The election was conducted at the commission’s regular business meeting Dec. 18.
Belser, who joined the commission in February, represents residents in the District 2, which includes Barnwell, Lexington and Aiken counties and portions of Orangeburg and Richland counties.
Williams, who represents District 6, is a judge advocate in the Army Reserve at the rank of captain.
The Public Service Commission next meets at 2 p.m. Wednesday in Columbia. On the agenda are several items related to rate adjustment applications by Blue Granite Water Co., which provides services to communities throughout South Carolina.
The agenda also includes a petition by the S.C. Office of Regulatory Staff asking for a rulemaking proceeding to decide appropriate parameters and standards regarding a utility’s use of customer data.