DC Water has contracted Pepco Holdings, Inc. subsidiary Pepco Energy Services, Inc. to design, build and operate a combined heat and power plant at DC Water’s Blue Plains Advanced Wastewater Treatment Plant. The 153 acre plant, the largest advanced wastewater treatment facility in the world, serves about 725 square miles of the District of Columbia, Virginia and Maryland, with a capacity of 370million gallons per day.
The CHP project will be the first in North America to use biogas from an AWTP facility. The project to be designed and built by Pepco Energy Services for Us81 million, will produce a minimum of 14MW of electric power that will supply the Blue Plains facility with almost 30% of the AWTP’s average power demand, enough electricity to power 8,000 homes.
Pepco will also provide on-site operations and maintenance services worth US89 million over the 15 year contract term, in addition to designing and building the CHP plant. The overall project value is estimated at US170 million.
The plant will be part of DC Water’s new thermal hydrolysis and anaerobic digestion project, the largest in the world. The CHP plant will provide the thermal hydrolysis project with high-pressure steam that will increase the rate of biogas production and neutralize contaminants in waste steam.
The plant will include three Solar Mercury 50 low-nitrogen oxide gas turbines, digester gas cleaning and compression equipment, heat recover steam generators, duct burners, a backup boiler, electrical equipment needed to operate in parallel with the utility grid and ancillary systems, including water treatment and process control systems.
DC Water’s greenhouse gas emissions will be reduced by 40% and the risk of increased disposal costs and increases in future power costs will be hedged by the CHP facility.