S.C. Code § 2-7-40
In multi-county senatorial districts, all references in existing statutes relative to county affairs and appointments to the members of a county legislative delegation or language of similar import, except in statutes relating to appointments required to be made upon the advice and consent of the Senate, in a determination of action by the delegation under the statutes, shall mean a majority of the members of the House of Representatives resident in the county when such county is without a resident Senator and one half of such members when such county has a resident Senator and shall include in all such counties with or without a resident Senator at least one Senator thereof in those districts having not more than two Senators and at least two Senators in those districts having at least three Senators; provided, however, that this section shall not apply to any county having more than five members of the House of Representatives.
S.C. Code § 2-7-40