S.C. Code § 49-17-1090
Within thirty days after the work is completed an itemized bill for the actual expenses incurred by the railroad company for opening its tracks shall be made and presented to the superintendent of construction of the drainage improvement. Such bill, however, shall not include the cost of putting in a new bridge or strengthening or enlarging an old one. The superintendent of construction shall audit this bill and, if found correct, approve it and file it with the secretary of the board of drainage commissioners. The commissioners shall deduct from this bill the cost of the excavation or other work done by the drainage commission on the right of way of the railroad company at the contract price and pay the difference, if any, to the railroad company.
S.C. Code § 49-17-1090