We read 19 results from Chelmsford Water District’s 2025 water quality report. No results over a legal limit; 4 above a health goal or guideline.
Serves about 28,750 people · Water system ID MA3056000 · 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 |
|---|---|---|---|---|
| Arsenichighest measured · range ND to 1.1 · listed as a violation in the report · sampled 2024 · Sources · 2025 report, page 6 | 1.1 ppb | 0.004 ppb | 10 ppb | Above the health goal275x the health goal |
| Gross alpha (radioactivity)highest measured · listed as a violation in the report · sampled 2023 · Sources · 2025 report, page 7 | 2.9 pCi/L | 0 pCi/L | 15 pCi/L | Above the health goalThe health goal is zero |
| Lead90th percentile of 30 homes tested, 0 over the action level · listed as a violation in the report · Customer taps · 2025 report, page 5 | 2.4 ppb | 0.2 ppb | 15 ppb (action level) | Above the health goal12x the health goal |
| Radium-226highest measured · range 0.3 to 0.7 · listed as a violation in the report · sampled 2023 · Sources · 2025 report, page 7 | 0.7 pCi/L | 0.05 pCi/L | 5 pCi/L | Above the health goal14x the health goal |
| 2,4-D (weed killer)highest measured · range ND to 0.14 · listed as a violation in the report · Sources · 2025 report, page 7 | 0.14 ppb | 70 ppb | 70 ppb | Below the health goal |
| Bariumhighest measured · range 0.02 to 0.04 · listed as a violation in the report · sampled 2024 · Sources · 2025 report, page 6 | 0.04 ppm | 2 ppm | 2 ppm | Below the health goal |
| Copper90th percentile of 30 homes tested, 0 over the action level · listed as a violation in the report · Customer taps · 2025 report, page 5 | 0.16 ppm | 0.3 ppm | 1.3 ppm (action level) | Below the health goal |
| Dalapon (herbicide)highest measured · range ND to 0.18 · listed as a violation in the report · Sources · 2025 report, page 7 | 0.18 ppb | 200 ppb | 200 ppb | Below the health goal |
| Nitrate (as N)highest measured · range 0.13 to 1.55 · listed as a violation in the report · Sources · 2025 report, page 6 | 1.55 ppm | 10 ppm | 10 ppm | Below the health goal |
| Perchloratehighest measured · range 0.19 to 0.25 · listed as a violation in the report · Sources · 2025 report, page 6 | 0.25 ppb | 1 ppb | 6 ppb | Below the health goal |
| Picloram (herbicide)highest measured · range ND to 0.39 · listed as a violation in the report · Sources · 2025 report, page 7 | 0.39 ppb | 500 ppb | 500 ppb | Below the health goal |
| Sulfateaverage · range 11.8 to 16.7 · Sources · 2025 report, page 8 | 14.3 ppm | — | 250 ppm guideline | Within the guideline |
| Bromodichloromethaneaverage · range 0.7 to 20 · Distribution system · 2025 report, page 7 | 15.1 ppb | None set | None | No health limit |
| Bromoformaverage · range ND to 1.3 · Distribution system · 2025 report, page 7 | 0.45 ppb | None set | None | No health limit |
| Chloroformaverage · range 1 to 87 · Distribution system · 2025 report, page 7 | 40.3 ppb | None set | None | No health limit |
| Dibromochloromethaneaverage · range 1.1 to 9.6 · Distribution system · 2025 report, page 7 | 5.81 ppb | None set | None | No health limit |
| PFBS (a PFAS)average · range 1.91 to 5.8 · Sources · 2025 report, page 8 | 3.58 ppt | None set | None | No health limit |
| PFHxA (a PFAS)average · range 2.24 to 4.33 · Sources · 2025 report, page 8 | 3.22 ppt | None set | None | No health limit |
| Sodiumaverage · range 82.5 to 101 · Sources · 2025 report, page 8 | 88.7 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 Chelmsford Water District’s water between Oct 2023 and Oct 2024. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.
- PFOA8.9 pptFound in 7 of 8 samples · highest resultAbove the federal limit that takes effect in 2029 (4 ppt)
- PFOS7.2 pptFound in 5 of 8 samples · highest resultAbove the federal limit that takes effect in 2029 (4 ppt)
- PFBS4.2 pptFound in 1 of 8 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-226
What removes it: Reverse osmosis.
Lead
Found: Lead
What removes it: Certified carbon block or RO.
PFAS ("forever chemicals")
Found: PFOA (EPA testing), PFOS (EPA testing)
What removes it: Reverse osmosis.
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