We read 15 results from Wa of Western Nassau’s 2025 water quality report. No results over a legal limit; 7 above a health goal or guideline.
Serves about 120,000 people · Water system ID NY2902830 · Read the district’s 2025 report (opens in a new tab)
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Results from the 2025 report
Each number is copied from the district’s report and links to the page it’s printed on. Where the report lists several plants, wells or purchased water, the highest is shown.
| Contaminant | Result | Health goal | Legal limit | What it means |
|---|---|---|---|---|
| Chromium-6highest measured · range ND to 0.31 · Wells · 2025 report, page 4 | 0.31 ppb | 0.02 ppb | 10 ppb | Above the health goal16x the health goal |
| Gross alpha (radioactivity)highest measured · range 1.34 to 4.56 · Wells · 2025 report, page 4 | 4.56 pCi/L | 0 pCi/L | 15 pCi/L | Above the health goalThe health goal is zero |
| Lead90th percentile of 60 homes tested, 0 over the action level · Customer taps (60 samples) · 2025 report, page 4 | 1.4 ppb | 0.2 ppb | 15 ppb (action level) | Above the health goal7x the health goal |
| Perchloratehighest measured · range ND to 2.4 · Wells · 2025 report, page 4 | 2.4 ppb | 1 ppb | 6 ppb | Above the health goal2.4x the health goal |
| PFOA (a PFAS)highest measured · range ND to 6.22 · Wells · 2025 report, page 5 | 6.22 ppt | 0.007 ppt | 10 ppt (New York) now; 4 ppt from 2029 | Above the federal limit that takes effect in 20291.6x the 4 ppt federal limit that takes effect in 2029; below the 10 ppt New York limitNot a violation yet: EPA's 4 ppt limit is final, but water systems don't have to meet it until 2029. |
| PFOS (a PFAS)highest measured · range ND to 2.41 · Wells · 2025 report, page 5 | 2.41 ppt | 1 ppt | 10 ppt (New York) now; 4 ppt from 2029 | Above the health goal2.4x the health goal |
| Radium (combined 226 + 228)highest measured · range 0.49 to 4.42 · Wells · 2025 report, page 4 | 4.42 pCi/L | 0 pCi/L | 5 pCi/L | Above the health goalThe health goal is zero |
| Chlorinehighest measured · range 0.53 to 1.3 · Distribution system · 2025 report, page 4 | 1.3 ppm | None set | 4 ppm | Below the legal limit |
| Copper90th percentile of 60 homes tested, 0 over the action level · Customer taps (60 samples) · 2025 report, page 4 | 0.14 ppm | 0.3 ppm | 1.3 ppm (action level) | Below the health goal |
| Disinfection byproducts (TTHM)highest running annual average · range ND to 10.3 · Distribution system (site 2) · 2025 report, page 5 | 5.48 ppb | None set | 80 ppb | Below the legal limit |
| Nitrate (as N)highest measured · range ND to 6.5 · Wells · 2025 report, page 4 | 6.5 ppm | 10 ppm | 10 ppm | Below the health goal |
| Total dissolved solidshighest measured · range 59 to 251 · Wells · 2025 report, page 4 | 251 ppm | — | 500 ppm guideline | Within the guideline |
| 1,4-Dioxanehighest measured · range ND to 0.84 · Wells · 2025 report, page 4 | 0.84 ppb | None set | None | No health limit |
| Hardnesshighest measured · range 0.49 to 6.37 · Wells · 2025 report, page 4 | 6.37 gpg (109 ppm) | — | — | Moderately hard |
| Sodiumhighest measured · range 3.2 to 59 · Wells · 2025 report, page 4 | 59 ppm | None set | None | No health limit |
Utility results describe the whole system, measured where water enters the pipes, not your tap. Your home’s plumbing can add lead or copper.
EPA testing for PFAS and lithium
EPA’s own nationwide testing (UCMR 5) found these in Wa of Western Nassau’s water between Jun 2023 and Jan 2024. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- PFOA10 pptFound in 5 of 26 samples · highest resultAbove the federal limit that takes effect in 2029 (4 ppt)
- PFOS6.1 pptFound in 2 of 26 samples · highest resultAbove the federal limit that takes effect in 2029 (4 ppt)
- PFHxS4.5 pptFound in 2 of 26 samples · highest resultNo federal limit in force for this one
- PFBS3.6 pptFound in 3 of 26 samples · highest resultNo federal limit in force for this one
Source: EPA UCMR 5 occurrence data. The highest single result is shown; one high sample doesn’t mean every glass is that high.
What you can do
Nothing here is an emergency notice: if the district has a violation, it must tell customers directly. If you’d like to lower these at your tap, these are the treatments that remove them, and the catalog shows the models certified for each. Ranking is by certified removal; commissions never change the order.
Radium and uranium
Found: Gross alpha (radioactivity), Radium (combined 226 + 228)
What removes it: Reverse osmosis.
Lead
Found: Lead
What removes it: Certified carbon block or RO.
Industrial chemicals and pesticides
Found: Perchlorate
What removes it: Carbon block or RO.
PFAS ("forever chemicals")
Found: PFOA (a PFAS), PFOS (a PFAS), PFOA (EPA testing), PFOS (EPA testing)
What removes it: Reverse osmosis.
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