S.C. Code Ann. § 23-20-30: Mutual aid agreements.

(A) Any county, incorporated municipality, or other political subdivision of this State may enter into mutual aid agreements as may be necessary for the proper and prudent exercise of public safety functions. All agreements must adhere to the requirements contained in Section 23-20-40.

(B) Nothing in this chapter may be construed to alter, amend, or affect any rights, duties, or responsibilities of law enforcement authorities established by South Carolina's constitutional or statutory laws or established by the ordinances of South Carolina's political subdivisions, except as expressly provided for in this chapter.