County · New York
Suffolk County, New York: drinking water records
This overview covers 108 ZIP codes and 27 community water systems in Suffolk County. It also stands in for 1 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 |
|---|---|---|---|---|---|
| Suffolk County Water Authority NY5110526 | 1,100,000 | 14,418 | 10 | 1 | 1.3 ppb |
| Riverhead Water District NY5103705 | 35,000 | 600 | 4 | 1 | 2.2 ppb |
| South Huntington Water District NY5103263 | 81,760 | 660 | 0 | 0 | 1 ppb |
| Greenlawn Water District NY5103271 | 42,000 | 720 | 3 | 0 | 6.3 ppb |
| Dix Hills Water District NY5103276 | 34,522 | 480 | 2 | 0 | 1.7 ppb |
| Smithtown Water District NY5105656 | 19,635 | 60 | 0 | 0 | 2.7 ppb |
| Hampton Bays Water District NY5103704 | 12,500 | 300 | 1 | 0 | 1 ppb |
| St James Water District NY5103266 | 10,587 | 60 | 6 | 0 | 1.0 ppb |
| Ocean Beach Water District NY5103280 | 4,500 | 120 | 0 | 0 | 1.2 ppb |
| Brookhaven National Laboratory NY5111891 | 3,500 | 240 | 1 | 0 | 2.7 ppb |
| Eagle Lake Mobile Home Park LA1103110 | 300 | 0 | 0 | 4 | 0 ppb |
| Robert Moses State Park NY5117671 | 11,600 | 0 | 0 | 0 | 6.9 ppb |
| Northport VA Hospital NY5111894 | 3,088 | 0 | 0 | 0 | 3.3 ppb |
| Greenport Water District NY5103703 | 2,050 | 0 | 0 | 0 | 3.2 ppb |
| Riverside Water District NY5105655 | 2,050 | 0 | 0 | 0 | 1.1 ppb |
| Saltaire Water District NY5103281 | 2,000 | 0 | 0 | 0 | 3.6 ppb |
| Seaview Water Company NY5110600 | 1,400 | 0 | 0 | 0 | 4.5 ppb |
| Calverton Hills Owners Association NY5112134 | 897 | 0 | 0 | 0 | 0 ppb |
| Shelter Island Heights Association NY5103243 | 500 | 0 | 0 | 0 | 1.1 ppb |
| Fishers Island Water Works NY5103294 | 380 | 0 | 0 | 0 | 1.1 ppb |
| West Gilgo Beach Association NY5110607 | 300 | 0 | 0 | 0 | 2.9 ppb |
| West Neck Water District NY5110623 | 100 | 0 | 0 | 0 | 1.3 ppb |
| Peconic River Mobile Home Park NY5101296 | 75 | 0 | 0 | 0 | 3 ppb |
| Oak Beach Public Water Supply NY5130214 | 66 | 0 | 0 | 0 | 3.8 ppb |
| Peconic View Mobile Home Park NY5101291 | 40 | 0 | 0 | 0 | 3.2 ppb |
ZIP reports in Suffolk County
No ZIP report in this county is published yet.
These ZIP codes are covered by this overview because their utility has too little EPA data for a separate page: 06390.
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.