Progressive design-build delivers a high-risk, high-reward bioenergy facility

The $271 million Piscataway Bioenergy Facility in Prince George’s County, Maryland, (part of the Washington, DC, metro area) is one of the most technically sophisticated sewage facilities ever completed in the United States. It’s only the seventh facility in the United States to implement thermal hydrolysis, a two-stage process that treats sludge with high-pressure boiling and then releases pressure rapidly to break down microorganism cell walls and kill pathogens, creating Class A biosolids that are safe for land use (fertilizer).

The facility also uses an advanced combined heat and power (CHP) system and anaerobic digestion combined with wash water treatment technology to produce and treat biogases (including methane). The gases are converted into renewable natural gas, which is partly used to heat and power the facility and partly sold on to power Montgomery County’s Ride On bus fleet. The fertilizer and biogas are a revenue stream for WSSC Water, projected to deliver $4 million in annual revenue, as well as a cost cutter that will save WSSC Water customers $3.4 million annually in operating costs. As it scales up, Piscataway will collect and process biosolids from all five of WSSC Water’s treatment facilities and potentially accept trucked-in biosolids from other regional sites.