S.C. Code § 55-9-30
The division and the municipalities, counties, airport commissions, special purpose districts, and other political subdivisions of this State may, separately or jointly, acquire, establish, construct, expand, own, lease, control, equip, improve, maintain, operate, regulate and police airports for the use of aircraft, either within or without the geographical limits of such municipalities, counties and other political subdivisions and may use for such purpose or purposes any available property owned or controlled by the division or such municipalities, counties or other political subdivisions; but no county shall exercise the authority hereby conferred outside of its geographical limits except in an adjoining county and this only jointly with such adjoining county.
S.C. Code § 55-9-30