(a) Applicability. All community and nontransient,
noncommunity water systems shall comply with the requirements of this
section regarding organic contaminants. For purposes of this section,
systems using groundwater under the direct influence of surface water
shall meet the organic sampling requirements given for surface water
systems.
(b) Maximum contaminant levels (MCLs) for organic contaminants.
The concentration of synthetic and volatile organic chemicals shall
not exceed the MCLs specified in this section.
(1) The following are MCLs for synthetic organic chemical
(SOC) contaminants.
Attached Graphic
(2) The following are MCLs for volatile organic chemical
(VOC) contaminants.
Attached Graphic
(3) Each public water system must certify annually
to the executive director (using third-party or manufacturer's certification)
that when acrylamide or epichlorohydrin are used in drinking water
systems, the combination (or product) of dose and monomer level does
not exceed 0.05% dosed at 1.0 milligrams per liter (mg/L) (or equivalent)
for acrylamide and 0.01% dosed at 20 mg/L (or equivalent) for epichlorohydrin.
(c) Monitoring requirements for organic contaminants.
Public water systems shall monitor for organic contaminants at the
locations and frequency in paragraphs (1) and (2) of this subsection.
All monitoring conducted under the requirements of this section must
be conducted at sites designated in the public water system's monitoring
plan. All samples must be taken during periods of normal operation.
(1) SOC monitoring requirements. Monitoring of the
SOC contaminants shall be conducted at the frequency and locations
given in this paragraph.
(A) SOC monitoring locations. Monitoring of the SOC
contaminants shall be conducted at the following locations.
(i) Systems shall routinely sample at sample sites
representative of each entry point to the distribution system.
(ii) Subsequent samples must be taken at the same sample
site unless the executive director determines that a change in conditions
makes a different sample site more representative of the water available
to customers.
(iii) The executive director must approve any change
in sampling location.
(B) Initial SOC monitoring frequency. Prior to using
a new source of water as drinking water, public water systems shall
monitor at the frequency established by the executive director to
ensure that the water distributed to customers will comply with the
MCLs for SOCs.
(C) Routine SOC monitoring frequency. Monitoring of
the SOC contaminants shall be conducted at the following frequency.
(i) Community and nontransient, noncommunity water
systems shall take four consecutive quarterly samples for each SOC
contaminant listed in subsection (b)(1) of this section during each
compliance period beginning with the initial compliance period.
(ii) Community and nontransient, noncommunity water
systems serving more than 3,300 persons that do not detect a contaminant
in the initial compliance period may reduce the sampling frequency
at that sample site to a minimum of two consecutive quarterly samples
in one year during each repeat compliance period.
(iii) Community and nontransient, noncommunity water
systems serving 3,300 persons or fewer that do not detect a contaminant
in the initial compliance period may reduce the sampling frequency
at that sample site to a minimum of one sample during each repeat
compliance period.
(iv) Each public water system shall monitor at the
time designated by the executive director within each compliance period.
(D) Increased SOC monitoring. The executive director
may change the monitoring frequency for SOCs.
(i) Entry points that exceed the SOC MCLs of subsection
(b)(1) of this section as determined by subsection (f) of this section
must be monitored quarterly. After a minimum of four quarterly samples
shows the system is in compliance and the executive director determines
the system is reliably and consistently below the MCL, as determined
by the methods specified in subsection (f) of this section, the executive
director may allow the system to monitor annually. Systems that monitor
annually must monitor during the quarter that previously yielded the
highest analytical result.
(ii) The executive director may change the monitoring
frequency if an organic SOC contaminant is detected in any sample.
(I) If an organic SOC contaminant is detected in any
sample, the system must monitor quarterly at each entry point to the
distribution system at which a detection occurs.
(II) After a system collects a minimum of two consecutive
quarterly samples at a groundwater sample site, the executive director
may decrease the quarterly monitoring requirement specified in subclause
(I) of this clause, if the sample site is reliably and consistently
below the MCL.
(III) After a system collects a minimum of four consecutive
quarterly samples at a surface water sample site or a groundwater
under the direct influence of surface water sample site, the executive
director may decrease the quarterly monitoring requirement specified
in subclause (I) of this clause, if the sample site is reliably and
consistently below the MCL.
(IV) After the executive director determines that a
sample site is reliably and consistently below the MCL, the executive
director may allow the sample site to be monitored annually. Systems
that monitor annually must monitor during the quarter that previously
yielded the highest analytical result.
(V) Sample sites that have three consecutive annual
samples with no detection of a contaminant may be granted a waiver
at the discretion of the executive director. The executive director
will consider the waiver for each compliance period.
(VI) If monitoring results in detection of one or more
of certain related contaminants (i.e., heptachlor and heptachlor epoxide),
then subsequent monitoring shall analyze for all related contaminants.
(iii) The executive director may increase the required
SOC monitoring frequency, where necessary, to detect variations within
the system (e.g., fluctuations in concentration due to seasonal use,
changes in water source, etc.).
(iv) The executive director may require a confirmation
sample for positive or negative results. If a confirmation sample
is required by the executive director, the result must be averaged
with the first sampling result and the average used for the compliance
determination as specified in subsection (f) of this section. The
executive director has discretion to delete results of obvious sampling
errors from this calculation.
(E) Waivers for SOC monitoring. The executive director
may grant a waiver to reduce the SOC monitoring frequency from the
monitoring frequency requirements of subparagraphs (B) and (C) of
this paragraph, based on previous use of the contaminant within the
watershed or zone of influence of the water source. Examples of use
of a contaminant include transport, storage, or disposal. If a determination
by the executive director reveals no previous use of the contaminant
within the watershed or zone of influence, a waiver may be granted.
If the executive director cannot determine whether the contaminant
has been used in the watershed or if the contaminant has been used
previously, then the following factors shall be used to determine
whether a waiver is granted:
(i) previous analytical results;
(ii) 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
drinking water sources, 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 insects, weeds, or pests on agricultural areas, forest
lands, home and garden property, or other land application uses;
(iii) the environmental persistence and transport of
the pesticide herbicide or contaminant;
(iv) how well the water source is protected against
contamination due to such factors as depth of the well, type of soil,
and the integrity of well construction. Surface water systems must
consider watershed vulnerability and protection;
(v) elevated nitrate levels at the water supply source;
and
(vi) use of polychlorinated byphenyls (PCBs) in equipment
used in the production, storage, or distribution of water (i.e., PCBs
used in pumps, transformers, etc.).
(F) Compositing for SOC monitoring. The executive director
may reduce the total number of samples required from a system for
analysis by allowing the use of compositing. Composite samples from
a maximum of five entry points to the distribution system are allowed.
Compositing of samples must be done in the laboratory and analyzed
within 14 days of sample collection.
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