County · New York
Nassau County, New York: drinking water records
This overview covers 69 ZIP codes and 40 community water systems in Nassau County. It also stands in for 0 ZIP codes whose utility has too little EPA data for a page of its own.
System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.
Water systems with the most complete records
| Water system | People served | PFAS survey results | PFAS found | Health-based violations | Lead, 9 in 10 homes at or below |
|---|---|---|---|---|---|
| Liberty Utilities New York - Lynbrook NY2902835 | 220,000 | 1,050 | 3 | 3 | 4.2 ppb |
| Liberty Utilities New York - Merrick NY2902840 | 135,000 | 357 | 0 | 3 | 0 ppb |
| Jericho WD NY2902831 | 58,000 | 975 | 5 | 1 | 0 ppb |
| Long Beach City NY2902834 | 35,000 | 60 | 0 | 1 | 1.1 ppb |
| Plainview WD NY2902845 | 34,000 | 300 | 1 | 2 | 0 ppb |
| Wa of Western Nassau NY2902830 | 120,000 | 780 | 8 | 0 | 1.4 ppb |
| Town of Hempstead Water Department NY2900000 | 110,000 | 780 | 1 | 0 | 1 ppb |
| Hempstead (V) NY2902827 | 56,000 | 120 | 1 | 0 | 0 ppb |
| Hicksville WD NY2902829 | 48,000 | 480 | 1 | 0 | 1 ppb |
| Freeport (V) NY2902823 | 45,000 | 180 | 0 | 0 | 1.3 ppb |
| South Farmingdale WD NY2902854 | 44,700 | 416 | 0 | 0 | 1 ppb |
| Manhasset Lakeville WD NY2902836 | 43,000 | 570 | 5 | 0 | 1.6 ppb |
| Massapequa WD NY2902837 | 43,000 | 540 | 0 | 0 | 0 ppb |
| Port Washington WD NY2912267 | 34,000 | 540 | 6 | 0 | 2 ppb |
| Bethpage WD NY2902817 | 33,000 | 300 | 4 | 0 | 0 ppb |
| West Hempstead WD NY2902857 | 32,031 | 120 | 0 | 0 | 1.1 ppb |
| Glen Cove City NY2902826 | 28,000 | 240 | 2 | 0 | 3.9 ppb |
| Rockville Centre (V) NY2902848 | 24,700 | 240 | 0 | 0 | 1 ppb |
| Garden City (V) NY2902824 | 23,272 | 360 | 3 | 0 | 9.3 ppb |
| Mineola (V) NY2902839 | 20,600 | 240 | 4 | 0 | 2.2 ppb |
| Westbury WD NY2902856 | 20,500 | 540 | 3 | 0 | 0 ppb |
| Franklin Square WD NY2902822 | 20,000 | 180 | 0 | 0 | 0 ppb |
| Garden City Park WD NY2902825 | 18,000 | 300 | 3 | 0 | 2.6 ppb |
| Roslyn WD NY2902851 | 17,000 | 480 | 2 | 0 | 0 ppb |
| Albertson WD NY2902815 | 13,500 | 240 | 7 | 0 | 0 ppb |
ZIP reports in Nassau County
No ZIP report in this county is published yet.
Sources and scope
EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Page generated 2026-09-03.
Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.