Bioassessment and Biocriteria Program Status for South Carolina: Streams and Wadeable Rivers
State Program Contact
Water Quality Standards
The link to South Carolina's WQS that are in effect for Clean Water Act purposes is provided. These are the WQS approved by EPA.
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Designated Aquatic Life Uses
All water use classifications protect for a balanced indigenous aquatic community of fauna and flora. In addition, Trout Natural and Trout Put, Grow, and Take classifications protect for reproducing trout populations and stocked trout populations, respectively.
__X__ Narrative, with assessments based in part on numeric values
_____ No criteria
South Carolina DHEC R.61-68, Water Classifications and Standards (PDF) (62 pp, 690 K) (Page 10)
2. Where surface water quality exceeds levels necessary to support propagation of fish, shellfish, and wildlife, and recreation in and on the water, that quality shall be maintained and protected unless the Department finds, after intergovernmental coordination and public participation, that allowing lower water quality is necessary to important economic or social development in the areas where the waters are located.
4. Certain natural conditions may cause a depression of dissolved oxygen in surface waters while existing and classified uses are still maintained. The Department shall allow a dissolved oxygen depression in these naturally low dissolved oxygen waterbodies as prescribed below pursuant to the 13 Act, Section 48-1-83, et seq., 1976 Code of Laws:
a. Under these conditions the quality of the surface waters shall not be cumulatively lowered more than 0.1 mg/l for dissolved oxygen from point sources and other activities, or
b. Where natural conditions alone create dissolved oxygen concentrations less than 110 percent of the applicable water quality standard established for that waterbody, the minimum acceptable concentration is 90 percent of the natural condition. Under these circumstances, an anthropogenic dissolved oxygen depression greater than 0.1 mg/l shall not be allowed unless it is demonstrated that resident aquatic species shall not be adversely affected. The Department may modify permit conditions to require appropriate instream biological monitoring.
c. The dissolved oxygen concentrations shall not be cumulatively lowered more than the deficit described above utilizing a daily average unless it can be demonstrated that resident aquatic species shall not be adversely affected by an alternate averaging period.
What biological assemblages are used in the bioassessment program?
Benthic macroinvertebrates, fish, phytoplankton, and chlorophyll
Are bioassessments used to support 303(d) listings?
Yes. Listing methodology: Impaired Waters and Contaminant Limits - 303(d), TMDL (PDF) (110 pp, 3 MB)
How are assemblages used to make impairment decisions?
Refer to most current revision of SCDHEC’s aquatic science programs webpage for Technical Reports and Standard Operating Procedures.
Other uses of biocriteria or bioassessment within the water quality program:
Antidegradation, 305(b) surface water condition assessments, TMDL development and assessment, non-point source assessments, BMP evaluation, and restoration goals
Technical Support Information and Documents:
Outstanding National Resource Waters: Exceptional national recreational and/or ecological resource.
Outstanding Resource Waters: Exceptional recreational and/or ecological resource and suitable for drinking water source with minimal treatment.
No degradation of existing uses is permitted regardless of classification and no degradation of natural conditions is allowed in Outstanding Resource Waters or Outstanding National Resource Waters.
Technical reference material:
Impaired Waters and Contaminant Limits - 303(d), TMDL
Stressor identification/causal analysis approach: