The Great Neck Water Pollution Control District (GNWPCD) is a commissioner-run special district within the Town of North Hempstead. Funded by taxpayers and commercial, institutional, and industrial users, the District is overseen by an elected Board of Commissioners. The GNWPCD serves over 25,000 residents in the villages of Great Neck, Saddle Rock, and Kensington, as well as parts of Thomaston and Great Neck Plaza east of Middle Neck Road, and all unincorporated areas north of the railroad and a portion of Manhasset.

The GNWPCD operates a wastewater treatment plant designed for a daily capacity of 5.3 million gallons. The sewage is transported to the plant through 72 miles of sanitary sewers, aided by 10 sewage pump stations.