A Belt Filter Press is a biosolids/sludge dewatering device that applies mechanical pressure to a chemically conditioned slurry, which is sandwiched between two tensioned belts, by passing through a serpentine of decreasing diameter rolls. The machine can be divided into three zones: gravit zone, where free draining water is drained through a porous belt; wedge zone, where the solids are prepared for pressure application; and pressure zone, where medium and then high pressure is applied to the conditioned solids. Typically, a belt filter press receives a slurry ranging from 1-4% feed solids and produces a final product of 12-35% cake solids. Performance of the belt press depends on the nature of the solids being processed.
The District installed and operates two Moyno progressive cavity, positive displacement sludge feed pumps in 1985 that reached the end of their useful lives. Due to the extent to which the drive units had worn down, the District replaced the feed pump assemblies completely in 2010.