S.C. Code Ann. § 31-12-40
(B) If the federal property subject to disposal is contained wholly within one county, which county does not lie in an MSA extending over more than one South Carolina county and is not included in a multicounty authority under subsections (C) or (D), the authority must include:
(C) If the federal property subject to disposal is contained within more than one county, with no portion of the counties lying within an MSA which extends over more than one South Carolina county, the authority must include:
(D)
(1) If the federal property subject to disposal is contained wholly or partially within a county, all or a portion of which lies in an MSA which extends over more than one South Carolina county, the authority must include: