What was found in Avon'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 | 3330 µg/L 33% of the EPA limit 10000 µg/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019
Highest in the city: 3800 µg/L — AVON WATER CO · 11,590 people · 2019 | 3/3 | SYR4 |
| Nitrate-Nitrite | 2838 µg/L 28% of the EPA limit 10000 µg/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019
Highest in the city: 3780 µg/L — AVON WATER CO · 11,590 people · 2019 | 3/3 | SYR4 |
| Barium | 310.2 µg/L 16% of the EPA limit 2000 µg/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019
Highest in the city: 1050.72 µg/L — AVON WATER CO · 11,590 people · 2018 | 3/3 | SYR4 |
| Copper | 965.75 µg/L 74% of the EPA limit 1300 µg/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 3/3 | SYR4 |
| Fluoride | 50 µg/L 1.3% of the EPA limit 4000 µg/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019
Highest in the city: 182.15 µg/L — CTWC - NAUGATUCK REG-COLLINSVILLE SYS · 6,324 people · 2019 | 2/3 | SYR4 |
| TTHM | 57.54 µg/L 72% of the EPA limit 80 µg/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 3/3 | SYR4 |
| Chloroform | 52 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 40 µg/L 67% of the EPA limit 60 µg/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 3/3 | SYR4 |
| Trichloroacetic Acid | 25.05 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 3/3 | SYR4 |
| Lead | 12.3 µg/L 82% of the EPA limit 15 µg/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019
Highest in the city: 18.6 µg/L — AVON WATER CO · 11,590 people · 2019 | 3/3 | SYR4 |
| Dichloroacetic Acid | 16 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 3/3 | SYR4 |
| Bromodichloromethane | 7.015 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 3/3 | SYR4 |
| Monochloroacetic Acid | 5.55 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 3/3 | SYR4 |
| Dibromochloromethane | 3.555 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019
Highest in the city: 5.2 µg/L — AVON WATER CO · 11,590 people · 2019 | 3/3 | SYR4 |
| Gross Alpha, Excl. Radon And U | 4.2 pCi/L 28% of the EPA limit 15 pCi/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 2/3 | SYR4 |
| Arsenic | 3.2 µg/L 32% of the EPA limit 10 µg/L Highest in the city: AVON WATER CO · 11,590 people · 2018 | 1/3 | SYR4 |
| Bromoform | 1.25 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019
Highest in the city: 2.98 µg/L — AVON WATER CO · 11,590 people · 2019 | 2/3 | SYR4 |
| Tetrachloroethylene | 2.615 µg/L 52% of the EPA limit 5 µg/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 1/3 | SYR4 |
| Dibromoacetic Acid | 1.995 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019
Highest in the city: 2.43 µg/L — AVON WATER CO · 11,590 people · 2019 | 2/3 | SYR4 |
| Combined Uranium | 2.18 µg/L 7.3% of the EPA limit 30 µg/L Highest in the city: AVON WATER CO · 11,590 people · 2018 | 1/3 | SYR4 |
| Chromium | 1.92 µg/L 1.9% of the EPA limit 100 µg/L Highest in the city: AVON WATER CO · 11,590 people · 2018 | 1/3 | SYR4 |
| Combined Radium (-226 And -228) | 1.6 pCi/L 32% of the EPA limit 5 pCi/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 3/3 | SYR4 |
| cis-1,2-Dichloroethylene | 1.395 µg/L 2% of the EPA limit 70 µg/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 1/3 | SYR4 |
| Selenium | 1 µg/L 2% of the EPA limit 50 µg/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 1/3 | SYR4 |
| Monobromoacetic Acid | 0.7260 µg/L No EPA limit set Highest in the city: AVON WATER CO · 11,590 people · 2019 | 1/3 | SYR4 |
| 1,1,1-Trichloroethane | 0.6200 µg/L 0.3% of the EPA limit 200 µg/L Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2019 | 1/3 | SYR4 |
| Chlordane | 0.2940 µg/L 15% of the EPA limit 2 µg/L Highest in the city: AVON WATER CO · 11,590 people · 2019 | 1/3 | SYR4 |
| PFOS | 0.0060 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2023
Highest in the city: 0.0080 µg/L — AVON WATER CO · 11,590 people · 2025 | 3/3 | UCMR-5 |
| Pfba | 0.0070 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2023 | 1/3 | UCMR-5 |
| PFOA | 0.0060 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2023
Highest in the city: 0.0070 µg/L — AVON WATER CO · 11,590 people · 2025 | 3/3 | UCMR-5 |
| Pfhxa | 0.0040 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2023 | 2/3 | UCMR-5 |
| Pfpea | 0.0040 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2023 | 1/3 | UCMR-5 |
| PFBS | 0.0030 µg/L No EPA limit set Highest in the city: AVON WATER CO · 11,590 people · 2025 | 1/3 | UCMR-5 |
| PFHXS | 0.0030 µg/L No EPA limit set Main supplier: CTWC - UNIONVILLE SYSTEM · 14,693 people · 2023 | 1/3 | UCMR-5 |
| Lead | 0.0024 mg/L 16% of the EPA limit 0.0150 mg/L Main supplier: 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 Avon
| Supplier | Population served |
|---|---|
| CTWC - UNIONVILLE SYSTEM | 14,693 |
| AVON WATER CO | 11,590 |
| CTWC - NAUGATUCK REG-COLLINSVILLE SYS | 6,324 |
Frequently asked questions about Avon tap water
Is Avon tap water safe to drink?
EPA testing detected 35 contaminants in the water serving Avon. 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 Avon?
3 public water suppliers report drinking-water monitoring for Avon, Connecticut to the EPA. Each is listed above with its population served.
What contaminants are in Avon's water?
The contaminants EPA monitoring detected in Avon include Nitrate, Nitrate-Nitrite, Barium, Copper, Fluoride. 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.