We read 10 results from Westerly Water Department’s 2022 water quality report. No results over a legal limit; 3 above a health goal or guideline.
Serves about 35,298 people · Water system ID RI1559512 · Read the district’s 2022 report (opens in a new tab)
Open this district in the water lookupCompare with your own test results, see the district map and get matched filters.
Results from the 2022 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 |
|---|---|---|---|---|
| Copper90th percentile of 30 homes tested, 0 over the action level · listed as a violation in the report · sampled 2024 · Customer taps · 2022 report, page 3 | 0.89 ppm | 0.3 ppm | 1.3 ppm (action level) | Above the health goal3x the health goal |
| PFOA (a PFAS)average · range ND to 7.54 · sampled 2024 · Treated water · 2022 report, page 3 | 3.28 ppt | 0.007 ppt | 20 ppt (Rhode Island) now; 4 ppt from 2029 | Above the health goal469x the health goal |
| PFOS (a PFAS)average · range ND to 6.69 · sampled 2024 · Treated water · 2022 report, page 3 | 1.92 ppt | 1 ppt | 20 ppt (Rhode Island) now; 4 ppt from 2029 | Above the health goal1.9x the health goal |
| Bariumhighest measured · range 0.01 to 0.09 · listed as a violation in the report · sampled 2023 · Treated water · 2022 report, page 3 | 0.09 ppm | 2 ppm | 2 ppm | Below the health goal |
| Chlorinehighest measured · range ND to 1.94 · listed as a violation in the report · sampled 2024 · Distribution system · 2022 report, page 3 | 1.94 ppm | None set | 4 ppm | Below the legal limit |
| Disinfection byproducts (HAA5)highest measured · range 6 to 15.1 · listed as a violation in the report · sampled 2024 · Distribution system · 2022 report, page 3 | 15.1 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)highest measured · range ND to 32.2 · listed as a violation in the report · sampled 2024 · Distribution system · 2022 report, page 3 | 32.2 ppb | None set | 80 ppb | Below the legal limit |
| Fluoridehighest measured · range ND to 0.17 · listed as a violation in the report · sampled 2023 · Treated water · 2022 report, page 3 | 0.17 ppm | 1 ppm | 4 ppm | Below the health goal |
| Nitrate (as N)highest measured · range 0.02 to 3.66 · listed as a violation in the report · sampled 2024 · Treated water · 2022 report, page 3 | 3.66 ppm | 10 ppm | 10 ppm | Below the health goal |
| Sodiumaverage · range 9.8 to 45.1 · sampled 2024 · Treated water · 2022 report, page 3 | 20.6 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. 1 number we weren’t sure about is held back until a person checks.
EPA testing for PFAS and lithium
EPA’s own nationwide testing (UCMR 5) found these in Westerly Water Department’s water between May 2025 and Sep 2025. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- PFOA9 pptFound in 7 of 14 samples · highest resultAbove the federal limit that takes effect in 2029 (4 ppt)
- PFOS7 pptFound in 5 of 14 samples · highest resultAbove the federal limit that takes effect in 2029 (4 ppt)
- PFBS3 pptFound in 4 of 14 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.
Copper
Found: Copper
What removes it: Reverse osmosis.
PFAS ("forever chemicals")
Found: PFOA (a PFAS), PFOS (a PFAS), PFOA (EPA testing), PFOS (EPA testing)
What removes it: Reverse osmosis.
More districts: Rhode Island water quality · All states · Something look wrong? Tell us