South Carolina Code of Regulations › Chapter 61 - DEPARTMENT OF HEALTH AND ENVIRONMENTAL CONTROL › Subchapter 61-58.9 - Variances and Exemptions › Section 61-58.9.I - Variances and Exemptions from the Maximum Contaminant Levels for Radionuclides

Current through Register Vol. 48, No. 6, June 28, 2024
(1)
			 The following are identified as the best available technology, treatment
			 techniques, or other means available for achieving compliance with the maximum
			 contaminant levels for radionuclides listed in R.61-58.5.H(2),
			 (3), (4), and (5), for the purposes of
			 issuing variances and exemptions, as shown in Table A to this paragraph.
TABLE A: BAT FOR RADIONUCLIDES LISTED IN
							 R.61-58.5.H
Contaminant
BAT
Combined radium-226 and radium-228
Ion exchange, reverse osmosis, lime softening.
Uranium
Ion exchange, reverse osmosis, lime softening,
							 coagulation/filtration.
Gross alpha particle activity (excluding radon and
							 uranium)
Reverse osmosis.
Beta particle and photon radioactivity
Ion exchange, reverse osmosis.
(2) In
			 addition, the following are identified as the best available technology,
			 treatment techniques, or other means available for achieving compliance with
			 the maximum contaminant levels for the radionuclides listed in R.61-58.5.H(2),
			 (3), (4), and (5), for the purposes of
			 issuing variances and exemptions to small drinking water systems, defined here
			 as those serving 10,000 persons or fewer, as shown in Table C to this
			 paragraph.
TABLE B: LIST OF SMALL SYSTEMS COMPLIANCE
							 TECHNOLOGIES FOR RADIONUCLIDES AND LIMITATIONS TO USE
Unit technologies
Limitations (see footnotes)
Operator skill level required [FN1]
Raw water quality range & considerations
							 [FN1]
1. Ion exchange (IE)
( [FNa])
Intermediate
All ground waters.
2. Point of use (POU [FN2]) IE
( [FNb])
Basic
All ground waters.
3. Reverse osmosis (RO)
( [FNc])
Advanced
Surface waters usually require pre-filtration.
4. POU [FN2] RO
( [FNb])
Basic
Surface waters usually require pre-filtration.
5. Lime softening
( [FNd])
Advanced
All waters.
6. Green sand filtration
( [FNe])
Basic
7. Co-precipitation with barium sulfate
( [FNf])
Intermediate to Advanced
Ground waters with suitable water quality.
8.
Electrodialysis/electrodialysis reversal
Basic to Intermediate
All ground waters.
9. Pre-formed hydrous manganese oxide
							 filtration
( [FNg])
Intermediate
All ground waters.
10. Activated alumina
( [FNa]), ( [FNh])
Advanced
All ground waters; competing anion concentrations may
							 affect regeneration frequency
11. Enhanced coagulation/filtration
( [FNi])
Advanced.
Can treat a wide range of water qualities.
[FN1] National Research Council (NRC). Safe Water
							 from Every Tap: Improving Water Service to Small Communities. National Academy
							 Press. Washington, D.C. 1997.
[FN2] A POU, or "point-of-use" technology is a
							 treatment device installed at a single tap used for the purpose of reducing
							 contaminants in drinking water at that one tap. POU devices are typically
							 installed at the kitchen tap. See the April 21, 2000 NODA for more details.
							 Limitations Footnotes: Technologies for Radionuclides:
[FNa] The regeneration solution contains high
							 concentrations of the contaminant ions. Disposal options should be carefully
							 considered before choosing this technology.
[FNb] When POU devices are used for compliance,
							 programs for long-term operation, maintenance, and monitoring must be provided
							 by water utility to ensure proper performance.
[FNc] Reject water disposal options should be
							 carefully considered before choosing this technology. See other RO limitations
							 described in the SWTR compliance technologies table.
[FNd] The combination of variable source water
							 quality and the complexity of the water chemistry involved may make this
							 technology too complex for small surface water systems.
[FNe] Removal efficiencies can vary depending on
							 water quality.
[FNf] This technology may be very limited in
							 application to small systems. Since the process requires static mixing,
							 detention basins, and filtration, it is most applicable to systems with
							 sufficiently high sulfate levels that already have a suitable filtration
							 treatment train in place.
[FNg] This technology is most applicable to small
							 systems that already have filtration in place.
[FNh] Handling of chemicals required during
							 regeneration and pH adjustment may be too difficult for small systems without
							 an adequately trained operator.
[FNi] Assumes modification to a
							 coagulation/filtration process already in place.
TABLE C: BAT FOR SMALL COMMUNITY WATER SYSTEMS FOR
							 THE RADIONUCLIDES LISTED IN R.61-58.5.H
Contaminant
Compliance technologies [FN1] for system size
							 categories (population served)
25-500
501-3,300
3,300-10,000
Combined radium-226 and radium-228
1, 2, 3, 4, 5, 6, 7, 8, 9
1, 2, 3, 4, 5, 6, 7, 8, 9
1, 2, 3, 4, 5, 6, 7, 8, 9
Gross alpha particle activity
3, 4
3, 4
3, 4
Beta particle activity and photon activity
1, 2, 3, 4
1, 2, 3, 4
1, 2, 3, 4
Uranium
1, 2, 4, 10, 11
1, 2, 3, 4, 5, 10, 11
1, 2, 3, 4, 5, 10, 11
[FN1] Note: Numbers correspond to those technologies
							 found listed in the Table B to this paragraph.
(3)
			 The Department shall require community water systems to install and/or use any
			 treatment technology identified in Table A to this section, or in the case of
			 small water systems (those serving 10,000 persons or fewer), Table B and Table
			 C of this 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 technology, the system cannot meet the MCL, that system shall be
			 eligible for a variance under the provisions of this section.
(4) If a community water system can
			 demonstrate through comprehensive engineering assessments, which may include
			 pilot plant studies, that the treatment technologies identified in this section
			 would only achieve a de minimus reduction in the contaminant level, the
			 Department may issue a schedule of compliance that requires the system being
			 granted the variance to examine other treatment technologies as a condition of
			 obtaining the variance.
(5) If the
			 Department determines that a treatment technology identified under paragraph
			 (4) of this section is technically feasible, the Administrator or the
			 Department may require the system to install and/or use that treatment
			 technology in connection with a compliance schedule issued under the provisions
			 of this section. The Department's determination shall be based upon studies by
			 the system and other relevant information.
(6) The Department may require a community
			 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.H
			 of this regulation, to avoid an unreasonable risk to health.
(7) Community water systems that use bottled
			 water as a condition for receiving a variance or an exemption from the
			 requirements of R.61-58.5.H
			 of this regulation must meet the requirements specified in Section F(7)(a)
			 through (c) above.
(8) Community
			 water systems that use point-of-use or point-of-entry devices as a condition
			 for obtaining a variance or an exemption from the radionuclides SPDWRs must
			 meet the conditions in Section F(8) above.