The Washington Suburban Sanitary Commission's (WSSC) governing body has approved the first phase of the largest and most technically advanced project undertaken by the commission in its 100-year history. When completed, a $250 million bio-energy project at the Piscataway Water Resource Recovery Facility in Prince George’s County will be among the first nationwide to incorporate an advanced thermal hydrolysis: a two-stage process in which sludge is subjected to high-pressure boiling and rapidly decompressed. The sludge is sterilized, which improves digestion performance by making it more biodegradable and acceptable for agricultural application. There have been more than 30 installations globally since Norway installed the first facility in 1996.
The commission's facility will turn biosolids from five wastewater treatment plants into renewable energy. Reducing the amount of biosolids left over from the treatment process will reduce hauling and disposal costs. Producing significantly cleaner (Class A) biosolids will enable the commission to generate revenue by selling the product as fertilizer. The utility will also save money by eliminating the use of lime, which is currently applied to biosolids to control odor.
As an added benefit, the thermal hydrolysis process will generate renewable fuel to help run the plant. This process produces methane gas, which will be captured to provide the Piscataway facility with a reliable power source that is completely off the grid. The new process will reduce greenhouse gas emissions by 15%.
“This will save our customers more than $3 million per year and underscores our commitment to green energy,” says General Manager and CEO Carla Reid. “This transformative project continues our innovative spirit.”
Awarded to PC Construction Co., the $44 million Phase One contract includes design and early construction, including demolishing on-site facilities and relocating utilities. Phase Two is expected to be awarded fall 2019. The entire project should be complete and operational in spring 2024.
