S.C. Code Ann. § 11-35-1825
The state engineer's office shall develop a procedure and a list of criteria for pre-qualifying construction bidders. The criteria shall include, but not be limited to, prior performance, recent past references on all aspects of performance, financial stability, and experience on similar construction projects. A governmental body may use the prequalification process only for projects where the construction involved is unique in nature or over ten million dollars in value as determined by and subject to the approval of the state engineer's office. All prequalification projects shall be under the supervision of the state engineer's office, unless the project falls within the governmental body's procurement certification limits.
When the prequalification process is employed, only those bidders who are prequalified through this procedure are entitled to submit a bid for the project. The determination of which bidders are prequalified, and thereby entitled to bid, is not protestable under Section 11-35-4210 or any other provision of this code.