S.C. Code Ann. § 6-15-50

The parties to the contract may obligate themselves to provide funds for the operation and maintenance of the sewer facilities, and when so obligated shall be required to include the quantum of such obligation in each annual budget of the contracting party, and shall be fully empowered to raise the same by ad valorem taxes levied in the manner that other ad valorem taxes are levied by or on behalf of such contracting party, or to raise the same through the imposition of a sewer service charge.