If you live in Chicago, you probably pour a glass of water from the tap without thinking too much about it. Maybe you have heard about lead in Chicago water, PFAS, or disinfection byproducts and started to wonder: Is Chicago tap water safe to drink in 2025? And do you really need a water filter?
This guide walks you through Chicago drinking water in clear, simple language. You will see where the water comes from, which contaminants in Chicago matter most, what the numbers look like, and what that means for your health. You will also learn how to test your water and how to pick the best water filter for Chicago homes.
Is Chicago tap water safe to drink in 2025?
The short, honest answer is this: Chicago’s tap water is legal to drink, but not free of risk.
The City of Chicago gets Chicago’s drinking water entirely from Lake Michigan. The city treats it at large water treatment plants and sends it through pipes to about 2.7 million people. The Chicago Department of Water Management (DWM) and the Illinois EPA report that the city has had 0 violations of EPA Maximum Contaminant Levels (MCLs) as of 2025. That means Chicago drinking water meets current federal legal limits.
But legal and ideal are not the same thing.
The Environmental Protection Agency (EPA) sets two main kinds of numbers:
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MCL (Maximum Contaminant Level): A legal limit. Water systems must stay below this.
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MCLG (Maximum Contaminant Level Goal): A health-based goal. This is the level where no known or expected health risk is predicted over a lifetime. It is not enforceable.
Independent groups, including the Environmental Working Group (EWG), also publish strict health-based guidelines that are often lower than legal limits. When we compare Chicago water quality to these more protective goals, we see a different picture.
Chicago has about 11 contaminants above MCLGs or other health-based guidelines, including:
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Total trihalomethanes (TTHMs) and haloacetic acids (HAAs / HAA5 / HAA9), which are disinfection byproducts (DBPs) formed when chlorine reacts with organic matter in the water.
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Lead, with a 90th percentile level around 9 parts per billion (ppb).
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Chromium-6 (hexavalent chromium) around 0.19 ppb.
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Radium 226/228 around 0.89 picocuries per liter (pCi/L).
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PFAS (per- and polyfluoroalkyl substances) detected at low levels in some tests.
Where Chicago’s drinking water comes from
Before understanding the risks and protections in place, it helps to see exactly how Chicago’s drinking water begins its journey—from Lake Michigan to your tap.
Lake Michigan drinking water and Chicago’s treatment plants
Chicago draws its drinking water entirely from Lake Michigan. Huge intake structures called cribs sit in the lake, some beneath the lake surface several miles offshore. Water flows from the cribs through tunnels to two main water treatment plants:
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The Jardine Water Purification Plant, near Navy Pier, which is one of the largest in the world.
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The Sawyer Water Purification Plant, on the South Side.
These plants treat water from Lake Michigan and pump it to homes, schools, and businesses throughout the city of Chicago and some suburbs. The system is large and old, but it is also well-studied and heavily monitored. The Chicago Department of Water Management tests the water at many points from the plant to the tap.
Because the source is a Great Lake, Chicago’s water quality depends on protecting Lake Michigan from industrial waste, sewage overflows, and runoff that carries organic matter and chemicals. These upstream issues can affect what treatment steps are needed and how many disinfection byproducts get formed later.
How disinfection creates byproducts (TTHMs, HAA9)
When you smell chlorine in your Chicago tap water, you are noticing the disinfectant that protects you from bacteria and viruses. But that same chlorine also reacts with leftover natural organic matter from the lake to create disinfection byproducts (DBPs).
Two key DBP groups in Chicago’s water are:
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Total trihalomethanes (TTHMs)
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Haloacetic acids (HAAs), including HAA5 and HAA9
In Chicago, recent data show:
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TTHMs average about 16.3 ppb, which is well below the 80 ppb EPA MCL, but more than 50 times higher than the EPA’s MCLG of around 0.32 ppb. The MCLG is set close to zero because some of these chemicals are probable human carcinogens.
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HAAs are also present at levels below the legal limit but above health-based goals used by groups like EWG.
DBPs often vary by season and location. Warmer months, longer time in pipes, and higher organic loads can push DBP levels higher in some parts of the city.
Key contaminants in Chicago water and latest data
Once you know the source, the next step is understanding which contaminants matter most in Chicago and what recent testing shows.
Lead in Chicago water: sources, levels, and trends
Lead in Chicago is one of the most serious concerns. The problem does not come from water from Lake Michigan itself. It comes from the pipes that carry the water into and through buildings.
Chicago has more lead service lines than almost any city in the U.S. A service line is the pipe that connects the water main in the street to your home. Many older homes also have indoor pipes, solder, or fixtures that are made of lead or contain lead.
When water sits in these pipes, especially overnight, the corrosion can cause lead to leach into the water. That means the first water out of the tap in the morning can have the highest level of lead.
Recent data show:
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The 90th percentile lead level in the city’s required testing is around 9 ppb. This is below the EPA action level of 15 ppb, so the city does not face a legal violation. But it is far above the ideal of 0 ppb, since no safe level of lead in drinking water is known, especially for children.
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Testing in Chicago Public Schools (CPS) has found about 10% of fixtures above 5 ppb, the state’s stricter action level for schools.
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Independent home tests have sometimes found much higher localized lead levels, especially in older neighborhoods and buildings with partial lead service line replacements.
Because lead exposure can harm brain development, behavior, and cardiovascular health, especially in children and pregnant people, many health experts now say that any detectable lead in drinking water is a concern, not just levels above 15 ppb.
Disinfection byproducts: TTHMs and haloacetic acids (HAA9)
As mentioned earlier, TTHMs and HAAs form when chlorine reacts with organic matter. Some of the main TTHMs found in Chicago’s tap water include:
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Chloroform
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Bromodichloromethane
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Dibromochloromethane
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Bromoform
Long-term exposure to these DBPs has been linked with a higher risk of bladder cancer, possible colon cancer, and liver and kidney toxicity.
The key numbers for Chicago:
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TTHMs average around 16.3 ppb, under the 80 ppb MCL but much higher than the near-zero MCLG.
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Measured HAAs, such as HAA5 and HAA9, are also below the legal MCL but above strict health-based guidelines.
These chemicals are part of the trade-off for safe disinfection. They are a main reason many residents choose activated carbon filtration, which can reduce DBP levels at the tap.
Chromium-6, radium, and PFAS in Chicago tap water
In addition to lead and DBPs, several other emerging contaminants get attention in discussions of Chicago water quality:
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Chromium-6 (hexavalent chromium): This is a carcinogen at very low doses. Chicago samples show about 0.19 ppb, which is no violation of any current federal MCL (there is only a limit for total chromium), but is about 9.5 times higher than the EWG guideline of 0.02 ppb.
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Radium 226/228: These radioactive elements occur naturally in some rocks and also come from industrial activities. Chicago data around 0.89 pCi/L are well below the 5 pCi/L EPA MCL, but much higher than EWG’s 0.05 pCi/L guideline.
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PFAS (per- and polyfluoroalkyl substances): These “forever chemicals” are used in non-stick pans, firefighting foam, and many products. The EPA is in the process of setting strict PFAS standards in drinking water. Chicago tests have detected PFAS at trace levels in some samples. PFAS are linked to certain cancers, immune changes, and hormone disruption.
These numbers show that while Chicago’s water respects legal limits, there is room to reduce exposure even further with good water filtration systems, especially at the tap (EPA, 2025).
Chicago contaminant levels vs. key benchmarks
| Contaminant | Typical Chicago Value | EPA MCL (Legal Limit) | EPA MCLG / EWG Guideline | Health Concern |
| Lead (90th percentile) | ~9 ppb | 15 ppb (action level) | 0 ppb | Neurological, developmental harm |
| TTHMs | ~16.3 ppb | 80 ppb | ~0.32 ppb MCLG | Cancer risk (mainly bladder) |
| HAA5/HAA9 | Detected (below MCL) | 60 ppb (for HAA5) | Near-zero | Cancer, liver/kidney effects |
| Chromium-6 | ~0.19 ppb | No specific MCL | 0.02 ppb (EWG) | Carcinogen |
| Radium 226/228 | ~0.89 pCi/L | 5 pCi/L | 0.05 pCi/L (EWG) | Bone cancer risk |
| PFAS | Trace levels | New EPA limits pending | Very low draft limits | Cancer, hormone, immune effects |
Health impacts: what Chicago residents should know
Seeing the numbers is only part of the picture; it’s equally important to understand how these contaminants can affect long-term health.
Vulnerable populations and cumulative exposure
Health risks from Chicago drinking water do not usually show up as sudden illness after a single glass. They build over time. That is why experts talk about “cumulative exposure” (WHO, 2023).
This long-term exposure matters more for:
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Infants and children, whose brains and bodies are still growing.
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Pregnant people, since contaminants can affect the fetus.
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Older adults and people with existing kidney, liver, or immune problems.
These groups are more sensitive to contaminants like:
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Lead, which builds up in bones and can stay in the body for years.
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Chromium-6, which is a carcinogen.
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DBPs like TTHMs and HAAs.
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PFAS, which stay in the body for long periods and affect many systems.
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Radium, which can deposit in bones and raise bone cancer risk.
Even if each single contaminant is below its own MCL, they add up over decades.
Cancer and chronic disease risks from contaminants
Several contaminants found in Chicago’s tap water are linked to cancer or chronic disease in scientific studies:
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TTHMs and HAAs: Long-term exposure has been linked to bladder cancer and possible colon and rectal cancers. Some studies also suggest impacts on the liver and kidneys.
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Chromium-6: Classified as a known human carcinogen when inhaled and a probable carcinogen when swallowed in water. Even low levels over many years may raise the chance of certain cancers.
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Radium: A radioactive carcinogen. It can collect in bones and raise the risk of bone cancer and other issues over long periods.
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PFAS: Linked in research to kidney and testicular cancer, thyroid problems, changes in cholesterol, and possible immune effects.
Health agencies like the EPA, WHO, and CDC rely on these studies when setting or updating standards. As science improves, legal limits often change, which is one reason many people choose to stay ahead of the curve by using filtration now.
Neurological and developmental concerns from lead
Among all contaminants, lead is still the one that worries health experts the most in older cities like Chicago.
Lead can:
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Lower IQ in children.
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Affect attention, learning, and behavior.
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Increase risk of ADHD-like symptoms.
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In adults, raise blood pressure, harm kidneys, and affect the nervous system.
The CDC and other health agencies state that there is no known safe blood lead level in children. Because water in Chicago can carry elevated levels of lead from service lines and old plumbing, many doctors now advise families to filter water used for drinking and making baby formula if they live in older housing.
Testing Chicago tap water at home: step-by-step
To move from general citywide data to your own household reality, the next section walks you through how to test your water accurately at home.
What should I test my Chicago tap water for?
If you want to know what you and your family are drinking, testing is the best way to move from guesswork to facts.
For water in Chicago, priority tests often include:
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Lead and copper – highest priority because of health impact and old plumbing.
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TTHMs and HAAs – usually tested by a lab, not simple strips.
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Chromium-6 and PFAS – require more specialized lab tests.
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Basic checks like pH, hardness, iron, manganese, and chlorine – can often be done with simple home kits.
Simple DIY test strips are useful for basic parameters, but certified labs give more reliable numbers for metals and complex chemicals.
How to collect samples correctly (DIY and lab testing)
Good sampling matters. A poor sample can hide a problem or make things seem worse than they are. Here is a simple step-by-step guide:
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Read the instructions from the lab or test kit carefully before you start.
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For lead testing, collect a first-draw sample:
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Do not use the tap for at least 6 hours (for example, overnight).
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Take the sample from the cold water tap you use for drinking.
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Fill the sample bottle right away when you first turn on the tap.
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If the lab also asks for a flushed sample, run the water for several minutes and then fill a second bottle.
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Use clean, provided containers and do not rinse them out unless the instructions say to.
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Do not touch the inside of the bottle or cap.
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Label each bottle with the date, time, and which tap you used.
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Send or deliver the samples to the lab as soon as possible, keeping them cool if the instructions require it.
You can ask your city or county health department about free or low-cost testing programs, especially for lead. You can also look up Illinois EPA-certified labs that accept residential samples.
Interpreting results: EPA standards vs. health-based goals
When your results come back, you may see units like ppb (parts per billion), ppm (parts per million), or pCi/L (picocuries per liter). Here is how to think about them:
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EPA MCL: If your result is above this, it is a legal problem, and the water utility usually must act.
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EPA MCLG or EWG guideline: If your result is above these but below the MCL, your water is legal but not at the ideal health-based level.
If your test shows:
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Lead above 1–5 ppb: Many experts say you should start planning for filtration or using an alternative source for babies and pregnant people, even if it is below 15 ppb.
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TTHMs or HAAs above health-based goals but below MCL: Consider a carbon filter to cut DBP exposure.
If any result exceeds an MCL, contact the water utility and local health department for guidance.
Where to send water for professional analysis in Illinois
For lab testing in Illinois, you can:
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Check the Illinois EPA website for a list of certified drinking water laboratories that accept homeowner samples.
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Ask the City of Chicago DWM or your local health department for information on free lead testing programs and approved labs.
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In some cases, local universities or public health labs run community testing projects.
Using a certified lab gives you data you can compare directly with regulatory standards.
Best water filtration options for Chicago homes
After you know what’s in your water and what your test results mean, the final step is choosing the right filtration system tailored to Chicago’s specific water challenges.
Matching filtration systems to Chicago water problems
Because Chicago water quality issues are fairly well-known, you can match filtration systems to the city’s main challenges:
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Lead: Best removed by certified carbon block filters, some faucet-mounted filters, and reverse osmosis (RO) systems.
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DBPs (TTHMs, HAAs): Reduced by high-quality activated carbon in pitchers, faucet filters, or under-sink units.
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PFAS: Some advanced carbon filters and many RO systems can reduce certain PFAS.
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Chromium-6 and radium: More effectively reduced by RO systems.
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Hard water: Managed with a water softener for the whole house, separate from drinking water filtration.
You can use whole-house filters to handle hardness and chlorine for showers and laundry, and point-of-use filters (under-sink or faucet) for your drinking and cooking water.
Comparing common filter types: pros, cons, and costs
Here is a quick comparison of common water filtration options in Chicago.
| Filter Type | Typical Use | Good For | Limits / Notes | Cost Level* |
| Pitcher filter | Fridge / table | Chlorine taste, some lead, some DBPs | Small capacity, frequent refills | Low |
| Faucet-mounted filter | At kitchen sink | Lead, chlorine, some DBPs, some VOCs | May not fit all faucets | Low–Medium |
| Under-sink carbon | Dedicated drinking tap | Lead (if certified), DBPs, VOCs | Does not remove hardness or all PFAS | Medium |
| Reverse osmosis (RO) | Under-sink, separate tap | Lead, chromium, radium, PFAS, many salts | Uses wastewater, needs maintenance | Medium–High |
| Whole-house filter | All taps in home | Sediment, chlorine, some organics | Not enough alone for lead and PFAS | Medium–High |
| Water softener | All plumbing | Hardness (calcium, magnesium) | Does not remove chemicals or lead | Medium |
*Cost level is a general guide for equipment only and may vary.
For Chicago residents, a common setup is:
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A whole-house softener or basic filter if hardness or chlorine is annoying, plus
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A certified under-sink carbon filter or RO system at the kitchen sink for drinking and cooking water.
FAQs
1. Is it safe to drink tap water in Chicago?
Chicago tap water meets all federal and state legal standards, with regular testing reported in the city’s water quality report and consumer confidence report. The water is treated with chlorine and fluoride to provide safe drinking water throughout the city. While legal limits are met, some common contaminants like disinfection byproducts and trace PFAS remain above ideal health-based goals. Hardness varies, typically 7–10 grains per gallon, reflecting calcium and magnesium content. For most healthy adults, Chicago tap water is considered safe, and many residents enjoy great-tasting water directly from the tap.
2. Should I filter Chicago water?
Filtering Chicago tap water can improve taste and reduce exposure to common contaminants such as lead, chromium-6, and disinfection byproducts. Certified water filters or reverse osmosis systems are especially recommended in homes with older plumbing or partial lead service lines. While water hardness from calcium and magnesium does not pose a health risk, filtration can remove chemicals while preserving great-tasting water. Using a filter alongside proper flushing habits complements the city’s treatment with fluoride and ensures safer drinking water throughout the home.
3. What are the current lead levels in Chicago's water?
Chicago lead in water remains below the EPA action level, with the city reporting a 90th percentile around 9 ppb in the latest consumer confidence report. Even so, no level of lead is considered fully safe, so residents in older homes are encouraged to test their water. Lead can leach from pipes, solder, and fixtures, especially after stagnation. Chicago tap water otherwise maintains good water quality, with fluoride added for dental health and moderate hardness from calcium and magnesium at roughly 7–10 grains per gallon, supporting great-tasting water throughout the city.
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