Wastewater EngineeringAdvanced Wastewater Treatment Facility

Suffolk County Department of Public WorksPort Jefferson Wastewater Treatment Plant

Hypoxia is the condition that occurs when there are low levels of oxygen in the bottom waters of the Long Island Sound during late summer. Hypoxia is linked to the overabundance of nitrogen, which stimulates the excessive growth of algae. When the algae decompose oxygen is consumed. There is so much oxygen consumed by the algae that other organisms suffocate and many die off.

To alleviate the hypoxia problem, a Total Maximum Daily Load (TMDL) of nitrogen to the Long Island Sound was adopted by the states of New York and Connecticut to achieve water quality standards for dissolved oxygen.

Under Phase III of the Long Island Sound Study, an overall reduction of 58.5% nitrogen loading must be achieved. Allocation of the reduction of nitrogen between point and non-point sources resulted in Suffolk County plants having to remove 80.69 percent of their 1990 baseline nitrogen value. It requires that the Port Jefferson WWTP reduce its nitrogen loading from 202 lbs/day to 39 lbs/day. At the design flow of 1.10 mgd this equates to a total nitrogen effluent limitation of approximately 4 mg/l. This $23 million project is scheduled to be completed in the first quarter of 2008.