S.C. Code Ann. § 5-31-1160

It shall not be lawful for any person to extend service pipes attached to the mains and water supply on any premises within or without a municipality without first obtaining permission therefor in writing from the municipality or the commissioners of public works or other body charged with the duties of commissioners of public works in municipalities which have no such commissioners and before any workman or plumber shall perform any work connected with the extension of such service pipes written permission for such extension shall be obtained.