310 CMR 22.06
Inorganic Chemical Maximum Contaminant Levels, Monitoring Requirements and Analytical
Methods
(1) Monitoring. A Supplier of Water shall collect samples of water as specified in 310 CMR
22.06(4) and provide for analysis of such samples for inorganic chemical contaminants listed in
310 CMR 22.06(2) consistent with the requirements set forth in 310 CMR 22.06(5) through (9)
and methods set forth in 310 CMR 22.06(16).
All analytical results shall be rounded to the same number of significant figures as the
applicable MCL or SMCL.
(2) Inorganic Maximum Contaminant Levels (MCLs). The Maximum Contaminant Levels for
inorganic contaminants specified in 310 CMR 22.06(2)(b) through (g) and (k) through (q) apply
to Community Water Systems and Non-transient Non-community Water Systems. The
Maximum Contaminant Level specified in 310 CMR 22.06(2)(a) only applies to Community
Water Systems. The Maximum Contaminant Levels specified in 310 CMR 22.06(2)(h) through
(j) apply to Community, Non-transient Non-community, and Transient Non-community Water
Systems. The Maximum Contaminant Level for arsenic is 0.05 milligrams per liter for
Community Water Systems and Non-transient Non-community Water Systems until
January 23, 2006.
22.06: continued
MAXIMUM CONTAMINANT LEVELS FOR INORGANIC CHEMICALS
Contaminant
MCL (mg/l)
(a) Fluoride (C)
(b) Asbestos (C, NTNC)
7 Million Fibers/liter (longer than 10 µm)
(c) Arsenic (C,NTNC)
(d) Barium (C,NTNC)
(e) Cadmium (C,NTNC)
(f) Chromium (C,NTNC)
(g) Mercury (C,NTNC)
(h) Nitrate (C,NTNC,TNC)
10 (as Nitrogen)
(i) Nitrite (C,NTNC,TNC)
1 (as Nitrogen)
(j) Total Nitrate
& Nitrite (C,NTNC,TNC)
10 (as Nitrogen)
(k) Selenium (C,NTNC)
(l) Antimony (C,NTNC)
(m) Beryllium (C,NTNC)
(n) Cyanide (as free Cyanide) (C,NTNC)
(o) Nickel (C,NTNC)
[Reserved] (Under review)
(p) Thallium (C,NTNC)
(q) Perchlorate (C,NTNC)
C =
Community Water Systems; NTNC = Non-transient Non-community Water Systems;
TNC =
Transient Non-community Water Systems
The Department will review and revise as necessary the perchlorate MCL within six years of its promulgation,
taking into account new data on health effects, sources and occurrence, Treatment Techniques and associated issues,
analytical feasibility and any other relevant information.
(3) Inorganic Chemicals (IOC). Sampling and Analytical Requirements: Community Water
Systems and Non-transient Non-community Water Systems shall conduct monitoring to
determine compliance with the Maximum Contaminant Levels specified in 310 CMR 22.06(2)
in accordance with 310 CMR 22.06. Transient, Non-community Water Systems shall conduct
monitoring to determine compliance with the MCLs for nitrate, nitrite and total nitrate in
310 CMR 22.06(2)(h) through (j) (as appropriate) in accordance with 310 CMR 22.06.
(4) Sampling Protocol. Monitoring shall be as follows:
(a) Ground Water Sampling Points. Groundwater systems shall take one sample at every
entry point to the Distribution System which is representative of each well after treatment
(Sampling Point) beginning in the Compliance Period starting January 1, 1993. The system
shall take each sample at the same Sampling Point unless conditions make another Sampling
Point more representative of each source or treatment plant.
(b) Surface Water Sampling Points. Surface water systems (Note: or purposes of 310 CMR
22.06(4)(b), Surface Water systems include systems with a combination of surface and
ground sources) shall take a minimum of one sample at every entry point to the Distribution
System after any application of treatment or in the Distribution System at a point which is
representative of each source after treatment ( Sampling Point) beginning in the Compliance
Period beginning January 1, 1993. The system shall take each sample at the same Sampling
Point unless conditions make another Sampling Point more representative of each source or
treatment plant.
(c) Multiple Sources. If a 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 is representative of
all sources being used).
(d) Composite 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 1/5 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. Compositing of source with previous detects is not allowed, unless otherwise
authorized by the Department.
22.06: continued
1. If the concentration in the composite sample is greater than or equal to 1/5 of the
MCL of any inorganic chemical, then a follow-up sample must be analyzed within 14
days from each Sampling Point included in the composite. These samples must be
analyzed for the contaminants that exceeded 1/5 of the MCL in the composite sample.
Detection limits for each analytical method and MCL are the following:
DETECTION LIMITS FOR INORGANIC CONTAMINANTS
Contaminant
MCL(mg/l)
Methodology
Detection Limit (mg/l)
Antimony
Atomic Absorption; furnace
ICP-Mass Spectrometry
Hydride-Atomic absorption
Arsenic
Atomic Absorption; Furnace
Atomic Absorption; Platform-Stabilized Temperature
Atomic Absorption; Gaseous Hydride
ICP- Mass Spectrometry
Asbestos
7 MFL
Transmission Electron Microscopy
0.2 MFL
Barium
Atomic Absorption; furnace technique
Atomic Absorption; direct aspiration
Inductively Coupled Plasma
(0.001)
Beryllium
Atomic Absorption; furnace
Atomic Absorption; platform
Inductively Coupled Plasma
ICP-Mass Spectrometry
Cadmium
Atomic Absorption; furnace technique
Inductively Coupled Plasma
Chromium
Atomic Absorption; furnace technique
Inductively Coupled Plasma
(0.001)
Cyanide
Distillation, Spectrophotometric
Distillation, Automated, Spectrophotometric
Distillation, Selective Electrode
3, 4
Distillation, Amenable, Spectrophotometric
UV, Distillation, Spectrophotometric
Micro Distillation, Flow Injection,
Spectrophotometric
Ligand Exchange with Amperometry
Mercury
Manual Cold Vapor Technique
Automated Cold Vapor Technique
Nickel
Reserved
Nitrate
10 (as N)
Manual Cadmium Reduction
Automated Hydrazine Reduction
Automated Cadmium Reduction
Ion Selective Electrode
Ion Chromatography
Capillary Ion Electrophoresis
Nitrite
1 (as N)
Spectrophotometric
Automated Cadmium Reduction
Manual Cadmium Reduction
Ion Chromatography
Capillary Ion Electrophoresis
Perchlorate
Ion Chromatography
LC/MS or LC/MS/MS
IC/MS or IC/MS/MS
Selenium
Atomic Absorption; furnace
Atomic Absorption: gaseous hydride
Sodium
See 310 CMR 22.06A
Thallium
Atomic Absorption; furnace
Atomic Absorption; platform
ICP-Mass Spectrometry
22.06: continued
MFL = million fibers per liter >10 µm.
Using a 2X preconcentration step as noted in Method 200.7. Lower MDLs may be achieved when using
a 4X preconcentration.
Screening methods for total cyanides.
Measures "free" cyanides when distillation, digestion, or ligand exchange is omitted.
Lower MDLs are reported using stabilized temperature graphite furnace atomic absorption.
The MCL for arsenic is effective January 23, 2006. Until then, the MCL is 0.05 mg/l.
The MDL reported for EPA method 200.9 (Atomic Absorption; Platform---Stabilized Temperature) was
determined using a 2x concentration step during sample digestion. The MDL determined for samples
analyzed using direct analyses (i.e., no sample digestion) will be higher. Using multiple deposition, EPA
200.9 is capable of obtaining MDL of 0.0001 mg/l.
Using selective ion monitoring, EPA Method 200.8 (ICP-MS) is capable of obtaining a MDL of 0.0001
mg/l.
Analysis must be conducted using EPA Method 314.0, revision 1.0, November 1999 as modified to
achieve the stated detection limit or EPA Method 314.1.
Minimum Reporting Level (MRL). EPA Method 314.0 is capable of obtaining a MDL of less than
0.0010 mg/l.
Measures total cyanides when UV-digestor is used, and “free” cyanides when UV-digestor is bypassed.
2. If the population served by the system is >3,300 persons, then compositing may only
be permitted at Sampling Points within a single system. In systems serving <3,300
persons, compositing among different systems may be allowed with the approval of the
Department, provided the five-sample limit is maintained.
3. If duplicates of the original sample taken from each Sampling Point used in the
composite are available, the system may use these instead of resampling. The duplicates
must be analyzed and the results reported to the Department within 14 days after
completion of the composite analyses or before the holding time for the control sample
is exceeded, whichever is sooner.
(e) Frequency Requirements for IOC Monitoring. The frequency of monitoring for asbestos
shall be in accordance with 310 CMR 22.06(5); the frequency of monitoring for antimony,
arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium
and thallium shall be in accordance with 310 CMR 22.06(6); the frequency of monitoring for
nitrate shall be in accordance with 310 CMR 22.06(7); the frequency of monitoring for nitrite
shall be in accordance with 310 CMR 22.06(8); and the frequency of monitoring for
perchlorate shall be in accordance with 310 CMR 22.06(9).
(f) 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 inorganic chemicals under 310 CMR 22.06, provided that the
system from which the water is obtained has conducted the analyses required under
310 CMR 22.06, unless otherwise specified by the Department. These systems are not
exempt from 310 CMR 22.06(5) asbestos sampling.
(5) Asbestos Sampling Frequency. The frequency of monitoring conducted to determine
compliance with the Maximum Contaminant Level for asbestos specified in 310 CMR 22.06(2)
shall be conducted as follows:
(a) Initial Sampling Frequency. Each Community and Non-transient, Non-community
Water System is required to monitor for asbestos during the first three-year Compliance
Period of each nine-year Compliance Cycle beginning in the Compliance Period starting
January 1, 1993 as specified in 310 CMR 22.06(5)(e) through (g).
(b) Sampling During Waiver. If the system believes it is not vulnerable to either asbestos
contamination in its source water or due to corrosion of asbestos-cement pipe, or both, it may
apply to the Department for a waiver of the monitoring requirement in 310 CMR 22.06(5)(a).
If the Department grants the waiver, the system will be required to monitor pursuant to
310 CMR 22.06(5)(d).
(c) Basis of an Asbestos Waiver. The granting of a waiver will be based on a consideration
of the following factors:
1. Potential asbestos contamination of the water source; and
2. The use of asbestos-cement pipe for finished water distribution and the corrosive
nature of the water.
22.06: continued
(d) Effect of an Asbestos Waiver. A waiver remains in effect until the completion of the
three-year Compliance Period. Systems not receiving a waiver must monitor in accordance
with the provisions of 310 CMR 22.06(5)(a).
(e) Distribution System Sampling Criteria for Asbestos. A system vulnerable to asbestos
contamination due solely to corrosion of asbestos-cement pipe shall take at a minimum one
sample at a tap approved by the Department. This tap location must be served by
asbestos-cement pipe and under conditions where asbestos contamination is most likely to
occur. Additional sample locations (taps) may be required if in the Department's opinion the
use of asbestos-cement is extensive and contamination is likely to occur in several areas of
the system.
(f) Source Water Sampling Criteria for Asbestos. A system vulnerable to asbestos
contamination due solely to source water shall monitor in accordance with the provisions of
310 CMR 22.06(2) and (4).
(g) Combined Asbestos Vulnerability. A system vulnerable to asbestos contamination due
both to its source water supply and corrosion of asbestos-cement pipe shall monitor in
accordance with 310 CMR 22.06(5)(e) and (f).
(h) Exceeding the Asbestos MCL. A system which exceeds the Maximum Contaminant
Levels as defined by 310 CMR 22.06(2) shall report to the Department within seven days and
shall monitor quarterly beginning in the following quarter.
(i) Average Exceeding MCL. When the average of four analyses made pursuant to
310 CMR 22.06(5)(h), 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.
(j) Asbestos Reliably & Consistently below the MCL. The quarterly monitoring
requirement may be decreased to the frequency specified in 310 CMR 22.06(5)(a) provided
the Department has determined that the system is reliably and consistently below the
Maximum Contaminant Level and a groundwater system has taken a minimum of two
quarterly samples and a surface (or combined surface/ground) water system has taken a
minimum of four quarterly samples.
(k) Grandfathered Asbestos Data. If monitoring data collected after January 1, 1990 are
generally consistent with the requirements of 310 CMR 22.06(5), the data may be used with
the Department's approval, to satisfy the monitoring requirement for the Initial Compliance
Period beginning January 1, 1993.
(6) Sampling Frequency for IOCs. The frequency of monitoring conducted to determine
compliance with the Maximum Contaminant Levels in 310 CMR 22.06(2) for antimony, arsenic,
beryllium, barium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium and
thallium shall be as follows:
(a) IOCs Sampling Frequency. Groundwater systems shall take one sample at each
Sampling Point once every three years. Surface Water systems (or combined surface/ground)
shall take one sample annually at each Sampling Point.
(b) IOCs Sampling Waiver. The system may apply to the Department for a waiver from the
monitoring frequencies specified in 310 CMR 22.06(6)(a).
(c) IOC Sampling During a Waiver. A condition of the waiver shall require that a system
shall take a minimum of one sample while the waiver is effective. The term during which
the waiver is effective shall not exceed one Compliance Cycle (i.e., nine years).
(d) Basis of an IOC Waiver & Grandfathered Data. A waiver may be granted by the
Department provided the Surface Water systems have monitored annually for at least three
years and groundwater systems have conducted a minimum of three rounds of monitoring.
(Analytical monitoring results must have been representative of all sources at the time of
sampling.) Both surface and groundwater systems shall demonstrate that all previous
analytical results were less than the Maximum Contaminant Level. Systems that use a new
water source are not eligible for a waiver until three rounds of monitoring from the New
Source have been completed.
22.06: continued
(e) Basis of the IOC Sampling Frequency During a Waiver. The granting of a waiver by the
Department will be based on the following:
1. Reported concentrations from all previous monitoring;
2. The degree of variation in reported concentrations; and
3. Other factors which may affect contaminant concentrations such as changes in
groundwater pumping rates, changes in the system's configuration, changes in the
system's operating procedures, or changes in stream flows or characteristics.
(f) Effect of an IOC Waiver. A Supplier of Water must have received a written approval
from the Department which shall set forth the basis for the determination. The determination
may be initiated by the Department or upon an application by the Public Water System. The
Public Water System shall specify the basis for its request. The Department may revise its
determination of the appropriate monitoring frequency, if the system submits new monitoring
data or when other data relevant to the system's appropriate monitoring frequency become
available.
(g) Exceeding an IOC MCL. Systems which exceed a Maximum Contaminant Levels as
defined by 310 CMR 22.06(2) shall report to the Department within seven days and shall
monitor quarterly beginning in the following quarter.
(h) Average Exceeding MCL. When the average of four analyses made pursuant to
310 CMR 22.06(6)(g), 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.
(i) IOCs Reliably & Consistently below the MCL. If the system is reliably and consistently
below the Maximum Contaminant Level, the quarterly monitoring requirement may be
decreased with the Department's approval to the frequencies specified in 310 CMR
22.06(6)(a). Systems requesting this decrease must have taken at a minimum two quarterly
samples for a groundwater system and four quarterly samples for a Surface Water system.
(j) All new Public Water Systems or systems that use a New Source of water that begin
operation after January 22, 2004 must demonstrate compliance with the MCL within a period
of time as specified by the Department. The system 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 22.06(6).
(7) Sampling Frequency for Nitrate. All Public Water Systems (Community, Non-transient
Non-community, and Transient Non-community Water Systems) shall monitor to determine
compliance with the Maximum Contaminant Level for nitrate specified in 310 CMR 22.06(2).
(a) Initial Nitrate Sampling. Community and Non-transient Non-community Water Systems
served by groundwater source shall monitor annually beginning January 1, 1993; systems
served by Surface Water shall monitor quarterly beginning January 1, 1993.
(b) Transient Non-community Nitrate Sampling Frequency. Each Transient Non-
community Water System shall monitor annually beginning January 1, 1993.
(c) Ground Water Repeat Nitrate Sampling Frequency. For all Public Water Systems: the
repeat monitoring frequency for groundwater systems shall be quarterly for at least one year
following any one sample in which the concentration is >50% the MCL. A groundwater
system may reduce the sampling frequency to annually with the Department's approval, after
four consecutive quarterly samples are reliably and consistently less than the MCL.
(d) Surface Water Repeat Nitrate Sampling Frequency. All Public Water Systems with
Surface Water Sources may reduce the sampling frequency to annually with the Department's
approval, if all analytical results from four consecutive quarters are <50% of the MCL. A
Surface Water system shall return to quarterly monitoring if any one sample is $50% of the
MCL.
(e) Scheduling Annual Nitrate Repeat Samples. After the initial round of quarterly
sampling is completed, all Public Water Systems which are monitoring quarterly because the
concentration of any one sample was >50% of the MCL shall take subsequent annual
samples during the quarter(s) which previously resulted in the highest analytical result.
22.06: continued
(8) Sampling Frequency for Nitrite. All Public Water Systems (Community, Non-transient
Non-community, and Transient Non-community Water Systems) shall monitor to determine
compliance with the Maximum Contaminant Level for nitrite in 310 CMR 22.06(2).
(a) Initial Nitrite Sampling. All Public Water Systems shall take one sample at each
Sampling Point in the Compliance Period beginning January 1, 1993 and ending
December 31, 1995.
(b) Under the Nitrite Trigger Level. After the initial sample, systems where an analytical
result for nitrite is <50% of the MCL shall monitor at the frequency specified by the
Department.
(c) Above the Nitrite Trigger Level. For Community, Non-transient Non-community, and
Transient Non-community Water Systems, the repeat monitoring frequency for any water
system shall be quarterly for at least one year following any one sample in which the
concentration is >50% of the MCL. With the Department's approval, a system may reduce
the sampling frequency to annually if the system is reliably and consistently less than the
MCL.
(d) Scheduling of Annual Nitrite Repeat Samples. Systems which are monitoring annually
shall take each subsequent sample during the quarter(s) which previously resulted in the
highest analytical result.
(9) Sampling Frequency for Perchlorate.
(a) Initial Monitoring. Community and Non-transient Non-community systems shall
complete initial monitoring for perchlorate as specified in 310 CMR 22.06(9)(a).
1. Effective January 1, 2007, for systems served by groundwater, perchlorate shall be
monitored twice, once during the month of April and once during the month of
September.
2. Effective January 1, 2007, for systems served by surface water, perchlorate shall be
monitored for four consecutive quarters.
(b) Grandfathered Perchlorate Data. If the perchlorate monitoring data collected by a Public
Water System after January 1, 2004 is consistent with the requirements of 310 CMR
22.06(9), such data may be used with the Department's approval to satisfy the initial
monitoring requirements specified in 310 CMR 22.06(9)(a).
(c) Exceeding the Perchlorate MCL. A Public Water System that exceeds the Maximum
Contaminant Level (MCL) for perchlorate in 310 CMR 22.06(2) shall follow the reporting
and confirmation procedures in 310 CMR 22.06(10)(c).
(d) Repeat Perchlorate Sampling Frequency. If, after completing the initial monitoring
required in 310 CMR 22.06(9)(a), no perchlorate is detected, a Public Water System may
thereafter reduce the sampling frequency to once per year.
(e) Exceeding the Perchlorate Trigger Level. The repeat monitoring frequency for any
Public Water System shall be on a quarterly basis for at least one year following any one
sample in which the concentration is > 0.0010 mg/L (unqualified). With the Department's
approval, a system may reduce the sampling frequency to once per year, provided the
monitoring for perchlorate done by the system is Reliably and Consistently below the MCL.
(f) Eligibility for a Waiver. A Public Water System may apply for a waiver from the
monitoring requirements for perchlorate specified in 310 CMR 22.06(9) in accordance with
the IOC waiver provisions in 310 CMR 22.06(6)(b) through (f).
(g) The Department may, on a case-by-case basis, require a Public Water System to monitor
for perchlorate more frequently than otherwise provided in 310 CMR 22.06(9)(b) through
(f).
(10) Confirmation Sampling.
(a) Deadline for IOCs Confirmation Samples. Where the results of sampling for antimony,
arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel,
selenium, or thallium indicate an exceedance of the Maximum Contaminant Level, one
additional sample shall be collected as soon as possible after the initial sample was taken (but
not to exceed two weeks) at the same Sampling Point.
22.06: continued
(b) Deadline for Nitrate & Nitrite Confirmation Samples. Where nitrate or nitrite sampling
results indicate an exceedance of the Maximum Contaminant Level, the system shall take a
confirmation sample within 24 hours of the system's receipt of notification of the analytical
results of the first sample and shall report to the Department within seven days. Systems
unable to comply with the 24-hour sampling requirement must immediately notify the
consumers served by the area served by the Public Water System in accordance with
310 CMR 22.16. Systems exercising this option must take and analyze a confirmation
sample within two weeks of notification of the analytical results of the first sample.
(c) Deadline for Perchlorate Confirmation Samples. Whenever the perchlorate sampling
results indicate an exceedance of the Maximum Contaminant Level, the system shall take a
confirmation sample using EPA Method 331.0 or EPA Method 332.0 in accordance with
310 CMR 22.06(10)(c)1. and 2. within 24 hours of the system's receipt of written notification
of the analytical results. For the purposes of 310 CMR 22.06(10)(c), written notification of
the analytical results means notification by email, fax, or letter. The system shall report the
initial sample result that exceeded the MCL to the Department within seven days. Systems
that are unable to take a confirmation sample within 24 hours of the system's receipt of
written notification of the analytical results, shall immediately contact the Department for
further direction. When taking a confirmation sample as required by 310 CMR 22.06(10)(c):
1. The system shall obtain an analysis and written notification turnaround time for the
confirmation sample of no more than three days.
2. The system shall report the confirmation sample results to the Department within
three days of the system's receipt of the written notification of the analytical results.
(d) Compliance Calculations & Confirmation Samples. The results of the initial and
confirmation sample shall be averaged. The resulting average shall be used to determine the
system's compliance in accordance with 310 CMR 22.06(13). Obvious sampling errors may
be deleted with the approval of the Department.
(11) Increased Sampling Frequency. The Department may require more frequent monitoring
than specified in 310 CMR 22.06(5) through (9) or may require confirmation samples for
positive and negative results at its discretion.
(12) PWS Request for Increased Sampling Frequency. Systems may apply to the Department
to conduct more frequent monitoring than the minimum monitoring frequencies specified in
310 CMR 22.06.
(13) Compliance Calculations. Compliance with the Maximum Contaminant Levels set out in
310 CMR 22.06(2) 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) Sampling Frequencies Greater than Annual. For systems monitoring more than once per
year, compliance with the MCL, with the exception of nitrate, nitrite and perchlorate, is
determined by a Running Annual Average at each Sampling Point.
(b) Sampling Frequencies of Annual or Less. Each Supplier of Water monitoring annually
or less frequently whose sample result exceeds an MCL, with the exception of nitrate, nitrite
and perchlorate, must begin quarterly sampling. The system will not be considered in
violation of the MCL until it has completed one year of quarterly sampling.
(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
(average concentration) 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) Compliance Calculations for Nitrate & Nitrite. Compliance with the Maximum
Contaminant Levels for nitrate and nitrite is determined based on one sample if the levels of
these contaminants are below the MCLs. If the level of nitrate or nitrite exceeds the MCL
in the initial sample, a confirmation sample is required in accordance with 310 CMR
22.06(10)(b) and (d), and compliance shall be determined based on the average of the initial
and confirmation samples.
22.06: continued
(g) Compliance Calculations for Perchlorate. Compliance with the Maximum Contaminant
Level for perchlorate is determined based on one sample if the level is below the MCL. If
the level of perchlorate exceeds the MCL in the initial sample a confirmation sample is
required in accordance with 310 CMR 22.06(10)(c) and (d), and compliance shall be
determined based on the average of the initial and the confirmation sample. The Department
may allow or require additional sampling.
(h) Average Exceeding Nitrate, Nitrite and Perchlorate MCL. When the average of
analyses made pursuant to 310 CMR 22.06(7) through (9), (10)(b) and (c), 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 pursuant to 310 CMR
22.16. Monitoring after public notification shall be at a frequency designated by the
Department.
(i) Arsenic sampling results shall be reported to the nearest 0.001 mg/l.
(14) Sampling Schedules: Each Public Water System shall monitor at the time designated by
the Department during each Compliance Period.
(15) Reporting MCL Violation: A system which exceeds the MCL listed in 310 CMR 22.06(2)
and is out of compliance shall report the exceedance to the Department within seven days.
(16) Analytical and Sampling Methods for Inorganics:
(a) Analytical Methods for IOCs: Analysis for the listed inorganic contaminants shall be
conducted using the following methods:
INORGANIC CONTAMINANTS ANALYTICAL METHODS
Reference (Method Number)
Contaminant
Methodology
EPA
ASTM
SM
SM Online
Other
Antimony
Atomic Absorption:
3113B
3113 B-99
Furnace
Atomic Absorption:
platform
ICP-Mass Spectrometry
D-3697-92, 02
Hydride-Atomic Absorption
D2972-97C, 03C
Arsenic
Atomic Absorption: Furnace
3113B
3113 B-99
D-2972-97, 03B
Atomic Absorption; Hydride
3114B
3114 B-97
Inductively Coupled Plasma
3120B
3120 B-99
ICP-Mass Spectrometry
Atomic Absorption; Platform
Differential Pulse Anodic
Stripping Voltametry
Method 100116
Asbestos
Transmission Electron
Microscopy
Transmission Electron
Microscopy
Barium
Atomic Absorption; Furnace
3113B
3113B-99
Atomic Absorption; Direct
3111D
3111D-99
Inductively Coupled Plasma
3120B
3120B-99
ICP-Mass Spectrometry
D3645-97, 03B
Beryllium
Atomic Absorption; Furnace
3113B
3113B-99
Atomic Absorption; Platform
Inductively Coupled Plasma
3120B
3120B-99
ICP-Mass Spectrometry
22.06: continued
Contaminant
Methodology
EPA
ASTM
SM
SM Online
Other
Cadmium
Atomic absorption; Furnace
3113B
3113B-99
Inductively-coupled Plasma
ICP-Mass Spectrometry
Atomic Absorption; Platform
Chromium
Atomic absorption; Furnace
3113B
3113B-99
Inductively Coupled Plasma
3120B
3120B-99
ICP-Mass Spectrometry
Atomic Absorption; Platform
D2036-98A
Cyanide
Manual Distillation
4500-CN C
-
Manual Distillation followed
by: Spectrophotometric,
Amenable
D2036-98B
4500-C NG
4500-CN G-99
-
-
Manual Distillation followed
by Spectrophotometric,
Manual
D2036-98A
4500-CN E
4500-CN E-99
I-3300-85
-
-
Spectrophotometric, Semi-
automated
Selective Electrode
4500-CN F
4500-CN F-99
-
-
UV, Distillation,
Spectrophotmetric Micro
Distillation, Flow Injection
Kelada-0118
Spectrophotometric
QuikChem10-204-00-
1-X19
Ligand Exchange and
Amperometry
D6888-04
OIA-1677-DW
Mercury
Manual cold vapor
D3223-97,02
3112B
3112B-99
Automated cold vapor
ICP-Mass Spectrometry
Nickel
Atomic Absorption: Furnace
3113B
3113B-99
Atomic Absorption: Platform
Atomic Absorption Direct
3111B
3113B-99
Inductively Coupled Plasma
3120B
3120-99
ICP-Mass Spectrometry
Nitrate
Manual cadmium reduction
D3867-90B
4500-NO E
4500-NO E-00
-
-
Automated cadmium reduction
D3867-90A
4500-NO F
4500-NO F-00
-
-
Ion selective electrode
4500-NO D
4500-NO D-0
-
-
Ion chromatography
D4327-97,03
4110B
4110B-00
B-1011
Capillary Ion Electrophoresis
D6508-00, Rev.224
Nitrite
Spectrophotometric
4500-NO B
4500- NO B-00
-
-
Automated cadmium reduction
D3867-90A
4500-NO F
4500-NO F-00
-
-
D3867-90B
Manual cadmium reduction
4500-NO E
4500-NO E-00
-
-
Ion chromatography
D4327-97,03
4110B
4110B-00
B-1011
Capillary Ion Electrophoresis
D6508-00, Rev.224
Perchlorate
Ion chromatography
LC/MS or LC/MS/MS
IC/MS or IC/MS/MS
Selenium
Hydride-Atomic absorption;
D3859-98,03A
3114B
3114B-97
D3859-98,03B
Atomic Absorption: Furnace
3113B
3113B-99
ICP-Mass Spectrometry
Atomic Absorption; Platform
Thallium
Atomic absorption; Platform
ICP-Mass Spectrometry
S)))))))))))))))))))))))))))))))))))))))))))))))))Q
22.06: continued
The procedures shall be done in accordance with the documents listed below. The incorporation by reference
of the following documents listed in footnotes 1-11 and 15 was approved by the Director of the Federal
Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies of the documents may be obtained
from the sources listed below. Information regarding obtaining these documents can be obtained from the
Safe Drinking Water Hotline at 900-426-4791. Documents may be inspected at EPA’s Drinking Water
Docket, 401 M Street, SW., Washington, DC 20460 (Telephone 202-260-3027); or at the Office of Federal
Register, 800 North Capital Street, NW., Suite 700, Washington, DC.
Methods of Chemical Analysis of Water and Wastes, EPA-600/4-79-020, March 1983. Available at NTIS,
PB84-128677.
Methods for the Determination of Metals in Environmental Samples - Supplement I, EPA-600/R-94/111
May 1994. Available at NTIS, PB 95-125472.
Annual Book of ASTM Standards, 1994 , 1996, or 1999 Vols. 11.01 and 11.02, American Society for
Testing and Materials. The previous versions of D1688-95A, D1688-95C (copper), D3559-95D (lead),
D1293-95 (pH), D1125-95A, (conductivity) and D859-94 (silica) are also approved. These previous
versions D1688-90A, C; D3559-90D, D1293-84, D1125-91A and D859-88, respectively are located in
the Annual Book of ASTM Standards, 1994, Vols. 11.01. Copies may be obtained from the American
Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428.
18 , 19 , and 20 edition of Standard Methods for the Examination of Water and Wastewater, 18 (1982),
th
th
th
th
19 (1995), and 20 (1998) editions, American Public Health Association; either edition may be used.
th
th
Copies may be obtained from the American Public Health Association, 1015 Fifteenth Street NW,
Washington, DC 20005. The cited methods published in any of these three editions may be used, except
that the versions of 3111B, 3111D, 3113B and 3114B in the 20 edition may not be used.
th
Method I-2601-90, Methods for Analysis by the U.S. Geological Survey National Water Quality
Laboratory – Determination of Inorganic and Organic Constituents in Water and Fluvial Sediments,
Open File Report 93-125, 1993; For Methods I-1030-85; I-1601-85; I-1700-85; I-2598-85, I-2700-85; and
I-3300-85 See Techniques of Water Resources Investigation of the U.S. Geological Survey, Book 5,
Chapter A-1, 3 edition, 1989; Available from Information Services, U.S. Geological Survey, Federal
rd
Center, Box 25286, Denver, CO 80225-0425.
Methods for the Determination of Inorganic Substances in Environmental Samples, EPA 600/R-93/100,
August 1993. Available at NTIS, PB94-120821.
The procedure shall be done in accordance with Technical Bulletin 601 Standard Method of Test for
Nitrate in Drinking Water, July 1994, PN 221890-001, Analytical Technology, Inc. Copies may be
obtained from ATI Orion, 529 Main Street, Boston, MA 02129.
Method B-1011, Standard Method of Test for Nitrate in Drinking Water, July 1994, PN 221890-001,
Analytical Technology, Inc. Copies may be obtained from ATI Orion, 529 Main Street, Boston, MA
02129.
Method 100.1, Analytical Methods for Determination of Asbestos Fibers in Water, EPA/600/4-83/043,
September 1983, Available at NTIS, PB83-206471.
Method 100.2, Determination of Asbestos Structures Over 10 :m in Length in Drinking Water,
EPA/600/R-94/134, June 1994. Available at NTIS, PB94-201902.
Because MDLs reported in EPA Methods 200.7 and 200.9 were determined using a 2X preconcentration
step during sample digestion, MDLs determined when samples are analyzed by direct analysis (i.e., no
sample digestion) will be higher. For direct analysis of cadmium and arsenic by Method 200.7, and arsenic
by Method 3120B sample preconcentration using pneumatic nebulization may be required to achieve lower
detection limits. Preconcentration may also be required for direct analysis of antimony, lead, and thallium
by Method 200.9; antimony and lead by Method 3113B; and lead by Method D3559-90D unless multiple
infurnace depositions are made.
If ultrasonic nebulization is used in the determination of arsenic by Method 200.8 the arsenic must be in
the pentavalent state to provide uniform signal response. For direct analysis of arsenic with the Method
200.8 using ultrasonic nebulization, samples and standards must contain 1 mg/L of sodium hypochlorite.
[Deleted].
Revision 1.0, November, 1999, Determination of Perchlorate in Drinking Water Using Ion
Chromatography as modified to achieve performance requirements in 310 CMR 22.06(4).
EPA Method 314.1: Determination of Perchlorate in Drinking Water Using Inline Column
Concentration/Matrix Elimination Ion Chromatography with Suppressed Conductivity Detection.
EPA Method 331.0: Determination of Perchlorate in Drinking Water by Liquid Chromatography
Electrospray Ionization Mass Spectrometry.
22.06: continued
EPA Method 332.0: Determination of Perchlorate in Drinking Water Using Ion Chromatography with
Suppressed Conductivity and Electrospray Ionization Mass Spectrometry.
The description for the Kelada-01 Method, Kelada Automated Test Methods for Total Cyanide, Acid
Dissociable Cyanide, and Thiocyanate, Revision 1.2, August 2001, EPA #821-B-01-009 for cyanide is
available from the National Technical Information Service (NTIS), PB 2001-108275, 5285 Port Royal
Road, Springfield, VA 22161. The toll-free telephone number is 800-553-6847. Note: A 450-W UV
lamp may be used in this method instead of the 550-W lamp specified if it provides performance within
the quality control (QC) acceptance criteria of the method in a given instrument. Similarity, modified flow
cell configurations and flow conditions may be used in the method, provided that the QC acceptance
criteria are met.
The description for the QuikChem Method 10-204-00-1-X, Digestion and distillation of total cyanide in
drinking and wastewaters using MICRO DIST and determination of cyanide by flow injection analysis,
“Revision 2.1, November 30, 2000, for cyanide is available from Lachat Instruments, 6645 W. Mill Rd.,
Milwaukee, WI 53218. Telephone: 414-358-4200.
Methods for the Determination of Organic and Inorganic Compounds in Drinking Water, Vol.1, EPA 815-
R-00-014, August 2000. Available at NTIS, PB2000-106981.
Method OIA -1677, DW Available Cyanide by Flow Injection, Ligand Exchange, and Amperometry,
January 2004. EPA-821-R-04-001, Available from ALPKEM, A Division of OL Analytical, P.O. Box
9010, College Station, TX 77842-9010.
Sulfide levels below those detected using lead acetate paper may produce positive method interferences.
Test samples using a more sensitive sulfide method to determine if a sulfide interference is present, and
treat samples accordingly.
Standard Methods Online are available at
http://www.standardmethods.org. The year in which each
method was approved by the Standards Methods Committee is designated by the last two digits in the
method number. The methods listed are the only online versions that may be used.
Method D6508, Rev.2, Test Method for Determination of Dissolved Inorganic Anions in Aqueous
Matrices Using Capillary Ion Electrophoresis and Chromate Electrolyte.
(b) Analytical Methods for Fluoride: Analyses for fluoride shall be conducted using the
following methods:
Reference (Method Number)
Methodology
EPA
ASTM
SM
SM Online
Other
Ion Chromatography
D4327-97
4110B
4110B-00-
Manual Distillation; Colorimetric
SPADNS
4500F-B,D
4500F-B,D-97
Manual Electrode
D1179-93,99B
4500F-C
4500F-C-97
Automated Alizarin fluorine blue -
lanthanum with distillation (complexone)
4500F-E
129-71W 3
Automated ion selective electrode
380-75WE4
Capillary Ion Electrophoresis
D6508, Rev. 27
Annual Book of ASTM Standards, part 31 Water. American Society for Testing and Materials, 1916
Race Street, Philadelphia, Pennsylvania 19103.
Standard Methods for the Examination of Water and Wastewater, 18 , 19 , and 20 edition, American
th
th
th
Public Health Association, American Water Works Association, Water Pollution Control Federation,
1992, 1995, and 1998.
Fluoride in Water and Wastewater, Industrial Method # 129-71W. Technicon Industrial Systems.
December 1972. Copies may be obtained from Bran & Luebbe, 1025 Busch Parkway, Buffalo Grove,
IL 60089.
Fluoride in Water and Wastewater, Technicon Industrial Systems. February 1976. Copies may be
obtained from Bran & Luebbe, 1025 Busch Parkway, Buffalo Grove, IL 60089.
Methods for the Determination of Inorganic Substances in Environmental Samples, EPA-600/R-93/100,
August 1993. Available at NTIS, PB94-120821.
Methods for the Determination of Organic and Inorganic Compounds in Drinking Water, Vol.1, EPA 815-
R-00-014, August 2000, Available at NTIS, PB2000-106981.
22.06: continued
Method 6508, Rev.2, Test Method for Determination of Dissolved Inorganic Anions in Aqueous Matrices
Using Capillary Ion Electrophoreses and Chromate Electrolyte, available from Waters Corp., 34 Maple
St., Milford, MA 01757, Telephone: 508/482-2131, Fax: 508/482-3625.
Standard Methods Online are available at
http://www.standardmethods.org. The year in which each
method was approved by the Standard Methods Committee is designated by the last two digits in the
method number. The methods listed are the only online versions that may be used.
(c) Sample Collection Methods for IOCs: Sample collection for antimony, arsenic,
asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, nitrate,
nitrite, perchlorate, selenium and thallium under 310 CMR 22.06 shall be conducted using
the sample preservation, container, and maximum holding time procedures specified in the
table below:
Contaminant
Preservative
Container
Time
Antimony
Con HNO to pH<2
P or G
six months
Arsenic
Con HNO to pH<2
P or G
six months
Asbestos
Cool, 4°C
P or G
48 hours
Barium
Con HNO to pH<2
P or G
six months
Beryllium
Con HNO to pH<2
P or G
six months
Cadmium
Con HNO to pH<2
P or G
six months
Chromium
Con HNO to pH<2
P or G
six months
Cyanide
Cool,4°C, NAOH to pH>12
P or G
14 days
Fluoride
None
P or G
one month
Mercury
Con HNO to pH<2
P or G
28 days
Nickel
Conc HNO
P or G
six months
Nitrate
Chlorinated
Cool, 4°C
P or G
14 days
Chlorinated
Con H SO to pH<2
P or G
28 days
Non-chlorinated
Cool 4°C
P or G
48 hours
Non-chlorinated
Con H SO to pH<2
P or G
28 days
Nitrite
Cool, 4°C
P or G
48 hours
Perchlorate
None
P or G
28 days
Selenium
Con HNO to pH<2
P or G
six months
Thallium
Con HNO to pH<2
P or G
six months
For cyanide determinations samples must be adjusted with sodium hydroxide to pH 12 at the time of
collection. When chilling is indicated the sample must be shipped and stored at 4°C or less. Acidification
of nitrate or metals samples may be with a concentrated acid or a dilute (50% by volume) solution of the
applicable concentrated acid. Acidification of samples for metals analyses is encouraged and allowed at
the laboratory rather than at the time of sampling provided the shipping time and other instruction in
Section 8.3 of EPA methods 200.78 or 200.8 or 200.9 are followed.
P = plastic, hard or soft; G = glass, hard or soft.
In all cases, samples should be analyzed as soon after collection as possible. Follow additional (if any)
information on preservation, containers, or holding times that is specified in the method.
See method(s) for the information for preservation.
22.06: continued
(17) BATs for IOCs: The following are the best technology, Treatment Technique, or other
means available for achieving compliance with the Maximum Contaminant Level for inorganic
contaminants identified in 310 CMR 22.06(2) except fluoride:
BAT FOR INORGANIC CONTAMINANTS LISTED IN 310 CMR 22.06(2)
CHEMICAL NAME
BAT(s)
Antimony
2,7
Arsenic
1, 2, 5, 6, 7, 9, 125
Asbestos
2, 3, 8
Barium
5, 6, 7, 9
Beryllium
1, 2, 5, 6, 7
Cadmium
2, 5, 6, 7
Chromium
2, 5, 6 , 7
Cyanide
5, 7, 13
Mercury
2 , 4, 6 , 7
Nickel
5, 6, 7
Nitrate
5, 7, 9
Nitrite
5, 7
Perchlorate
Selenium
1, 2 , 6, 7, 9
Thallium
1, 5
Key to BATs in Table
1 = Activated Alumina
2 = Coagulation/Filtration (Not BAT for Systems <500 service connections)
3 = Direct and Diatomite Filtration
4 = Granular Activated Carbon
5 = Ion Exchange
6 = Lime Softening (not BAT for systems <500 service connections)
7 = Reverse Osmosis
8 = Corrosion Control
9 = Electrodialysis
10 = Chlorine
11 = Ultraviolet
12 = Oxidation/Filtration
13 = Alkaline Chlorination
BAT only if influent Hg concentrations <10 µg/l.
BAT for Chromium III only
BAT for Selenium IV only
BAT for Arsenic V. Pre-oxidation may be required to convert Arsenic III to Arsenic V.
To obtain high removals; iron to arsenic ratio must be at least 20.1.
(18) The Administrator, pursuant to the Safe Drinking Water Act, Title 14, § 1412, hereby
identifies in the following table the affordable technology, Treatment Technique, or other means
available to systems serving 10,000 persons or fewer for achieving compliance with the
Maximum Contaminant Level for arsenic:
22.06: continued
SMALL SYSTEM COMPLIANCE TECHNOLOGIES (SSCTS) FOR ARSENIC
Small System Compliance Technology
Affordable for Listed Small System Categories3
Activated Alumina (centralized) . . . . . . . . . . . . . . . . . . . . All size categories.
Activated Alumina (Point-of-Use) . . . . . . . . . . . . . . . . . .
All size categories.
Coagulation/Filtration . . . . . . . . . . . . . . . . . . . . . . .
501–3,300, 3,301–10,000.
Coagulation-assisted Microfiltration . . . . . . . . . . . . 501–3,300, 3,301–10,000.
Electrodialysis reversal . . . . . . . . . . . . . . . . . . . . . .
501–3,300, 3,301–10,000.
Enhanced Coagulation/Filtration . . . . . . . . . . . . . . . . . . . . All size categories.
Enhanced lime softening (pH> 10.5) . . . . . . . . . . . . . . . . . All size categories.
Ion Exchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . All size categories.
Lime Softening . . . . . . . . . . . . . . . . . . . . . . . . . . . .
501–3,300, 3,301–10,000.
Oxidation/Filtration
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
All size categories.
Reverse Osmosis (centralized) . . . . . . . . . . . . . . . .
501–3,300, 3,301–10,000.
Reverse Osmosis (Point-of-Use)
. . . . . . . . . . . . . . . . . . .
All size categories.
Section 1412(b)(4)(E)(ii) of SDWA specifies that SSCTs must be affordable and technically feasible for
small systems.
SSCTs for Arsenic V. Pre-oxidation may be required to convert Arsenic III to Arsenic V.
The SDWA (ibid.) specifies three categories of small systems: (i) those serving 25 or more, but fewer than
501, (ii) those serving more than 500, but fewer than 3,301, and (iii) those serving more than 3,300, but
fewer than 10,001.
When POU or POE devices are used for compliance, programs to ensure proper long-term operation,
maintenance, and monitoring must be provided by the water system to ensure adequate performance.
Unlikely to be installed solely for arsenic removal. May require pH adjustment to optimal range if high
removals are needed.
Technologies reject a large volume of water—may not be appropriate for areas where water quantity may
be an issue.
To obtain high removals, iron to arsenic ratio must be at least 20:1.