Ohio Administrative Code › Title 3745 - Ohio Environmental Protection Agency › Chapter 3745-81 - Primary Drinking Water Rules › Section 3745-81-24 - Organic chemical monitoring requirements

Current through all regulations passed and filed through July 1, 2024
Monitoring requirements for organic chemical contaminants of
				drinking water are stated in this rule. Analytical procedures which are
				acceptable for monitoring for organic contaminants in drinking water are listed
				in rule
				3745-81-27
				of the Administrative Code. Analyses under this rule shall only be conducted by
				laboratories that are certified for these analyses under Chapter 3745-89 of the
				Administrative Code. Community public water systems and nontransient
				noncommunity public water systems shall monitor for organic chemicals according
				to a schedule provided by the director.
(A) Monitoring for volatile organic chemicals
			 with maximum contaminant levels (MCLs) listed in paragraph
			 (C) of
			 rule
			 3745-81-12
			 of the Administrative Code shall be conducted by community public water systems
			 and nontransient noncommunity public water systems as follows:
(1) Groundwater systems shall monitor with a
			 minimum of one sample at each respective sampling point during each compliance
			 period. Surface water systems shall monitor with a minimum of one sample
			 annually at each sampling point. After the first set of samples, each repeat
			 sample shall be taken at the same sampling point as used before unless
			 conditions make another sampling point more representative of a source,
			 treatment plant, or part of the distribution system.
(2) If a public water system draws water from
			 more than one source and the sources are combined before distribution, the
			 public water system shall monitor at each sampling point during periods of
			 normal operating conditions and shall keep a record of and report the sources
			 providing water for each sample. When a sample does not contain water from all
			 the sources which serve the sampling point, the public water system shall
			 prepare and follow a schedule such that the next monitoring sample at this
			 sampling point for the same volatile organic chemicals will include water from
			 sources not included in the previous sample or samples. Thus, successive
			 samples from the same sampling point for the same volatile organic chemicals
			 shall sample water supplied from different sources until all the sources
			 supplying that sampling point have been monitored.
(3) Each
			 new community and new nontransient noncommunity public water system and public
			 water systems that use a new source of water shall monitor initially with four
			 consecutive quarterly samples for each contaminant listed in paragraph
			 (C) of
			 rule
			 3745-81-12
			 of the Administrative Code beginning in the first quarter of the next calendar
			 year after operation of the new source of system begins. New public water
			 systems shall sample at each sampling point; systems with a new source of water
			 shall sample at the sampling point related to the new source.
(4) If the initial monitoring for the
			 contaminants listed in paragraph (C) of rule
			 3745-81-12
			 of the Administrative Code has been completed and the public water system did
			 not detect any contaminant listed in paragraph (C) of rule
			 3745-81-12
			 of the Administrative Code, then the public water system shall monitor with one
			 sample annually. For any contaminant detected during the initial monitoring,
			 the public water system shall continue quarterly monitoring until eligible for
			 a reduction under paragraph (A)(6)(b) of this rule.
(5) The director may, after a minimum of
			 three years of annual monitoring with no detection of any contaminant listed in
			 paragraph (C) of rule
			 3745-81-12
			 of the Administrative Code, reduce monitoring by a groundwater system to one
			 sample during each compliance period.
(6) If a contaminant listed in paragraph
			 (C) of
			 rule
			 3745-81-12
			 of the Administrative Code is detected at a level exceeding 0.0005 milligram
			 per liter in any sample, then:
(a) The public
			 water system shall monitor quarterly at each sampling point which resulted in a
			 detection. If a public water system is monitoring annually or less frequently
			 for a previously detected contaminant, then the public water system does not
			 have to return to quarterly monitoring for that contaminant unless the sample
			 result exceeds eighty per cent of the MCL.
(b) The director may decrease the quarterly
			 monitoring requirement specified in paragraph (A)(6)(a) of this rule to annual
			 monitoring provided the director has determined that the public water system
			 does not exceed eighty per cent of the MCL for that contaminant. In no case
			 shall the director make this determination unless a groundwater system has
			 monitored with a minimum of two consecutive quarterly samples and a surface
			 water system has monitored with a minimum of four consecutive quarterly
			 samples.
(c) Public water systems
			 which monitor annually for a previously detected contaminant shall monitor
			 during the quarters which previously yielded the highest
			 analytical result.
(7)
			 The director may require a confirmation sample for positive or negative
			 results. If a confirmation sample is required by the director, the result shall
			 be averaged with the first sampling result and the average used for the
			 compliance determination as specified by paragraph (A)(8) of this
			 rule.
(8) Compliance with paragraph
			 (C) of
			 rule
			 3745-81-12
			 of the Administrative Code shall be determined based on the analytical results
			 obtained at each sampling point.
(a) For
			 public water systems which are conducting monitoring at a frequency greater
			 than annually, compliance is determined by a running annual average of all
			 samples taken at each sampling point. If the running annual average of any
			 sampling point is greater than the MCL, then the public water system is out of
			 compliance. The system will not be considered in violation of the MCL until it
			 has completed one year of quarterly sampling. If, however, the initial sample
			 or a subsequent sample would cause the running annual average to exceed the
			 MCL, then the public water system is out of compliance immediately. Any samples
			 below the detection limit shall be counted as zero for purposes of determining
			 the running annual average.
(b) For
			 public water systems monitoring annually or less frequently, when the average
			 of a result and a required confirmation sample exceeds eighty per cent of the
			 MCL, the public water system shall begin quarterly monitoring at that sample
			 point. If a confirmation sample was not collected, the public water system
			 shall begin quarterly monitoring if the level of the initial sample exceeds
			 eighty per cent of the MCL. Compliance with a MCL will be determined by a
			 running annual average as stated in paragraph (A)(8)(a) of this rule. If one
			 sampling point is in violation of the MCL, the system is in violation of the
			 MCL.
(c) If a public water system
			 fails to collect the required number of samples, compliance will be based on
			 the total number of samples collected.
(9) Analysis for the contaminants listed in
			 paragraph (C) of rule
			 3745-81-12
			 of the Administrative Code shall be conducted using the methods in rule
			 3745-81-27
			 of the Administrative Code.
(10) Analysis under this rule shall only be
			 conducted by laboratories that are approved under Chapter 3745-89 of the
			 Administrative Code.
(11) The
			 director has discretion to delete results of obvious sampling or analytical
			 errors.
(12) The director may
			 increase required monitoring where necessary to detect variations within the
			 public water system.
(13) Each
			 approved laboratory shall determine the method detection limit (MDL), as
			 defined in the appendix to rule
			 3745-89-03
			 of the Administrative Code, at which it is capable of detecting volatile
			 organic chemicals. The acceptable MDL is 0.0005 milligram per liter. This
			 concentration is the detection concentration for purposes of this
			 rule.