What was found in Acton's water
The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate | 4660 µg/L 47% of the EPA limit 10000 µg/L Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 2/2 | SYR4 |
| Fluoride | 1025 µg/L 26% of the EPA limit 4000 µg/L Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2018 | 2/2 | SYR4 |
| Copper | 126.75 µg/L 9.8% of the EPA limit 1300 µg/L Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019
Highest in the city: 151.35 µg/L — PINE HILL CONDOMINIUM · 95 people · 2019 | 2/2 | SYR4 |
| Barium | 79.25 µg/L 4% of the EPA limit 2000 µg/L Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2018
Highest in the city: 92 µg/L — PINE HILL CONDOMINIUM · 95 people · 2013 | 2/2 | SYR4 |
| TTHM | 82.345 µg/L 103% of the EPA limit, at the 95th percentile of samples — 80 µg/L Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| Chloroform | 56.6 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| Arsenic | 31 µg/L 310% of the EPA limit, at the 95th percentile of samples — 10 µg/L Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| Combined Uranium | 20.595 µg/L 69% of the EPA limit 30 µg/L Highest in the city: PINE HILL CONDOMINIUM · 95 people · 2019 | 1/2 | SYR4 |
| Bromodichloromethane | 19.505 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| Total Haloacetic Acids (HAA5) | 12.655 µg/L 21% of the EPA limit 60 µg/L Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| Dibromochloromethane | 11.78 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| Trichloroacetic Acid | 9.66 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| 1,1-Dichloroethylene | 7.17 µg/L 102% of the EPA limit, at the 95th percentile of samples — 7 µg/L Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| Monobromoacetic Acid | 5.376 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| Dichloroacetic Acid | 4.4255 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| Bromoform | 4.08 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| Monochloroacetic Acid | 3.45 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| Dibromoacetic Acid | 2.329 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2019 | 1/2 | SYR4 |
| Chromium | 1.8 µg/L 1.8% of the EPA limit 100 µg/L Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2018 | 1/2 | SYR4 |
| Pfba | 0.0206 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2024 | 1/2 | UCMR-5 |
| PFOA | 0.0134 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2024 | 1/2 | UCMR-5 |
| Pfpea | 0.0084 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2024 | 1/2 | UCMR-5 |
| Pfhxa | 0.0071 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2024 | 1/2 | UCMR-5 |
| Pfhpa | 0.0052 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2024 | 1/2 | UCMR-5 |
| PFOS | 0.0049 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2024 | 1/2 | UCMR-5 |
| PFBS | 0.0037 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2024 | 1/2 | UCMR-5 |
| Lead | 0.0036 mg/L 24% of the EPA limit 0.0150 mg/L Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2025 | 2/2 | LCR |
| PFHXS | 0.0032 µg/L No EPA limit set Main supplier: ACTON WATER SUPPLY DISTRICT · 21,285 people · 2024 | 1/2 | UCMR-5 |
Each bar shows the measured level as a share of the EPA limit: green is
well under, amber is close to it, red is over. For lead and copper the
limit applies to exactly the 90th-percentile figure shown, so red there
means a real exceedance. For everything else the limit applies to a
running annual average while the figure is the 95th percentile of the
system's samples — over 100% is worth reading, but is not by itself a
violation.
Formal violations are listed separately.
These are the utilities' own EPA-reported results, not a city-wide
average. A detection means the lab measured the
substance — it isn't the same as exceeding a legal limit. Hover a source
tag to see the EPA program and years behind each figure.
Water suppliers serving Acton
| Supplier | Population served |
|---|---|
| ACTON WATER SUPPLY DISTRICT | 21,285 |
| PINE HILL CONDOMINIUM | 95 |
Frequently asked questions about Acton tap water
Is Acton tap water safe to drink?
EPA testing detected 28 contaminants in the water serving Acton. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.
How many water suppliers serve Acton?
2 public water suppliers report drinking-water monitoring for Acton, Massachusetts to the EPA. Each is listed above with its population served.
What contaminants are in Acton's water?
The contaminants EPA monitoring detected in Acton include Nitrate, Fluoride, Copper, Barium, TTHM. The full list, with the level at the main supplier and the data source, is in the table above.
Where does this data come from?
Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.