The City of Gallatin, Tenn., which previously landfilled Class B biosolids at a cost of $250,000 per year, now uses a lime stabiliation process to create Class A material for free distribution to the public.
The 4.5 mgd (average dry weather) wastewater treatment plant in Gallatin sends process sludges to aerobic digesters. A centrifuge then dewaters the material into cake that goes through the lime stabilization process and then into a warehouse for storage for 72 hours. The material looks like sand and has the consistency of cornmeal, according to chief wastewater plant operator Brandon Traughber. It contains about 2 percent
