S.C. Code Ann. § 44-55-610

In each county in this State containing a city having a population of more than seventy thousand according to the official United States census, the construction, installation and use of septic tanks shall be regulated by the provisions of this article and specifications and rules and regulations adopted by the county board of health and shall be approved by the county board of health, whose certificate of approval shall be accepted by all agencies and the courts of this State as evidence of such approval and of installation in compliance with the provisions of this article and of such specifications, rules and regulations.