UAJA ComposT History

Background
Waste biosolids, often called sludge, are a by-product of any wastewater treatment system, and proper use or disposal of these solids is an environmental challenge. Prior to 1990, UAJA land-applied (spread over agricultural fields) all solids generated from a 3.5 million gallons per day (MGD) wastewater flow. But anticipated flows beyond 3.5 MGD (currently almost 5.0 MGD), difficulties in acquiring acceptable land (on  which to spread sludge), and voluminous record keeping and changing regulatory requirements forced the UAJA Board to review available alternatives for solids handling. In addition, central Pennsylvania’s winter climate prohibs land application for several months each year, meaning that sludge has to be stockpiled or land-filled during December, January, February, and sometimes March. Solids handling options included: continued land-application with land-filling during winter months, incineration, and composting.

Due to current regulatory and physical problems associated with land-application and land-filling, the Board elected to discintinue these methods. After evaluating in detail the options of incineration and composting, we found that the capital investment for these options were nearly identical, however composting was selected due to its lower operating costs. Composting has another advantage; incineration produces ash which has to be disposed of (presumably in a landfill), while composting produces a usable end product - without the need for disposal.

The Spring Creek Composting Facility was completed in late 1990 as part of a major upgrade of the Spring Creek Pollution Control Facility (plant capacity increased from 3.84 mgd to 6.0 million gallons per day) with major revisions to the biological treatment and phosphorus removal methods incorporated into the design. A critical component of the solids handling system, the sludge dewatering process was constructed as part of the treatment plant upgrade. The composting facility is designed to handle 50 wet tons of biosolids per day in a climate-controlled, weather-proof building.