarking.
1. Each supplier of
water required to develop a disinfection profile under the provisions of 310
CMR 22.20D(a) and (b) who decides to make a significant change to a
disinfection practice shall consult with the Department prior to making the
change. A significant change to disinfection practice is any of the following:
a. A change to the point of
disinfection;
b. A change to the
disinfectant(s) used in the treatment plant;
c. A change to the disinfection
process;
d. A physical
modification(s) that directly or indirectly effects the detention time of any
unit process;
e. Any other
modification identified by the Department.
2. Each supplier of water who proposes to
modify its disinfection practice shall calculate the disinfection benchmark
using the following procedure:
a. For each
year of profiling data collected and calculated under 310 CMR 22.20D(3)(b), the
supplier of water shall determine the lowest average monthly Giardia
lamblia inactivation in each year of profiling data. The supplier of
water shall determine the average Giardia lamblia inactivation
for each calendar month for each year of profiling data by dividing the sum of
daily Giardia lamblia of inactivation by the number of values
calculated for that month.
b. The
disinfection benchmark is the lowest monthly average value (for systems with
one year of profiling data) or average of lowest monthly average values (for
systems with more than one year of profiling data) of the monthly logs of
Giardia lamblia inactivation in each year of profiling
data.
3. Each supplier
of water who uses either chloramines or ozone for primary disinfection shall
also calculate the disinfection benchmark for Viruses using a method approved
by the Department.
4. Each supplier
of water shall submit the information required in 310 CMR 22.20D(3)(c) and the
information required in 310 CMR 22.20D(3)(c)4.a. through c. to the Department
as part of the consultation process including:
a. A description of the proposed
change
b. The disinfection profile
for Giardia lamblia (and, if necessary, Viruses) under 310 CMR
22.20D(3)(b) and benchmark as required by 310 CMR 22.20D(3)(c)2.; and
c. An analysis of how the proposed change
will affect the current levels of disinfection.
(4) Filtration. Each supplier of water using a system subject to the requirements of 310 CMR 22.20D that does not meet all of the criteria of 310 CMR 22.20D(2) and the criteria in 310 CMR 22.20A(2) for avoiding filtration shall provide treatment consisting of both disinfection, as specified in 310 CMR 22.20A(3)(b), and filtration treatment that complies with the requirements of 310 CMR 22.20A(4)(b) or (c) and 22.20D(4)(a) or (b) and by December 31, 2001.
(a)
Conventional Filtration Treatment or Direct
Filtration.
1. Each supplier of
water using conventional filtration or direct filtration, shall maintain a
turbidity level in representative samples of a system's filtered water of less
than or equal to 0.3 NTU in at least 95% of the measurements taken each month,
measured as specified in
310 CMR 22.20A(5)(a)
and (c).
2. Each supplier of water must maintain a
turbidity level of representative samples of a system's filtered water that at
no time exceed one NTU, measured as specified in
310 CMR 22.20A(5)(a)
and (c).
3. A supplier of water who uses lime
softening may acidify representative samples prior to analysis in accordance
with a protocol approved by the Department.
(b) Filtration technologies other than
conventional filtration treatment, direct filtration, slow sand filtration, or
diatomaceous earth filtration.
1. A supplier
of water may use a filtration technology not listed in
310 CMR 22.20A(4)(b)
or (c) or 22.20D(4)(a) if the supplier of
water demonstrates to the Department, using pilot plant studies or other means,
that the alternative filtration technology, in combination with disinfection
treatment that meets the requirements of
310 CMR
22.20A(3)(b), consistently
achieves 99.9% removal and/or inactivation of Giardia lamblia
cysts and 99.99% removal and/or inactivation of Viruses, and 99%
removal of Cryptosporidium oocysts, and the Department
approves the use of the filtration technology. For each approval, the supplier
of water shall maintain the turbidity level of representative samples of the
system's filtered water at less than or equal to 0.3 NTU at least 95% of the
time and that the system shall not exceed one NTU at any time.
2. The performance standards of slow sand
filters and diatomateous earth filters are the same as indicated in
310 CMR
22.20A.
(5) Monitoring Requirements for Systems Using Filtration Treatment.
(a) In addition to monitoring required by
310 CMR
22.20A(5), a supplier of
water who relies upon a public water system subject to the requirements of 310
CMR 22.20D that provides conventional filtration treatment or direct filtration
shall conduct continuous monitoring of turbidity for each individual filter
using an approved method in
310 CMR
22.20A(5)(a), and shall
calibrate turbidimeters using the procedure specified by the manufacturer. The
supplier of watershall record the results of individual filter monitoring every
15 minutes.
(b) If there is a
failure in the continuous turbidity monitoring equipment, the supplier of water
shall conduct grab sampling every four hours in lieu of continuous monitoring,
but for no more than five working days following the failure of the
equipment.
(6) Reporting and Recordkeeping Requirements. In addition to the reporting and recordkeeping requirements in 310 CMR 22.20A(6), a supplier of water who is subject to the requirements of 310 CMR 22.20D who provides conventional filtration treatment or direct filtration shall report monthly to the Department the information specified in 310 CMR 22.20D(6)(a) and (b) beginning January 1, 2002. In addition to the reporting and recordkeeping requirements in 310 CMR 22.20A(6), a supplier of water who is subject to the requirements of 310 CMR 22.20D that provides filtration approved under 310 CMR 22.20D(4)(b) shall report monthly to the Department the information specified in 310 CMR 22.20D(6)(a) beginning January 1, 2002. This reporting in 310 CMR 22.20D(6)(a) is in lieu of the reporting specified in 310 CMR 22.20A(6).
(a) The supplier of water shall report
turbidity measurements as required by 310 CMR 22.20D(4) within ten days after
the end of each month the system serves water to the public. Information that
shall be reported to the Department includes:
1. The total number of filtered water
turbidity measurements taken during the month.
2. The number and percentage of filtered
water turbidity measurements taken during the month which are less than or
equal to the turbidity limits specified in 310 CMR 22.20D(4)(a) or
(b).
3. The date and value of any
turbidity measurements taken during the month which exceed one NTU for systems
using conventional filtration treatment or direct filtration, or exceed the
maximum level set by the Department in 310 CMR 22.20D(4)(b).
(b) The supplier of water shall
maintain the results of individual filter monitoring taken as required in 310
CMR 22.20D(5) for at least three years. Each supplier of water shall report
that individual filter turbidity monitoring was conducted in accordance with
310 CMR 22.20D(5) within ten days after the end of each month the system serves
water to the public. Each supplier of water shall report individual filter
turbidity measurement results taken under 310 CMR 22.20D(5) within ten days
after the end of each month the system serves water to the public only if
measurements demonstrate one or more of the conditions in 310 CMR
22.20D(6)(b)1. through 3. Each supplier of water who uses lime softening may
apply to the Department for alternative exceedance levels for the levels
specified in 310 CMR 22.20D(6)(b)1. through 4. if the supplier can demonstrate
that higher turbidity levels in individual filters are due to lime carryover
only and not due to degraded filter performance. A supplier of water shall
report the filter number, the turbidity measurement, and the date(s) on which
an exceedance occurred for any individual filter that has a measured turbidity
level of greater than 1.0 NTU in two consecutive measurements taken 15 minutes
apart. In addition, the supplier of water shall either produce a filter profile
for the filter within seven days of the exceedance (if the supplier is not able
to identify an obvious reason for the abnormal filter performance) and report
that the profile has been produced or report the obvious reason for the
exceedance.
1. For any individual filter that
has a measured turbidity level of greater than 0.5 NTU in two consecutive
measurements taken 15 minutes apart at the end of the first four hours of
continuous filter operation after the filter has been backwashed or otherwise
taken offline, the supplier of water shall report the filter number, the
turbidity, and the date(s) on which the exceedance occurred. In addition, the
supplier of water shall either produce a filter profile for the filter within
seven days of the exceedance (if the system is not able to identify an obvious
reason for the abnormal filter performance) and report that the profile has
been produced or report the obvious reason for the exceedance.
2. For any individual filter that has a
measured turbidity level of greater than 1.0 NTU in two consecutive
measurements taken 15 minutes apart at any time in each of three consecutive
months, the supplier of water shall report the filter number, the turbidity
measurement, and the date(s) on which the exceedance occurred. In addition, the
supplier of water shall conduct a self-assessment of the filter within 14 days
of the exceedance and report that the self-assessment was conducted. The
self-assessment shall consist of at least the following components: assessment
of filter performance; development of a filter profile; identification and
prioritization of factors limiting filter performance; assessment of the
applicability of corrections; and preparation of a filter self-assessment
report.
3. For any individual
filter that has a measured turbidity level of greater than 2.0 NTU in two
consecutive measurements taken 15 minutes apart at any time in each of two
consecutive months, the supplier of water shall report the filter number, the
turbidity measurement, and the date(s) on which the exceedance occurred. In
addition, the supplier of water shall arrange for the Department to conduct a
Comprehensive Performance Evaluation no later than 30 days following the
exceedance and have the evaluation completed no later than 90 days following
the exceedance.
(c)
Additional Reporting Requirements.
1. If at any at time the turbidity exceeds
one NTU in representative samples of filtered water in a system using
conventional treatment or direct filtration, the supplier of water shall inform
the Department as soon as possible, but not later than the end of the next
business day.
2. If at any at time
the turbidity exceeds one NTU in representative samples of filtered water in a
system using filtration technologies other than conventional filtration
treatment, direct filtration, slow sand filtration, or diatomaceous earth
filtration, the supplier of water shall inform the Department as soon as
possible, but not later than the end of the next business day.
Disclaimer: These regulations may not be the most recent version. Massachusetts may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
This site is protected by reCAPTCHA and the Google
Privacy Policy and
Terms of Service apply.
