S.C. Code Ann. § 57-7-70

If any city or incorporated town owns its own waterworks or sewerage, which extends beyond the city or town limits, the city or town may in any particular case, after giving written notice to the county supervisor of its desire so to do and receiving the consent of the supervisor, proceed with the work without compliance with the requirements of Section 57-7-60, and in any such case such city or town shall be responsible to the county for the repair of the road, it being optional with the city or town to bring itself within the provisions of this section with the consent of the supervisor.