PFAS in tap water, Nassau County, New York
10 of 33 water systems had PFAS-4 above our 0.5 ng/L benchmark at the latest sample. Highest: Albertson WD, 27.1 ng/L. 13 had PFOA or PFOS above the 4 ng/L federal MCL in at least one sample.
33 community water systems · 1,342,339 people served · newest sample June 17, 2026
Water systems in Nassau County
| Water system | People served | PFAS-4 at the latest sample | Entry points | Latest sample |
|---|---|---|---|---|
| Liberty Utilities New York - Lynbrook | 220,000 | 15.5 ng/L above the 2029 federal MCL | 18 | August 13, 2025 |
| Liberty Utilities New York - Merrick | 135,000 | below the 3 to 4 ng/L reporting limit | 8 | July 10, 2025 |
| WA of Western Nassau | 120,000 | below the 3 to 4 ng/L reporting limit above the 2029 federal MCL in an earlier sample | 13 | January 25, 2024 |
| Town of Hempstead Water Department | 110,000 | below the 3 to 4 ng/L reporting limit | 13 | December 18, 2024 |
| Jericho WD | 58,000 | below the 3 to 4 ng/L reporting limit | 20 | November 12, 2025 |
| Hempstead (V) | 56,000 | 4.7 ng/L above the 2029 federal MCL | 2 | July 30, 2024 |
| Hicksville WD | 48,000 | below the 3 to 4 ng/L reporting limit | 8 | June 17, 2026 |
| Freeport (V) | 45,000 | below the 3 to 4 ng/L reporting limit | 3 | May 28, 2024 |
| South Farmingdale WD | 44,700 | below the 3 to 4 ng/L reporting limit | 7 | July 30, 2024 |
| Manhasset Lakeville WD | 43,000 | below the 3 to 4 ng/L reporting limit above the 2029 federal MCL in an earlier sample | 10 | August 22, 2025 |
| Massapequa WD | 43,000 | below the 3 to 4 ng/L reporting limit | 9 | July 15, 2025 |
| Long Beach City | 35,000 | below the 3 to 4 ng/L reporting limit | 1 | September 19, 2024 |
| Plainview WD | 34,000 | below the 3 to 4 ng/L reporting limit | 5 | November 14, 2024 |
| Port Washington WD | 34,000 | below the 3 to 4 ng/L reporting limit above the 2029 federal MCL in an earlier sample | 9 | June 9, 2026 |
| Bethpage WD | 33,000 | below the 3 to 4 ng/L reporting limit | 5 | July 25, 2023 |
| West Hempstead WD | 32,031 | below the 3 to 4 ng/L reporting limit | 2 | April 25, 2024 |
| Glen Cove City | 28,000 | 4.5 ng/L above the 2029 federal MCL | 4 | May 6, 2024 |
| Rockville Centre (V) | 24,700 | below the 3 to 4 ng/L reporting limit | 4 | March 19, 2025 |
| Garden City (V) | 23,272 | 11.4 ng/L above the 2029 federal MCL | 6 | June 17, 2026 |
| Mineola (V) | 20,600 | 4 ng/L above the 2029 federal MCL | 4 | May 26, 2026 |
| Westbury WD | 20,500 | 7.6 ng/L above the 2029 federal MCL | 9 | December 9, 2025 |
| Franklin Square WD | 20,000 | below the 3 to 4 ng/L reporting limit | 3 | October 8, 2024 |
| Garden City Park WD | 18,000 | below the 3 to 4 ng/L reporting limit above the 2029 federal MCL in an earlier sample | 5 | January 29, 2025 |
| Roslyn WD | 17,000 | 5.4 ng/L above the 2029 federal MCL | 8 | June 25, 2025 |
| Albertson WD | 13,500 | 27.1 ng/L above the 2029 federal MCL | 4 | June 20, 2025 |
| Liberty Utilities New York - Sea Cliff | 13,400 | below the 3 to 4 ng/L reporting limit | 2 | May 1, 2024 |
| Carle Place WD | 9,005 | below the 3 to 4 ng/L reporting limit | 3 | November 12, 2025 |
| Farmingdale (V) | 8,744 | below the 3 to 4 ng/L reporting limit | 2 | December 8, 2025 |
| Oyster Bay WD | 8,700 | below the 3 to 4 ng/L reporting limit | 2 | March 2, 2026 |
| Locust Valley WD | 7,500 | 14.6 ng/L | 5 | October 8, 2024 |
| Williston Park (V) | 7,287 | 13.3 ng/L above the 2029 federal MCL | 2 | August 28, 2023 |
| Bayville (V) | 6,700 | below the 3 to 4 ng/L reporting limit | 3 | September 16, 2024 |
| Old Westbury (V) | 4,700 | below the 3 to 4 ng/L reporting limit | 1 | September 16, 2025 |
Not sure which one is yours? The systems report their own service areas to EPA. Check your water bill or your utility's Consumer Confidence Report.
Cities and towns
ZIP codes in Nassau County
Census ZIP code tabulation areas that overlap the county. A ZIP served by one system opens that system's page; a ZIP shared by several systems lists them.
- 11001
- 11003
- 11010
- 11020
- 11021
- 11023
- 11024
- 11030
- 11040
- 11042
- 11050
- 11501
- 11507
- 11509
- 11510
- 11514
- 11516
- 11518
- 11520
- 11530
- 11542
- 11545
- 11547
- 11550
- 11552
- 11553
- 11554
- 11557
- 11558
- 11559
- 11560
- 11561
- 11563
- 11565
- 11566
- 11568
- 11570
- 11572
- 11575
- 11576
- 11577
- 11579
- 11580
- 11581
- 11590
- 11596
- 11598
- 11709
- 11710
- 11714
- 11735
- 11756
- 11758
- 11762
- 11771
- 11783
- 11791
- 11793
- 11801
- 11803
- 11804
How to read these numbers
We compare PFAS-4 (PFOA + PFOS + PFNA + PFHxS) with this site's 0.5 ng/L benchmark, the same line as on the European pages. UCMR 5 reporting limits are 3 to 4 ng/L. So any quantified PFAS-4 compound is above the benchmark, and a clean result reads "below the 3 to 4 ng/L reporting limit", never zero. The US legal limit is the 4 ng/L federal MCL for PFOA and PFOS, which systems must meet from April 26, 2029 ("above the 2029 federal MCL").
EPA: "UCMR 5 results do not indicate compliance or noncompliance with the PFAS drinking water standards". Samples are taken where water enters the distribution system, not at your tap. A system may have changed sources or added treatment since. Source: U.S. Environmental Protection Agency (EPA), Office of Water, PFAS National Primary Drinking Water Regulation (NPDWR). Regulation details retrieved September 19, 2026. Every system page tracks the 2029 compliance date and the proposed rescission of the PFHxS, PFNA, HFPO-DA and Hazard Index limits.
This site is a data project, not an official source. If in doubt, check with your water supplier or local authority.