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.E - Organic Chemicals Other Than Total Trihalomethanes, Sampling and Analytical Requirements

Current through Register Vol. 48, No. 6, June 28, 2024
(1) The
			 monitoring requirements for organic contaminants specified in R.61-58.5(D)(2)(a)(D)(2)(a)shall
			 apply to all community water systems. The monitoring requirements for organic
			 contaminants specified in 61-58.5(D)(2)(b)shall apply to community water
			 systems and non-transient non-community water systems.
(2) [Reserved]
(3) [Reserved]
(4) [Reserved]
(5) [Reserved]
(6) [Reserved]
(7) Analytical methods used to comply with
			 Section D(2)(b) above, shall be made using EPA-approved methods listed in 40
			 CFR 141. Analysis of the contaminants listed in Section D(2)(b) above, for the
			 purposes of determining compliance with the maximum contaminant level shall be
			 conducted as follows:
(a) Groundwater systems
			 shall take a minimum of one sample at every entry point to the distribution
			 system which is representative of each well after treatment (hereafter called a
			 sampling point). Each sample must be taken at the same sampling point unless
			 conditions make another sampling point more representative of each source or
			 treatment plant.
(b) Surface water
			 systems shall take a minimum of one sample at points in the distribution system
			 that are representative of each source or at each entry point to the
			 distribution system after treatment (hereafter called a sampling point). Each
			 sample must be taken at the same sampling point unless conditions make another
			 sampling point more representative of each source or treatment plant. [Note:
			 For purposes of this paragraph, surface water systems include systems with a
			 combination of surface and ground sources.]
(c) If the system draws water from more than
			 one source and the sources are combined before distribution, the system must
			 sample at an entry point to the distribution system during periods of normal
			 operating conditions (i.e., when water representative of all sources is being
			 used).
(d) Monitoring frequency:
(i) Each community and non-transient
			 non-community water system shall take four consecutive quarterly samples for
			 each contaminant listed in Section D(2)(b) above, during each compliance period
			 beginning with the initial compliance period.
(ii) Systems serving more than 3,300 persons
			 which do not detect a contaminant in the initial compliance period, may reduce
			 the sampling frequency to a minimum of two quarterly samples in one year during
			 each repeat compliance period.
(iii) Systems serving 3,300 persons or less
			 which do not detect a contaminant in the initial compliance period may reduce
			 the sampling frequency to a minimum of one sample during each repeat compliance
			 period.
(e) Each
			 community and non-transient water system may apply to the Department for a
			 waiver from the requirement of paragraph (7)(d) of this section. A system must
			 reapply for a waiver for each compliance period.
(f) The Department may grant a waiver after
			 evaluating the following factor(s): Knowledge of previous use (including
			 transport, storage, or disposal) of the contaminant within the watershed or
			 zone of influence of the system. If a determination by the Department reveals
			 no previous use of the contaminant within the watershed or zone of influence, a
			 waiver may be granted. If previous use of the contaminant is unknown or it has
			 been used previously, then the following factors shall be used to determine
			 whether a waiver is granted.
(i) Previous
			 analytical results.
(ii) The
			 proximity of the system to a potential point or non-point source of
			 contamination. Point sources include spills and leaks of chemicals at or near a
			 water treatment facility or at manufacturing, distribution, or storage
			 facilities, or from hazardous and municipal waste landfills and other waste
			 handling or treatment facilities. Non-point sources include the use of
			 pesticides to control insect and weed pests on agricultural areas, forest
			 lands, home and gardens, and other land application uses.
(iii) The environmental persistence and
			 transport of the pesticide or PCBs.
(iv) How well the water source is protected
			 against contamination due to such factors as depth of the well and the type of
			 soil and the integrity of the well casing.
(v) Elevated nitrate levels at the water
			 supply source.
(vi) Use of PCBs in
			 equipment used in the production, storage, or distribution of water (i.e., PCBs
			 used in pumps, transformers, etc.).
(g) If an organic contaminant listed in
			 Section D(2)(b) above, is detected (as defined by paragraph (7)(r) of this
			 section) in any sample, then:
(i) Each system
			 must monitor quarterly at each sampling point which resulted in a
			 detection.
(ii) The Department may
			 decrease the quarterly monitoring requirement specified in paragraph (7)(g)(i)
			 of this section provided it has determined that the system is reliably and
			 consistently below the maximum contaminant level. In no case shall the
			 Department make this determination unless a groundwater system takes a minimum
			 of two quarterly samples and a surface water system takes a minimum of four
			 quarterly samples.
(iii) After the
			 Department determines the system is reliably and consistently below the maximum
			 contaminant level the Department may allow the system to monitor annually.
			 Systems which monitor annually must monitor during the quarter that previously
			 yielded the highest analytical result.
(iv) Systems which have 3 consecutive annual
			 samples with no detection of a contaminant may apply to the Department for a
			 waiver as specified in paragraph (7)(f) of this section.
(v) Groundwater systems which have detected
			 one or more of the following two-carbon organic compounds: trichloroethylene,
			 tetrachloroethylene, 1,2,-dichloroethane, 1,1,1-trichloroethane,
			 cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, or 1,1-dichloroethylene
			 shall monitor quarterly for vinyl chloride. A vinyl chloride sample shall be
			 taken at each sampling point at which one or more of the two-carbon organic
			 compounds was detected. If the results of the first analysis do not detect
			 vinyl chloride, the Department may reduce the quarterly monitoring frequency of
			 vinyl chloride monitoring to one sample during each compliance period. Surface
			 water systems are required to monitor for vinyl chloride as specified by the
			 Department.
(h) Systems
			 which violate the requirements of Section D(2)(b) above, as determined by
			 paragraph (7)(k) of this section must monitor quarterly. After a minimum of
			 four quarterly samples show the system is in compliance and the Department
			 determines the system is reliably and consistently below the MCL, as specified
			 in paragraph (7)(k) of this section, the system shall monitor at the frequency
			 specified in paragraph (7)(g)(iii) of this section.
(i) The Department may require a confirmation
			 sample for positive or negative results. If a confirmation sample is required
			 by the Department, the result must be averaged with the first sampling result
			 and the average used for the compliance determination as specified by paragraph
			 (7)(k) of this section. The Department has the discretion to delete results of
			 obvious sampling errors from this calculation.
(j) The Department may reduce the total
			 number of samples a system must analyze by allowing the use of compositing.
			 Composite samples from a maximum of five sampling points are allowed, provided
			 that the detection limit of the method used for analysis is less than one-fifth
			 of the MCL. Compositing of samples must be done in the laboratory and analyzed
			 within 14 days of sample collection.
(i) If
			 the concentration in the composite sample detects one or more contaminants
			 listed in Section D(2)(b) above, then a follow-up sample must be taken within
			 14 days at each sampling point included in the composite, and be analyzed for
			 that contaminant.
(ii) If
			 duplicates of the original sample taken from each sampling point used in the
			 composite are available, the system may use these duplicates instead of
			 resampling. The duplicate must be analyzed and the results reported to the
			 Department within 14 days of collection.
(iii) If the population served by the system
			 is more than 3,300 persons, then compositing may only be permitted by the
			 Department at sampling points within a single system. In systems serving 3,300
			 persons or less, the Department may permit compositing among different systems
			 provided the 5-sample limit is maintained.
(k) Compliance with Section D(2)(b) above,
			 shall be determined based on the analytical results obtained at each sampling
			 point. If one sampling point is in violation of an MCL, the system is in
			 violation of the MCL.
(i) For systems
			 monitoring more than once per year, compliance with the MCL is determined by a
			 running annual average at each sampling point.
(ii) Systems monitoring annually or less
			 frequently whose sample result exceeds the regulatory detection level as
			 defined by paragraph (7)(r) of this section must begin quarterly sampling. The
			 system will not be considered in violation of the MCL until it has completed
			 one year of quarterly sampling.
(iii) If any sample result will cause the
			 running annual average to exceed the MCL at any sampling point, the system is
			 out of compliance with the MCL immediately.
(iv) If a system fails to collect the
			 required number of samples, compliance will be based on the total number of
			 samples collected.
(v) If a sample
			 result is less than the detection limit, zero will be used to calculate the
			 annual average.
(l)
			 [Reserved]
(m) Analysis for PCBs
			 shall be conducted using EPA-approved methods listed in 40 CFR 141.
(i) [Reserved]
(ii) [Reserved]
(iii) Compliance with the PCB MCL shall be
			 determined based upon the quantitative results of analyses using EPA-approved
			 methods listed in 40 CFR 141.
(n) If monitoring data collected after
			 January 1, 1990, are generally consistent with the requirements of this
			 section, then the Department may allow systems to use that data to satisfy the
			 monitoring requirement for the initial compliance period beginning January 1,
			 1993.
(o) The Department may
			 increase the required monitoring frequency, where necessary, to detect
			 variations within the system (e.g., fluctuations in concentration due to
			 seasonal use, changes in water source).
(p) The Department has the authority to
			 determine compliance or initiate enforcement action based upon analytical
			 results and other information compiled by the Department.
(q) Each public water system shall monitor at
			 the time designated by the Department within each compliance period.
(r) Detection as used in this paragraph shall
			 be defined as greater than or equal to the following concentrations for each
			 contaminant.
Contaminant
Detection Limit
Atrazine
0.0001 mg/l
Benzo[a]pyrene
0.00002 mg/l
Carbofuran
0.0009 mg/l
Chlordane
0.0002 mg/l
Dalapon
0.001 mg/l
Dibromochloropropane (DBCP)
0.00002 mg/l
Di (2-ethylhexly) adipate
0.0006 mg/l
Di (2-ethylhexly) phthalate
0.0006 mg/l
Dinoseb
0.0002 mg/l
Diquat
00004 mg/l
2,4-D
00001 mg/l
Endothall
0.009 mg/l
Endrin
0.00001 mg/l
Ethylene dibromide (EDB)
0.00001 mg/l
Glyphosate
0.006 mg/l
Heptachlor
0.00004 mg/l
Heptachlor epoxide
0.00002 mg/l
Hexachlorobenzene
0.0001 mg/l
Hexachlorocyclopentadiene
0.0001 mg/l
Lindane
0.00002 mg/l
Methoxychlor
0.0001 mg/l
Oxamyl
0.002 mg/l
Picloram
0.0001 mg/l
Polychlorinated biphenyls (PCBs) (as
							 decachlorobiphenyl)
0.0001 mg/l
Pentachlorophenol
0.00004 mg/l
Simazine
0.00007 mg/l
Toxaphene
0.001 mg/l
2,3,7,8-TCDD (Dioxin)
0.000000005 mg/l
2,4,5-TP (Silvex)
0.0002 mg/l
(s)
			 All new systems or systems that used a new source of water that begin operation
			 after January 22, 2004 must demonstrate compliance with the MCL within a period
			 of time specified by the Department. The system must also comply with the
			 initial sampling frequencies specified by the Department to ensure a system can
			 demonstrate compliance with the MCL. Routine and increased monitoring
			 frequencies shall be conducted in accordance with the requirements in this
			 section.