310 CMR 22.20F
Long Term 1 Enhanced Surface Water Treatment Rule
(1) General Requirements.
(a) 310 CMR 22.20F establishes requirements for filtration and disinfection that are in
addition to criteria under 310 CMR 22.20A. The requirements of 310 CMR 22.20F apply
to public water systems serving fewer than 10,000 people using a surface water source or
ground water source under the direct influence of surface water, beginning January 1, 2005
unless otherwise specified. 310 CMR 22.20F 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 fewer than 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 22.20F in addition to the requirements identified in 310 CMR 22.20A. The
treatment technique requirements set out in 310 CMR 22.20F consist of installing and
properly operating water treatment processes that 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 in 310 CMR
22.20F(4)(a) through (5)(e).
(c) A public water system subject to the requirements of 310 CMR 22.20F shall also meet
the following requirements:
1. It shall cover any finished water reservoir that started construction on or after March
15, 2002 as described in 310 CMR 22.20F(2)(a) and (b).
2. If it is an unfiltered system, it shall comply with the updated watershed control
requirements described in 310 CMR 22.20F(3)(a) through (c).
3. If it is a community or non-transient non-community water systems, it shall develop
a disinfection profile as described in 310 CMR 22.20F(4)(a) through (g).
4. If it is considering making a significant change to its disinfection practices, it shall
develop a disinfection benchmark and consult with the Department for approval of the
change as described in 310 CMR 22.20F(5)(a) through (e).
5. If it is a filtered system, it shall comply with the combined filter effluent requirements
as described in 310 CMR 22.20F(6)(a) through (d).
6. If it is a filtered system that uses conventional or direct filtration, it shall comply with
the individual filter turbidity requirements as described in 310 CMR 22.20F(7)(a)
through (e).
7. It shall comply with the applicable reporting and record keeping requirements as
described in 310 CMR 22.20F(8)(a) and (b).
22.20F: continued
(2) Finished Water Reservoirs.
(a) Each supplier of water serving fewer than 10,000 people using a surface water source
or ground water source under the direct influence of surface water is subject to 310 CMR
22.20F(2)(b).
(b) If the supplier of water begins construction of a finished water reservoir on or after
March 15, 2002 the reservoir shall be covered. Finished water reservoirs for which the
supplier of water began construction prior to March 15, 2002 are not subject to 310 CMR
22.20F(2), but are subject to 310 CMR 22.20A.
(3) Additional Watershed Control Requirements for Unfiltered Systems.
(a) Each supplier of water serving fewer than 10,000 people using a surface water source
or ground water source under the direct influence of surface water which does not provide
filtration shall continue to comply with all of the filtration avoidance criteria in 310 CMR
22.20A(2), as well as the additional watershed control requirements in 310 CMR
22.20F(3)(b).
(b) The supplier of water must take any additional steps necessary to minimize the potential
for contamination by Cryptosporidium oocysts in the source water. The supplier of water’s
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, which may have an adverse effect on source
water quality.
(c) During an onsite inspection conducted under the provisions of 310 CMR
22.20A(2)(b)5., the Department will determine whether the watershed control program is
adequate to limit potential contamination by Cryptosporidium oocysts. The adequacy of the
program will be based on the comprehensiveness of the watershed review; the effectiveness
of the program to monitor and control detrimental activities occurring in the watershed; and
the extent to which the supplier of water has maximized land ownership and/or controlled
land use within the watershed.
(4) Disinfection Profiling.
(a) Each supplier of water, community or non-transient non-community water system,
serving fewer than 10,000 people using a surface water source or ground water source under
the direct influence of surface water shall develop a disinfection profile unless the
Department determines that the system’s profile is unnecessary. The Department may
approve the use of a more representative data set for disinfection profiling than the data set
required in 310 CMR 22.20F(4)(c) through (g).
(b) The Department may only determine that a system’s profile is unnecessary if a system’s
TTHM and HAA5 levels are below 0.064 mg/L and 0.048 mg/L, respectively. To determine
these levels, TTHM and HAA5 samples must be collected after January 1, 1998, during the
month with the warmest water temperature, and at the point of maximum residence time in
the distribution system.
(c) A disinfection profile shall be developed using the following three steps:
1. The supplier of water shall collect data for several parameters from the plant as
required in 310 CMR 22.20F(4)(d) over the course of 12 months. If the system serves
between 500 and 9,999 persons the supplier of water must begin to collect data no later
than July 1, 2003. If the system serves fewer than 500 persons the supplier of water must
begin to collect data no later than January 1, 2004;
2. The supplier of water shall use the data to calculate weekly log inactivation as
required in 310 CMR 22.20F(4)(e) and (f); and
3. The supplier of water shall use these weekly log inactivations to develop a
disinfection profile as specified in 310 CMR 22.20F(4)(g).
(d) The supplier of water shall monitor the following parameters to determine the total log
inactivation using the analytical methods in 310 CMR 22.20A(5)(a), once per week on the
same calendar day, over 12 consecutive months:
1. The temperature of the disinfected water at each residual disinfectant concentration
sampling point during peak hourly flow;
2. If the system uses chlorine, the pH of the disinfected water at each residual
disinfectant concentration sampling point during peak hourly flow;
22.20F: continued
3. The disinfectant contact time(s) (“T”) during peak hourly flow; and
4. The residual disinfectant concentration(s) (“C”) of the water before or at the first
customer and prior to each additional point of disinfection during peak hourly flow.
(e) Use the tables in 310 CMR 22.20A(5)(b)3.e. to determine the appropriate CT
value.
The supplier of water shall calculate the total inactivation ratio as follows, and multiply the
value by 3.0 to determine the log inactivation of Giardia lamblia:
1. If the supplier of water uses only one point of disinfectant application, the supplier
of water shall determine the total inactivation ratio for the disinfection segment based on
either of the following methods:
a. Determine one inactivation ratio (CTcalc/CT
) before or at the first customer
during peak hourly flow; or
b. Determine successive CTcalc/CT
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 system must calculate
the total inactivation ratio by determining (CTcalc/CT
) for each sequence and then
add the (CTcalc/CT
) values together to determine (3CTcalc/CT
).
2. If the supplier of water uses more than one point of disinfectant application before
the first customer, the supplier of water shall determine the (CTcalc/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 using the
procedure specified in 310 CMR 22.20F(4)(e)1.b.
(f) If the supplier of water uses chloramines, ozone, or chlorine dioxide for primary
disinfection, the supplier of water shall also calculate the logs of inactivation for Viruses and
develop an additional disinfection profile for Viruses using methods approved by the
Department.
(g) Each supplier of water will use each log inactivation as a data point in the disinfection
profile. The supplier of water will have obtained 52 measurements (one for every week of
the year). This will allow the supplier of water and the Department the opportunity to
evaluate how microbial inactivation varied over the course of the year by looking at all 52
measurements (the Disinfection Profile). The supplier of water shall retain the Disinfection
Profile data in graphic form, such as a spreadsheet, which must be available for review by
the Department as part of a sanitary survey. The supplier of water shall use this data to
calculate a benchmark if they are considering changes to disinfection practices.
(5) Disinfection Benchmark.
(a) A supplier of water serving fewer than 10,000 people using a surface water source or
ground water source under the direct influence of surface water required to develop a
disinfection profile under 310 CMR 22.20F(4), shall develop a Disinfection Benchmark if
the supplier of water decides to make a significant change to the disinfection practice. The
supplier of water shall consult with the Department for approval before implementing a
significant disinfection practice change.
(b) Significant changes to disinfection practice include:
1. Changes to the point of disinfection;
2. Changes to the disinfectant(s) used in the treatment plant;
3. Changes to the disinfection process; or
4. Any other modification identified by the Department.
(c) If the supplier of water is considering a significant change to its disinfection practice,
the supplier of water shall calculate a disinfection benchmark(s) as described in 310 CMR
22.20F(5)(d) and (e) and provide the benchmark(s) to the Department. The supplier of water
may only make a significant disinfection practice change after consulting with and obtaining
the approval of the Department. The system shall submit the following information to the
Department as part of the consultation and approval process:
1. A description of the proposed change,
2. The disinfection profile for Giardia lamblia (and, if necessary, Viruses) and
disinfection benchmark,
3. An analysis of how the proposed change will affect the current levels of disinfection,
and
4. Any additional information requested by the Department.
22.20F: continued
(d) If the supplier of water is making a significant change to its disinfection practice, the
supplier of water shall calculate a disinfection benchmark using the following procedure:
1. Using the data the supplier of water collected to develop the Disinfection Profile,
determine the average Giardia lamblia inactivation for each calendar month by dividing
the sum of all Giardia lamblia inactivations for that month by the number of values
calculated for that month.
2. Determine the lowest monthly average value out of the twelve values. This value
becomes the disinfection benchmark.
(e) If the supplier of water uses chloramines, ozone or chlorine dioxide for primary
disinfection, the supplier of water shall calculate the disinfection benchmark from the data
the system collected for Viruses to develop the disinfection profile in addition to the Giardia
lamblia disinfection benchmark calculated under 310 CMR 22.20F(5)(d). This viral
benchmark shall be calculated in the same manner used to calculate the Giardia lamblia
disinfection benchmark in 310 CMR 22.20F(5)(d).
(6) Combined Filter Effluent Requirements.
(a) Each supplier of water that serves fewer than 10,000 people using a surface water source
or ground water source under the direct influence of surface water is required to filter, and
each supplier of water that utilizes filtration other than slow sand filtration or diatomaceous
earth filtration shall meet the combined filter effluent (CFE) turbidity requirements of
310 CMR 22.20F(6)(b) through (d). If the supplier of water uses slow sand or diatomaceous
earth filtration the supplier of water is not required to meet the CFE turbidity limits of
310 CMR 22.20F, but such supplier of water shall continue to meet the CFE turbidity limits
in 310 CMR 22.20A(4).
(b) Each supplier of water that serves fewer than 10,000 people using a surface water source
or ground water source under the direct influence of surface water is required to filter, and
each supplier of water that utilizes filtration other than slow sand filtration or diatomaceous
earth filtration shall meet two strengthened CFE turbidity limits as follows:
1. The first CFE turbidity limit is a “95 percentile” turbidity limit that the system shall
th
meet in at least 95% of the turbidity measurements taken each month. Measurements
must continue to be taken as described in 310 CMR 22.20A(5)(b)1. and 3. Monthly
reporting shall be completed according to 310 CMR 22.20F(8).
a. If the supplier of water uses conventional filtration or direct filtration, the
turbidity level of representative samples of a system's filtered water shall be 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).
b. If the supplier of water uses “alternative filtration” the turbidity level of
representative samples of the system's filtered water shall be 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. The second CFE turbidity limit is a “maximum” turbidity limit that the system may
not exceed at any time during the month. Measurements shall continue to be taken as
described in 310 CMR 22.20A(5)(b)1. and 3. Monthly reporting shall be completed
according to 310 CMR 22.20F(8)(a). The following is a description of the required
limits for specific filtration technologies:
a. If the supplier of water uses conventional filtration or direct filtration, the
“maximum” turbidity level is one NTU.
b. If the supplier of water uses “alternative filtration” the “maximum” turbidity level
is one NTU.
(c) Each supplier of water that serves fewer than 10,000 people using a surface water source
or ground water source under the direct influence of surface water that uses a system that
consists of alternative filtration (filtration other than slow sand filtration, diatomaceous earth
filtration, conventional filtration, or direct filtration) is required to conduct a demonstration.
The supplier of water shall demonstrate to the Department, using pilot plant studies or other
means, that the system’s filtration, in combination with disinfection treatment, consistently
achieves:
1. 99% removal of Cryptosporidium oocysts;
2. 99.9% removal and/or inactivation of Giardia lamblia cysts; and
3. 99.99% removal and/or inactivation of Viruses.
22.20F: continued
(d) Each supplier of water serving fewer than 10,000 people using a surface water source
or ground water source under the direct influence of surface water that practices lime
softening, may acidify representative CFE turbidity samples prior to analysis using a protocol
approved by the Department.
(7) Individual Filter Turbidity Requirements.
(a) Each supplier of water serving fewer than 10,000 people using a surface water source
or ground water source under the direct influence of surface water that utilizes conventional
filtration or direct filtration, shall conduct continuous monitoring of turbidity for each
individual filter at the filtration facility. The following requirements apply to continuous
turbidity monitoring:
1. Monitoring must be conducted using an approved method in 310 CMR 22.20A(5)(a);
2. Calibration of turbidimeters shall be conducted using procedures specified by the
manufacturer;
3. Results of turbidity monitoring shall be recorded at least every 15 minutes;
4. Monthly reporting must be completed according to 310 CMR 22.20F(8)(a); and
5. Records shall be maintained according to 310 CMR 22.20F(8)(b).
(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 until the
turbidimeter is back on-line. The system has 14 days to resume continuous monitoring
before a violation is incurred.
(c) If the system only consists of one or two, the supplier of water may conduct continuous
monitoring of the CFE turbidity in lieu of individual filter effluent turbidity monitoring.
Continuous monitoring shall meet the same requirements set forth in 310 CMR
22.20F(7)(a)1. through 4. and (b).
(d) If the supplier of water conducts continuous turbidity monitoring, follow-up action is
required as follows:
1. If the turbidity of an individual filter or the turbidity of the CFE for systems with two
filters that monitor CFE in lieu of individual filters exceeds 1.0 NTU in two consecutive
recordings 15 minutes apart, the supplier of water shall report to the Department by the
tenth day of the following month and include the filter number(s), corresponding date(s),
turbidity value(s) which exceeded 1.0 NTU, and the cause (if known) for the
exceedance(s).
2. If the supplier of water was required to report to the Department for three months in
a row and turbidity exceeded 1.0 NTU in two consecutive recordings 15 minutes apart
at the same filter or CFE for systems with two filters that monitor CFE in lieu of
individual filters, the supplier of water shall conduct a self-assessment of the filter(s)
within 14 days of the day the filter exceeded 1.0 NTU in two consecutive measurements
for the third straight month unless a Comprehensive Performance Evaluation (CPE) as
specified in 310 CMR 22.20F(7)(d)3. was required. Systems with two filters that
monitor CFE in lieu of individual filters shall conduct a self-assessment on both filters.
The self-assessment must 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. If a self-assessment is required, the date
that it was triggered and the date that it was completed shall be included.
3. If the supplier of water was required to report to the Department for two months in
a row and turbidity exceeded 2.0 NTU in two consecutive recordings 15 minutes apart
at the same filter or CFE for systems with two filters that monitor CFE in lieu of
individual filters, the supplier of water shall arrange to have a CPE conducted by the
Department no later than 60 days following the day the filter exceeded 2.0 NTU in two
consecutive measurements for the second straight month. If a CPE has been completed
by the Department within the 12 prior months or the supplier of water and the
Department are jointly participating in an ongoing Comprehensive Technical Assistance
(CTA) project at the system, a new CPE is not required. If conducted, a CPE must be
completed and submitted to the Department no later than 120 days following the day the
filter exceeded 2.0 NTU in two consecutive measurements for the second straight month.
22.20F: continued
(e) If the supplier of water practices lime softening, the supplier of water may apply to the
Department for alternative turbidity exceedance levels for the levels specified in 310 CMR
22.20F(7)(d). The supplier of water shall be able to demonstrate to the Department that
higher turbidity levels are due to lime carryover only, and not due to degraded filter
performance.
(8) Reporting and Recordkeeping.
(a) In addition to the reporting and recordkeeping requirements in 310 CMR 22.20A, each
supplier of water who is subject to the requirements of 310 CMR 22.20F shall report the
following information to the Department at the frequency specified, if the supplier of water
is subject to the specific requirement.
1. Combined filter requirements that shall be reported within ten days after the end of
each month shall include:
a. The total number of filtered water turbidity measurements taken during the
month.
b. 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
22.20F(7).
c. The date and value of any turbidity measurements taken during the month which
exceed 1.0 NTU for systems using conventional filtration treatment or direct
filtration, or exceed the maximum level set by the Department 310 CMR 22.20F(7).
2. The individual turbidity requirements that shall be reported within ten days after the
end of each month, except as otherwise provided in 310 CMR 22.20F(8)2.c. and
310 CMR 22.20F(8)2.e., shall include:
a. That the supplier of water conducted individual filter turbidity monitoring during
the month.
b. The filter number(s), corresponding date(s), and turbidity value(s) that exceeded
1.0 NTU during the month, and the cause (if known) for the exceedance(s) but only
in if two consecutive measurements exceeded 1.0 NTU.
c. If a self-assessment is required, the date that it was triggered and the date that it
was completed. If the self-assessment was triggered during the last four days of the
month, the date that it was triggered and the date that it was completed shall be
reported within 14 days after the date the self-assessment was triggered.
d. If a CPE is required and the date that it was triggered.
e. Copy of completed CPE report within 120 days after the CPE was triggered.
3. Disinfection Profiling shall include:
a. Results of optional monitoring that show TTHM levels <0.064 mg/l and HAA5
levels <0.048 mg/l (only if the system wishes to forgo profiling) or that the system
has begun disinfection profiling.
i. For systems serving 500–9,999 by July 1, 2003;
ii. For systems serving fewer than 500 by January 1, 2004.
4. Disinfection Benchmarking shall include: A description of the proposed change in
disinfection, the system’s disinfection profile for Giardia lamblia (and, if necessary,
Viruses) and disinfection benchmark, and an analysis of how the proposed change will
affect the current levels of disinfection anytime a significant change in disinfection
practices is being considered.
(b) Each supplier of water who is subject to the requirements of 310 CMR 22.20F shall, in
addition to recordkeeping requirements under 310 CMR 22.20A(6), maintain records in
accordance with 310 CMR 22.17(12).