Tap water and home risks
Is Chicago tap water safe?
Chicago's main water supplier is Chicago, serving about 2,721,308 people from surface water (rivers, lakes, reservoirs). Here is what EPA's public records show, as of October 2026.
PFAS results
Chicago was tested for 29 PFAS compounds between January 2024 and October 2024. None was detected. PFOA and PFOS stayed at or below EPA's 4 ng/L limit.
| Compound | Highest result | EPA limit | Detected |
|---|---|---|---|
| PFOA | not detected | 4 ng/L | 0 of 8 samples |
| PFOS | not detected | 4 ng/L | 0 of 8 samples |
EPA's limits of 4 ng/L for PFOA and PFOS were set in 2024; utilities must meet them by April 2029 (EPA has proposed allowing some systems until 2031). These results come from EPA's UCMR 5 screening program, not compliance tests. Compounds not shown were tested and not detected.
Lead and copper
In the most recent round of home tap sampling (June 2026), 90% of samples had 6.4 ppb of lead or less. The federal action level is 15 ppb; EPA's health goal for lead is zero.
| Sampling period ended | Lead, 90th percentile |
|---|---|
| June 2026 | 6.4 ppb |
| December 2025 | 8.8 ppb |
| June 2025 | 7.3 ppb |
| December 2024 | 7.1 ppb |
| December 2023 | 7.7 ppb |
| December 2022 | 6.8 ppb |
| December 2021 | 5.6 ppb |
| December 2018 | 9.1 ppb |
The 90th percentile is the level that 90% of sampled homes were at or below. It describes the system, not your tap.
Health-based violations since 2016
EPA records no health-based violations for Chicago since January 2016. Monitoring and reporting violations, which are paperwork issues, are not counted here.
Radon in Cook County
Cook County is in EPA radon Zone 2 (moderate potential). Radon is a gas from the ground that enters homes through the foundation; the zone describes the area's potential, not your house. EPA recommends testing every home.
What you can do
- Lead usually comes from a home's own service line and pipes, not the treatment plant. If your home was built before 1986, ask Chicago for your service line material or test your tap.
- Radon varies house to house even in moderate zones. EPA recommends testing every home.
Check a ZIP code
Some neighborhoods in Chicago get water from a different system. Enter your ZIP to see the systems and county that cover it.
Other cities
Sources: EPA ECHO Safe Drinking Water Act data (2026Q3, published October 2026), EPA UCMR 5 occurrence data (August 2026), EPA Map of Radon Zones, US Census Bureau Vintage 2024 estimates. See the methodology.