(a) Analysis for
the following contaminants shall be conducted to determine compliance with
section
11-20-7
in accordance with the methods in
40 C.F.R. §
141.25(a) or the alternative
methods listed in Appendix A to subpart C of 40 C.F.R. 141, or their equivalent
determined by the State in accordance with section
11-20-14.
(b) When the identification and measurement
of radionuclides other than those listed in subsection (a) of this section is
required, the following references are to be used, except in cases where
alternative methods have been approved in accordance with section
11-20-14.
(1)
Procedures for Radiochemical
Analysis of Nuclear Reactor Aqueous Solutions, H.L. Krieger and S.
Gold, EPA-R4-73-014. USEPA, Cincinnati, Ohio, May 1973
(2)
HASL Procedure Manual,
Edited by John H. Harley, HASL, 300, ERDA Health and Safety Laboratory, New
York, NY., 1973.
(c) For
the purpose of monitoring radioactivity concentrations in drinking water, the
required sensitivity of the radioanalysis is defined in terms of a detection
limit. The detection limit shall be that concentration which can be counted
with a precision of plus or minus 100 percent at the 95 percent confidence
level (1.96ó where ó is the standard deviation of the net
counting rate of the sample).
(1) To
determine compliance with section
11-20-7(b),
(c), and (e), the detection limit shall not exceed the concentrations in Table
B of this paragraph.
TABLE B - Detection limits for gross alpha particle activity,
Radium 226, Radium 228 and Uranium
Contaminant
|
Detection Limit
|
Gross alpha particle activity
|
3 pCi/L
|
Radium 226
|
1 pCi/L
|
Radium 228
|
1 pCi/L
|
Uranium
|
1 "g/L
|
(2)
To determine compliance with section
11-20-7(d)
the detection limits shall not exceed the concentrations listed in Table C of
this paragraph.
TABLE C - Detection limits for man-made beta particle and
photon emitters
Radionuclide
|
Detection Limit
|
Tritium
|
1,000 pCi/L
|
Strontium-89
|
10 pCi/L
|
Strontium-90
|
2 pCi/L
|
Iodine-131
|
1 pCi/L
|
Cesium-134
|
10 pCi/L
|
Gross beta
|
4 pCi/L
|
Other radionuclides
|
1/10 of applicable limit
|
(d)
To judge compliance with the maximum contaminant levels listed in
section
11-20-07,
averages of data shall be used and shall be rounded to the same number of
significant figures as the maximum contaminant level for the substance in
question.
(e) The State has the
authority to determine compliance or initiate enforcement action based upon
analytical results or other information compiled by their sanctioned
representatives and agencies.
(f)
Monitoring and compliance requirements for gross alpha particle activity,
radium-226, radium-228, and uranium.
(1)
Community water systems (CWSs) must conduct initial monitoring to determine
compliance with
40 C.F.R. §
141.66(b), (c), and (e) by
December 31, 2007. For the purposes of monitoring for gross alpha particle
activity, radium-226, radium-228, uranium, and beta particle and photon
radioactivity in drinking water, "detection limit" is defined as in section
11-20-13(c).
(A) Applicability and sampling location for
existing community water systems or sources. All existing CWSs using ground
water, surface water or systems using both ground and surface water (for the
purpose of this section hereafter referred to as systems) must sample at every
entry point to the distribution system that is representative of all sources
being used (hereafter called a sampling point) under normal operating
conditions. The system must take each sample at the same sampling point unless
conditions make another sampling point more representative of each source or
the State has designated a distribution system location, in accordance with
subsection (f)(2)(B)(iii) of this section.
(B)
Applicability and sampling locations for new community water
systems or sources. All new CWSs or CWSs that use a new source of water must
begin to conduct initial monitoring for the new source within the first quarter
after initiating use of the source. CWSs must conduct more frequent monitoring
when ordered by the State in the event of possible contamination or when
changes in the distribution system or treatment processes occur which may
increase the concentration of radioactivity in finished water.
(2) Initial monitoring. Systems
must conduct initial monitoring for gross alpha particle activity, radium-226,
radium-228, and uranium as follows:
(A)
Systems without acceptable historical data, as defined below, must collect four
consecutive quarterly samples at all sampling points before December 31,
2007.
(B) Grandfathering of data:
States may allow historical monitoring data collected at a sampling point to
satisfy the initial monitoring requirements for that sampling point, for the
following situations.
(i) To satisfy initial
monitoring requirements, a community water system having only one entry point
to the distribution system may use the monitoring data from the last compliance
monitoring period that began between June 2000 and December 8, 2003.
(ii) To satisfy initial monitoring
requirements, a community water system with multiple entry points and having
appropriate historical monitoring data for each entry point to the distribution
system may use the monitoring data from the last compliance monitoring period
that began between June 2000 and December 8, 2003.
(iii) To satisfy initial monitoring
requirements, a community water system with appropriate historical data for a
representative point in the distribution system may use the monitoring data
from the last compliance monitoring period that began between June 2000 and
December 8, 2003, provided that the State finds that the historical data
satisfactorily demonstrate that each entry point to the distribution system is
expected to be in compliance based upon historical data and reasonable
assumptions about the variability of contaminant levels between entry points.
The State must make a written finding indicating how the data conforms to these
requirements.
(C) For
gross alpha particle activity, uranium, radium-226, and radium-228 monitoring,
the State may waive the final two quarters of initial monitoring for a sampling
point if the results of the samples from the previous two quarters are below
the detection limit.
(D) If the
average of the initial monitoring results for a sampling point is above the
MCL, the system must collect and analyze quarterly samples at that sampling
point until the system has results from four consecutive quarters that are at
or below the MCL, unless the system enters into another schedule as part of a
formal compliance agreement with the State.
(3) Reduced monitoring. States may allow
community water systems to reduce the future frequency of monitoring from once
every three years to once every six or nine years at each sampling point based
on the following criteria:
(A) If the average
of the initial monitoring results for each contaminant (i.e., gross alpha
particle activity, uranium, radium-226, or radium-228) is below the detection
limit specified in Table B, in section
11-20-13(c)(1),
the system must collect and analyze for that contaminant using at least one
sample at that sampling point every nine years.
(B) For gross alpha particle activity and
uranium, if the average of the initial monitoring results for each contaminant
is at or above the detection limit but at or below " the MCL, the system must
collect and analyze for that contaminant using at least one sample at that
sampling point every six years. For combined radium-226 and radium-228, the
analytical results must be combined. If the average of the combined initial
monitoring results for radium-226 and radium-228 is at or above the detection
limit, but at or below " the MCL, the system must collect and analyze for that
contaminant using at least one sample at that sampling point every six
years.
(C) For gross alpha particle
activity and uranium, if the average of the initial monitoring results for each
contaminant is above ½ the MCL but at or below the MCL, the system must
collect and analyze at least one sample at that sampling point every three
years. For combined radium-226 and radium-228, the analytical results must be
combined. If the average of the combined initial monitoring results for
radium-226 and radium-228 is above ½ the MCL but at or below the MCL,
the system must collect and analyze at least one sample at that sampling point
every three years.
(D) Systems must
use the samples collected during the reduced monitoring period to determine the
monitoring frequency for subsequent monitoring periods (e.g., if a system's
sampling point is on a nine year monitoring period, and the sample result is
above ½ the MCL, then the next monitoring period for that sampling
points is three years).
(E) If a
system has a monitoring result that exceeds the MCL while on reduced
monitoring, the system must collect and analyze quarterly samples at that
sampling point until the system has results from four consecutive quarters that
are below the MCL, unless the system enters into another schedule as part of a
formal compliance agreement with the State.
(4) Compositing: To fulfill quarterly
monitoring requirements for gross alpha particle activity, radium-226,
radium-228, or uranium, a system may composite up to four consecutive quarterly
samples from a single entry point if analysis is done within a year of the
first sample. States will treat analytical results from the composited as the
average analytical result to determine compliance with the MCLs and the future
monitoring frequency. If the analytical result from the composited sample is
greater than " MCL, the State may direct the system to take additional
quarterly samples before allowing the system to sample under a reduced
monitoring schedule.
(5) A gross
alpha particle activity measurement may be substituted for the required
radium-226 measurement provided that the measured gross alpha particle activity
does not exceed 5 pCi/l. A gross alpha particle activity measurement may be
substituted for the required uranium measurement provided that the measured
gross alpha particle activity does not exceed 15 pCi/l. The gross alpha
measurement shall have a confidence interval of 95% (1.65[SIGMA], where [SIGMA]
is the standard deviation of the net counting rate of the sample) for
radium-226 and uranium. When a system uses a gross alpha particle activity
measurement in lieu of a radium-226 and/or uranium measurement, the gross alpha
particle activity analytical result will be used to determine the future
monitoring frequency for radium-226 and/or uranium. If the gross alpha particle
activity result is less than detection,½ the detection limit will be
used to determine compliance and the future monitoring frequency.
(g) Monitoring and compliance
requirements for beta particle and photon radioactivity. To determine
compliance with the maximum contaminant levels in §141.66(d) for beta
particle and photon radioactivity, a system must monitor at a frequency as
follows:
(1) Community water systems (both
surface and ground water) designated by the State as vulnerable must sample for
beta particle and photon radioactivity. Systems must collect quarterly samples
for beta emitters and annual samples for tritium and strontium-90 at each entry
point to the distribution system (hereafter called a sampling point), beginning
within one quarter after being notified by the State. Systems already
designated by the State must continue to sample until the State reviews and
either reaffirms or removes the designation.
(A)
If the gross beta particle activity minus the naturally occurring
potassium-40 beta particle activity at a sampling point has a running annual
average (computed quarterly) less than or equal to 50 pCi/L (screening level),
the State may reduce the frequency of monitoring at that sampling point to once
every 3 years. Systems must collect all samples required in subsection (g)(1)
during the reduced monitoring period.
(B) For systems in the vicinity of anuclear
facility, the State may allow the CWS to utilize environmental surveillance
data collected by the nuclear facility in lieu of monitoring at the system's
entry point(s), where the State determines if such data is applicable to a
particular water system. In the event that there is a release from a nuclear
facility, systems which are using surveillance data must begin monitoring at
the community water system's entry point(s) in accordance with subsection
(g)(1).
(2) Community
water systems (both surface and ground water) designated by the State as
utilizing waters contaminated by effluents from nuclear facilities must sample
for beta particle and photon radioactivity. Systems must collect quarterly
samples for beta emitters and iodine-131 and annual samples for tritium and
strontium-90 at each entry point to the distribution system (hereafter called a
sampling point), beginning within one quarter after being notified by the
State. Systems already designated by the State as systems using waters
contaminated by effluents from nuclear facilities must continue to sample until
the State reviews and either reaffirms or removes the designation.
(A) Quarterly monitoring for gross beta
particle activity shall be based on the analysis of monthly samples or the
analysis of a composite of three monthly samples. The former is
recommended.
(B) For iodine-131, a
composite of five consecutive daily samples shall be analyzed once each
quarter. As ordered by the State, more frequent monitoring shall be conducted
when iodine-131 is identified in the finished water.
(C) Annual monitoring for strontium-90 and
tritium shall be conducted by means of the analysis of a composite of four
consecutive quarterly samples or analysis of four quarterly samples. The latter
procedure is recommended.
(D) If
the gross beta particle activity minus the naturally occurring potassium-40
beta particle activity at a sampling point has a running annual average
(computed quarterly) less than or equal to 15 pCi/L (screening level), the
State may reduce the frequency of monitoring at that sampling point to every 3
years. Systems must collect the same type of samples required in paragraph (2)
during the reduced monitoring period.
(E)
For systems in the vicinity of a nuclear facility, the State may
allow the CWS to utilize environmental surveillance data collected by the
nuclear facility in lieu of monitoring at the system's entry point(s), where
the State determines if such data is applicable to a particular water system.
In the event that there is a release from a nuclear facility, systems which are
using surveillance data must begin monitoring at the community water system's
entry point(s) in accordance with paragraph (2).
(3) Community water systems designated by the
State to monitor for beta particle and photon radioactivity cannot apply to the
State for a waiver from the monitoring frequencies specified in paragraph (1)
or (2).
(4) Community water systems
may analyze for naturally occurring potassium-40 beta particle activity from
the same or equivalent sample used for the gross beta particle activity
analysis. Systems are allowed to subtract the potassium-40 beta particle
activity value from the total gross beta particle activity value to determine
if the screening level is exceeded. The potassium-40 beta particle activity
must be calculated by multiplying elemental potassium concentrations (in mg/L)
by a factor of 0.82.
(5) If the
gross beta particle activity minus the naturally occurring potassium-40 beta
particle activity exceeds the appropriate screening level, an analysis of the
sample must be performed to identify the major radioactive constituents present
in the sample and the appropriate doses must be calculated and summed to
determine compliance with
40 C.F.R. §
141.66(d)(1), using the
formula in
40 C.F.R. §
141.66(d)(2). Doses must
also be calculated and combined for measured levels of tritium and strontium to
determine compliance.
(6) Systems
must monitor monthly at the sampling point(s) which exceed the maximum
contaminant level in
40 C.F.R. §
141.66(d) beginning the
month after the exceedance occurs. Systems must continue monthly monitoring
until the system has established, by a rolling average of 3 monthly samples,
that the MCL is being met. Systems who establish that the MCL is being met must
return to quarterly monitoring until they meet the requirements set forth in
paragraph (1)(A) or (2)(D).
(h) General monitoring and compliance
requirements for radionuclides.
(1) The State
may require more frequent monitoring than specified in subsections (f) and (g)
of this section, or may require confirmation samples at its discretion. The
results of the initial and confirmation samples will be averaged for use in
compliance determinations.
(2)
Each public water system shall monitor at the time designated by the State
during each compliance period.
(3)
Compliance. Compliance with
40 C.F.R. §
141.66(b) through (c) will
be determined based on the analytical result(s) obtained at each sampling
point. If one sampling point is in violation of an MCL, the system is in
violation of the MCL.
(A) For systems
monitoring more than once per year, compliance with the MCL is determined by a
running annual average at each sampling point. If the average of any sampling
point is greater than the MCL, then the system is out of compliance with the
MCL.
(B) For systems more than once
per year, if any sample result will cause the running average to exceed the MCL
at any sample point, the system is out of compliance with the MCL
immediately.
(C) Systems must
include all samples taken and analyzed under the provisions of this section in
determining compliance, even if that number is greater than the minimum
required.
(D) If a system does not
collect all required samples when compliance is based on a running annual
average of quarterly samples, compliance will be based on the running average
of the samples collected.
(E) If a
sample result is less than the detection limit, zero will be used to calculate
the annual average, unless a gross alpha particle activity is being used in
lieu of radium-226 and/or uranium. If the gross alpha particle activity result
is less than detection," the detection limit will be used to calculate the
annual average.
(4)
States have the discretion to delete results of obvious sampling or analytic
errors.
(5) If the MCL for
radioactivity set forth in
40 C.F.R. §
141.66(b) through (e) is
exceeded, the operator of a community water system must give notice to the
State pursuant to
40 C.F.R. §
141.31 and to the public as required by
subpart Q of this part.