- Albertson Water District
- Franklin Square Water District
- Garden City Water District
- Hicksville Water District
- Locust Valley Water District
- Manhasset-Lakeville Water District
- Massapequa Water District
- New York American Water District
- Oyster Bay Water District
- Plainview Water District
- Port Washington Water District
- Roslyn Water District
- of Hempstead Water District
- Village of Garden City
- Westbury Water district
- Bayville Water
- Bethpage Water District
- Carle Place Water District
- Cathedral Gardens Water District
- Garden City Water District
- Freeport Water Dept
- Manhasset-Lakeville Water District
- Garden City Park WD
- Glen Cove Water Dist
- Glenwood Water Dist
- Village of East williston
- Village of Farmingdale
- Village of Freeport
- Village of Hempstead
- Jericho Water District
- Long Beach WD
- Old Westbury Water District
- Rockville Centre Water District
- Sands Point Water District
- South Farmingdale WD
- Town of Hempstead Water Department
- Village of Garden City Water Dept
- Village of Hempstead
- Village of Mineola
- Village of Plandome
- Village of Westbury DPW
- West Hempstead Water District
- Water Authority of Great Neck
- Water Authority of Great Neck North
- Water Authority Western Nassau
- Westbury Water District
Nassau County
