S.C. Code Ann. § 12-28-1920

The department may assign qualified persons who are not state police officers to supervise or operate permanent or portable weigh stations. A person assigned under this section may stop, inspect, and issue citations to operators of trucks and trailers, barges or vessels having a declared gross weight of eleven thousand pounds or more, and buses, at a permanent weigh station, or other inspection point, or while operating a clearly marked state police vehicle for violations of this chapter.