S.C. Code Ann. § 47-20-90 – Permit decisions

(A) The department shall act on all permits to prevent, so far as reasonably possible considering relevant standards under state and federal laws, an increase in pollution of the waters and air of the State from any new or enlarged sources.
(B) The department also shall act on all permits so as to prevent degradation of water quality due to the cumulative and secondary effects of permit decisions. Cumulative and secondary effects are impacts attributable to the collective effects of a number of animal feeding operations in a defined area and include the effects of additional projects similar to the requested permit in areas available for development in the vicinity. All permit decisions shall ensure that the waste treatment and utilization alternative with the least adverse impact on the environment be utilized. Cumulative and secondary effects shall include, but are not limited to, runoff from land application of animal waste and an animal feeding operation, evaporation and atmospheric deposition of elements, ground-water or aquifer contamination, buildup of elements in the soil, and other potential and actual point and nonpoint sources of pollution in the vicinity.