Tap water · IL
Chicago Department of Water Management
EPA system ID IL0316000 · serves about 2,721,308 people. Every US utility must publish an annual water quality report — here’s the official one (2025), and below it, our plain-English translation.
Read the official report →What Chicago Department of Water Management found in 2025
14 detected analytes from the utility’s own annual report, hand-normalized — nothing was near or over a federal health-based limit.
| Detected | Level | Limit | % of limit | Status |
|---|---|---|---|---|
| TTHM [TOTAL TRIHALOMETHANES] | 26.4 ppb | 80 ppb | 33% | Within limit |
| CHLORINE (as Cl2) | 1 ppm | 4 ppm | 25% | Within limit |
| HAA5 [HALOACETIC ACIDS] | 13.8 ppb | 60 ppb | 23% | Within limit |
| GROSS ALPHA (EXCLUDING RADON & URANIUM) | 3.1 pCi/L | 15 pCi/L | 21% | Within limit |
| COMBINED RADIUM 226/228 | 0.95 pCi/L | 5 pCi/L | 19% | Within limit |
| FLUORIDE | 0.75 ppm | 4 ppm | 19% | Within limit |
| TOTAL COLIFORM BACTERIA | 0.6 % pos/mo | 5 % pos/mo | 12% | Within limit |
| ARSENIC | 0.54 ppb | 10 ppb | 5% | Within limit |
| TOTAL NITRATE & NITRITE | 0.36 ppm | 10 ppm | 4% | Within limit |
| NITRATE | 0.36 ppm | 10 ppm | 4% | Within limit |
| BARIUM | 0.019 ppm | 2 ppm | 1% | Within limit |
| SULFATE | 27.2 ppm | — | — | No federal limit |
| SODIUM | 9.1 ppm | — | — | No federal limit |
| Turbidity (highest) | 0.29 NTU | — | — | No federal limit |
Levels and limits are as printed in the utility’s report (“limit” is the EPA MCL, action level, residual limit, or secondary guideline that applies to that row; “ND” = not detected). Utilities publish these reports annually — we re-check every covered utility each July, after the federal publication deadline. Detected doesn’t mean dangerous — most detections sit far below their limits. This is education, not medical advice.
Your tap, if it were a bottle
How Chicago Department of Water Management water stacks up against the bottled aisle
Same minerals, same units — the tap values below come from the utility’s report, placed next to the closest match in our bottled-water database.
| Mineral | Your tap | Closest bottled match |
|---|---|---|
| Sodium | 9.1 mg/L | Contrex at 9.4 mg/L |
| Sulfate | 27.2 mg/L | Ice Mountain at 27 mg/L |
Tap values are the headline levels from the utility’s annual report (often a highest or average figure); bottled values are label- or report-derived. A closest match is a numeric comparison, not an equivalence or an endorsement.
Zip codes covered
60601 · 60602 · 60603 · 60604 · 60605 · 60606 · 60607 · 60608 · 60609 · 60610 · 60611 · 60612 · 60613 · 60614 · 60615 · 60616 · 60617 · 60618 · 60619 · 60620 · 60621 · 60622 · 60623 · 60624 · 60625 · 60626 · 60628 · 60629 · 60630 · 60631 · 60632 · 60634 · 60636 · 60637 · 60638 · 60639 · 60640 · 60641 · 60642 · 60643 · 60644 · 60645 · 60646 · 60647 · 60649 · 60651 · 60652 · 60653 · 60654 · 60655 · 60656 · 60657 · 60659 · 60660 · 60661 · 60666
Boundary zips partially served by other systems are deliberately unlisted — check your exact zip.