South Carolina Code of Regulations › Chapter 61 - DEPARTMENT OF HEALTH AND ENVIRONMENTAL CONTROL › Subchapter 61-58.5 - Maximum Contaminant Levels in Drinking Water › Section 61-58.5.G - Microbiological Contaminant Sampling and Analytical Requirements

Current through Register Vol. 48, No. 6, June 28, 2024
These sampling and analytical requirements shall apply to
				community and non-community water systems. Analytical methods used to comply
				with Section F above, shall be made using EPA-approved methods listed in 40 CFR
				141.
(1) Routine Monitoring.
(a) Community and non-community water systems
			 shall collect total coliform samples at sites which are representative of water
			 throughout the distribution system according to a written sample siting plan.
			 These plans are subject to Department review and revision.
(b) The monitoring frequency for total
			 coliforms for community water systems is based on the population served by the
			 system, as follows:
Population Served
Minimum # of Samples Per Month
25 to 1,000 [FN1]
1
1,001 to 2,500
2
2,501 to 3,300
3
3,301 to 4,100
4
4,101 to 4,900
5
4,901 to 5,800
6
5,801 to 6,700
7
6,701 to 7,600
8
7,601 to 8,500
9
8,501 to 12,900
10
12,901 to 17,200
15
17,201 to 21,500
20
21,501 to 25,000
25
25,001 to 33,000
30
33,001 to 41,000
40
41,001 to 50,000
50
50,001 to 59,000
60
59,001 to 70,000
70
70,001 to 83,000
80
83,001 to 96,000
90
96,001 to 130,000
100
130,001 to 220,000
120
220,001 to 320,000
150
320,001 to 450,000
180
450,001 to 600,000
210
600,001 to 780,000
240
780,001 to 970,000
270
970,001 to 1,230,000
300
1,230,001 to 1,520,000
330
1,520,001 to 1,850,000
360
1,850,001 to 2,270,000
390
2,270,001 to 3,020,000
420
3,020,001 to 3,960,000
450
3,960,000 or more
480
[FN1] Includes public water systems which have at
							 least fifteen (15) service connections, but serve fewer than twenty-five (25)
							 persons.
If a community water system serving twenty-five (25) to
				one-thousand (1,000) persons has no history of total coliform contamination in
				its current configuration and a sanitary survey conducted in the past five
				years shows that the system is supplied solely by a protected groundwater
				source and is free of sanitary defects, the Department may reduce the
				monitoring frequency specified above, except that in no case may the Department
				reduce the monitoring frequency to less than one sample per quarter. The
				Department must approve the reduced monitoring frequency in writing.
(i) [Reserved]
(ii) Community water systems shall make at a
			 minimum one fecal or total coliform density measurement each day from the raw
			 water source, and one coliform density or presence/absence measurement from the
			 finished water, if treating surface water. This requirement may be waived by
			 the Department on a case-by-case basis if a public water supply can demonstrate
			 that such monitoring is unnecessary.
(c) The monitoring frequency for total
			 coliforms for non-community water systems is as follows:
(i) A non-community water system using only
			 ground water (except ground water under the direct influence of surface water)
			 and serving one-thousand (1,000) persons or fewer shall monitor each calendar
			 quarter that the system provides water to the public, except that the
			 Department may reduce this monitoring frequency, in writing, if a sanitary
			 survey shows that the system is free of sanitary defects. Beginning June 29,
			 1994, the Department cannot reduce the monitoring frequency for a non-community
			 water system using only ground water (except ground water under the direct
			 influence of surface water) and serving one-thousand (1,000) persons or fewer
			 to less than once per year.
(ii) A
			 non-community water system using only ground water (except ground water under
			 the direct influence of surface water) and serving more than one-thousand
			 (1,000) persons during any month shall monitor at the same frequency as a
			 like-sized community water system, as specified in paragraph (1)(b) of this
			 section, except that the Department may reduce this monitoring frequency, in
			 writing, for any month the system serves one-thousand (1,000) persons or fewer.
			 The Department cannot reduce the monitoring frequency to less than once per
			 year. For systems using ground water under the direct influence of surface
			 water, paragraph (1)(c)(iv) of this section applies.
(iii) A non-community water system using
			 surface water, in total or in part, shall monitor at the same frequency as a
			 like-sized community water system, as specified in paragraph (1)(b) of this
			 section, regardless of the number of persons it serves.
(iv) A non-community water system using
			 ground water under the direct influence of surface water shall monitor at the
			 same frequency as a like-sized community water system, as specified in
			 paragraph (1)(b) of this section. The system shall begin monitoring at this
			 frequency beginning six (6) months after the Department determines that the
			 ground water is under the direct influence of surface water.
(d) The community or non-community
			 water system shall collect samples at regular time intervals throughout the
			 month, except that a system which uses ground water (except ground water under
			 the direct influence of surface water), and serves 4,900 persons or fewer, may
			 collect all required samples on a single day if they are taken from different
			 sites.
(e) A community or
			 non-community water systems that uses surface water or ground water under the
			 direct influence of surface water and does not practice filtration in
			 compliance with R.61-58.10 shall collect at
			 least one sample near the first service connection each day the turbidity level
			 of the source water, measured as specified in R.61-58.10.F(2)(b),
			 exceeds 1 NTU. This sample shall be analyzed for the presence of total
			 coliforms. When one or more turbidity measurements in any day exceed 1 NTU, the
			 system shall collect this coliform sample within 24 hours of the first
			 exceedance, unless the Department determines that the system, for logistical
			 reasons outside the system's control, cannot have the sample analyzed within
			 thirty (30) hours of collection. Sample results from this coliform monitoring
			 shall be included in determining compliance with the MCL for total coliforms in
			 Section F above.
(f) Special
			 purpose samples, such as those taken to determine whether disinfection
			 practices are sufficient following pipe placement, replacement, or repair,
			 shall not be used to determine compliance with the MCL for total coliforms in
			 Section F above. Repeat samples taken pursuant to paragraph (2) of this section
			 are not considered special purpose samples, and shall be used to determine
			 compliance with the MCL for total coliforms in Section F above.