The D.C. Water and Sewer Authority recently scrapped a massive upgrade to its wastewater treatment capability after the projected cost soared by $250 million in one year.
The “egg-shaped digester” was the District’s proposed new method for handling the 1,300 wet tons of “biosolids” — the remnant sludge of the wastewater treatment process — that emerge daily from the 150-acre Blue Plains Treatment Plant. The plan was to build eight, 108-foot-tall, 4.5 million gallon digesters. Once operational, they would cut the biosolid volume in half, limit the stench that wafts from the plant and drastically reduce the number of trucks required to haul the sludge away — saving more than $16 million a year.
But a $600 million price tag, 64 percent more than the most recent estimate and three times the original budget, killed the deal. The authority, which received only one bid for the construction phase, cited an “abnormal spike in material costs and the project length” as “major factors in limiting bids and doubling the cost.”
“My understanding is the market forces had everything to do with it,” WASA chief of staff Johnnie Hemphill said.
Authority officials say they will develop a new biosolid management plan, which may or may not include the digesters, during the next three years, taking into account the construction market, regulatory initiatives and evolving wastewater treatment technologies.
WASA uses 70 trucks a day to move its biosolids from Blue Plains in Southeast Washington — the second-largest advanced wastewater treatment facility in the world — to various agricultural sites, where the waste is recycled as fertilizer.
