3745-81-14. Maximum contaminant levels for microbiological contaminants  


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  • (A) Until March 31, 2016, a public water system which monitors with at least forty samples per month is in compliance with the maximum contaminant level (MCL) for total coliforms when no more than 5.0 per cent of the total number of samples during a month are total coliform-positive.

    (B) Until March 31, 2016, a public water system which monitors with fewer than forty samples per month is in compliance with the MCL for total coliforms when no more than one sample during a month is total coliform-positive.

    (C) Until March 31, 2016, a public water system is in violation of the MCL for total coliforms, and may pose an acute risk to human health, if any repeat sample collected in accordance with rule 3745-81-21 of the Administrative Code meets any of the following:

    (1) Fecal coliform-positive.

    (2) Escherichia coli-positive (E. coli-positive).

    (3) Total coliform-positive following a fecal coliform-positive routine sample.

    (4) Total coliform-positive following an E. coli-positive routine sample.

    (D) Beginning April 1, 2016, a public water system is in violation of the MCL for E. coli, and may pose an acute risk to human health, for samples collected in accordance with rules 3745-81-50 to 3745-81-55 of the Administrative Code if any of the following occur:

    (1) The system has an E. coli-positive repeat sample following a total coliform-positive routine sample.

    (2) The system has a total coliform-positive repeat sample following an E.coli-positive routine sample.

    (3) The system fails to collect all required repeat samples following an E. coli-positive routine sample.

    (4) The system fails to test for E. coli when any repeat sample is total coliform-positive.

    (E) Until March 31, 2016, a public water system shall determine compliance with the MCL for total coliforms as set forth in paragraphs (A), (B) and (C) of this rule for each period in which the public water system is required to monitor for total coliforms.

    (F) Beginning April 1, 2016, a public water system shall determine compliance with the MCL for E. coli as set forth in paragraph (D) of this rule for each period in which the public water system is required to monitor for total coliforms.

    (G) Until March 31, 2016, a public water system which exceeds any MCL for total coliforms set forth in paragraphs (A), (B) and (C) of this rule shall do all of the following:

    (1) Report the violation to the director no later than the end of the next business day after the public water system learns of the violation.

    (2) Notify the public in accordance with rule 3745-81-32 of the Administrative Code.

    (3) Determine the source of contamination.

    (4) Eliminate the source of contamination.

    (H) 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 MCL. The director identifies the following as the best available technology for achieving compliance with the MCL for total coliforms and E. coli as set forth in this rule :

    (1) Protection of wells from fecal contamination by coliforms 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.


Effective: 4/1/2016
Five Year Review (FYR) Dates: 01/15/2016 and 04/01/2021
Promulgated Under: 119.03
Statutory Authority: 6109.04
Rule Amplifies: 6109.03, 6109.04
Prior Effective Dates: 12/27/78, 11/26/80, 3/1/88, 5/22/89, 12/31/90, 9/13/93, 4/1/99, 8/3/04, 1/1/08