Westchester Co New Rochelle STP - New Rochelle, New York Wastewater Treatment Plant

Westchester Co New Rochelle STP is a municipal wastewater treatment facility serving the City of New Rochelle in Westchester County, New York. The plant handles wastewater from a population of about 90,434, placing it in the medium-to-large agglomeration category under US regulatory frameworks. As a US facility, the plant operates under the Clean Water Act and is subject to National Pollutant Discharge Elimination System (NPDES) permits issued by the New York State Department of Environmental Conservation. For plants of this scale, secondary treatment is typically required, with additional nutrient removal standards in sensitive watersheds like Long Island Sound. The plant's treated effluent ultimately reaches the Long Island Sound, an ecologically significant estuary that supports diverse marine life, including shellfish beds and migratory fish. The Sound is a critical habitat for species such as winter flounder and Atlantic sturgeon, and its water quality is closely monitored to prevent eutrophication from nitrogen loading.

The plant discharges into the Long Island Sound watershed, a major estuary that connects to the Atlantic Ocean. The Sound is a productive ecosystem supporting commercial and recreational fisheries, as well as migratory birds. Nutrient pollution from wastewater is a key concern, as it can lead to hypoxia and harmful algal blooms, impacting aquatic life and coastal communities.