These maximum contaminant levels shall apply to all public water systems.(1) Until March 31, 2016, the total coliform MCL is based on the presence or absence of total coliforms in a sample, rather than coliform density. (a) For a system which collects at least forty (40) samples per month, if no more than five (5.0) percent of the samples collected during a month are total coliform-positive, the system is in compliance with the MCL for total coliforms.(b) For a system which collects fewer than forty (40) samples per month, if no more than one (1) sample collected during a month is total coliform -positive, the system is in compliance with the MCL for total coliforms.(2) Until March 31, 2016, any fecal coliform-positive repeat sample or E. coli-positive repeat sample, or any total coliform-positive repeat sample following a fecal coliform-positive or E. coli-positive routine sample constitutes a violation of the MCL for total coliforms. For purposes of the public notification requirements in R.61 58.6.E, this is a violation that may pose an acute risk to health.(3) Beginning April 1, 2016, a system is in compliance with the MCL for E. coli for samples taken under provisions of R.61-58.17 unless any of the conditions identified in R.61-58.5.F(3)(a) through (d) occur. For purposes of the public notification requirements in R.61-58.6.E, violation of the MCL may pose an acute risk to health. (a) The system has an E. coli-positive repeat sample following a total coliform-positive routine sample.(b) The system has a total coliform-positive repeat sample following an E. coli-positive routine sample.(c) The system fails to take all required repeat samples following an E. coli-positive routine sample.(d) The system fails to test for E. coli when any repeat sample tests positive for total coliform.(4) Until March 31, 2016, a public water system must determine compliance with the MCL for total coliforms in R.61-58.5.F(1) and (2) for each month in which it is required to monitor for total coliforms. Beginning April 1, 2016, a public water system must determine compliance with the MCL for E. coli in R.61-58.5.F(3) for each month in which it is required to monitor for total coliforms.(5) The United States Environmental Protection Agency Administrator, pursuant to section1412 of the federal Safe Drinking Water Act, has identified the following as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant level for total coliforms in R.61-58.5.F(1)and (2) and for achieving compliance with the maximum contaminant level for E. coli in R.61-58.5.F(3): (a) Protection of wells from fecal contamination by appropriate placement and construction;(b) Maintenance of a disinfection residual throughout the distribution system;(c) Proper maintenance of the distribution system including appropriate pipe placement and repair procedures, main flushing programs, proper operation and maintenance of storage tanks and reservoirs, cross connection control, and continual maintenance of positive water pressure in all parts of the distribution system;(d) Filtration and/or disinfection of surface water, as described in R.61-58.10, or disinfection of ground water, as described in R.61-58.16, using strong oxidants such as chlorine, chlorine dioxide, or ozone; and(e) For systems using ground water, compliance with the requirements of an EPA-approved Department Wellhead Protection Program developed and implemented under section1428 of the federal Safe Drinking Water Act.(6) The United States Environmental Protection Agency Administrator, pursuant to section1412 of the federal Safe Drinking Water Act, identifies the technology, treatment techniques, or other means available identified in R.61-58.5.F(5) as affordable technology, treatment techniques, or other means available to systems serving 10,000 or fewer people for achieving compliance with the maximum contaminant level for total coliforms in R.61-58.5.F(1) and (2) and for achieving compliance with the maximum contaminant level for E. coli in R.61-58.5.F(3).
S.C. Code Regs. § 61-58.5.F
Amended by State Register Volume 38, Issue No. 9, eff. 9/26/2014.