Henry Hoss, chairman of the county’s Water and Wastewater Treatment Authority, has resigned, officials said Tuesday.

During Tuesday’s County Commission meeting, Chairman Jim Coppinger told other commissioners that Mr. Hoss had stepped down. County Mayor Claude Ramsey is expected to make an interim appointment to the board as early as next week, Mr. Coppinger said.

Mr. Hoss could not be reached for comment.

Mr. Ramsey said Tuesday he would not release any names of potential board members.

“We appreciate Mr. Hoss’s 15 years of service, and we wish him well,” the county mayor said.

The WWTA has come under heat from the commission recently after an almost two-month delay in giving requested legal bills to county commissioners. The authority also has weathered controversy over an $8 monthly fee to examine and repair sewer lines to 24,000 customers and for looking at possible expansions of the sewer system outside Hamilton County.

County Commissioner John Allen Brooks said Tuesday that action needed to be taken after looking through the authority’s legal bills and seeing that more than $100,000 had been paid to Chattanooga attorney John Anderson during 2008.

He said charges included a meeting that cost $3,400, a $390 lunch and $500 for telephone calls.

“It indicated to us, just going through the bills, that John Anderson was going wild,” Mr. Brooks said.

Mr. Anderson could not be reached for comment.

Mr. Coppinger said Mr. Ramsey plans to place someone with financial experience on the board.

Mr. Brooks said he will not vote to support any future board member unless that person has financial experience.

“I do not believe the saga of the WWTA is over,” he said. “But Mr. Hoss’s resignation is a first step.”