S.C. Code § 6-21-60
Any municipality proposing to construct and operate a natural gas system for the benefit of the municipality and its surrounding territory shall also be empowered to construct and operate natural gas systems in any other municipalities, regardless of the county in which situate, if lying within twenty miles of its transmission line or main, if the governing body of such other municipalities give their consent thereto, and upon such terms and conditions as may be agreed upon. In such circumstances, the municipality which shall undertake the construction of the natural gas system shall possess and may exercise all powers granted by this chapter in such other municipalities as fully and as effectually as it shall possess such powers with respect to itself. For the purpose of this chapter, the term "transmission line" shall mean the pipelines or mains connecting the distribution system of the municipality with the source of supply of natural gas.
S.C. Code § 6-21-60