NCSD 3 Cedar Creek STP - Seaford, New York Wastewater Treatment Plant

NCSD 3 Cedar Creek STP is a major wastewater treatment facility located in Seaford, New York, within Nassau County on Long Island. Serving a population of approximately 550,650, it is classified as a large agglomeration under US regulatory frameworks. The plant is part of the Nassau County Sewer District 3 infrastructure, managing municipal wastewater from the surrounding communities. As a large-scale facility, NCSD 3 Cedar Creek STP is expected to provide at least secondary treatment under the US Clean Water Act, with National Pollutant Discharge Elimination System (NPDES) permits governing its discharge. The designed capacity is 1.00 million gallons per day, reflecting the plant's role in handling significant wastewater volumes. Treatment processes typically include biological treatment, sedimentation, and disinfection to meet effluent standards. The plant's treated effluent is discharged into local waterways that drain to the Atlantic Ocean via the South Shore of Long Island. This coastal discharge requires careful management to protect sensitive marine ecosystems, including shellfish beds and recreational waters. The plant's operation supports water quality in the region, mitigating nutrient pollution and safeguarding downstream habitats.

The plant discharges into the South Shore estuaries of Long Island, which flow into the Atlantic Ocean. These waters support diverse aquatic life, including finfish and shellfish, and are important for recreational use. Nutrient loading from wastewater can contribute to algal blooms and hypoxia, making advanced treatment and permit compliance critical for ecosystem health.