WSSC Piscataway WRRF Bioenergy Project

This $271 million bioenergy facility is the largest and most technically advanced project WSSC Water has constructed in its 106-year history and is one of only seven in the country to incorporate an advanced Thermal Hydrolysis Process (THP) to efficiently transform biosolids. All biosolids from WSSC Water’s six water resource recovery facilities are now delivered to the new facility for processing, transforming how Maryland’s largest water utility handles biosolids.

The facility converts wastewater biosolids into biogas, which is then used by Combined Heat and Power (CHP) engines to help power the facility, with a portion of the bioenergy generated being sold to Montgomery County to power part of its Ride On bus fleet. In addition, the facility will produce fewer and cleaner biosolids – Class A biosolids – that can be marketed as a soil amendment. The facility is projected to generate approximately $4 million per year in revenue, save WSSC Water customers approximately $3.4 million per year in operating costs, and further reduce WSSC Water’s greenhouse gas emissions.

The project included:

• A 45-cubic-yard cake receiving facility
• Two 500-cubic yard cake storage silos to feed the new 92.6 dtpd Cambi B6-4 Thermal Hydrolysis Process
• A new solids building containing seven two-meter 3-belt presses for pre- and post-dewatering
• Two new 1.5 million gallon anaerobic digesters and a digester control building
• Pre-cast post tensioned concrete tanks for a new 375,000 gpd sidestream deammonification treatment facility
• A chemical odor control system and a cake storage facility
• New CHP facility consisting of three 5,000 lbs/hr steam boilers and three 1.5 MW generators

Construction was completed on budget and on schedule, providing a regional facility capable of treating up to 92 dry tons of biosolids per day.

READ MORE ABOUT THIS PROJECT IN ENR AND INFORMED INFRASTRUCTURE.