Chicago
IL

Is Chicago, IL Tap Water Safe to Drink?

Chicago, IL tap water meets EPA drinking water standards, but recent EPA testing detected trace levels of PFAS compounds and lithium across all 59 ZIP codes served. None of the detected levels exceeded EPA limits or guidelines, though the presence of PFAS at any level is worth understanding, particularly for sensitive households.

9Water systems
59ZIP codes
0%ZIPs above EPA guideline
Metro areaChicago-Naperville-Elgin, IL-IN
Latest data2025-09-10

Where Does Chicago Get Its Water?

Chicago's drinking water comes from Lake Michigan, one of the largest freshwater sources in the world. The City of Chicago operates the primary municipal water system, with several neighboring utilities also drawing from the same regional supply.

Two major treatment facilities serve the city: the Jardine Water Purification Plant, which handles water for the north and central portions of the system, and the South Water Purification Plant, which serves the south side. Both are among the largest water treatment plants in the country.

Smaller systems in the area, including those serving Des Plaines, Elmwood Park, and Rosemont, receive water through interconnections with the Chicago system. The University of Illinois Chicago Medical Center also operates its own registered water system drawing from this supply.

How Is Chicago Tap Water Treated?

Chicago's water goes through a multi-step treatment process before it reaches your tap. This includes coagulation to remove particles, filtration, and granular activated carbon treatment, which helps reduce organic compounds and some chemical contaminants.

Disinfection relies on free chlorine to kill bacteria and viruses throughout the distribution system. A residual amount of chlorine remains in the water as it travels through pipes, which is normal and required by federal rules to protect against microbial contamination on the way to your home.

The treatment process also incorporates powdered activated carbon and other steps to address taste, odor, and emerging contaminants. This layered approach reflects the scale and complexity of treating water for a city the size of Chicago.

What's in Chicago Tap Water?

The most widely detected substance in recent EPA testing was lithium, found in all 59 ZIP codes at a peak level of 9 micrograms per liter. There is currently no federal maximum contaminant level for lithium in drinking water, so this detection does not represent a violation of any rule.

Several PFAS compounds were also detected. PFTrDA, a long-chain PFAS, was found across all 59 ZIP codes at a peak of 0.007 micrograms per liter. Two other PFAS compounds, 11Cl-PF3OUdS and HFPO-DA (also known as GenX), were detected at or near their reporting limits of 0.005 micrograms per liter. None of these exceeded EPA guidelines.

PFAS are a large family of manufactured chemicals used in industrial and consumer products. They can enter source water through industrial discharges, stormwater runoff, and other pathways. Lake Michigan can receive inputs from a wide catchment area, which may explain trace detections even at a well-treated system like Chicago's.

ContaminantPeak detectedEPA guidelineZIPs detectedStatus
lithium 9 µg/L — 0 ZIPs Within guideline
PFTrDA 0.007 µg/L — 0 ZIPs Within guideline
11Cl-PF3OUdS 0.005 µg/L 0.005 µg/L 1 ZIP Within guideline
11Cl-PF3OUdS 0.005 µg/L — 0 ZIPs Within guideline
HFPO-DA 0.005 µg/L — 0 ZIPs Within guideline

Health Risk Profile for Chicago

The PFAS compounds detected in Chicago's water were all below EPA drinking water guidelines. The EPA finalized enforceable maximum contaminant levels for several PFAS compounds in 2024, and the levels measured here fall beneath those federal limits. That said, some health researchers continue to study whether any level of PFAS exposure carries long-term risk.

Infants, pregnant individuals, and people with compromised immune systems are generally considered more sensitive to contaminants at low levels. For these groups, using a certified filter for PFAS provides an added layer of protection even when tested levels are below regulatory thresholds.

For Chicago tap water, a filter certified to NSF/ANSI 58 (reverse osmosis) or NSF/ANSI P473 is the most effective option for reducing PFAS. NSF/ANSI is an independent third-party certification program, so look for those labels on the product box or the manufacturer's website. A filter certified to NSF/ANSI 42 can also reduce chlorine taste and odor if that is a concern.

For most healthy adults, Chicago's tap water poses a low risk based on current data. The science on low-level PFAS exposure is still developing, and the EPA may revise its standards as research continues. Checking the city's annual Consumer Confidence Report is a good way to stay current on local water quality.

Best Broad-Spectrum Filters for This Water Profile

This city profile includes PFAS detections, chlorine disinfection, and other dissolved contaminants. Reverse osmosis (RO) systems certified under NSF/ANSI 58 provide broad reduction coverage; for PFAS specifically, confirm NSF/ANSI P473 or equivalent PFAS reduction certification.

Waterdrop G3P600 Reverse Osmosis System
Under-sink RO system

8-stage tankless RO system certified to NSF/ANSI 58, reduces 1,000+ contaminants including PFAS, lead, arsenic, fluoride, and nitrates.

See recommendations matched to your exact address: choose your ZIP code below.

Frequently Asked Questions about Chicago Tap Water

Is Chicago tap water safe to drink?

Chicago's tap water currently meets all EPA drinking water standards. Recent testing detected trace amounts of PFAS compounds and lithium across the city, but none exceeded federal limits or guidelines. For most residents, the water is safe to drink as-is. Households with infants, pregnant individuals, or immunocompromised members may want to consider a certified PFAS-reducing filter as a precaution.

What contaminants are in Chicago tap water?

Recent EPA testing found lithium at up to 9 micrograms per liter and three PFAS compounds: PFTrDA at up to 0.007 micrograms per liter, 11Cl-PF3OUdS at up to 0.005 micrograms per liter, and HFPO-DA at up to 0.005 micrograms per liter. All detections were below EPA limits or reporting thresholds. No contaminant tested above any guideline.

Where does Chicago get its drinking water?

Chicago draws its drinking water from Lake Michigan. The City of Chicago operates two large treatment facilities, the Jardine Water Purification Plant and the South Water Purification Plant, which together treat water for millions of residents. Several surrounding communities, including Des Plaines, Elmwood Park, and Rosemont, receive water through connections to the Chicago system.

Do I need a water filter in Chicago?

A filter is not required by any health authority for most Chicago residents. If you want added protection against trace PFAS compounds detected in the water, look for a filter certified to NSF/ANSI 58 (reverse osmosis) or NSF/ANSI P473. For chlorine taste and odor, a filter certified to NSF/ANSI 42 works well. NSF/ANSI is an independent third-party certification you can verify on the label.

How often is Chicago tap water tested?

Chicago's water is tested continuously and reported annually through the EPA-required Consumer Confidence Report. The detection data shown here comes from recent EPA monitoring conducted through 2025, which included testing for PFAS and other emerging contaminants under a national EPA sampling program. Utilities are required to test for dozens of regulated contaminants on schedules set by federal rules.

What is the best water filter for Chicago?

Given the trace PFAS compounds and chlorine disinfection found in Chicago's water, a filter certified to both NSF/ANSI 58 and NSF/ANSI P473 offers the broadest protection. Reverse osmosis systems with these certifications reduce PFAS effectively. If you only want to improve taste and reduce chlorine, a pitcher or under-sink filter certified to NSF/ANSI 42 is a simpler option. Check the manufacturer's certification documentation before buying.

Tap water reports by ZIP in Chicago

Water utilities serving Chicago, IL

Service area boundaries are approximate and based on state filings or modeled estimates. Contact your utility to confirm exact service at a specific address.

Modeled boundaries are shown with a dashed outline.

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