S.C. Code Ann. § 48-1-80

In adopting the classification of waters and the standards of purity and quality, consideration shall be given to: (1) The size, depth, surface area covered, volume, direction, rate of flow, stream gradient and temperature of the water; (2) The character of the district bordering such water and its peculiar suitability for the particular uses and with a view to conserving it and encouraging the most appropriate use of the lands bordering on such water for residential, agricultural, industrial or recreational purposes; (3) The uses which have been made, are being made or may be made of such waters for transportation, domestic and industrial consumption, irrigation, bathing, fishing and fish culture, fire prevention, sewage disposal or otherwise; and (4) The extent of present defilement or fouling of such waters which has already occurred or resulted from past discharges therein.