What was found in Williston'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 | 1200 µg/L 12% of the EPA limit 10000 µg/L Highest in the city: WILLISTON FIRE DISTRICT 1 · 212 people · 2019 | 1/3 | SYR4 |
| Nitrate-Nitrite | 900 µg/L 9% of the EPA limit 10000 µg/L Highest in the city: WILLISTON FIRE DISTRICT 1 · 212 people · 2013 | 1/3 | SYR4 |
| Copper | 875 µg/L 67% of the EPA limit 1300 µg/L Highest in the city: WILLISTON FIRE DISTRICT 1 · 212 people · 2017 | 1/3 | SYR4 |
| TTHM | 27.8 µg/L 35% of the EPA limit 80 µg/L Highest in the city: WILLISTON FIRE DISTRICT 1 · 212 people · 2017 | 2/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 24 µg/L 40% of the EPA limit 60 µg/L Highest in the city: OAK HILL ESTATES WATER SYSTEM · 52 people · 2019 | 2/3 | SYR4 |
| Chloroform | 23.075 µg/L No EPA limit set Highest in the city: OAK HILL ESTATES WATER SYSTEM · 52 people · 2019 | 2/3 | SYR4 |
| Dichloroacetic Acid | 14.01 µg/L No EPA limit set Highest in the city: OAK HILL ESTATES WATER SYSTEM · 52 people · 2019 | 2/3 | SYR4 |
| Trichloroacetic Acid | 11.44 µg/L No EPA limit set Highest in the city: OAK HILL ESTATES WATER SYSTEM · 52 people · 2019 | 2/3 | SYR4 |
| Bromodichloromethane | 7.7 µg/L No EPA limit set Highest in the city: WILLISTON FIRE DISTRICT 1 · 212 people · 2017 | 2/3 | SYR4 |
| Dibromochloromethane | 5.625 µg/L No EPA limit set Highest in the city: WILLISTON FIRE DISTRICT 1 · 212 people · 2017 | 1/3 | SYR4 |
| Lead | 2.6 µg/L 17% of the EPA limit 15 µg/L Highest in the city: WILLISTON FIRE DISTRICT 1 · 212 people · 2019 | 1/3 | SYR4 |
| Dibromoacetic Acid | 2 µg/L No EPA limit set Highest in the city: WILLISTON FIRE DISTRICT 1 · 212 people · 2017 | 1/3 | SYR4 |
| Bromoform | 1 µg/L No EPA limit set Highest in the city: WILLISTON FIRE DISTRICT 1 · 212 people · 2017 | 1/3 | SYR4 |
| Combined Radium (-226 And -228) | 0.8190 pCi/L 16% of the EPA limit 5 pCi/L Highest in the city: WILLISTON FIRE DISTRICT 1 · 212 people · 2013 | 1/3 | SYR4 |
| Lead | 0.0012 mg/L 8% of the EPA limit 0.0150 mg/L Main supplier: WILLISTON WATER DEPT · 7,259 people · 2025
Highest in the city: 0.0020 mg/L — WILLISTON FIRE DISTRICT 1 · 212 people · 2023 | 3/3 | LCR |
Water suppliers serving Williston
| Supplier | Population served |
|---|---|
| WILLISTON WATER DEPT | 7,259 |
| WILLISTON FIRE DISTRICT 1 | 212 |
| OAK HILL ESTATES WATER SYSTEM | 52 |
Frequently asked questions about Williston tap water
Is Williston tap water safe to drink?
EPA testing detected 15 contaminants in the water serving Williston. 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 Williston?
3 public water suppliers report drinking-water monitoring for Williston, Vermont to the EPA. Each is listed above with its population served.
What contaminants are in Williston's water?
The contaminants EPA monitoring detected in Williston include Nitrate, Nitrate-Nitrite, Copper, TTHM, Total Haloacetic Acids (HAA5). 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.