310 CMR 22.07G
Per- and Polyfluoroalkyl Substances (PFAS) Monitoring and Analytical Requirements
(1) General Applicability. Every Supplier of Water operating a Community Water System or
Non-transient, Non-community Water System shall be subject to 310 CMR 22.07G(3) through
(17).
(2) Special Applicability for Transient, Non-community Water Systems. Every Supplier of
Water operating a Transient, Non-community Water System shall collect, analyze and report the
results of one sample from each Sampling Point, or alternate sampling location required by the
Department pursuant to 310 CMR 22.07G(4)(a) or (b), no later than September 30, 2022. All
such monitoring shall be performed in compliance with the provisions addressing monitoring
protocols, invalidation of PFAS samples, PFAS analytical requirements, PFAS reporting
requirements, PFAS6 minimum reporting levels and electronic filing requirement set forth in
310 CMR 22.07G(4), (9), (12), (13), (16) and (17).
(3) Per- and Polyfluoroalkyl Substances.
(a) PFAS. PFAS shall mean per- and polyfluoroalkyl substances.
(b) PFAS Detection. PFAS Detection shall mean a concentration of any PFAS measured
in accordance with 310 CMR 22.07G(12) which is greater than or equal to the analytical
laboratory's applicable Minimum Reporting Level (or MRL).
(c) PFAS6. PFAS6 shall mean the sum of the concentrations of the six contaminants listed
in the following table:
CAS No.
Contaminant
1763-23-1
Perfluorooctane Sulfonic Acid (PFOS)
335-67-1
Perfluorooctanoic Acid (PFOA)
355-46-4
Perfluorohexane Sulfonic Acid (PFHxS)
375-95-1
Perfluorononanoic Acid (PFNA)
375-85-9
Perfluoroheptanoic Acid (PFHpA)
335-76-2
Perfluorodecanoic Acid (PFDA)
(d) PFAS6 Maximum Contaminant Level. The PFAS6 Maximum Contaminant Level
(MCL) shall be 0.000020 milligrams per liter (mg/l) or 20 nanograms per liter (ng/l).
(e) Review of PFAS and Drinking Water. Not later than December 31, 2023, and once
every three years thereafter, the Department shall perform a review of relevant developments
in the science, assessment and regulation of PFAS in drinking water for the purpose of
evaluating whether to amend 310 CMR 22.07G(3) in light of any advancements in analytical
or treatment technology, toxicology and/or any other relevant information. Information about
this review shall be made available to the public.
(4) Monitoring Protocols. For the purpose of determining compliance with the PFAS6 MCL
set forth in 310 CMR 22.07G(3)(d), monitoring shall be conducted as follows:
(a) Single Source Entry Points. Each Public Water System that draws water from a single
source shall take a minimum of one sample at every entry point to the Distribution System
which is representative of each of its sources after treatment (Sampling Point). Each sample
shall be taken at the same Sampling Point, unless the Department determines, based upon
local conditions (e.g., facility design), that an alternate sampling location(s) would be more
representative of each source or treatment plant.
22.07G: continued
(b) Multiple Source Entry Points. Any Public Water System that draws water from more
than one source, where the sources are combined before distribution, shall sample at every
entry point to the Distribution System which is representative of all such combined sources
after treatment (Sampling Point) during periods of normal operating conditions (i.e., when
water representative of all sources is being used). If all sources are not operated
simultaneously under normal operating conditions, then additional samples shall be collected
representing each source that is operated alone and/or each combination of sources that are
operated together. Each sample shall be taken at the same Sampling Point unless the
Department determines, based upon local conditions (e.g., facility design), that an alternate
sampling location(s) would be more representative of each source or treatment plant.
(c) Consecutive Systems. Unless required by the Department to evaluate PFAS levels,
each Consecutive Public Water System shall be exempt from conducting compliance
monitoring for PFAS under 310 CMR 22.07G for its purchased portion of water, provided
that the Public Water System from which the water is obtained has conducted the monitoring
required under 310 CMR 22.07G.
(5) Initial Monitoring.
(a) Applicability. 310 CMR 22.07G(5) shall apply to each Sampling Point, or alternate
sampling location required by the Department pursuant to 310 CMR 22.07G(4)(a) or (b),
where:
1. there have been no PFAS Detections;
2. there has been a PFAS Detection, but the average of the PFAS6 in such detection and
of PFAS6 in an associated Confirmatory Sample is less than or equal to 0.000010 mg/l;
or
3. subsequent to a PFAS Detection described in 310 CMR 22.07G(5)(a)2., there have
been no PFAS Detection(s) where PFAS6 as determined for such detections is greater
than 0.000010 mg/l.
(b) Frequency and Timing.
1. Except as provided in 310 CMR 22.07G(5)(b)2. or 3., for each such location required
to be sampled pursuant to 310 CMR 22.07G(5), four consecutive quarterly samples shall
be collected and each such sample shall be analyzed for PFAS in accordance with
310 CMR 22.07G(12). Each sample shall be collected the first month of every quarter
during initial monitoring. A Supplier of Water serving the specified population shall
commence initial monitoring on the date set forth in 310 CMR 22.07G(5)(b)1.a.
through c.:
a. greater than 50,000 individuals, January 1, 2021;
b. 50,000 individuals or fewer, but greater than 10,000 individuals, April 1, 2021;
or
c. 10,000 or fewer individuals, October 1, 2021.
2. If a Supplier of Water meets any of the following conditions after the applicable
commencement date described in 310 CMR 22.07G(5)(b)1., it shall commence initial
monitoring of such locations within the first full calendar quarter of delivering water to
the public:
a. begins operation of a new Public Water System; or
b. puts a New Source on-line.
3. If a Supplier of Water reactivates an existing source or opens a Seasonal System after
the applicable commencement date described in 310 CMR 22.07G(5)(b)1., it shall
commence initial monitoring of such locations within the first month of delivering water
to the public.
(c) Waivers. Any Public Water System subject to 310 CMR 22.07G(5), all of whose
analytical results for the first two quarters of monitoring described in 310 CMR 22.07G(5)(b)
are below the applicable MRLs, may submit a written request to waive the third and fourth
quarters of such monitoring, subject to the Department's written approval based upon a
determination that there is no known or suspected PFAS contamination in the vicinity of the
Public Water System or its sources of water.
(6) Routine Monitoring.
(a) Applicability. 310 CMR 22.07G(6) shall apply to any Sampling Point, or alternate
sampling location required by the Department pursuant to 310 CMR 22.07G(4)(a) or (b), at
which there are no PFAS Detections during initial monitoring or during three years of annual
monitoring.
22.07G: continued
(b) Frequency and Timing. A Public Water System may reduce the monitoring frequency
for such locations in each subsequent Compliance Period to the following number of quarters
all within any one calendar year, the selection of which quarters shall be subject to the
Department's prior written approval:
1. if serving more than 3,300 individuals, to a minimum of one sample taken in the first
month of any two selected quarters; or
2. if serving fewer than or equal to 3,300 individuals, to a minimum of one sample
taken in the first month of any one selected quarter.
(c) Waivers.
1. Eligibility and Duration. Commencing January 1, 2023, any Supplier of Water
subject to 310 CMR 22.07G(6) may submit a written request to the Department for a
waiver from the monitoring requirements set forth in 310 CMR 22.07G(6)(b)1. or 2. for
up to a single Compliance Period. A Supplier of Water may reapply to the Department
for a waiver for each successive Compliance Period, provided however that sampling
shall occur at least once during the first Compliance Period of each successive
Compliance Cycle.
2. Application. Each waiver request made pursuant to 310 CMR 22.07G(6)(c)1. shall
include a description of land uses (both current and prior) within the Watershed, Zone
II or IWPA, that may potentially contribute PFAS to the Public Water System's source(s)
of water supply including, without limitation, all known manufacture, storage, use or
disposal of PFAS or PFAS containing materials.
3. Basis. Approval of a waiver request made pursuant to 310 CMR 22.07G(6)(c)1. shall
be subject to the Department's written determination that there is no reason to suspect
PFAS contamination in the vicinity of the Public Water System or its sources of water.
Such determination shall be based on the information submitted pursuant to 310 CMR
22.07G(6)(c)2. and any other relevant information known to the Department including,
without limitation, the following factors:
a. previous analytical results;
b. proximity of the Public Water System or its sources of water to potential sources
of contamination including but not limited to manufacturing, distribution, or storage
facilities; hazardous and solid waste landfills and other waste handling or treatment
facilities; locations where fires are known to have been extinguished with aqueous
film forming foam; wastewater treatment plants; airports; current and former military
bases; facilities where fire training occurs; and areas where the application of
bio-solids occurs;
c. proximity of the Public Water System or its sources of water to known spills or
leaks of chemicals including, but not limited to, any release, site or disposal site as
defined under 310 CMR 40.0000: Massachusetts Contingency Plan;
d. environmental persistence and transport of PFAS;
e. how well the source(s) of water supply is protected against contamination due to
such factors as the depth of the well, the type of soil, the integrity of the well casing,
and other relevant protective measures;
f. completed remediation activities that removed sources of PFAS;
g. source operations (e.g., manifold or seasonal sources, blending, flow rates); and
h. use of existing treatment processes which have the potential to reduce PFAS
concentrations in the finished water.
(7) PFAS Detections.
(a) Applicability. 310 CMR 22.07G(7) shall apply to any Sampling Point, or alternate
sampling location required by the Department pursuant to 310 CMR 22.07G(4)(a) or (b),
following:
1. the first PFAS Detection during either initial or routine monitoring;
2. the second or later PFAS Detection during initial monitoring where PFAS6 as
determined for such second or later detection is greater than 0.000010 mg/l;
3. the second or later PFAS Detection during routine monitoring where PFAS6 as
determined for such second or later detection is greater than 0.000010 mg/l, unless the
Department determines in writing that such location is Reliably and Consistently Below
the MCL; or
4. the receipt by the Department of an analytical result during quarterly or annual
monitoring which the Department determines is outside the historic range of PFAS
results.
(b) Reporting. Any PFAS Detection described in 310 CMR 22.07G(7)(a)1., 2., or 3. shall
be reported to the Department within seven days of receipt of such result from the laboratory.
22.07G: continued
(c) Confirmatory Sampling. The Supplier of Water shall obtain a Confirmatory Sample for
any analytical result described in 310 CMR 22.07G(7)(a), as soon as possible after receipt
of such result from the laboratory or notification from the Department, as applicable, and no
later than two weeks from such date. Provided, however, a Supplier of Water may request
a one-time extension not to exceed two weeks for obtaining such Confirmatory Sample,
using a form specified by the Department, upon a demonstration of need due to
circumstances beyond its control (e.g., system design, etc.) to the satisfaction of and at the
sole discretion of the Department.
(d) Source Sampling. If a PFAS Detection described in 310 CMR 22.07G(7)(a)1., 2. or 3.
represents multiple sources, then samples representing the individual source water shall also
be collected and analyzed for PFAS.
(e) Public Education. Any Supplier of Water subject to 310 CMR 22.07G(7), where there
has been a PFAS Detection and the average of such detection and an associated Confirmatory
Sample exceeds the PFAS6 MCL, shall provide public education materials regarding the
exceedance in accordance with the following requirements:
1. notice of the exceedance shall be provided using materials approved by the
Department;
2. such materials shall be provided to all persons served by the affected Public Water
System, including without limitation consumers who do not receive water bills;
3. such materials shall be provided as soon as practical and no later than 30 days after
receipt of Confirmatory Sample results from the laboratory;
4. in any community where such Supplier of Water's consumers include:
a. either:
i. 10% or more non-English speaking residents who speak a common language;
or
ii. more than 1000 non-English speaking residents who speak a common
language, such materials must contain information in the language(s) appropriate
for each such group of residents regarding the importance of the notice.
b. 25% or more non-English speaking residents who speak a common language,
such materials must contain a statement in the appropriate language(s) for each such
group of residents which includes a telephone number or address where those
residents may contact the affected Public Water System to obtain a translated copy
of the materials or assistance in the appropriate language(s).
5. such materials shall be provided by mail and/or other method approved by the
Department (e.g., a Non-transient Non-community Water System may be permitted to
post the materials in one or more conspicuous locations in the facility for a minimum
number of days);
6. such materials shall include all results from both the PFAS Detection and the
Confirmatory Sample; the average PFAS6 concentration of the samples; the PFAS6
MCL as provided in 310 CMR 22.07G(3)(d) and the definition of MCL as provided in
310 CMR 22.02(1); an explanation of the health effects of PFAS6; steps consumers can
take to reduce exposure to PFAS in drinking water; and contact information for the
Supplier of Water;
7. until either the Public Water System obtains a monitoring result at or below the
PFAS6 MCL at such locations as described in 310 CMR 22.07G(7)(a) or the Supplier
of Water takes the contaminated source(s) off-line:
a. if such materials were mailed, updated materials shall be re-mailed quarterly;
b. if such materials were posted, for an approved minimum number of days, updated
materials shall be re-posted quarterly for the same minimum number of days;
c. if such materials were published in a local newspaper, updated materials shall be
re-published quarterly; and/or
d. if such materials were provided by other Department-approved methods, updated
materials shall be provided quarterly by the same methods; and
8. a copy of such materials shall be submitted to the Department upon initial and each
subsequent issuance if required by 310 CMR 22.07G(7)(e)7. along with a written
certification by the Supplier of Water that the materials have been distributed in
compliance with 310 CMR 22.07G(7)(e)1. through 6.
(8) Increased Monitoring Frequency Following PFAS Detection.
(a) Applicability. 310 CMR 22.07G(8) shall apply to each Sampling Point, or alternate
sampling location required by the Department pursuant to 310 CMR 22.07G(4)(a) or (b), at
which there has been a PFAS Detection.
22.07G: continued
(b) Monthly Monitoring.
1. Except as provided in 310 CMR 22.07G(8)(b)2., a Supplier of Water shall monitor
such locations on a monthly basis to determine compliance with the PFAS6 MCL as per
310 CMR 22.07G(10), if:
a. there has been a PFAS Detection and the average of PFAS6 in such detection and
of PFAS6 in an associated Confirmatory Sample is greater than 0.000010 mg/l; or
b. the Department determines in writing that a location subject to quarterly or annual
monitoring is no longer Reliably and Consistently Below the MCL.
2. After completing the first quarter of monthly monitoring pursuant to 310 CMR
22.07G(8)(b)1., a Supplier of Water who is in violation of the PFAS6 MCL, determined
as per 310 CMR 22.07G(10), may request written approval from the Department to use
the results from a single sample taken in the first month of each subsequent quarter to
determine compliance with the PFAS6 MCL rather than using the average of the three
monthly samples otherwise required, subject to the following:
a. upon such written approval, if any such single sample alone exceeds the PFAS6
MCL, such Supplier of Water shall be in violation of the PFAS6 MCL immediately
and shall provide public notice in accordance with 310 CMR 22.16; and
b. if any such single sample is less than or equal to the PFAS6 MCL, then such
Supplier of Water shall continue monthly monitoring during the remaining two
months of the quarter and compliance with the PFAS6 MCL shall be determined as
per 310 CMR 22.07G(10).
(c) Quarterly Monitoring. If any such location has had PFAS treatment installed and the
Department determines in writing that such location is Reliably and Consistently Below the
MCL, then the Supplier of Water shall monitor that location in the first month of each
quarter.
(d) Annual Monitoring. A Supplier of Water shall monitor such locations on an annual
basis during the first month of the calendar quarter that previously yielded the highest
analytical result. A Supplier of Water shall conduct this annual monitoring if:
1. all of the following are true:
a. all four quarters of initial monitoring pursuant to 310 CMR 22.07G(5)(a) have
been completed;
b. the first PFAS Detection occurred during such initial monitoring and the average
of PFAS6 in such detection and of PFAS6 in an associated Confirmatory Sample is
less than or equal to 0.000010 mg/l; and
c. for any second or later PFAS Detection occurring during such initial monitoring
with PFAS6 greater than 0.000010 mg/l, the average of PFAS6 in such second or
later detection and of PFAS6 in the Confirmatory Sample associated with each such
detection is less than or equal to 0.000010 mg/l;
2. the Department determines in writing that a location subject to monthly monitoring
under 310 CMR 22.07G(8)(b), without the installation of PFAS treatment, is Reliably
and Consistently Below the MCL;
3. the Department determines in writing that a location subject to quarterly monitoring
under 310 CMR 22.07G(8)(c), taking into consideration any documentation provided by
such Supplier of Water and any other relevant factors, would be Reliably and
Consistently Below the MCL without PFAS treatment; or
4. a location subject to routine monitoring under 310 CMR 22.07G(6):
a. has its first PFAS Detection and the average of PFAS6 in such detection and of
PFAS6 in an associated Confirmatory Sample is less than or equal to 0.000010 mg/l;
or
b. has a second or later PFAS Detection with a PFAS6 less than or equal to
0.000010 mg/l and the Department determines in writing that such location is not
Reliably and Consistently Below the MCL.
(9) Invalidation of PFAS Samples. All PFAS results shall be subject to the Department's
review and may be invalidated where the associated quality control information indicates a
failure in sample collection, sample preparation or analytical measurement. Invalidated results
shall not be used in determining compliance with the PFAS6 MCL established in 310 CMR
22.07G(3)(d). Unless waived in writing by the Department as unnecessary (e.g., based upon the
frequency of ongoing monitoring), a Supplier of Water shall collect and analyze a replacement
sample for each invalidated result of a PFAS listed in 310 CMR 22.07G(3)(c).
22.07G: continued
(10) PFAS6 Compliance Calculations. Compliance with the PFAS6 MCL established in
310 CMR 22.07G(3)(d) shall be determined in accordance with the requirements set forth below.
If any one sampling location is in violation, then the Public Water System shall be considered
in violation.
(a) For a Supplier of Water monitoring monthly, compliance shall be determined once per
calendar quarter:
1. after completing a full quarter of monthly monitoring; and
2. by calculating a quarterly average of that quarter's monthly compliance monitoring
result(s) at each Sampling Point, or alternate sampling location required by the
Department pursuant to 310 CMR 22.07G(4)(a) or (b), rounded to the same number of
significant figures as the Maximum Contaminant Level.
(b) The quarterly average calculation requirements are as follows:
1. If multiple compliance monitoring samples are collected in any given calendar
month, then the results of those samples shall be averaged in order to establish a single
representative contaminant concentration for that calendar month. (An initial sample and
a Confirmatory Sample collected in the same month, shall be averaged both for the
purpose of determining whether additional monthly samples would be required, and for
the purpose of determining the representative contaminant concentration for the first
month. An initial sample and a Confirmatory Sample collected in different months shall
still be averaged for the purpose of determining whether additional monthly samples
would be required, but shall not be averaged for the purpose of determining the
representative contaminant concentration for the first month. Instead, because the
Confirmatory Sample was collected in the second month, on the one hand if no other
sample was collected in the second month, then it shall serve as the second month's
representative contaminant concentration. But, on the other hand if a second sample was
collected during the second month, then there would be two samples collected during the
second month, namely the Confirmatory Sample (for the first month's initial sample) and
the second month's sample, and they shall be averaged together to determine the second
month's representative contaminant concentration.)
2. If any Supplier of Water fails to collect the required number of samples, compliance
shall be determined based on the total number of samples collected. (E.g., if no samples
were collected in one month, then the quarterly average would be the sum of the
representative contaminant concentrations from the other two months, divided by two.)
3. If an analytical result is less than the MRL, then the quarterly average shall be
calculated using zero as the concentration for that PFAS.
(c) A Supplier of Water monitoring quarterly or less frequently who detects PFAS6 within
its Public Water System shall not be in violation, except as provided in 310 CMR
22.07G(10)(d), until:
1. it has conducted monthly sampling pursuant to 310 CMR 22.07G(8)(b); and
2. a calculation made in accordance with 310 CMR 22.07G(10)(a) and (b) would result
in a violation.
(d) If any sample result would cause the quarterly average to exceed the PFAS6 MCL at any
Sampling Point, or alternate sampling location required by the Department pursuant to
310 CMR 22.07G(4)(a) or (b), then the Public Water System shall be in violation
immediately and shall be subject to the requirements 310 CMR 22.07G(11).
(11) When a Quarterly Average Exceeds the PFAS6 MCL. If a quarterly average calculated
pursuant to 310 CMR 22.07G(10)(a) and (b) and rounded to the same number of significant
figures as the Maximum Contaminant Level, exceeds the PFAS6 MCL, then the Supplier of
Water shall:
(a) report to the Department in accordance with 310 CMR 22.15,
(b) provide public notice in accordance with 310 CMR 22.16, and
(c) comply with the requirements of 310 CMR 22.03(14) and such other applicable
provisions of 310 CMR 22.00, as specified by the Department.
(12) PFAS Analytical Requirements.
(a) Methods of Analysis. Analysis for PFAS listed in 310 CMR 22.07G(3)(c) shall be
conducted using either of the following EPA methods:
1. Method 537. U.S. Environmental Protection Agency September 2009.
Determination of Selected Perfluorinated Alkyl Acids in Drinking Water by Solid Phase
Extraction and Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS). Ver.
1.1. EPA Document #: EPA/600/R-08/092; or
22.07G: continued
2. Method 537.1. U.S. Environmental Protection Agency November 2018.
Determination of Selected Per- and Polyfluorinated Alkyl Substances in Drinking Water
by Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry
(LC/MS/MS). Ver. 1.0. EPA Document #: EPA/600/R-18/352.
(b) Scope of Analysis. All samples analyzed pursuant to 310 CMR 22.07G shall be
analyzed for the full scope of PFAS covered by the method selected in 310 CMR
22.07G(12)(a).
(13) PFAS Reporting Requirements. All analytical results, for all PFAS within the scope of
the analytical method selected in 310 CMR 22.07G(12)(a), whether obtained pursuant to a
requirement of 310 CMR 22.00 or on a voluntary basis, shall be reported to the Department in
accordance with 310 CMR 22.15.
(14) Use of Previously Collected PFAS Data.
(a) Eligibility. A Supplier of Water, prior to the applicable commencement date of initial
monitoring specified in 310 CMR 22.07G(5)(b)1., may request the Department's written
approval to substitute monitoring data which was obtained during different calendar quarters
and prior to such commencement date for up to an equivalent number of sequential quarters
of initial monitoring otherwise required pursuant to 310 CMR 22.07G(5).
(b) Basis of Approval. Such approval shall be based upon a determination as to whether
the substitute monitoring data was collected and analyzed in a manner consistent with or
otherwise equivalent to the requirements of 310 CMR 22.07G. A Supplier of Water shall
notify the Department, prior to the commencement date of initial monitoring specified in
310 CMR 22.07G(5)(b)1., of its intention to substitute such approved monitoring data.
(c) Requirements following Notification. Following the notification required by 310 CMR
22.07G(14)(b), such Supplier of Water shall be subject to the requirements of 310 CMR
22.07G, subject to any Department approved modification taking into account any actions
the Supplier of Water has taken in response to such substitute monitoring data (e.g., public
notification, installation of treatment, etc.), as if the analytical results for such approved
monitoring data were received on the date of such notification.
(15) Monitoring Schedules. A Supplier of Water shall monitor its Public Water System during
each Compliance Period in accordance with the requirements 310 CMR 22.07G, unless
otherwise directed in writing by the Department based on emergency considerations, laboratory
capacity, and Public Water System operational considerations.
22.07G: continued
(16) PFAS6 Minimum Reporting Levels. Laboratories conducting PFAS analysis for each
contaminant listed at 310 CMR 22.07G(3)(c) shall be capable of obtaining individual MRLs less
than or equal to 0.0000020 mg/l or 2.0 ng/l.
(17) Electronic Filing Requirement. All analytical results required to be submitted to the
Department pursuant to 310 CMR 22.07G shall be made by electronic submission, in accordance
with 310 CMR 22.03(13).