S.C. Code Regs. § § 103-504
No existing public utility supplying wastewater disposal to the public, or any individual, corporation, partnership, association, establishment, or firm undertaking the construction or acquisition of a utility, shall hereafter sell, acquire, transfer, begin the construction or operation of any utility system, or of any extension thereof, by the sale of stock or otherwise, without first obtaining from the commission a certificate that the sale, transfer, or acquisition is in the public interest, or that public convenience and necessity require or will require construction or operation of any utility system, or extension. Such certificate shall be granted only after the applicable information set forth in Subarticle 2, 103-510 et seq., has been filed with the commission and provided to the ORS, and after notice has been given to the Department of Health and Environmental Control and to other interested wastewater utilities, and to the public, and after due hearing. Provided, however, that this regulation shall not be construed to require any existing utility to secure a certificate for an extension within or to territory already served by it, necessary in the ordinary course of its business. But, if any utility in constructing or extending its lines, plant or system unreasonably interferes, or is about to unreasonably interfere, with the service or system of any other utility, the commission may make such order, and prescribe such terms and conditions, in harmony with this regulation, as are just and reasonable.
S.C. Code Regs. § 103-504