S.C. Code § 7-13-1150
When the canvassing and counting of the votes are completed, the chairman of the managers, or one of them to be designated in writing by the managers, shall deliver to the board of voter registration and elections the poll list, the boxes containing the ballots and a written return of the result of the election in the voting precinct. Managers shall account to the board of voter registration and elections of the county for all ballots delivered to them and make the following returns, (a) the number of official ballots furnished to each voting precinct, (b) the number of official ballots spoiled and returned by voters, (c) the number of official ballots returned to the board of voter registration and elections and (d) the number of official ballots actually voted.
The board of voter registration and elections shall keep in possession all unused ballots, as well as those that have been spoiled, until the time for contesting the election has expired. Any ballot that has been lost must be accounted for by a certificate from the chairman of the managers of the particular precinct covering the circumstances.
S.C. Code § 7-13-1150