Ohio Administrative Code › Title 3745 - Ohio Environmental Protection Agency › Chapter 3745-81 - Primary Drinking Water Rules › Section 3745-81-50 - Revised total coliform rule - general monitoring requirements

Current through all regulations passed and filed through July 1, 2024
(A)
The director may determine that a public water system
			 shall apply best available technology in order to reduce the level of a
			 contaminant to below its maximum contaminant level (MCL). The director
			 identifies the following as the best available technology for achieving
			 compliance with the MCL for Escherichia coli (total coliforms and E. coli) as
			 set forth in this rule:
(1)
									Protection of wells from E. coli contamination by
			 appropriate placement and construction in accordance with Chapter 3745-9 of the
			 Administrative Code.
(2)
									Maintenance of a disinfectant residual throughout the
			 distribution system in accordance with rule
			 3745-81-72
			 of the Administrative Code and paragraph (C) of rule
			 3745-83-01
			 of the Administrative Code.
(3)
									Proper
			 maintenance of the distribution system including appropriate pipe replacement
			 and repair procedures, main flushing programs, proper operation and maintenance
			 of storage tanks and reservoirs, continual maintenance of positive water
			 pressure in all parts of the distribution system and backflow prevention as
			 described in Chapter 3745-95 of the Administrative Code.
(4)
									Filtration or
			 disinfection by public water systems using surface water, in whole or in part,
			 as required by rules
			 3745-81-64
			 to
			 3745-81-69
			 and
			 3745-81-71
			 to
			 3745-81-75
			 of the Administrative Code, or disinfection of ground water, as required by
			 rules
			 3745-81-41
			 to
			 3745-81-45
			 of the Administrative Code, using strong oxidants such as chlorine, chlorine
			 dioxide or ozone.
(5)
									Where appropriate, the development and implementation
			 of a source water assessment and protection program approved by the
			 director.
(B)
			 Sample siting plans:
(1) Each public water
			 system shall develop a written sample siting plan  that identifies a sample collection schedule and
			 sampling sites that are representative of water throughout the distribution
			 system. Such plans are subject to review and revision by the director. A public
			 water system shall collect total coliform samples according to the written
			 sample siting plan. Monitoring required in rules
			 3745-81-51
			 and
			 3745-81-52
			 of the Administrative Code shall take place at a designated compliance sampling
			 location. Routine and repeat sample sites and any sampling points necessary to
			 meet rules
			 3745-81-41
			 to
			 3745-81-45
			 of the Administrative Code shall be included in the sample siting plan.
			 Seasonal systems monitoring on a quarterly schedule shall designate the time
			 period for monitoring based on site-specific considerations, such as periods of
			 highest demand or highest vulnerability to contamination.
(2) Each public water system shall monitor
			 with routine samples taken at regular time intervals throughout the month in
			 accordance with the system's sample siting plan, except that systems using only
			 ground water and serving four thousand nine hundred or fewer people may collect
			 all required samples on a single day if taken from different sites.
(3) Every public water system shall take at
			 least the minimum number of required samples even if the system has had an
			 E.Coli
									
									MCL
									 as
			 set forth in rule
			 3745-81-54
			 of the Administrative Code or has exceeded the coliform treatment technique
			 triggers as set forth in rule
			 3745-81-53
			 of the Administrative Code.
(4) A
			 public water system may conduct more compliance monitoring than is required by
			 this rule and rules
			 3745-81-51
			 to
			 3745-81-53
			 of the Administrative Code to investigate and discover potential problems in
			 the distribution system. If the additional routine samples are taken in
			 accordance with the existing sample siting plan and are representative of the
			 water throughout the distribution system, the results of the samples must be
			 included in calculating whether the coliform treatment technique trigger in
			 paragraph (A)(1)(a) or (A)(1)(b) of rule
			 3745-81-53
			 of the Administrative Code has been exceeded.
(5) Each public water system shall identify
			 repeat monitoring locations in the sample siting plan. Unless the provisions of
			 the following paragraphs are met, the system shall monitor with at least one
			 repeat sample from the sampling tap where the original total coliform-positive
			 sample was taken, and at least one repeat sample at a tap within five service
			 connections upstream and at least one repeat sample at a tap within five
			 service connections downstream of the original sampling site. If a total
			 coliform-positive sample is at the end of the distribution system, or one
			 service connection away from the end of the distribution system, the system
			 shall still take all required repeat samples; however, the director may allow
			 an alternative sampling location in lieu of the requirement to monitor with at
			 least one repeat sample upstream or downstream of the original sampling site.
			 Except as provided for in paragraph (B)(5)(b) of this rule, each public water
			 system required to conduct triggered source water monitoring as set forth in
			 paragraph (A) of rule
			 3745-81-42
			 of the Administrative Code shall take a ground water source sample in addition
			 to repeat samples required in this rule and rules
			 3745-81-51
			 to
			 3745-81-53
			 of the Administrative Code.
(a) A system may
			 propose repeat monitoring locations to the director that the system considers
			 to be representative of a pathway for contamination of the distribution system.
			 A system may elect to specify either alternative fixed locations or criteria
			 for selecting repeat sampling sites on a situational basis in a standard
			 operating procedure (SOP) in the system's sample siting plan. The system shall
			 design the SOP to focus the repeat samples at locations that best verify and
			 determine the extent of potential contamination of the distribution system area
			 based on specific situations. The director may modify the SOP or require
			 alternative monitoring locations as needed.
(b) Ground water systems serving one thousand
			 people or fewer may propose repeat sampling locations to the director that
			 differentiate potential source water and distribution system contamination
			 (e.g., by sampling at entry points to the distribution system). If acceptable
			 to the director, a ground water system with a single well required to conduct
			 triggered source water monitoring may take one of the repeat samples at the
			 monitoring location required for triggered source water monitoring as set forth
			 in paragraph (A) of rule
			 3745-81-42
			 of the Administrative Code if the system demonstrates to the director that the
			 sample siting plan remains representative of water quality in the distribution
			 system.
(i) If a repeat sample taken at the
			 monitoring location required for triggered source water monitoring is E.
			 coli-positive, the public water system is in violation of the MCL for E. coli
			 and shall conduct additional source water monitoring in accordance with
			 paragraph (A)(3) of rule
			 3745-81-42
			 of the Administrative Code. If the system takes more than one repeat sample at
			 the monitoring location required for triggered source water monitoring, the
			 system may reduce the number of additional source water samples required in
			 paragraph (A)(3) of rule
			 3745-81-42
			 of the Administrative Code by the number of repeat samples taken at that
			 location that were not E. coli-positive.
(ii) If the system takes more than one repeat
			 sample at the monitoring location for triggered source water monitoring in
			 paragraph (A) of rule
			 3745-81-42
			 of the Administrative Code, and more than one repeat sample is E.
			 coli-positive, the system has violated the MCL for E. coli and shall comply
			 with rule
			 3745-81-61
			 of the Administrative Code.
(iii)
			 If all repeat samples taken at the monitoring location required for triggered
			 source water monitoring are E. coli-negative and a repeat sample taken at a
			 monitoring location other than the one required for triggered source water
			 monitoring is E. coli-positive, the system has violated the MCL for E. coli,
			 but is not required to conduct additional source water monitoring in accordance
			 with paragraph (A)(3) of rule
			 3745-81-42
			 of the Administrative Code.
(6) The director may review, revise and
			 accept, as appropriate, repeat sampling proposed by public water systems under
			 paragraphs (B)(5)(a) and (B)(5)(b) of this rule. The system shall demonstrate
			 that the sample siting plan remains representative of the water quality in the
			 distribution system. The director may determine that monitoring at the entry
			 point to the distribution system (especially for ground water systems having
			 minimal treatment as defined in rule
			 3745-81-01
			 of the Administrative Code) is effective to differentiate between potential
			 source water and distribution system problems.