A plan to expand the St. George Sewer Treatment Plant and attract more industry to northern Dorchester County remained on track Friday, and work could begin soon.

The Berkeley-Charleston-Dorchester Council of Governments voted unanimously Friday to approve expanding the plant's capacity from 800,000 gallons a day to 1.8 million gallons a day.

Dorchester County bought the plant from the town last year to improve its operations and to expand the facility. Its limited size has been viewed as a major stumbling block in luring industry to the county's rural northern end.

"We took this on to correct a problem, but this is a big part of our overall strategy to bring in new industry to Dorchester County," County Council Chairman Jamie Feltner said.

The expansion project -- and repairing the collapsed Duke Street sewer line -- will cost about $9.1 million and are scheduled to be completed by June 2011.

The St. George sewer plant opened in 1976, used a secondary treatment system and discharged into Polk Swamp. Its sludge is dried and taken to the Dorchester County landfill.

The improvements will add a third treatment layer that will improve treatment quality and add capacity. It still will discharge into Polk Swamp, but Feltner said industry could use the discharge for cooling towers or similar uses.

"This provides another incentive for any industry that uses water for cooling in their processes," he said. "I'm really excited about that."

The county already has an industrial site certified by the state Commerce Department just a few miles outside St. George along U.S. Highway 78.

The Council of Governments maintains the tri-county's sewage plan to ensure that the new systems maintain water quality.

Feltner said the plant expansion could help improve the water quality in the Ashley and Edisto rivers, which are both fed in part by Polk Swamp.

The council deferred a vote on whether to expand the service area covered by Mount Pleasant Waterworks. Samuel Robinson, Awendaw's new mayor, had asked for the delay.

Reach Robert Behre at rbehre@postandcourier.com or 937-5771.