We read 7 results from Chicago’s 2025 water quality report. No results over a legal limit; 2 above a health goal or guideline.
Serves about 2,746,388 people · Water system ID IL0316000 · Read the district’s 2025 report (opens in a new tab)
Open this district in the water lookupCompare with your own test results, see the district map and get matched filters.
Results from the 2025 report
Each number is copied from the district’s report and links to the page it’s printed on. Where the report lists several plants, wells or purchased water, the highest is shown.
| Contaminant | Result | Health goal | Legal limit | What it means |
|---|---|---|---|---|
| Gross alpha (radioactivity)average · range 2.8 to 3.1 · sampled 2020 · Chicago treatment plants · 2025 report, page 5 | 3.1 pCi/L | 0 pCi/L | 15 pCi/L | Above the health goalThe health goal is zero |
| Radium (combined 226 + 228)average · range 0.83 to 0.95 · sampled 2020 · Chicago treatment plants · 2025 report, page 5 | 0.95 pCi/L | 0 pCi/L | 5 pCi/L | Above the health goalThe health goal is zero |
| Fluorideaverage · range 0.65 to 0.75 · Chicago treatment plants · 2025 report, page 5 | 0.75 ppm | 1 ppm | 4 ppm | Below the health goal |
| Nitrate (as N)average · range 0.32 to 0.36 · Chicago treatment plants · 2025 report, page 5 | 0.36 ppm | 10 ppm | 10 ppm | Below the health goal |
| Sulfateaverage · range 25.3 to 28.2 · Chicago treatment plants · 2025 report, page 5 | 27.2 ppm | — | 250 ppm guideline | Within the guideline |
| Turbidity (cloudiness)highest measured · Chicago treatment plants · 2025 report, page 5 | 0.29 NTU | None set | 1 NTU | Below the legal limit |
| Sodiumaverage · range 8.87 to 9.18 · Chicago treatment plants · 2025 report, page 5 | 9.18 ppm | None set | None | No health limit |
Utility results describe the whole system, measured where water enters the pipes, not your tap. Your home’s plumbing can add lead or copper. 1 number we weren’t sure about is held back until a person checks.
What you can do
Nothing here is an emergency notice: if the district has a violation, it must tell customers directly. If you’d like to lower these at your tap, these are the treatments that remove them, and the catalog shows the models certified for each. Ranking is by certified removal; commissions never change the order.
Radium and uranium
Found: Gross alpha (radioactivity), Radium (combined 226 + 228)
What removes it: Reverse osmosis.
More districts: Illinois water quality · All states · Something look wrong? Tell us