310 CMR 22.07A
Synthetic Organic Chemicals (SOC) Sampling and Analytical Requirements
(1) Synthetic Organic Chemicals MCLs. The following maximum contaminant levels for
organic contaminants apply to community water systems and non-transient, non-community
water systems.
CAS No.
Contaminant
MCL (mg/l)
(a)
15972-60-8
Alachlor
(b)
Reserved
(c)
Reserved
(d)
Reserved
(e)
1912-24-9
Atrazine
(f)
1563-66-2
Carbofuran
(g)
57-74-9
Chlordane
(h)
96-12-8
Dibromochloropropane
(i)
94-75-7
2,4-D
(j)
72-20-80
Endrin
(k)
106-93-4
Ethylene dibromide
(l)
76-44-8
Heptachlor
(m)
1024-57-3
Heptachlor epoxide
(n)
58-89-9
Lindane
(o)
72-43-5
Methoxychlor
(p)
1336-36-3
Polychlorinated biphenyls
(q)
87-86-5
Pentachlorophenol
(r)
8001-35-2
Toxaphene
(s)
93-72-1
2,4,5-TP
(t)
50-32-8
Benzo(a)pyrene
(u)
75-99-0
Dalapon
(v)
103-23-1
Di(2-ethylhexyl) adipate
(w)
117-81-7
Di(2-ethylhexyl) phthalate
(x)
88-85-7
Dinoseb
(y)
85-00-7
Diquat
(z)
145-73-3
Endothall
(aa)
1071-53-6
Glyphosate
(bb)
118-74-1
Hexachlorobenzene
(cc)
77-47-4
Hexachlorocyclopentadiene
(dd)
23135-22-0
Oxamyl (Vydate)
(ee)
1918-02-1
Picloram
(ff)
122-34-9
Simazine
(gg)
1746-01-6
2,3,7,8-TCDD(Dioxin)
3x10-8
(2) SOC Sampling Requirements. Beginning with the initial compliance period, analysis of the
contaminants listed in 310 CMR 22.07A(1)(a) through (gg) for the purposes of determining
compliance with the maximum contaminant level shall be conducted as follows:
(a) SOC Ground Water Monitoring Protocols. Groundwater systems shall take a minimum
of one sample at every entry point to the distribution system which is representative of each
well after treatment (sampling point). Each sample must be taken at the same sampling point
unless conditions make another sampling point more representative of each source or
treatment plant.
(b) SOC Surface Water Monitoring Protocols. Surface water systems [Note: For purposes
of 310 CMR 22.07A(2)(b), surface water systems include systems with a combination of
surface and ground sources.) shall take a minimum of one sample at points in the distribution
system that are representative of each source or at each entry point to the distribution system
after treatment (sampling point). Each sample must be taken at the same sampling point
unless conditions make another sampling point more representative of each source or
treatment plant.
(c) Multiple Sources. If the system draws water from more than one source and the sources
are combined before distribution, the system must sample at an entry point to the distribution
system during periods of normal operating conditions (i.e., when water representative of all
sources is being used).
22.07A: continued
(d) Consecutive System Monitoring. Public water systems that obtain water from another
public water system are exempt from conducting compliance monitoring for the purchased
portion of the system for the organic chemicals (SOC) under 310 CMR 22.07A, provided that
the system from which the water is obtained has conducted the analyses required under
310 CMR 22.07A, unless otherwise specified by the Department.
(3) SOC Monitoring Frequency.
(a) Each community and non-transient non-community water system shall take four
consecutive quarterly samples for each contaminant listed in 310 CMR 22.07A(1) during
each compliance period beginning with the compliance period starting January 1, 1993.
(b) Systems serving more than 3,300 persons which do not detect a contaminant in the
initial compliance period, may reduce the sampling frequency to a minimum of two quarterly
samples in one year during each repeat compliance period.
(c) Systems serving less than or equal to 3,300 persons which do not detect a contaminant
in the initial compliance period may reduce the sampling frequency to a minimum of one
sample during each repeat compliance period.
(4) SOC Sampling Waivers. Each community and non-transient water system may apply to the
Department for a waiver from the requirement of 310 CMR 22.07A(3). A system must reapply
for a waiver for each compliance period.
Basis of an SOC Sampling Waiver. The Department may grant a waiver after evaluating the
following factor(s): Knowledge of previous use (including transport, storage, or disposal) of the
contaminant within the watershed or zone of influence of the system. If a determination by the
Department reveals no previous use of the contaminant within the watershed or Zone II or
IWPA, a waiver may be granted. If previous use of the contaminant is unknown or it has been
used previously, then the following factors shall be used to determine whether a waiver is
granted.
(a) Previous analytical results.
(b) The proximity of the system to a potential point or non-point source of contamination.
Point sources include spills and leaks of chemicals at or near a water treatment facility or at
manufacturing, distribution, or storage facilities, or from hazardous and municipal waste
landfills and other waste handling or treatment facilities. Non-point sources include the use
of pesticides to control insect and weed pests on agricultural areas, forest lands, home and
gardens, and other land application uses.
(c) The environmental persistence and transport of the pesticide or PCBs.
(d) How well the water source is protected against contamination due to such factors as
depth of the well and the type of soil and the integrity of the well casing and other protective
measures considered relevant by the Department.
(e) Elevated nitrate levels at the water supply source.
(f) Use of PCBs in equipment used in the production, storage, or distribution of water (i.e.,
PCBs used in pumps, transformers, etc.).
(5) Detection of an SOC. If an organic contaminant listed in 310 CMR 22.07A(1) is detected
(as defined by 310 CMR 22.07A(16) in any sample, then:
(a) Each system shall report to the Department within seven days and shall monitor
quarterly at each sampling point which resulted in a detection.
(b) The Department may decrease the quarterly monitoring requirement specified in
310 CMR 22.07A(5)(a) provided it has determined that the system is reliably and
consistently below the maximum contaminant level. In no case shall the Department make
this determination unless a groundwater system takes a minimum of two quarterly samples
and a surface water system takes a minimum of four quarterly samples.
22.07A: continued
(c) After the Department determines the system is reliably and consistently below the
maximum contaminant level the Department may allow the system to monitor annually.
Systems which monitor annually must monitor during the quarter that previously yielded the
highest analytical result.
(d) Systems which have three consecutive annual samples with no detection of a
contaminant may apply to the Department for a waiver as specified in 310 CMR 22.07A(4).
(e) If monitoring results in detection of one or more of certain related contaminants
(heptachlor, heptachlor epoxide), then subsequent monitoring shall analyze for all related
contaminants.
(6) MCL Violation and Reliably/consistently below the MCL. Systems which violate the
requirements of 310 CMR 22.07A(1) as determined by 310 CMR 22.07A(9) must monitor
quarterly. After a minimum of four quarterly samples show the system is in compliance and the
Department determines the system is reliably and consistently below the MCL, as specified in
310 CMR 22.07A(9), the system shall monitor at the frequency specified in 310 CMR
22.07A(5)(c).
(7) SOC Confirmation Sampling. The Department may require a confirmation sample for
positive or negative results. If a confirmation sample is required by the Department, the result
must be averaged with the first sampling result and the average used for the compliance
determination as specified by 310 CMR 22.07A(9). The Department has discretion to delete
results of obvious sampling errors from this calculation.
(8) Composite SOC Sampling. The total number of samples which must be analyzed may be
reduced by compositing samples. Composite samples from a maximum of five sampling points
are allowed provided that the detection limit of the method used for analysis is less than one-fifth
of the MCL and none of the samples to be composited are representative of multiple sources.
Compositing of samples must be approved by the Department and must be done in the laboratory
and analyzed within the holding times specified by EPA-814B-92-002, Change 2 - September
1992 Manual for the Certification of Laboratories Analyzing Drinking Water, third edition.
Compositing of sources with previous detections greater than the detection limit is not allowed,
unless otherwise authorized by the Department.
(a) If the concentration in the composite sample exceeds the detection limit for one or more
contaminants listed in 310 CMR 22.07A(1), then a follow-up sample must be taken and
analyzed from each sampling point included in the company within 14 days after completion
of the composite analysis or before the holding time of the initial sample is exceeded,
whichever is sooner.
(b) If duplicates of the original sample taken from each sampling point used in the
composite are available, the system may use these duplicates instead of resampling. The
duplicate must be analyzed and the results reported to the Department within 14 days of
collection.
(c) If the population served by the system is >3,300 persons, then compositing may only be
permitted by the Department at sampling points within a single system. In systems serving
<3,300 persons, the Department may permit compositing among different systems provided
the 5-sample limit is maintained.
(9) SOC Compliance Calculations. Compliance with 310 CMR 22.07A(1) shall be determined
based on the analytical results obtained at each sampling point. If one sampling point is in
violation of an MCL, the system is in violation of the MCL.
(a) Greater than Annual. For systems monitoring more than once per year, compliance with
the MCL is determined by a running annual average at each sampling point.
(b) Annual or Less. Each supplier of water monitoring annually or less frequently whose
sample result exceeds the regulatory detection level as defined by 310 CMR 22.07A(16)
must begin quarterly sampling. The system will not be considered in violation of the MCL
until it has completed one year of quarterly sampling.
22.07A: continued
(c) If any sample result will cause the running annual average to exceed the MCL at any
sampling point, the system is out of compliance with the MCL immediately.
(d) If a supplier of water fails to collect the required number of samples, compliance will
be based on the total number of samples collected.
(e) If a sample result is less than the detection limit, zero will be used to calculate the annual
average.
(f) Average Exceeding SOC MCLs. When the average of four analyses made pursuant to
310 CMR 22.07A(5), rounded to the same number of significant figures as the maximum
contaminant level for the substance in question, exceeds the maximum contaminant level,
the supplier of water shall report to the Department pursuant to 310 CMR 22.15 and give
public notice to the public pursuant to 310 CMR 22.16. Monitoring after public notification
shall be at a frequency designated by the Department and shall continue until the maximum
contaminant level has not been exceeded in two successive samples or until a monitoring
schedule as condition to variance, exemption or enforcement action shall become effective.
(10) SOC Analytical Methods. Analysis for the contaminants listed in 310 CMR 22.07A(1)
shall be conducted using the following EPA methods or their equivalent as approved by EPA.
Methods 508A and 515.1 are contained in Methods for the Determination of Organic
Compounds in Drinking Water, EPA-600/4-88-039, December 1988, Revised, July 1991,
Methods 547, 550 and 550.1 are in, Methods for the Determination of Organic Compounds in
Drinking Water - Supplement I, EPA/600-4-90-020, July 1990. Methods 548.1, 549.1, 552.1 and
555 are in, Methods for the Determination of Organic Compounds in Drinking Water -
Supplement II, EPA/600/R-92/129, August 1992. Methods 502.2, 504.1, 505, 506, 507, 508,
508.1, 515.2, 524.2, 525.2, 531.1, 551.1 and 552.2 are in Methods for the Determination of
Organic Compounds in Drinking Water – Supplement III, EPA/600/R-95-131, August 1995.
Method 1613 is titled “Tetra-through Octa-Chlorinated Dioxins and Furans by Isotope-Dilution
HRGC/HRMS”, EPA/821-B-94-005, October 1994. These documents are available from the
National Technical Information Service, NTIS PB91-231480, PB91-146027, PB92-27703,
PB95-261616 and PB95-104774 (respectively), U.S. Department of Commerce, 5285 Port Royal
Road, Springfield, VA 22161. The phone number is 800-553-6847. The phone number is 513-
569-7586. Method 6610 is contained in Standard Methods for the Examination of Water and
Wastewater 18 Edition Supplement, 1994, or with the 19 edition (1995) or 20 edition (1998),
th
th
th
any of these three editions may be used. Method 6651 is contained in Standard Methods for the
Examination of Water and Wastewater 18 Edition, (1992), 19 edition (1995), or 20 edition
th
th
th
(1998); any of these three editions may be used. The APHA documents are available from
American Public Health Association, 1015 Fifteenth Street NW, Wash., D.C. 20005. Other
required analytical test procedures germane to the conduct of these analyses are contained in
Technical Notes on Drinking Water Methods, EPA/600/R-94-173, October 1994, NTIS PB95-
104766. EPA Methods 515.3 and 549.2 are available from U.S. Environmental Protection
Agency, National Exposure Research Laboratory [NERL]-Cincinnati, 26 West Martin Luther
King Drive, Cincinnati, OH 45268 ASTM Methods D 5317-93, 98 (Reapproved 2003) is
available in the Annual Book of ASTM Standards, (1999), Vol. 11.02, ASTM International, 100
Barr Harbor Drive, West Conshohocken, PA 19428, any edition containing the cited version of
the methods may be used. EPA Methods 515.4, “Determination of Chlorinated Acids in
Drinking Water by Liquid-Liquid Microextraction, Derivatization and Fast Gas
Chromatrography with Electron Capture Detection”, Revision 1.0, April 2000, EPA/815/B-
00/001 and EPA Methods 552.3, “Determination of Haloacetic Acids and Dalapon in Drinking
Water by Liquid-Liquid Microextraction, Derivatization, and Gas Chromatography with Electron
Capture Detection”, Revision 1.0, July 2003, EPA 815-B-03-002, can be accessed and
downloaded directly online at http://www.epa/gov/safewater/methods/sourcalt.html. Syngenta
Method AG-625, “Atrazine in Drinking Water by Immunoassay”, February 2001, is available
from Syngenta Crop Protection, Inc., 410 Swing Road, P.O. Box 18300, Greensboro, NC 27419.
Telephone: 336-632-6000. Method 531.2 “Measurement of N-methylcarbamoyloximes and N-
methylcarbamoyloximes and N-methylcarbamates in Water by Direct Aqueous Injection HPLC
with Postcolumn Derivatization”, Revision 1., September 2001, EPA 815-B-01-002, can be
a c c e s s e d
a n d
d o w n l o a d e d
d i r e c t l y
o n l i n e
a t
http://www.epa.gov/safewater/methods/sourcult.htnml.
22.07A: continued
Contaminant
EPA Method
SM
ASTM
Other
2,3,7,8-TCDD(dioxin)
2,4-D (as acid, salts and esters)515.2,555,515.1,
515.3, 515.4
D5317-93,98
(Reapproved 2003).
2,4,5-TP (Silvex)
515.2, 555, 515.1,
515.3, 515.4
D5317-93, 98
(Reapproved 2003).
Alachor
505, 507, 525.2,
508.1, 551.1
Atrazine
505, 507, 525.2,
508.1, 551.1
Syngenta AG-6254
Benzo(a)pyrene
525.2, 550, 550.1
Carbofuran
531.1, 531.2
Chlordane
505, 508, 525.2, 508.1
Dalapon
552.1, 515.1, 515.3,
552.2, 515.4
Di(2-ethylhexyl)adipate
506, 525.2
Di(2-ethylhexyl)phthalate
506, 525.2
Dibromochloropropane
(DBCP)
504.1, 551.1
Dinoseb
515.2, 555, 515.1,
515.3, 515.4
Diquat
Endothall
Endrin
505, 508, 525.2,
508.1, 551.1
Ethylene dibromide (EDB)
504.1, 551.1
Glyphosate
Heptachlor
505, 508, 525.2,
508.1, 551.1
Heptachlor Epoxide
505, 508, 525.2,
508.1, 551.1
Hexachlorobenzene
505, 508, 525.2,
508.1, 551.1
Hexachloro-
cyclopentadiene
505, 508, 525.2,
508.1, 551.1
Lindane
505, 508, 525.2,
508.1, 551.1
Methoxychlor
505, 508, 525.2,
508.1, 551.1
Oxamyl
531.1, 531,2
PCBs(as decachlorobiphenyl) 508A
PCBs (as Aroclors)
505, 508,508.1,525.2
Pentachlorophenol
515.2,525.2,555,
515.1, 515.3, 515.4
D5317-93, 98
(Reapproved 2003).
Picloram
515.2,555,
515.1, 515.3, 515.4
D5317-93, 98
(Reapproved 2003).
Simazine
505,507,525.2,
508.1,551.1
Toxaphene
505,508,508.1,
Footnotes
Substitution of the detector specified in Methods 505, 507, 508, or 508.1 for the purpose of achieving
lower detection limits is allowed as follows. Either an electron capture or nitrogen phosphorus detector
may be used provided all regulatory requirements and quality control criteria are met.
22.07A: continued
PCBs are qualitatively identified as Arolcolrs and measured for compliance purposes as
decachlorobiphenyl. Users of Method 505 may have more difficulty in achieving the required detection
limits than users of Methods 508.1, 525.2, or 508.
Accurate determination of the chlorinated esters requires hydrolysis of the sample as described in EPA
Methods 515.1, 515.2, 515.3, 515.4 and 555 and ASTM Methods D5317-93,98 (Reapproved 2003).
This method may not be used for the analysis of atrazine in any system where chlorine dioxide is used
for drinking water treatment. In samples from all other systems, any result for atrazine generated by
Method AG-625 that is greater than ½ the maximum contaminant level (MCL) (in other words, greater
than 0.0015mg/L or 1.5 ug/L) must be confirmed using another approved method for this contaminant
and should use additional volume of the original sample collected for compliance monitoring. In
instances where a result from Method AG-625 triggers such confirmatory testing, the confirmatory result
is to be used to determine compliance.
(11) Analysis for PCBs shall be conducted as follows:
(a) Each system that monitors for PCBs shall analyze each sample using either Method
508.1, 525.2, 508 or 505. The mean of the method detection limits of all Aroclors shall be
0.00025mg/l except for Aroclor 1221 which is 0.02 mg/l. Users of Method 505 may have
more difficulty in achieving the required Aloclor detection limits than using methods 508.1,
525.2 or 508.
1. A lab may conduct a scan for Aroclors using any one of the four methods mentioned
in 310 22.07A(11)(a).
2. A lab that is certified for any of the four methods listed in 310 22.07A(11)(a) is
eligible to conduct the scan for Aroclors.
(b) If PCBs (as one of seven Aroclors) are detected as designated in 310 CMR
22.07A(11)(a) the system shall reanalyze the sample using Method 508A to quantitate PCBs
(as decachlorobiphenyl).
(c) Compliance with the PCB MCL shall be determined based upon the quantitative results
of analyses using Method 508A.
(12) Grandfathered SOC Data: The Department may allow the use of monitoring data collected
after January 1, 1990, for purposes of satisfying the initial monitoring requirement of 310 CMR
22.07A(2), if in the opinion of the Department, the data are generally consistent with the
requirements of 310 CMR 22.07A(2). A single sample rather than four quarterly samples may
be allowed by the Department to satisfy the monitoring requirement for the initial compliance
period beginning January 1, 1993.
(13) Increased SOC Sampling: The Department may increase the required monitoring
frequency, where necessary, to detect variations within the system (e.g., fluctuations in
concentration due to seasonal use, changes in water source).
(14) Enforcement: The Department has the authority to determine compliance or initiate
enforcement action based upon analytical results and other information compiled by their
sanctioned representatives and agencies.
(15) Designated Sampling Schedules: Each public water system shall monitor at the time
designated by the Department within each compliance period.
22.07A: continued
(16) SOC Detection Limits: Detection as used in 310 CMR 22.07A(5) shall be defined as
greater than or equal to the following concentrations for each contaminant. (Please refer to the
Guidelines and Policies for further information regarding detection limits).
SOC DETECTION LIMITS
Contaminant
Detection Limit mg/l
Alachlor
Aldicarb
Aldicarb sulfoxide
Aldicarb sulfone
Atrazine
Benzo(a)pyrene
Carbofuran
Chlordane
Dalapon
Dibromochloropropane (DBCP)
Di (2-ethythexyl) adipate
Di (2-ethylhexyl) phthalate
Dinoseb
Diquat
2,4-D
Endothall
Endrin
Ethylene dibromide (EDB)
Glyphosate
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Hexachlorocyclopentadiene
Lindane
Methoxychlor
Oxamyl
Picloram
Polychlorinated biphenyls
(PCBs) (as decachlorobiphenyl)
Pentachlorophenol
Simazine
Toxaphene
2,3,7,8-TCDD (Dioxin)
2,4,5-TP (Silvex)
22.07A: continued
(17) SYNTHETIC ORGANIC BATs. The EPA Administrator, pursuant to the federal Safe
Drinking Water Act, § 1412, has identified as indicated in the Table below either granular
activated carbon (GAC), packed tower aeration (PTA), or oxidation (OX) as the best technology,
treatment technique, or other means available for achieving compliance with the maximum
contaminant level for organic contaminants identified in 310 CMR 22.07A(1):
BAT FOR ORGANIC CONTAMINANTS LISTED IN 310 CMR 22.07A(1)
CAS #
Chemical
GAC
PTA
OX
15972-60-8
Alachlor
X
116-06-3
Aldicarb
X
1646-88-4
Aldicarb sulfone
X
1646-87-3
Aldicarb sulfoxide
X
1912-24-9
Atrazine
X
50-32-8
Benzo[a)pyrene
X
1563-66-2
Carbofuran
X
57-74-9
Chlordane
X
75-99-0
Dalapon
X
96-12-8
Dibromochloropropane (DBCP)
X
X
75-09-2
Dichloreomethane
X
103-23-1
Di (2-ethylhexyl) adipate
X
X
117-81-7
Di (2-ethylhexyl) phthalate
X
88-85-7
Dinoseb
X
85-00-7
Diquat
X
94-75-7
2,4-D
X
72-20-8
Endrin
X
145-73-3
Endothall
X
106-93-4
Ethylene Dibromide (EDB)
X
X
1071-583-6
Glyphosate
X
76-44-8
Heptachlor
X
1024-57-3
Heptachlor epoxide
X
118-74-1
Hexachlorobenzene
X
77-47-3
Hexachlorocyclopentadiene
X
X
58-89-9
Lindane
X
72-43-5
Methoxychlor
X
1336-36-3
Polychlorinated biphenyls(PCB)
X
23135-22-0
Oxamyl (Vydate)
X
22.07A: continued
BAT FOR ORGANIC CONTAMINANTS LISTED IN 310 CMR 22.07A(1)
CAS #
Chemical
GAC
PTA
OX
87-86-5
Pentachlorophenol
X
1918-02-1
Picloram
X
93-72-1
2,4,5-TP (Silvex)
X
122-34-9
Simazine
X
120-82-1
1,2,4-Trichlorobenzene
X
X
79-00-5
1,1,2-Trichloroethane
X
X
1746-01-6
2,3,7,8-TCDD(Dioxin)
X
8001-35-2
Toxaphene
X
X
(18) New Systems/Sources. Each new supplier of water or supplier of water that uses a new
source of water that begins operation after January 22, 2004 must demonstrate compliance with
the MCL within a period of time specified by the Department. The supplier of water must also
comply with the initial sampling frequencies specified by the Department to ensure a system can
demonstrate compliance with the MCL. Routine and increased monitoring frequencies shall be
conducted in accordance with the requirements in 310 CMR 22.07A.