AUBURN  — Federal money might be available to help turn the Twin Cities' sewage treatment facilities into an energy generating plant.

"This helps us out, by solving one of our biggest problems — what to do with the solids we remove," said Mac Richardson, superintendent of the Lewiston-Auburn Water Pollution Control Authority. "It turns out, treating the water is the easy part. Getting water from the sewers cleaner than the water in the Androscoggin River is one thing, but what do you do with the stuff that's left?"

Currently, LAWPCA treats an average of 11 million gallons of sewage per day. Most of the solids are mixed with wood waste and used to create a high quality compost.

But John Donovan of consulting engineers Camp Dresser and McKee said the market for compost is down while the cost for wood waste has increased. As a result, much of the solids are mixed with lime and trucked to farms or land-filled.

One solution is to build a digestion energy recovery plant on the LAWPCA site in Lewiston. That would pump the solid waste tanks heated to 95 degrees for two weeks, removing an estimated 170,000 cubic feet of methane gas daily. That would be burned to produce electricity.

Richardson said the plant could generate $280,000 in new revenue through the sale of electricity and reduce the amount of compostable waste by 40 percent — eliminating the need for lime or for disposing of the waste.

All told, the facility would save LAWPCA about $920,000 per year.

Auburn Sewer District Superintendent said the project could qualify for a grant through the U.S. Department of Energy. The deadline to apply for that grant is November, Lamie said.

staylor@sunjournal.com