The Port Washington Water Pollution Control District (PWWPCD) owns and operates a wastewater treatment plant that was originally constructed in 1951 and utilized a trickling filter biological treatment process with a design flow of 4 MGD. Treated effluent from the plant is discharged into Manhasset Bay. The plant was upgraded in the 1987-1989 timeframe to achieve secondary treatment levels. As a result of effluent nitrogen restrictions imposed by the New York State Department of Environmental Conservation (NYSDEC ) in the late 1990’s based on the results of the Long Island Sound Study (LISS), the plant was again required to upgrade/modify the treatment system in accordance with a strict compliance schedule. D&B provided the engineering for the District to complete this project. Specifically, D&B was tasked to evaluate alternative treatment options and to design and provide construction management services for construction of the plant upgrades to meet the discharge standards. The project was completed ahead-of-schedule in 2011, below the original bid amount and satisfied all regulatory requirements.