Ohio Admin. Code 3745-81-26 - Radionuclide monitoring requirements
Community public water systems shall
(A) Monitoring requirements for gross alpha
particle activity , radium-226, radium-228, and uranium.
(1) 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
paragraph (D) of this rule.
(2) All
existing community public water systems shall sample at every sampling point
that is representative of all sources being used under normal operating
conditions for that sampling point . The system shall take each sample at the
same sampling point unless the director determines that conditions make another
sampling location more representative of each source .
(3) All new community public water systems or
community public water systems that use a new source of water shall begin
initial monitoring within the first quarter after initiating use of the
source .
(4) Initial monitoring.
Systems shall conduct initial monitoring for gross alpha particle activity ,
radium-226, radium-228, and uranium as follows:
(a) Systems shall collect four consecutive
quarterly samples at all sampling points.
(b) For gross alpha particle activity ,
uranium, radium-226, and radium-228 monitoring, the director 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.
(5) If the
average of the initial monitoring results for a sampling point is above the
maximum contaminant level (MCL ), the community public water system shall
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 .
(6) Reduced monitoring. The
director may allow community public 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 paragraph
(D) of this rule, the community public system shall 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 fifty per cent
of the MCL , the community public water system shall 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
shall 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 fifty per cent of the
(c) For gross alpha particle activity and
uranium, if the average of the initial monitoring results for each contaminant
is above fifty per cent of the MCL but at or below the MCL , the community
public water system shall collect and analyze at least one sample at that
sampling point every three years.
For combined radium-226 and radium-228, the analytical results
shall be combined. If the average of the combined initial monitoring results
for radium-226 and radium-228 is above fifty per cent of the
(d) Community public water systems shall 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 fifty per cent of MCL but at or below the MCL , then the next monitoring
period for that sampling point is at least one sample every three
years.)
(e) If a community public
water system has a monitoring result that exceeds the MCL while on reduced
monitoring, the system shall 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 .
(7) 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 five 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 fifteen pCi /L. The gross alpha measurement shall have a
confidence interval of ninety-five per cent ( 1.96 sigma where sigma is the
standard deviation of the net counting rate of the sample) for radium-226 and
uranium. When a community public water system uses a gross alpha particle
activity measurement in lieu of 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, fifty per cent of the
detection limit will be used to determine compliance and the future monitoring
frequency.
(B)
Monitoring requirements for beta particle and photon radioactivity.
(1) The director may designate a community
public water system as vulnerable to beta particle and photon radioactivity
contamination based on identified potential radioactive sources within the
drinking water source protection area delineated or endorsed by the agency
under Ohio's wellhead protection and source water assessment and protection
programs. Community public water systems designated by the director as
vulnerable shall sample for beta particle and photon radioactivity to determine
compliance with the maximum contaminant levels listed in rule
3745-81-15 asfollows:
(a) Community public water systems shall
collect quarterly samples for beta emitters and annual samples for tritium and
strotium-90 at each sampling point , beginning within one quarter after being
notified by the director . Systems designated as vulnerable shall continue to
sample until the director removes the designation.
(b) If the gross beta particle activity at a
sampling point has a running annual average (computed quarterly) less than or
equal to fifty pCi /L (screening level) and the combined monitoring results for
all measured contaminants (i.e. tritium. strontium-90, and any other
contaminants for beta particle and photon radioactivity as specified by rule
3745-81-15 of the Administrative
Code) are at or below the MCL , the director may reduce the frequency of
monitoring at that sampling point to once every three years. Systems shall
collect all samples required in paragraph (B)(1)(a) of this rule during the
reduced monitoring period.
(2) Community public water systems designated
by the director as utilizing waters contaminated by effluents from nuclear
facilities shall sample for beta particle and photon radioactivity to determine
compliance with the MCLs listed in rule
3745-81-15 of the Administrative
Code as follows:
(a) Community public water
systems shall collect monthly samples for gross beta particle activity and
quarterly samples for iodine-131, tritium, and strontium-90 at each sampling
point , beginning within one quarter after being notified in writing by the
director . For iodine-131, five consecutive daily samples shall be analyzed once
each quarter. As ordered by the director , more frequent monitoring shall be
conducted when iodine-131 is identified in the finished water . Systems
designated by the director as using waters contaminated by effluents from
nuclear facilities shall continue to sample until the director removes the
designation.
(b) If the gross beta
particle activity at a sampling point has a running annual average (computed quarterly) less than or equal
to fifteen pCi /L (screening level) and the combined monitoring results are at
or below the MCL for all measured contaminants (i.e., iodine-131, tritium,
strontium-90, etc.), the director may reduce the frequency of monitoring at
that sampling point to every three years. Community public water systems shall
collect all samples required in paragraph (B)(2)(a) of this rule during the
reduced monitoring period.
(3) A waiver from the monitoring frequencies
specified in paragraph (B)(1) or (B)(2) of this rule shall not be granted to
community public water systems designated by the director as vulnerable to beta
particle and photon radioactivity contamination.
(4) Community public water systems may
analyze for naturally occurring potassium-40 beta particle activity from the
same or equivalent sample used for gross beta particle activity analysis.
Systems may subtract the potassium-40 beta particle activity value from the
total gross beta activity. The potassium-40 beta particle activity shall be
calculated by multiplying elemental potassium concentrations (in mg/L) by a
factor of 0.82 picocuries of potassium-40 per milligram of potassium.
(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 shall be performed to
identify the major applicable radioactive constituents present in the sample
and the appropriate doses shall be calculated and summed to determine
compliance with the MCLs listed in rule
3745-81-15 of the Administrative
Code. Doses shall also be calculated and combined for measured levels of
tritium and strontium to determine compliance.
(6) Community public water systems shall
monitor monthly at the sampling point (s) which exceed the MCLs as determined in
rule 3745-81-15 of the Administrative
Code beginning the month after the exceedance occurs. Systems shall continue
monthly monitoring until the system has established, by a running average of
three monthly samples, that the MCL is being met. Systems who establish that
the MCL is being met shall return to quarterly monitoring until they meet the
requirements set forth in paragraph (B)(1)(b) or (B)(2)(b) of this
rule.
(7) For community public
water systems in the vicinity of a nuclear facility or other facility that is a
radioactive source , the director may allow the systems to utilize environmental
surveillance data collected by the nuclear facility (i.e., raw water data for
locations within the vicinity of the systems) in lieu of monitoring at the
system's sampling point (s), where the director determines that data is
applicable to a particular water system. In the event that there is a release
from a nuclear facility, community public water systems which are using
surveillance data shall begin monitoring at the system's sampling point (s) in
accordance with paragraph (B)(1) or (B)(2) of this rule.
(C) General monitoring and compliance
requirements for radionuclides.
(1) The
director may require more frequent monitoring than specified in paragraphs (A)
and (B) of this rule, or may require confirmation samples. The results of the
initial and confirmation samples will be averaged for use in compliance
determinations.
(2) To determine
compliance with the MCLs listed in rule
3745-81-15 of the Administrative
Code, 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.
(3) Compliance with the
MCLs listed in rule
3745-81-15 of the Administrative
Code will be determined based on the analytical result(s) obtained at each
sampling point . If the average of any sampling point is greater than the MCL ,
then the community public water system is in violation of the MCL .
(a) For community public water systems
monitoring more than once per year, compliance with the MCL is determined
quarterly 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 in violation of
the MCL .
(b) For community public
water systems monitoring more than once per year, if any sample result will
cause the running annual average to exceed to
the MCL at any
sampling point , the system is out of compliance with the MCL
immediately.
(c) Community public
water systems shall include all samples taken and analyzed under the provisions
of this rule in determining compliance, even if that number is greater than the
minimum required.
(d) If a
community public water system does not collect all required samples when
compliance is based on a running annual average, compliance will be based on
the running average of the total number of samples collected.
(e) If a sample result is less than the
detection limit, zero will be used to calculate the running annual average,
unless a gross alpha particle activity result is being used in lieu of
radium-226 or uranium. If the gross alpha particle activity result is less than
detection, fifty per cent of the detection limit will be used to calculate the
running annual average for radium-226 and/or uranium.
(4) The director has the discretion to delete
results of obvious sampling or analytical errors.
(5) If a MCL set forth in rule
3745-81-15 of the Administrative
Code is exceeded, the owner or operator of a community water system shall give
notice to the director pursuant to rule
3745-81-31 of the Administrative
Code and to the public as required by rule
3745-81-32 of the Administrative
Code.
(D) For the
purpose of monitoring radioactivity concentrations in drinking water, the
required sensitivity of the radioanalysis is defined in terms of a detection
limit.
(1) The detection limit shall be that
concentration which can be counted with a precision of plus or minus one
hundred per cent at the ninety-five per cent confidence level ( 1.96 sigma
where sigma is the standard deviation of the net counting rate of the
sample).
(2) To determine
compliance with rule
3745-81-15 of the Administrative
Code, the detection limits shall not exceed the concentrations listed in the
following table:
|
Radionuclide |
Detection limit |
|
Cesium-134 |
10 |
|
Iodine-131 |
1 |
|
Gross alpha |
3 |
|
Gross beta |
4 |
|
Radium-226 |
1 |
|
Radium-228 |
1 |
|
Strontium-89 |
10 |
|
Strontium-90 |
2 |
|
Tritium |
1,000 |
|
Uranium |
1 µg/L |
|
Other beta/photon emitters |
1/10 of the |
Notes
Promulgated Under: 119.03
Statutory Authority: 6109.04
Rule Amplifies: 6109.04
Prior Effective Dates: 12/27/1978, 05/22/1989, 09/15/2004, 04/15/2005, 02/22/2010, 02/23/2015
Promulgated Under: 119.03
Statutory Authority: 6109.04
Rule Amplifies: 6109.04
Prior Effective Dates: 12/27/78, 05/22/89, 09/15/04, 04/15/05, 02/22/10
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