If you live in the suburbs of Chicago, you've probably poured a glass of tap water without a second thought. Lake Michigan is right there. The city treats it. It arrives at your faucet. Done. Except it's not that simple anymore. Between PFAS contamination notices, aging infrastructure, and nitrate scares in the south suburbs, the question of what's actually in your suburban tap water has gotten a lot harder to wave off. Here's what the latest reports actually say — and what you should probably do about it.
Where Chicago Suburb Tap Water Actually Comes From
Most of the Chicago suburbs pull their drinking water from Lake Michigan, one of the largest freshwater sources on the planet. The City of Chicago's Department of Water Management (DWM) purifies and delivers nearly one billion gallons of water per day to residents of Chicago and roughly 120 surrounding suburbs. The water is drawn through offshore intake cribs located two to three miles out in the lake, then treated through a multi-step process:
Coagulation and sedimentation to remove particles
Sand and gravel filtration
Chlorine disinfection
Fluoridation for dental health Not every suburb uses Lake Michigan water, though. Communities further south and west — places like Joliet — have historically relied on deep sandstone aquifers. Joliet is actively transitioning off that aquifer by 2030 because the supply simply can't keep up. If you're looking at neighborhoods in Joliet, that's a factor worth weighing. The Illinois State Water Survey has been studying the region's shallow dolomite aquifer as well, where chloride contamination is a growing concern. If you're in DuPage County — maybe scoping out home prices — there's a decent chance your water comes through the DuPage Water Commission via Chicago's Jardine Water Filtration Plant. The Village of Addison, for example, has been on 100% Lake Michigan water since 1992. Glenview purchases from Wilmette, also sourced from the lake, and reports no actionable lead readings. The point: your suburb's water source matters. And it's not always what you'd assume.
What the Latest Water Quality Reports Found
Chicago's 2024 Water Quality Report confirmed that the city's tap water met or exceeded all EPA standards for safe drinking water. That sounds reassuring, and at a federal compliance level, it is. But the Environmental Working Group (EWG) paints a more detailed picture. Their analysis of Chicago-area water found 20 contaminants in the system, with 13 exceeding EWG's health-based guidelines — which are stricter than federal minimums. These include disinfection byproducts (a side effect of chlorine treatment) and trace-level contaminants that the EPA regulates loosely or not at all. For suburban systems specifically, the picture varies:
Illinois American Water's Chicago Suburban system was found to be in federal compliance for the most recent quarter assessed (April–June 2024).
Addison's 2024 report confirmed compliance with all state and federal requirements.
Glenview reports no actionable lead levels and safe drinking water across all tests. The takeaway isn't that your water is dangerous. It's that "in compliance" doesn't always mean "nothing to worry about." Federal limits are a floor, not a ceiling.
The PFAS Problem Across Illinois Suburbs
This is the big one. Per- and polyfluoroalkyl substances (PFAS) — commonly called "forever chemicals" — have become the defining water quality issue in Illinois suburbs. In 2021, the Illinois EPA completed a statewide investigation of PFAS in finished drinking water, sampling 1,428 entry points across 1,749 community water supplies. The results were not great for everyone. As of early 2026, 47 community water systems across 21 Illinois communities have been notified that their PFAS levels exceed both state and federal standards. That affects the drinking water of more than 400,000 residents. Communities on the list include:
Channahon
Crest Hill
Cary
Several towns in the Metro East region In March 2026, the state ordered those 21 communities to remove forever chemicals from their drinking water by 2029 — but the question of who pays for the treatment upgrades remains unresolved. Chicago itself has fared better on PFAS. The city has sampled for PFOS since 2011 and conducted additional rounds of testing in 2014, 2020, and again recently. All studies returned non-detect results, meaning any PFAS present was below what laboratory instruments could measure. But suburbs on groundwater sources are far more vulnerable, since PFAS is more commonly found in groundwater than in surface water like Lake Michigan. If your suburb hasn't published recent PFAS data, that's worth asking about.
Nitrate Alerts and Other Suburban Contamination Events
PFAS isn't the only issue. In June 2025, a drinking water warning was issued for several south suburban communities — including University Park, Kankakee, and Peotone — after testing revealed high nitrate levels that posed a health risk, particularly for infants. Anyone weighing the south suburbs should factor in which water source their town sits on. Aqua Illinois began distributing bottled water daily in University Park until the advisory was lifted. Nitrate contamination typically comes from agricultural runoff and fertilizer, and it's a persistent risk for communities drawing from shallow wells and aquifers downstate and in southern Cook County. Meanwhile, the broader suburban water infrastructure story isn't exactly comforting:
Lead service lines remain a concern in older suburbs. Chicago's "Lead-Safe Chicago" initiative covers eligible city residents and daycares, but many suburbs manage their own replacement timelines.
Disinfection byproducts (DBPs) — created when chlorine reacts with organic matter — show up in nearly every system that uses chlorine treatment. They're regulated, but the health-based thresholds from groups like EWG are significantly lower than the federal limits. None of this means you need to panic. But if you have an infant, an older home, or you're on a non-Lake Michigan water source, it's worth checking your suburb's Consumer Confidence Report (CCR), which every public water system is required to publish annually. Especially if you're moving out here with a young family, add the CCR to your due diligence list.
How to Check Your Suburb's Tap Water Quality
The good news: you don't have to guess. Here's how to actually find out what's in your water.
Your suburb's annual CCR: Every public water supplier must publish one. Search your village or city website, or call the water department. This report covers detected contaminants and whether they met federal limits.
Illinois EPA's Drinking Water Watch: The state maintains a searchable database where you can look up compliance data for your specific community water system.
EWG's Tap Water Database: Search by zip code at ewg.org/tapwater for a more detailed analysis that compares your water against health-based guidelines, not just legal limits.
Illinois EPA PFAS results: The state's PFAS Statewide Investigation page publishes sampling data for community water supplies across Illinois.
Home testing: If you want to go further, home water test kits can check for lead, nitrates, and other contaminants. Useful if you have older plumbing or a private well. The reporting infrastructure exists. Most people just don't know where to look — which is, honestly, the whole problem.
Your suburb's water is probably fine. But "probably fine" is doing a lot of heavy lifting when 400,000 Illinoisans just got told their PFAS levels are too high. Check the reports. Run the faucet for 30 seconds before you drink. And maybe stop telling yourself Lake Michigan handles everything.
