What was found in Evanston'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-Nitrite | 143 µg/L 1.4% of the EPA limit 10000 µg/L Main supplier: EVANSTON, CITY OF · 11,727 people · 2019
Highest in the city: 700 µg/L — LINDLEY PARK, LLC · 362 people · 2019 | 2/3 | SYR4 |
| Fluoride | 690 µg/L 17% of the EPA limit 4000 µg/L Highest in the city: LINDLEY PARK, LLC · 362 people · 2017 | 1/3 | SYR4 |
| Copper | 174 µg/L 13% of the EPA limit 1300 µg/L Main supplier: EVANSTON, CITY OF · 11,727 people · 2019
Highest in the city: 537.75 µg/L — BEAR RIVER REGIONAL JOINT POWERS · 1,200 people · 2018 | 3/3 | SYR4 |
| Barium | 200 µg/L 10% of the EPA limit 2000 µg/L Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 1/3 | SYR4 |
| TTHM | 78.7 µg/L 98% of the EPA limit 80 µg/L Main supplier: EVANSTON, CITY OF · 11,727 people · 2019
Highest in the city: 105.7 µg/L — BEAR RIVER REGIONAL JOINT POWERS · 1,200 people · 2019 | 2/3 | SYR4 |
| Chloroform | 71.46 µg/L No EPA limit set Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 1/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 64.58 µg/L 108% of the EPA limit, at the 95th percentile of samples — 60 µg/L Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 2/3 | SYR4 |
| Trichloroacetic Acid | 43.5 µg/L No EPA limit set Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 1/3 | SYR4 |
| Dichloroacetic Acid | 25 µg/L No EPA limit set Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 1/3 | SYR4 |
| Bromodichloromethane | 23.3 µg/L No EPA limit set Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 1/3 | SYR4 |
| Dibromochloromethane | 7.405 µg/L No EPA limit set Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 1/3 | SYR4 |
| Lead | 5 µg/L 33% of the EPA limit 15 µg/L Main supplier: EVANSTON, CITY OF · 11,727 people · 2019
Highest in the city: 6.92 µg/L — LINDLEY PARK, LLC · 362 people · 2018 | 3/3 | SYR4 |
| Gross Alpha, Excl. Radon And U | 2.435 pCi/L 16% of the EPA limit 15 pCi/L Main supplier: EVANSTON, CITY OF · 11,727 people · 2019
Highest in the city: 4.7455 pCi/L — LINDLEY PARK, LLC · 362 people · 2019 | 2/3 | SYR4 |
| Arsenic | 3 µg/L 30% of the EPA limit 10 µg/L Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 1/3 | SYR4 |
| Monochloroacetic Acid | 2.475 µg/L No EPA limit set Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 1/3 | SYR4 |
| Dibromoacetic Acid | 1.6 µg/L No EPA limit set Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 1/3 | SYR4 |
| Di(2-ethylhexyl) Phthalate | 1.2955 µg/L 22% of the EPA limit 6 µg/L Highest in the city: LINDLEY PARK, LLC · 362 people · 2019 | 1/3 | SYR4 |
| Monobromoacetic Acid | 0.7260 µg/L No EPA limit set Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 1/3 | SYR4 |
| Combined Uranium | 0.7000 µg/L 2.3% of the EPA limit 30 µg/L Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 1/3 | SYR4 |
| Hexachlorocyclopentadiene | 0.1285 µg/L 0.3% of the EPA limit 50 µg/L Main supplier: EVANSTON, CITY OF · 11,727 people · 2019 | 1/3 | SYR4 |
| Lead | 0.00073 mg/L 4.9% of the EPA limit 0.0150 mg/L Main supplier: EVANSTON, CITY OF · 11,727 people · 2025
Highest in the city: 0.0010 mg/L — LINDLEY PARK, LLC · 362 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 Evanston
| Supplier | Population served |
|---|---|
| EVANSTON, CITY OF | 11,727 |
| BEAR RIVER REGIONAL JOINT POWERS | 1,200 |
| LINDLEY PARK, LLC | 362 |
Frequently asked questions about Evanston tap water
Is Evanston tap water safe to drink?
EPA testing detected 21 contaminants in the water serving Evanston. 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 Evanston?
3 public water suppliers report drinking-water monitoring for Evanston, Wyoming to the EPA. Each is listed above with its population served.
What contaminants are in Evanston's water?
The contaminants EPA monitoring detected in Evanston include Nitrate-Nitrite, 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.