South Carolina Code of Regulations › Chapter 61 - DEPARTMENT OF HEALTH AND ENVIRONMENTAL CONTROL › Subchapter 61-58.10 - Filtration and Disinfection › Section 61-58.10.C - Criteria for Avoiding Filtration

Current through Register Vol. 48, No. 6, June 28, 2024
A public water system that uses a surface water source shall
				meet all of the conditions of paragraphs (1) and (2) of this section, and is
				subject to paragraph (3) of this section, beginning December 30, 1991, unless
				the Department has determined, in writing, that filtration is required. A
				public water system that uses a ground water source under the direct influence
				of surface water shall meet all of the conditions of paragraphs (1) and (2) of
				this section and is subject to paragraph (3) of this section, beginning 18
				months after the Department determines that it is under the direct influence of
				surface water, or December 30, 1991, whichever is later, unless the Department
				has determined, in writing, that filtration is required. If the Department
				determines, in writing, before December 30, 1991, that filtration is required,
				the system shall have installed filtration and meet the criteria for filtered
				systems specified in R.61-58.10(D)(2)(D)(2)
				and R.61-58.10(D)(2)(E)by June 61-58.10(D)(2)9, 1993. Within 18 months of the
				failure of a system using surface water or a ground water source under the
				direct influence of surface water to meet any one of the requirements of
				paragraphs (1) and (2) of this section or after June 29, 1993, whichever is
				later, the system shall have installed filtration and meet the criteria for
				filtered systems specified inR.61-58.10(E)(D)(2)
				and R.61-58.10(E).
(1) Source water
			 quality conditions.
(a) The fecal coliform
			 concentration must be equal to or less than 20/100 ml, or the total coliform
			 concentration must be equal to or less than 100/100 ml [measured as specified
			 in R.61-58.10(F)(1)(a) and (b) and (2)(a)(F)(1)(a)
			 and (b) and (2)(a)], in representative
			 samples of the source water immediately prior to the first or only point of
			 disinfectant application in at least 90 percent of the measurements made for
			 the 6 previous months that the system served water to the public on an ongoing
			 basis. If a system measures both fecal and total coliforms, the fecal coliform
			 criterion, but not the total coliform criterion, in this paragraph must be
			 met.
(b) The turbidity level cannot
			 exceed 5 NTU [measured as specified in R.61-58.10(F)(1)(d) and (2)(b)(F)(1)(d) and
			 (2)(b)] in representative samples of the
			 source water immediately prior to the first or only point of disinfectant
			 application unless:
(i) The Department
			 determines that any such event was caused by circumstances that were unusual
			 and unpredictable; and
(ii) As a
			 result of any such event, there have not been more than two events in the past
			 12 months the system served water to the public, or more than five events in
			 the past 120 months the system served water to the public, in which the
			 turbidity level exceeded 5 NTU. An "event" is a series of consecutive days
			 during which at least one turbidity measurement each day exceeds 5
			 NTU.