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Back River WWTP Upgrades Benefit the Bay.

Recently, the first phase of the Enhanced Nutrient Removal Upgrade (ENR) program was successfully commissioned at the City of Baltimore's 180 million gallons per day (MGD) Back River Wastewater Treatment Plant (WWTP), Maryland’s largest plant. The new state-of-the art facilities are integrated into the existing advanced treatment process and allow for more than 90% removal of nitrogen and phosphorus, before discharge to the receiving waters (Back River and Chesapeake Bay). Excessive levels of nitrogen and phosphorus (nutrients) in the water contribute to algae blooms and low oxygen levels (dead zones) that can lead to fish kills. The City is also constructing similar facilities at its second largest plant, Patapsco WWTP. Together, the two plants account for more than 70% of the State’s targeted reduction in nutrient point-source loads to the Chesapeake Bay. 

The ENR facilities at Back River WWTP include a biological deep-bed filter process, among the largest of its kind in the world, a 300 MGD Pump Station, an Operations Building with a plant-wide process control center, offices and a laboratory, along with chemical feed systems and other supporting facilities.

WRA led a team of sub-consultants to provide design services, as well as engineering and inspection support services during the construction, which began in 2013. Final construction completion is expected by December 2017. Archer Western Contractors, Ltd. (Walsh Construction Company) is the general contractor and Construction Management/Administration is provided by the Louis Berger Water Group. The construction cost is approximately $270 million, of which more than 90% is funded by the State’s Bay Restoration Fund.