The Big Bear Area Regional Wastewater Agency in Big Bear City, Calif., generated 5,800 tons of Class B biosolids per year. The 300 trips to the landfill were on winding mountain roads that dropped 7,000 feet in elevation.
Treatment plant workers dewatered digested biosolids with a belt filter press, producing 14 percent solids cake, dried further in two drying beds. However, long winters and sometimes rainy summers affected results. From 2000 to 2010, landfill costs increased from $32 to $100 per ton.
“We were paying a lot to haul water,” says plant superintendent Joe Hanford. “Reducing our biosolids volume became a major
