We read 19 results from Regional Water Authority’s 2025 water quality report. No results over a legal limit; 2 above a health goal or guideline.
Serves about 418,900 people · Water system ID CT0930011 · 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 |
|---|---|---|---|---|
| PFOA (a PFAS)average · range ND to 7.1 · sampled 2024 · Systemwide (UCMR 5) · 2025 report, page 14 | 0.76 ppt | 0.007 ppt | 4 ppt from 2029 | Above the health goal109x the health goal |
| PFOS (a PFAS)average · range ND to 10.7 · sampled 2024 · Systemwide (UCMR 5) · 2025 report, page 14 | 1.4 ppt | 1 ppt | 4 ppt from 2029 | Above the health goal1.4x the health goal |
| Bariumaverage · range 0.005 to 0.27 · Systemwide · 2025 report, page 11 | 0.08 ppm | 2 ppm | 2 ppm | Below the health goal |
| Chlorideaverage · range 9.94 to 89.1 · Systemwide · 2025 report, page 11 | 34 ppm | — | 250 ppm guideline | Within the guideline |
| Chlorineaverage · range 0.12 to 2.6 · Distribution system · 2025 report, page 11 | 1.5 ppm | None set | 4 ppm | Below the legal limit |
| Copper90th percentile of homes tested, 0 over the action level · sampled 2023 · Customer taps · 2025 report, page 10 | 0.27 ppm | 0.3 ppm | 1.3 ppm (action level) | Below the health goal |
| Disinfection byproducts (HAA5)average · range 2.9 to 75.5 · Distribution system · 2025 report, page 10 | 32 ppb | None set | 60 ppb | Below the legal limit |
| Disinfection byproducts (TTHM)average · range 6 to 76.5 · Distribution system · 2025 report, page 10 | 36 ppb | None set | 80 ppb | Below the legal limit |
| E. colias reported · Distribution system · 2025 report, page 10 | Not detected | 0 positive samples | 0 positive samples | Not detected |
| Fluorideaverage · range 0.21 to 1.24 · Systemwide · 2025 report, page 11 | 0.69 ppm | 1 ppm | 4 ppm | Below the health goal |
| Lead90th percentile of homes tested, 0 over the action level · sampled 2023 · Customer taps · 2025 report, page 10 | Not detected | 0.2 ppb | 15 ppb (action level) | Not detected |
| Manganeseaverage · range ND to 0.27 · Systemwide · 2025 report, page 12 | 0.04 ppm | — | 0.05 ppm guideline | Within the guideline |
| Nitrate (as N)average · range ND to 3.82 · Systemwide · 2025 report, page 11 | 0.73 ppm | 10 ppm | 10 ppm | Below the health goal |
| Sulfateaverage · range 6.5 to 35.9 · Systemwide · 2025 report, page 11 | 12.8 ppm | — | 250 ppm guideline | Within the guideline |
| Turbidity (cloudiness)average · range 0.05 to 2.5 · Aquifer wells, highest of 2 sources · 2025 report, page 13 | 0.14 NTU | None set | 1 NTU | Below the legal limit |
| PFBS (a PFAS)average · range ND to 3.5 · sampled 2024 · Systemwide (UCMR 5) · 2025 report, page 14 | 0.25 ppt | None set | None | No health limit |
| PFPeA (a PFAS)average · range ND to 3.1 · sampled 2024 · Systemwide (UCMR 5) · 2025 report, page 14 | 0.22 ppt | None set | None | No health limit |
| Radonaverage · range ND to 1,856 · sampled 2024 · Systemwide · 2025 report, page 12 | 554 pCi/L | None set | None | No health limit |
| Sodiumaverage · range 7.9 to 68.5 · Systemwide · 2025 report, page 12 | 22.5 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 Regional Water Authority’s water between Sep 2023 and Jun 2024. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- PFOA7.1 pptFound in 4 of 30 samples · highest resultAbove the federal limit that takes effect in 2029 (4 ppt)
- PFOS10.7 pptFound in 7 of 30 samples · highest resultAbove the federal limit that takes effect in 2029 (4 ppt)
- PFBS3.5 pptFound in 3 of 30 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.
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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