S.C. Code Regs. § 61-58.9.F

Current through Register Vol. 48, No. 07, July 26, 2024

Section 61-58.9.F - Variances and Exemptions from the Maximum Contaminant Levels for Organic and Inorganic Chemicals and Exemptions from the Treatment Technique for Lead and Copper

(1) The following are identified as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for volatile organic chemicals as listed in R.61-58.5.N and the organic chemicals listed in R.61-58.5.D(2):

BEST AVAILABLE TECHNOLOGIES FOR ORGANIC CONTAMINANTS
CAS Number	Contaminant	Granular Activated Carbon	Packed Tower Aeration	Oxidation
15972-60-8	Alachlor	X
116-06-3	Aldicarb	X
1646-88-4	Aldicarb sulfone	X
1646-87-3	Aldicarb sulfoxide	X
1912-24-9	Atrazine	X
71-43-2	Benzene	X	X
50-32-8	Benzo(a)pyrene	X
1563-66-2	Carbofuran	X
56-23-5	Carbon tetrachloride	X	X
57-74-9	Chlordane	X
75-99-0	Dalapon	X
94-75-7	2,4-D	X
103-23-1	Di(2-ethylhexyl) adipate	X	X
117-81-7	Di(2-ethylhexyl) phthalate	X
96-12-8	Dibromochloropropane (DBCP)	X
95-50-1	o-Dichlorobenzene	X	X
106-46-7	para-Dichlorobenzene	X	X
107-06-2	1,2-Dichloroethane	X	X
75-35-4	1,1-Dichloroethylene	X	X
156-59-2	cis-1,2-Dichloroethylene	X	X
156-60-5	trans-1,2-Dichloroethylene	X	X
75-09-2	Dichloromethane		X
78-87-5	1,2-Dichloropropane	X	X
88-85-7	Dinoseb	X
85-00-7	Diquat	X
145-73-3	Endothall	X
72-20-8	Endrin	X
100-41-4	Ethylbenzene	X	X
106-93-4	Ethylene dibromide (EDB)	X	X
1071-83-6	Gylphosate			X
76-44-8	Heptachlor	X
1024-57-3	Heptachlor epoxide	X
118-74-1	Hexachlorobenzene	X
77-47-3	Hexachlorocyclopentadiene	X	X
58-89-9	Lindane	X
72-43-5	Methoxychlor	X
108-90-7	Monochlorobenzene	X	X
23135-22-0	Oxamyl (Vydate)	X
87-86-5	Pentachlorophenol	X
1918-02-1	Picloram	X
1336-36-3	Polychlorinated biphenyls (PCB)	X
122-34-9	Simazine	X
100-42-5	Styrene	X	X
1746-01-6	2,3,7,8-TCDD (Dioxin)	X
127-18-4	Tetrachloroethylene	X	X
108-88-3	Toluene	X	X
8001-35-2	Toxaphene	X
93-72-1	2,4,5-TP (Silvex)	X
120-82-1	1,2,4-Trichlorobenzene	X	X
71-55-6	1,1,1-Trichloroethane	X	X
79-00-5	1,1,2-Trichloroethane	X	X
79-01-6	Trichloroethylene	X	X
75-01-4	Vinyl chloride		X
1330-20-7	Xylene	X	X

(2) The following are identified as the best technology, treatment techniques, or other means available for achieving compliance with the maximum contaminant levels for the inorganic contaminants listed in R.61-58.5(B)(2)(B)(2), except fluoride:

CHEMICAL NAME	BAT(S)
Antimony	2,7
Arsenic [FN4]	1,2,5,6,7,9,12 [FN5]
Asbestos	2,3,8
Barium	5,6,7,9
Beryllium	1,2,5,6,7
Cadmium	2,5,6,7
Chromium	2,5,6 [FN2],7
Cyanide	5,7,10
Mercury	2 [FN1],4,6 [FN1],7 [FN1]
Nickel	5,6,7
Nitrate	5,7,9
Nitrite	5,7
Selenium	1,2 [FN3],6,7,9
Thallium	1,5
[FN1] BAT only if influent Hg concentrations <10 g/L.
[FN2] BAT for Chromium III only.
[FN3] BAT for Selenium IV only.
[FN4] BATs for Arsenic V. Pre-oxidation may be required to convert Arsenic III to Arsenic V
[FN5] To obtain high removals, iron to arsenic ratio must be at least 20:1.
Key to BATs in Table
1 = Activated Alumina
2 = Coagulation/Filtration (not BAT for systems serving less than 500 service connections)
3 = Direct and Diatomite Filtration
4 = Granular Activated Carbon
5 = Ion Exchange
6 = Lime (not less than 500 service connections) BAT for systems softening
7 = Reverse Osmosis
8 = Corrosion Control
9 = Electrodialysis
10 = Chlorine
11 = Ultraviolet
12 = Oxidation/Filtration

(3) The Department identifies in the following table the affordable technology, treatment technique, or other means available to systems serving 10,000 persons or fewer for achieving compliance with the maximum contaminant level for arsenic:

SMALL SYSTEM COMPLIANCE TECHNOLOGIES (SSCTS) [FN1] FOR ARSENIC [FN2]
Small system compliance technology	Affordable for listed small system categories [FN3]
Activated Alumina (centralized) .........	All size categories
Activated Alumina (Point-of-Use) [FN4] ..	All size categories
Coagulation/Filtration [FN5] ............	501-3,300, 3,301-10,000
Coagulation-assisted Microfiltration ....	501-3,300, 3,301-10,000
Electrodialysis reversal [FN6] ..........	501-3,300, 3,301-10,000
Enhanced coagulation/filtration .........	All size categories
Enhanced lime softening (pH> 10-5) ......	All size categories
Ion Exchange ............................	All size categories
Lime Softening [FN5] ....................	501-3,300, 3,301-10,000
Oxidation/Filtration [FN7] ..............	All size categories
Reverse Osmosis (centralized) [FN6] .....	501-3,300, 3,301-10,000
Reverse Osmosis (Point-of-Use) [FN4] ....	All size categories
[FN1] Section 1412(b)(4)(E)(ii) of SDWA specifies that SSCTs must be affordable and technically feasible for small systems.
[FN2] SSCTs for Arsenic V. Pre-oxidation may be required to convert Arsenic III to Arsenic V.
[FN3] The Act (ibid.) specifies three categories of small systems: (i) those serving 25 or more, but fewer than 501, (ii) those serving more than 500, but fewer than 3,301, and (iii) those serving more than 3,300, but fewer than 10,001.
[FN4] When POU or POE devices are used for compliance, programs to ensure proper long-term operation, maintenance, and monitoring must be provided by the water system to ensure adequate performance.
[FN5] Unlikely to be installed solely for arsenic removal. May require pH adjustment to optimal range if high removals are needed.
[FN6] Technologies reject a large volume of waters-may not be appropriate for areas where water quantity may be an issue.
[FN7] To obtain high removals, iron to arsenic ratio must be at least 20:1.

(4) The Department shall require community water systems and non-transient, non-community water systems to install and/or use any treatment method identified in paragraphs 1 and 2 of the section as a condition for granting a variance except as provided in paragraph (4) of this section. If, after the system's installation of the treatment method, the system cannot meet the MCL, that system shall be eligible for a variance under the provisions of section B above.

(5) If a system can demonstrate through comprehensive engineering assessments, which may include pilot plant studies, that the treatment methods identified in paragraphs 1 and 2 of the section would only achieve a de minimis reduction in contaminants, the Department may issue a schedule of compliance that requires the system being granted the variance to examine other treatment methods as a condition of obtaining the variance.

(6) If the Department determines that a treatment method identified in paragraph (4) of this section is technically feasible, the Department may require the system to install and/or use that treatment method in connection with a compliance schedule issued under the provisions of R.61-58.9(B)(4)(c) through (g)(B)(4)(c) through (g). The Department's determination shall be based upon studies by the system and other relevant information.

(7) The Department may require a public water system to use bottled water, point-of-use devices, point-of-entry devices or other means as a condition of granting a variance or an exemption from the requirements of R.61-58.5.B. (2), D(2)(b) and N, to avoid an unreasonable risk to health. The Department may require a public water system to use bottled water and point-of-use devices or other means, but not point-of-entry devices, as a condition for granting an exemption from corrosion control treatment requirements for lead and copper in R.61-58.11.C and D to avoid an unreasonable risk to health. The Department may require a public water system to use point-of-entry devices as a condition for granting an exemption from the source water and lead service line replacement requirements for lead and copper under R.61-58.11.E or F to avoid an unreasonable risk to health.

(8) Public water systems that use bottled water as a condition for receiving a variance or exemption from the requirements of R.61-58.5.B(2), D(2)(b) and N, or an exemption from the requirements of R.61-58.11.C through F, must meet the requirements in either paragraph (a) or (b) of this section in addition to the requirements in paragraph (c) of this section:

(a) The public water system must develop and put in place a monitoring program approved by the Department that provides reasonable assurances that the bottled water meets all maximum contaminant levels. The public water system must monitor a representative sample of the bottled water for all contaminants regulated under R.61-58.5.B(2), D(2)(b) and N the first quarter that it supplies the bottled water to the public, and annually thereafter. Results of the monitoring program shall be provided to the Department annually.

(9) Public water systems that use point-of-use or point-of-entry devices as a condition for obtaining a variance or exemption from the maximum contaminant levels listed in R.61-58.5.B(2), D(2)(b) and N must meet the following requirements:

(a) It is the responsibility of the public water system to operate and maintain the point-of-use and/or point-of-entry treatment system.

(b) The public water system must develop a monitoring plan and obtain Department approval for the plan before point-of-use or point-of-entry devices are installed for compliance. This monitoring plan must provide health protection equivalent to a monitoring plan for central water treatment.

(c) Effective technology must be properly applied under a plan approved by the Department and the microbiological safety of the water must be maintained at all times.

(d) The public water system must provide adequate certification of performance, field testing, and, if not included in the certification process, a rigorous engineering design review of the point-of-use and/or point-of-entry devices.

(e) The design and application of the point-of-use and/or point-of-entry devices must consider the tendency for an increase in heterotrophic bacteria concentrations in water treated with activated carbon. It may be necessary to use frequent backwashing, post-contactor disinfection, and Heterotrophic Plate Count monitoring to ensure that the microbiological safety of the water is not compromised.

(f) All consumers shall be protected. Every building connected to the system must have a point-of-use or point-of-entry device installed, maintained, and adequately monitored. The Department must be assured by the public water system that every building is subject to treatment and monitoring, and that the rights and responsibilities of the public water system customer convey with title upon sale of the property.

(g) In requiring the use of a point-of-entry device as a condition for granting an exemption from the treatment requirements for lead and copper under R.61-58.11.E or F, the Department must be assured that use of the device will not cause increased corrosion of lead and copper bearing materials located between the device and the tap that could increase contaminant levels at the tap.

S.C. Code Regs. 61-58.9.F