What was found in Washington'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 | 2600 µg/L 26% of the EPA limit 10000 µg/L Main supplier: RUMSEY HALL SCHOOL · 398 people · 2019
Highest in the city: 3600 µg/L — DODGE FARM · 42 people · 2019 | 7/8 | SYR4 |
| Nitrate-Nitrite | 2600 µg/L 26% of the EPA limit 10000 µg/L Main supplier: RUMSEY HALL SCHOOL · 398 people · 2019
Highest in the city: 3495 µg/L — DODGE FARM · 42 people · 2019 | 7/8 | SYR4 |
| Copper | 1058.5 µg/L 81% of the EPA limit 1300 µg/L Main supplier: RUMSEY HALL SCHOOL · 398 people · 2019
Highest in the city: 1564 µg/L — AQUARION-JUDEA MAIN · 219 people · 2019 | 8/8 | SYR4 |
| Fluoride | 200 µg/L 5% of the EPA limit 4000 µg/L Main supplier: RUMSEY HALL SCHOOL · 398 people · 2019
Highest in the city: 548 µg/L — NEW PRESTON WATER CO · 139 people · 2019 | 8/8 | SYR4 |
| Barium | 38.5 µg/L 1.9% of the EPA limit 2000 µg/L Main supplier: RUMSEY HALL SCHOOL · 398 people · 2019
Highest in the city: 49.3 µg/L — AQUARION-JUDEA DEPOT · 68 people · 2018 | 7/8 | SYR4 |
| Lead | 7.05 µg/L 47% of the EPA limit 15 µg/L Main supplier: RUMSEY HALL SCHOOL · 398 people · 2019
Highest in the city: 19.8 µg/L — BEE BROOK CROSSING CONDOMINIUMS · 120 people · 2019 | 7/8 | SYR4 |
| TTHM | 17.43 µg/L 22% of the EPA limit 80 µg/L Highest in the city: THE FREDERICK GUNN SCHOOL, INC. · 300 people · 2019 | 5/8 | SYR4 |
| Chloroform | 8.212 µg/L No EPA limit set Highest in the city: THE FREDERICK GUNN SCHOOL, INC. · 300 people · 2019 | 5/8 | SYR4 |
| Total Haloacetic Acids (HAA5) | 5.35 µg/L 8.9% of the EPA limit 60 µg/L Highest in the city: DODGE FARM · 42 people · 2019 | 4/8 | SYR4 |
| Gross Alpha, Excl. Radon And U | 4.801 pCi/L 32% of the EPA limit 15 pCi/L Highest in the city: THE FREDERICK GUNN SCHOOL, INC. · 300 people · 2015 | 2/8 | SYR4 |
| Bromodichloromethane | 4.2325 µg/L No EPA limit set Highest in the city: THE FREDERICK GUNN SCHOOL, INC. · 300 people · 2019 | 5/8 | SYR4 |
| Combined Radium (-226 And -228) | 3.8 pCi/L 76% of the EPA limit 5 pCi/L Highest in the city: AQUARION-QUARRY RIDGE · 84 people · 2019 | 3/8 | SYR4 |
| Dibromochloromethane | 3.55 µg/L No EPA limit set Highest in the city: AQUARION-JUDEA DEPOT · 68 people · 2019 | 6/8 | SYR4 |
| Cyanide | 3 µg/L 1.5% of the EPA limit 200 µg/L Highest in the city: THE FREDERICK GUNN SCHOOL, INC. · 300 people · 2019 | 1/8 | SYR4 |
| Dichloroacetic Acid | 3 µg/L No EPA limit set Highest in the city: AQUARION-JUDEA MAIN · 219 people · 2019 | 4/8 | SYR4 |
| Dibromoacetic Acid | 2.27 µg/L No EPA limit set Highest in the city: DODGE FARM · 42 people · 2019 | 3/8 | SYR4 |
| Monobromoacetic Acid | 2.19 µg/L No EPA limit set Highest in the city: DODGE FARM · 42 people · 2019 | 1/8 | SYR4 |
| Bromoform | 2.1355 µg/L No EPA limit set Highest in the city: THE FREDERICK GUNN SCHOOL, INC. · 300 people · 2019 | 4/8 | SYR4 |
| Trichloroacetic Acid | 1.48 µg/L No EPA limit set Highest in the city: DODGE FARM · 42 people · 2019 | 4/8 | SYR4 |
| Combined Uranium | 1.1 µg/L 3.7% of the EPA limit 30 µg/L Highest in the city: NEW PRESTON WATER CO · 139 people · 2019 | 1/8 | SYR4 |
| Arsenic | 0.5000 µg/L 5% of the EPA limit 10 µg/L Main supplier: RUMSEY HALL SCHOOL · 398 people · 2019
Highest in the city: 1 µg/L — DODGE FARM · 42 people · 2019 | 2/8 | SYR4 |
| Chromium | 1 µg/L 1% of the EPA limit 100 µg/L Highest in the city: AQUARION-QUARRY RIDGE · 84 people · 2017 | 1/8 | SYR4 |
| Lead | 0.0010 mg/L 6.7% of the EPA limit 0.0150 mg/L Main supplier: RUMSEY HALL SCHOOL · 398 people · 2026
Highest in the city: 0.0065 mg/L — THE FREDERICK GUNN SCHOOL, INC. · 300 people · 2025 | 8/8 | LCR |
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 Washington
| Supplier | Population served |
|---|---|
| RUMSEY HALL SCHOOL | 398 |
| THE FREDERICK GUNN SCHOOL, INC. | 300 |
| AQUARION-JUDEA MAIN | 219 |
| NEW PRESTON WATER CO | 139 |
| BEE BROOK CROSSING CONDOMINIUMS | 120 |
| AQUARION-QUARRY RIDGE | 84 |
| AQUARION-JUDEA DEPOT | 68 |
| DODGE FARM | 42 |
Frequently asked questions about Washington tap water
Is Washington tap water safe to drink?
EPA testing detected 23 contaminants in the water serving Washington. 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 Washington?
8 public water suppliers report drinking-water monitoring for Washington, Connecticut to the EPA. Each is listed above with its population served.
What contaminants are in Washington's water?
The contaminants EPA monitoring detected in Washington include Nitrate, Nitrate-Nitrite, Copper, Fluoride, Barium. 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.