Is Chicago Tap Water Safe? City of Chicago water system’s EPA Records

City water quality

Is Chicago Tap Water Safe? What City of Chicago water system’s EPA Records Show

City of Chicago water system, which serves about 2,746,388 people in Illinois, reported no PFAS above reporting limits in the EPA’s UCMR5 monitoring (2023-2025). Non-detect means not found above the EPA’s reporting floor in that round — not that the water was never tested again. Its most recent EPA-record lead 90th-percentile was 8.8 ppb — under the current 15 ppb action level. The system has 2 health-based violations on its federal SDWA record.

EPA records (UCMR5 2023-2025 + SDWIS/ECHO)
City of Chicago water system
Worth a look
Population served (SDWIS)2,746,388
PFOA vs 4 ppt limitnon-detect
PFOS vs 4 ppt limitnon-detect
PFHxS vs 10 ppt limit (under reconsideration)non-detect
PFNA vs 10 ppt limit (under reconsideration)non-detect
GenX (HFPO-DA) vs 10 ppt limit (under reconsideration)non-detect
Lead 90th percentile (latest round)8.8 ppb
SDWA violations on record (health-based)213 (2)
These are the systems’ own EPA UCMR5 monitoring results — “reported above the limit,” not “in violation.” The EPA limit (4 ppt for PFOA and for PFOS) is a running annual average, so a system counts here when the AVERAGE of a full set of results at one of its sampling locations is above the limit — EPA’s own method. That is an occurrence flag, not a compliance finding: real compliance is determined from quarterly samples reported to the state. Enforcement phases in through 2029-2031.
A metro area is usually served by more than one water system — this page covers the area's largest. Suburbs and neighboring towns often have their own systems with their own results; check your exact ZIP for yours.

See the full interactive report for this system — every PFAS analyte, lead and copper rounds, violations, and the filter that handles what was found: open the Chicago report → Or check YOUR exact ZIP: check your water by ZIP →

Common questions about Chicago water

Is Chicago's tap water safe to drink?

Nothing in these records is above a current EPA limit, but there is something worth watching — a detection below the limit, an older exceedance, or a violation on record. See the card above. These are system-level records for public water systems, not a reading of any individual home’s tap, and they do not cover private wells. Confirm your own utility’s current Consumer Confidence Report, and test your tap if you’re unsure.

Does Chicago have PFAS in its drinking water?

City of Chicago water system reported no PFAS above reporting limits in UCMR5 monitoring.

Who supplies Chicago's drinking water?

City of Chicago water system (PWSID IL0316000) serves about 2,746,388 people, per EPA SDWIS records. A metro area is usually served by more than one water system — this page covers the area’s largest. Suburbs and neighboring towns often have their own systems with their own results; check your exact ZIP for yours.

How do I check my exact address?

Water systems report by system, not by address. Enter your ZIP on the water checker to see the system(s) serving it and what each reported.

Statewide, 2.9% of Illinois’s UCMR5-tested systems reported PFOA or PFOS over the EPA limit — see the Illinois water page.

See the 100 largest US water systems, water quality by state, and the national PFAS data study.

Sources: EPA UCMR5 occurrence data, Feb 2026 release (~95% complete; final reporting 2026) (2026-06); lead/copper + violations: EPA SDWIS via ECHO; population served: EPA SDWIS via ECHO (system-reported population served). PWSID IL0316000. Public-domain federal/state records; assembly by WaterByTheBook. Built 2026-07-25. Plain-markdown mirror: https://waterbythebook.com/md/chicago.md