Bird Island Treatment Plant

by Kim N. Irvine, Gary W. Pettibone, Salmatou Bako, Jim Caruso, Roseanne Frandina, Gary Aures, Jane Ork, and Dan Bentivogli

The Bird Island plant is the second largest WWTP in New York State and one of the twelve largest plants in the nation. It discharges the greatest effluent volume to the Niagara River of any facility. Between July 1991 and June 1996, the mean secondary sewage flow from the plant was 154 MGD.

Sanitary and storm flow reach the Bird Island plant from more than 834 mi of trunk and lateral sewers that serve the city of Buffalo and outlying districts. Municipal sanitary and septic wastes also are trucked from a wide area and then pumped into the Buffalo sewer system. In total, the Bird Island Treatment Plant serves a population of 675,000.

The water pumped from the final clarifiers at the plant is chlorinated in one of four chlorine contact chambers before discharge to the Niagara River through two lines at a depth of 20 to 30 ft. The clarified waste water has a residence time within the chlorine contact chamber of 15 min at design flow.

The maximum design capacity for full secondary treatment is 360 MGD. During storm events, flows may exceed 500 MGD, which results in only partial treatment of the excess flow using primary treatment and disinfection.