Nitrogen Control Program
Nitrogen discharges to the NY Harbor have been identified as a significant cause of hypoxia – essentially a lack of oxygen – in the Western Long Island Sound and portions of Jamaica Bay. These conditions can create hypoxic events, especially during the summer months. In order to address this regional water quality issue, the New York City Department of Environmental Protection (DEP) has initiated a comprehensive program to reduce nitrogen discharges and to collect performance and cost data concerning the implementation of biological nutrient removal (BNR) technologies at the city’s fourteen wastewater treatment plants. Several key elements of this overall program are described below.
The objectives of the current nitrogen control plan are to comply with both maximum monthly and twelve-month rolling average limits for total nitrogen (TN) and also to comply with Special Conditions in the NYSDEC State Pollutant Discharge Elimination System (SPDES) Discharge Permit, dated September 30, 1988. The permit was structured to provide no net increase in point source loading into Jamaica Bay and to reduce nitrogen loading into the Long Island Sound. Where applicable, testing programs have been initiated to meet current objectives or to evaluate future actions for nitrogen control.
For plants discharging into the Long Island Sound Management Zones, the following requirements were included in the Special Conditions of the SPDES Permit:
- Operational Changes
- Nitrogen Mass Balance/Process Control Testing
- Nitrogen Control Action Plan
- Nitrogen Removal Pilot Studies and Nitrogen Reduction Goals
- Phase I Pilot Work
- Phase II Pilot work
- Pilot Work Report and Implementation
- Nitrogen Control Feasibility Plan
In 2010 DEP reached a historic agreement to reduce the nitrogen loads discharged into Jamaica Bay by nearly 50 percent over the coming decade.