What was found in Lake Forest'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 |
|---|---|---|---|
| Fluoride | 1055.5 µg/L 26% of the EPA limit 4000 µg/L Main supplier: LAKE FOREST · 19,642 people · 2019
Highest in the city: 1378.5 µg/L — ELM OAK MUTUAL WATER SYSTEM · 50 people · 2018 | 2/2 | SYR4 |
| Nitrate | 620 µg/L 6.2% of the EPA limit 10000 µg/L Main supplier: LAKE FOREST · 19,642 people · 2019 | 2/2 | SYR4 |
| Nitrate-Nitrite | 430 µg/L 4.3% of the EPA limit 10000 µg/L Highest in the city: ELM OAK MUTUAL WATER SYSTEM · 50 people · 2018 | 1/2 | SYR4 |
| Barium | 24.599999999999998 µg/L 1.2% of the EPA limit 2000 µg/L Main supplier: LAKE FOREST · 19,642 people · 2019
Highest in the city: 318.2499999999999 µg/L — ELM OAK MUTUAL WATER SYSTEM · 50 people · 2018 | 2/2 | SYR4 |
| Copper | 312.14999999999986 µg/L 24% of the EPA limit 1300 µg/L Main supplier: LAKE FOREST · 19,642 people · 2018 | 2/2 | SYR4 |
| TTHM | 58.019999999999996 µg/L 73% of the EPA limit 80 µg/L Main supplier: LAKE FOREST · 19,642 people · 2019 | 2/2 | SYR4 |
| Chloroform | 38.63999999999998 µg/L No EPA limit set Main supplier: LAKE FOREST · 19,642 people · 2019 | 2/2 | SYR4 |
| Total Haloacetic Acids (HAA5) | 26.919999999999998 µg/L 45% of the EPA limit 60 µg/L Main supplier: LAKE FOREST · 19,642 people · 2019 | 2/2 | SYR4 |
| Gross Alpha, Excl. Radon And U | 22.859999999999992 pCi/L 152% of the EPA limit, at the 95th percentile of samples — 15 pCi/L Highest in the city: ELM OAK MUTUAL WATER SYSTEM · 50 people · 2019 | 1/2 | SYR4 |
| Bromodichloromethane | 14.559999999999997 µg/L No EPA limit set Main supplier: LAKE FOREST · 19,642 people · 2019 | 2/2 | SYR4 |
| Dichloroacetic Acid | 13.594999999999999 µg/L No EPA limit set Main supplier: LAKE FOREST · 19,642 people · 2019 | 2/2 | SYR4 |
| Combined Radium (-226 And -228) | 12.411 pCi/L 248% of the EPA limit, at the 95th percentile of samples — 5 pCi/L Highest in the city: ELM OAK MUTUAL WATER SYSTEM · 50 people · 2019 | 1/2 | SYR4 |
| Lead | 12.199999999999996 µg/L 81% of the EPA limit 15 µg/L Main supplier: LAKE FOREST · 19,642 people · 2018 | 2/2 | SYR4 |
| Trichloroacetic Acid | 11.639999999999995 µg/L No EPA limit set Main supplier: LAKE FOREST · 19,642 people · 2019 | 2/2 | SYR4 |
| Dibromochloromethane | 6.9552 µg/L No EPA limit set Main supplier: LAKE FOREST · 19,642 people · 2019 | 2/2 | SYR4 |
| Monochloroacetic Acid | 6.817 µg/L No EPA limit set Main supplier: LAKE FOREST · 19,642 people · 2019 | 2/2 | SYR4 |
| Dalapon | 2.8235 µg/L 1.4% of the EPA limit 200 µg/L Main supplier: LAKE FOREST · 19,642 people · 2019 | 1/2 | SYR4 |
| Bromoform | 2.671899999999998 µg/L No EPA limit set Main supplier: LAKE FOREST · 19,642 people · 2019 | 2/2 | SYR4 |
| Dibromoacetic Acid | 2.31 µg/L No EPA limit set Main supplier: LAKE FOREST · 19,642 people · 2019 | 2/2 | SYR4 |
| Selenium | 2.2 µg/L 4.4% of the EPA limit 50 µg/L Main supplier: LAKE FOREST · 19,642 people · 2019 | 1/2 | SYR4 |
| Arsenic | 0.9636 µg/L 9.6% of the EPA limit 10 µg/L Main supplier: LAKE FOREST · 19,642 people · 2019
Highest in the city: 1.3 µg/L — ELM OAK MUTUAL WATER SYSTEM · 50 people · 2018 | 2/2 | SYR4 |
| Combined Uranium | 0.9983 µg/L 3.3% of the EPA limit 30 µg/L Highest in the city: ELM OAK MUTUAL WATER SYSTEM · 50 people · 2019 | 1/2 | SYR4 |
| Monobromoacetic Acid | 0.6828 µg/L No EPA limit set Main supplier: LAKE FOREST · 19,642 people · 2019 | 1/2 | SYR4 |
| Lead | 0.0280 mg/L 187% above the EPA limit of 0.0150 mg/L Main supplier: LAKE FOREST · 19,642 people · 2025 | 2/2 | 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 Lake Forest
| Supplier | Population served |
|---|---|
| LAKE FOREST | 19,642 |
| ELM OAK MUTUAL WATER SYSTEM | 50 |
Frequently asked questions about Lake Forest tap water
Is Lake Forest tap water safe to drink?
EPA testing detected 24 contaminants in the water serving Lake Forest. 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 Lake Forest?
2 public water suppliers report drinking-water monitoring for Lake Forest, Illinois to the EPA. Each is listed above with its population served.
What contaminants are in Lake Forest's water?
The contaminants EPA monitoring detected in Lake Forest include Fluoride, Nitrate, Nitrate-Nitrite, Barium, Copper. 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.