What was found in Bristol'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 | 1847.4 µg/L 18% of the EPA limit 10000 µg/L Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019
Highest in the city: 3330 µg/L — CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 3/3 | SYR4 |
| Nitrate-Nitrite | 1735.57 µg/L 17% of the EPA limit 10000 µg/L Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019
Highest in the city: 2838 µg/L — CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 3/3 | SYR4 |
| Fluoride | 1015 µg/L 25% of the EPA limit 4000 µg/L Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019 | 3/3 | SYR4 |
| Copper | 194.5 µg/L 15% of the EPA limit 1300 µg/L Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019
Highest in the city: 965.75 µg/L — CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 3/3 | SYR4 |
| Barium | 229.5 µg/L 11% of the EPA limit 2000 µg/L Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019
Highest in the city: 451.495 µg/L — AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2017 | 3/3 | SYR4 |
| TTHM | 77 µg/L 96% of the EPA limit 80 µg/L Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019 | 3/3 | SYR4 |
| Lead | 66.75 µg/L 445% of the EPA limit, at the 95th percentile of samples — 15 µg/L Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019 | 3/3 | SYR4 |
| Chloroform | 66 µg/L No EPA limit set Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 45.65 µg/L 76% of the EPA limit 60 µg/L Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019 | 3/3 | SYR4 |
| Trichloroacetic Acid | 26 µg/L No EPA limit set Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019 | 3/3 | SYR4 |
| Dichloroacetic Acid | 20 µg/L No EPA limit set Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019 | 3/3 | SYR4 |
| Lithium | 11.8 µg/L No EPA limit set Highest in the city: AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2023 | 1/3 | UCMR-5 |
| Bromodichloromethane | 9.8675 µg/L No EPA limit set Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019 | 3/3 | SYR4 |
| Tetrachloroethylene | 7.45 µg/L 149% of the EPA limit, at the 95th percentile of samples — 5 µg/L Highest in the city: AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2019 | 2/3 | SYR4 |
| Gross Alpha, Excl. Radon And U | 1.39025 pCi/L 9.3% of the EPA limit 15 pCi/L Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019
Highest in the city: 7.03 pCi/L — AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2019 | 3/3 | SYR4 |
| Trichloroethylene | 6.1 µg/L 122% of the EPA limit, at the 95th percentile of samples — 5 µg/L Highest in the city: AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2019 | 1/3 | SYR4 |
| Dibromochloromethane | 2.4 µg/L No EPA limit set Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019
Highest in the city: 5.9 µg/L — AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2019 | 3/3 | SYR4 |
| Monochloroacetic Acid | 3.295 µg/L No EPA limit set Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019
Highest in the city: 5.55 µg/L — CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 2/3 | SYR4 |
| Bromoform | 0.7360 µg/L No EPA limit set Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019
Highest in the city: 3.59 µg/L — AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2019 | 3/3 | SYR4 |
| cis-1,2-Dichloroethylene | 2.85 µg/L 4.1% of the EPA limit 70 µg/L Highest in the city: AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2019 | 2/3 | SYR4 |
| Dibromoacetic Acid | 1.5 µg/L No EPA limit set Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019
Highest in the city: 2.84 µg/L — AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2019 | 3/3 | SYR4 |
| 1,2,4-Trichlorobenzene | 2 µg/L 2.9% of the EPA limit 70 µg/L Highest in the city: AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2019 | 1/3 | SYR4 |
| Combined Uranium | 1.7 µg/L 5.7% of the EPA limit 30 µg/L Highest in the city: AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2019 | 1/3 | SYR4 |
| Combined Radium (-226 And -228) | 0.9157 pCi/L 18% of the EPA limit 5 pCi/L Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019
Highest in the city: 1.6 pCi/L — CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 2/3 | SYR4 |
| Monobromoacetic Acid | 1.355 µg/L No EPA limit set Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2019 | 1/3 | SYR4 |
| Selenium | 1 µg/L 2% of the EPA limit 50 µg/L Highest in the city: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 1/3 | SYR4 |
| 1,1,2-Trichloroethane | 0.6300 µg/L 13% of the EPA limit 5 µg/L Highest in the city: AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2019 | 1/3 | SYR4 |
| 1,1,1-Trichloroethane | 0.6200 µg/L 0.3% of the EPA limit 200 µg/L Highest in the city: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 2/3 | SYR4 |
| Pfba | 0.0070 µg/L No EPA limit set Highest in the city: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2023 | 2/3 | UCMR-5 |
| PFOS | 0.0068 µg/L No EPA limit set Highest in the city: AQUARION-PLAINVILLE REGIONAL · 18,231 people · 2023 | 2/3 | UCMR-5 |
| PFOA | 0.0041 µg/L No EPA limit set Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2024
Highest in the city: 0.0060 µg/L — CTWC - UNIONVILLE SYSTEM · 14,693 people · 2023 | 3/3 | UCMR-5 |
| Pfhxa | 0.0040 µg/L No EPA limit set Highest in the city: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2023 | 1/3 | UCMR-5 |
| Pfpea | 0.0031 µg/L No EPA limit set Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2024
Highest in the city: 0.0040 µg/L — CTWC - UNIONVILLE SYSTEM · 14,693 people · 2023 | 2/3 | UCMR-5 |
| PFHXS | 0.0030 µg/L No EPA limit set Highest in the city: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2023 | 1/3 | UCMR-5 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: BRISTOL WATER DEPARTMENT · 52,079 people · 2026
Highest in the city: 0.0024 mg/L — CTWC - UNIONVILLE SYSTEM · 14,693 people · 2025 | 3/3 | 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 Bristol
| Supplier | Population served |
|---|---|
| BRISTOL WATER DEPARTMENT | 52,079 |
| AQUARION-PLAINVILLE REGIONAL | 18,231 |
| CTWC - UNIONVILLE SYSTEM | 14,693 |
Frequently asked questions about Bristol tap water
Is Bristol tap water safe to drink?
EPA testing detected 35 contaminants in the water serving Bristol. 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 Bristol?
3 public water suppliers report drinking-water monitoring for Bristol, Connecticut to the EPA. Each is listed above with its population served.
What contaminants are in Bristol's water?
The contaminants EPA monitoring detected in Bristol include Nitrate, Nitrate-Nitrite, Fluoride, Copper, 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.