County · Illinois
Cook County, Illinois: drinking water records
Explore EPA records for 163 community water systems across 167 ZIP codes in Cook County, then find water-testing resources and available recent monitoring-station readings.
Data as of EPA UCMR 5 final release, August 2026 (file dated Aug 28, 2026) · EPA SDWIS 2026Q2 (file dated Jul 9, 2026). How we build these pages
Drinking-water records
EPA survey and compliance records are historical reports. UCMR 5 results are available for 109 of the 163 listed systems in this snapshot. A system with no reported PFAS detection is not a test of every tap or every contaminant.
System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.
Water systems in this county
All 163 active community systems in the available county records, sorted by record completeness. Scroll the table to explore more systems.
| Water system | People served | PFAS survey results | PFAS found | Health-based violations | Lead, 9 in 10 homes at or below |
|---|---|---|---|---|---|
| Cicero IL0310510 | 83,000 | 120 | 0 | 1 | 5 ppbbelow the action level |
| Wheeling IL0314970 | 39,725 | 120 | 0 | 1 | 1.3 ppbbelow the action level |
| Calumet City IL0310390 | 37,000 | 240 | 2 | 2 | 12.4 ppbbelow the action level |
| Maywood IL0311830 | 24,090 | 120 | 0 | 1 | 5.4 ppbbelow the action level |
| South Holland IL0312970 | 22,000 | 240 | 1 | 2 | 7.9 ppbbelow the action level |
| Park Forest IL0314740 | 21,687 | 60 | 0 | 1 | 2.3 ppbbelow the action level |
| Bellwood IL0310150 | 19,156 | 120 | 0 | 1 | 9.1 ppbbelow the action level |
| Lemont IL0311620 | 17,500 | 240 | 0 | 1 | 20 ppbat or above the action level |
| Western Springs IL0313180 | 13,274 | 60 | 0 | 1 | 2.0 ppbbelow the action level |
| Richton Park IL0312550 | 12,504 | 180 | 0 | 2 | 7.4 ppbbelow the action level |
| Chicago IL0316000 | 2,721,308 | 240 | 0 | 0 | 7 ppbbelow the action level |
| Schaumburg IL0314890 | 75,750 | 120 | 0 | 0 | 1.4 ppbbelow the action level |
| Evanston IL0310810 | 74,486 | 120 | 0 | 0 | 8 ppbbelow the action level |
| Arlington Heights IL0314030 | 73,320 | 120 | 0 | 0 | 8.8 ppbbelow the action level |
| Palatine IL0312340 | 70,875 | 120 | 0 | 0 | 7.5 ppbbelow the action level |
| Skokie IL0312880 | 66,422 | 120 | 0 | 0 | 8.0 ppbbelow the action level |
| Des Plaines IL0310630 | 60,675 | 240 | 0 | 0 | 11.1 ppbbelow the action level |
| Oak Lawn IL0312220 | 58,362 | 120 | 0 | 0 | 8.1 ppbbelow the action level |
| Orland Park IL0312310 | 58,020 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Berwyn IL0310210 | 57,250 | 60 | 0 | 0 | 1.8 ppbbelow the action level |
| Tinley Park IL0314910 | 56,703 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Oak Park IL0312250 | 54,583 | 120 | 0 | 0 | 5.1 ppbbelow the action level |
| Hoffman Estates IL0311290 | 50,179 | 120 | 0 | 0 | 1.4 ppbbelow the action level |
| Glenview IL0311020 | 47,856 | 120 | 0 | 0 | 9.8 ppbbelow the action level |
| Buffalo Grove IL0314180 | 43,212 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Bartlett IL0314120 | 41,500 | 120 | 0 | 0 | 22.6 ppbat or above the action level |
| Mount Prospect IL0311980 | 41,000 | 120 | 0 | 0 | 4.3 ppbbelow the action level |
| Park Ridge IL0312460 | 39,800 | 120 | 0 | 0 | 6.8 ppbbelow the action level |
| Streamwood IL0313060 | 39,577 | 120 | 0 | 0 | 2.3 ppbbelow the action level |
| Hanover Park IL0314480 | 37,470 | 120 | 0 | 0 | 1.5 ppbbelow the action level |
| Northbrook IL0312070 | 34,407 | 120 | 0 | 0 | 11 ppbbelow the action level |
| Elk Grove Village IL0314400 | 31,802 | 120 | 0 | 0 | 4.2 ppbbelow the action level |
| Aqua Illinois-North Maine Utilities IL0315350 | 30,043 | 240 | 0 | 0 | 1.1 ppbbelow the action level |
| South Stickny Sd IL0317370 | 30,000 | 120 | 0 | 0 | 3.7 ppbbelow the action level |
| Niles IL0312010 | 29,350 | 120 | 0 | 0 | 9.9 ppbbelow the action level |
| Lansing IL0311590 | 29,076 | 120 | 0 | 0 | 5.5 ppbbelow the action level |
| Oak Forest IL0312190 | 27,478 | 120 | 1 | 0 | 0 ppbbelow the action level |
| Wilmette IL0313300 | 27,087 | 120 | 0 | 0 | 9.9 ppbbelow the action level |
| Chicago Heights IL0310450 | 26,184 | 120 | 0 | 0 | 5.9 ppbbelow the action level |
| Morton Grove IL0311950 | 25,297 | 120 | 0 | 0 | 17.6 ppbat or above the action level |
| Elmwood Park IL0310780 | 25,000 | 120 | 0 | 0 | 3.0 ppbbelow the action level |
| Harvey IL0311110 | 25,000 | 120 | 0 | 0 | 2.2 ppbbelow the action level |
| Melrose Park IL0311860 | 24,206 | 120 | 0 | 0 | 5.6 ppbbelow the action level |
| Rolling Meadows IL0312730 | 23,329 | 120 | 0 | 0 | 0.9 ppbbelow the action level |
| Blue Island IL0310240 | 21,494 | 120 | 0 | 0 | 10.0 ppbbelow the action level |
| Dolton IL0310690 | 20,510 | 120 | 0 | 0 | 2.8 ppbbelow the action level |
| Evergreen Park IL0310840 | 19,943 | 120 | 0 | 0 | 7.9 ppbbelow the action level |
| Homewood IL0311350 | 19,463 | 120 | 1 | 0 | 14 ppbbelow the action level |
| Alsip IL0310030 | 19,063 | 120 | 0 | 0 | 1.2 ppbbelow the action level |
| Brookfield IL0310330 | 18,776 | 120 | 0 | 0 | 7.6 ppbbelow the action level |
| Palos Hills IL0312400 | 18,530 | 120 | 0 | 0 | 0.8 ppbbelow the action level |
| Franklin Park IL0310960 | 18,467 | 120 | 0 | 0 | 5.7 ppbbelow the action level |
| Justice-Willow Springs Water Commission IL0315820 | 18,450 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Matteson IL0311800 | 18,293 | 120 | 0 | 0 | 8.6 ppbbelow the action level |
| Country Club Hills IL0310540 | 16,500 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Bridgeview IL0310270 | 16,467 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Westchester IL0313150 | 16,241 | 120 | 0 | 0 | 9 ppbbelow the action level |
| La Grange IL0311530 | 16,200 | 120 | 0 | 0 | 6.5 ppbbelow the action level |
| Palos Heights IL0312370 | 15,500 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Norridge IL0312040 | 15,251 | 120 | 0 | 0 | 6.6 ppbbelow the action level |
| Midlothian IL0311920 | 14,819 | 120 | 0 | 0 | 7.3 ppbbelow the action level |
| Hickory Hills IL0311200 | 14,505 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Forest Park IL0310900 | 14,340 | 120 | 0 | 0 | 4 ppbbelow the action level |
| Chicago Ridge IL0310480 | 14,130 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Hazel Crest IL0311170 | 13,792 | 120 | 0 | 0 | 5.3 ppbbelow the action level |
| Lincolnwood IL0311650 | 13,463 | 120 | 0 | 0 | 4.4 ppbbelow the action level |
| La Grange Park IL0311560 | 13,011 | 120 | 0 | 0 | 6.9 ppbbelow the action level |
| Northlake IL0314710 | 12,840 | 120 | 0 | 0 | 4.0 ppbbelow the action level |
| Markham IL0311770 | 12,500 | 120 | 1 | 0 | 1.5 ppbbelow the action level |
| Winnetka IL0313330 | 12,475 | 120 | 0 | 0 | 8.5 ppbbelow the action level |
| River Forest IL0312610 | 11,717 | 120 | 0 | 0 | 7.9 ppbbelow the action level |
| Schiller Park IL0312850 | 11,709 | 120 | 0 | 0 | 1.5 ppbbelow the action level |
| Il American-Chicago Suburban IL0315150 | 11,187 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Summit IL0310060 | 11,161 | 120 | 1 | 0 | 8 ppbbelow the action level |
| Worth IL0313360 | 10,970 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Crestwood IL0310600 | 10,826 | 120 | 0 | 0 | 2.1 ppbbelow the action level |
| Lyons IL0311710 | 10,304 | 120 | 0 | 0 | 6.1 ppbbelow the action level |
| River Grove IL0312640 | 10,282 | 120 | 0 | 0 | 6.1 ppbbelow the action level |
| Riverdale IL0312580 | 10,266 | 120 | 0 | 0 | 4.8 ppbbelow the action level |
| Leyden Twsp Water District IL0315880 | 10,000 | 120 | 0 | 0 | 10.7 ppbbelow the action level |
| Sauk IL0312790 | 9,921 | 120 | 1 | 0 | 0 ppbbelow the action level |
| Steger IL0314860 | 9,700 | 120 | 0 | 0 | 1.8 ppbbelow the action level |
| Flossmoor IL0310870 | 9,371 | 120 | 0 | 0 | 5.4 ppbbelow the action level |
| Riverside IL0312670 | 9,298 | 120 | 0 | 0 | 8.6 ppbbelow the action level |
| Lynwood IL0311680 | 9,149 | 120 | 0 | 0 | 1.1 ppbbelow the action level |
| Harwood Heights IL0311140 | 9,065 | 120 | 0 | 0 | 6.6 ppbbelow the action level |
| Glenwood IL0311050 | 8,956 | 120 | 0 | 0 | 0.9 ppbbelow the action level |
| Glencoe IL0310990 | 8,849 | 120 | 0 | 0 | 6.9 ppbbelow the action level |
| Calumet Park IL0310420 | 8,442 | 120 | 0 | 0 | 6 ppbbelow the action level |
| Hillside IL0311230 | 8,200 | 120 | 0 | 0 | 3 ppbbelow the action level |
| Broadview IL0310300 | 7,847 | 120 | 0 | 0 | 5.9 ppbbelow the action level |
| North Riverside IL0312160 | 7,071 | 120 | 0 | 0 | 7.4 ppbbelow the action level |
| Stickney IL0313000 | 6,902 | 120 | 0 | 0 | 3.3 ppbbelow the action level |
| La Grange Highlands Sanitary District IL0315860 | 6,600 | 120 | 0 | 0 | 12 ppbbelow the action level |
| Countryside IL0310570 | 6,420 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Il American-Fernway IL0315030 | 5,521 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Northfield IL0312100 | 5,470 | 120 | 0 | 0 | 17 ppbat or above the action level |
| Robbins IL0312700 | 5,415 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Posen IL0312520 | 5,331 | 120 | 0 | 0 | 3.6 ppbbelow the action level |
| Berkeley IL0310180 | 5,214 | 120 | 0 | 0 | 8.4 ppbbelow the action level |
| Olympia Fields IL0312280 | 4,922 | 120 | 0 | 0 | 4.2 ppbbelow the action level |
| Palos Park IL0311000 | 4,873 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Stone Park IL0313030 | 4,576 | 120 | 0 | 0 | 4.1 ppbbelow the action level |
| Hometown IL0311320 | 4,240 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Burnham IL0310360 | 3,989 | 240 | 0 | 0 | 14.2 ppbbelow the action level |
| Rosemont IL0312760 | 3,952 | 120 | 0 | 0 | 1.5 ppbbelow the action level |
| South Chicago Heights IL0312940 | 3,924 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Dixmoor IL0310660 | 2,973 | 120 | 2 | 0 | 2.7 ppbbelow the action level |
| South Palos Twsp Sanitary Dist IL0310140 | 2,800 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Kenilworth IL0311500 | 2,514 | 120 | 0 | 0 | 6.5 ppbbelow the action level |
| Central Stickney Sd IL0315570 | 2,400 | 0 | 0 | 1 | 9.2 ppbbelow the action level |
| Blackhawk Estates LLC IL0317765 | 1,238 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Glen Eden Estates Homeowners Association IL0315650 | 312 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Indian Head Park IL0311410 | 3,240 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Oasis MHP IL0315185 | 3,000 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Mission Brook Sd IL0315920 | 2,852 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Thornton IL0313090 | 2,386 | 0 | 0 | 0 | 2.8 ppbbelow the action level |
| Aqua Illinois-Timber Ridge IL1970410 | 2,322 | 0 | 0 | 0 | 1 ppbbelow the action level |
| Prospect Heights IL0312530 | 2,280 | 0 | 0 | 0 | 4.1 ppbbelow the action level |
| Phoenix IL0312490 | 1,994 | 0 | 0 | 0 | 6.8 ppbbelow the action level |
| Merrionette Park IL0311890 | 1,969 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sterling Estates MHP IL0315850 | 1,954 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Il American-Waycinden IL0317550 | 1,934 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Ford Heights IL0310720 | 1,813 | 0 | 0 | 0 | 1.0 ppbbelow the action level |
| East Hazel Crest IL0310750 | 1,500 | 0 | 0 | 0 | 1.0 ppbbelow the action level |
| Garden Home Sd IL0315620 | 1,472 | 0 | 0 | 0 | 0.9 ppbbelow the action level |
| Hodgkins IL0311260 | 1,472 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sunset MHP IL0310080 | 1,400 | 0 | 0 | 0 | 0 ppbbelow the action level |
| South Barrington IL0310200 | 1,175 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Harbor Point Estates MHP IL0317010 | 1,064 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Alpine Village MHP IL0315125 | 994 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Spring Lakes MHP IL0315145 | 940 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Willoway Terrace MHP IL0317595 | 900 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Glenbrook Sd IL0315310 | 822 | 0 | 0 | 0 | 7 ppbbelow the action level |
| Forest View IL0310930 | 800 | 0 | 0 | 0 | 6.2 ppbbelow the action level |
| Il American-Alpine Heights IL1970030 | 707 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Buckhorn Ranch Estates MHP IL0310070 | 702 | 0 | 0 | 0 | 0 ppbbelow the action level |
| River Oaks Estates MHP IL0310395 | 677 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Bedford Park IL0310120 | 602 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Franciscan Sisters of Chicago IL0310110 | 505 | 0 | 0 | 0 | 7.7 ppbbelow the action level |
| Golf IL0311080 | 497 | 0 | 0 | 0 | 9.3 ppbbelow the action level |
| Paradise MHP IL0310010 | 460 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Il American-Moreland IL0315910 | 445 | 0 | 0 | 0 | 4 ppbbelow the action level |
| La Grange Estates MHP IL0311540 | 440 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Candlelight Village MHP IL0315175 | 420 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Des Plaines MHP IL0317775 | 405 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Oak Lane MHC IL0311900 | 388 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Linway Estates MHP IL0315935 | 380 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Mc Cook IL0311740 | 280 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Lindentree Townhomes IL0310370 | 232 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Weatherstone Lakes MHP IL0312800 | 221 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Aqua Illinois-Summerdale IL0312050 | 145 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Il American-Midwest Palos IL0317050 | 126 | 0 | 0 | 0 | 5 ppbbelow the action level |
| Sunrise Senior Living IL0312540 | 82 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Edward Hines Jr V a Hospital IL0315617 | 60 | 0 | 0 | 0 | 1.3 ppbbelow the action level |
| Mid-Mark Water Commission IL0310230 | 25 | 0 | 0 | 0 | not reported |
| Broadview-Westchester Joint Water Agency IL0317580 | 1 | 0 | 0 | 0 | not reported |
| Brookfield-North Riverside Water Comm. IL0315130 | 1 | 0 | 0 | 0 | not reported |
| Hillside Berkeley Water Commission IL0315770 | 1 | 0 | 0 | 0 | not reported |
| Northwest Suburban Municipal Jawa IL0315400 | 1 | 0 | 0 | 0 | not reported |
| Northwest Water Commission IL0315300 | 1 | 0 | 0 | 0 | not reported |
| Il American-Lake Water Company IL0310290 | 0 | 0 | 0 | 0 | not reported |
| Morton Grove - Niles Water Commission IL0311960 | 0 | 0 | 0 | 0 | not reported |
Shaded rows report lead at or above the 15 ppb action level in their latest monitoring period. EPA sets that level for the value 9 in 10 sampled homes fall at or below; reaching it requires the utility to act, and it is not a measurement of any single tap. 4 systems in this table are at or above it. What an action level means
USGS · Monitoring stations
The water, more recently.
Available station readings in Cook County, Illinois. Each measurement keeps its time, unit and original source.
These readings describe water at a monitoring station. They do not test your tap, measure PFAS or lead, or determine whether water is safe to drink or swim in.
Recent observations load when this section comes into view.
How these readings update
We check for updates every 10 minutes while this section is visible and show supported observations from the last 48 hours. The time beside a reading is when USGS measured it; the checked time is when our service retrieved the response. We mark a reading more than 6 hours old as older. Provisional observations can change after USGS review. A missing reading does not mean zero or clean water.
Temperature, pH, dissolved oxygen, turbidity, conductivity, streamflow and water level are shown only where a station reports them. Different measurements have different units and sampling intervals. USGS data and documentation.
Your next step
Water testing, reports & local help.
Use these official directories to find your drinking-water agency, a certified laboratory and public water records. We have not yet added an individually reviewed local resource list for this county.
Official national directories
Water testing
Find your state’s private-well program
EPA’s state directory points well owners to local program information. Services and eligibility vary by state and county.
Water testing
Find a certified drinking-water laboratory
Use EPA’s directory to reach your state’s laboratory certification program. EPA does not provide on-request testing of residential drinking water.
Public records
Find your utility’s Consumer Confidence Report
EPA links to community water-system reports and explains how to read them. Look for your actual supplier rather than assuming every address in a county shares one system.
Public records
Explore USGS water observations
Find current and historical observations from USGS monitoring locations, including available stream, lake, and groundwater data. Measurements vary by station and do not replace a test of your household water.
A county overview cannot identify every property’s water provider. If you use a public water system, confirm its name on your bill and request its annual Consumer Confidence Report. Private wells need their own testing; public-system records do not describe a private well.
Understand water testing and laboratory reportsResource descriptions are compiled by Tap Water Lookup. Review dates describe our source check, not a new water sample. How we review sources · Suggest a correction
Explore your area
Local coverage in Cook County
167ZIP areas in this overview
Explore the water-system records, recent station readings and testing resources on this county page. They describe the systems and stations identified in each section; they are not a separate water test for every community.
Towns and communities
- Alsip
- Arlington Heights
- Barrington Hills
- Bellwood
- Berkeley
- Berwyn
- Blue Island
- Bridgeview
- Broadview
- Brookfield
- Burbank
- Calumet City
- Chicago
- Chicago Heights
- Chicago Ridge
- Cicero
- Country Club Hills
- Countryside
- Crestwood
- Des Plaines
- Dolton
- Elgin
- Elk Grove Village
- Elmwood Park
- Evanston
- Evergreen Park
- Flossmoor
- Forest Park
- Franklin Park
- Glencoe
- Glenview
- Glenwood
- Golf
- Harvey
- Hazel Crest
- Hickory Hills
- Hillside
- Hoffman Estates
- Hometown
- Homewood
- Justice
- Kenilworth
- La Grange Park
- Lansing
- Lemont
- Lincolnwood
- Lyons
- Markham
- Matteson
- Maywood
- Melrose Park
- Midlothian
- Morton Grove
- Mount Prospect
- Niles
- Norridge
- Northbrook
- Northlake
- Oak Forest
- Oak Lawn
- Oak Park
- Olympia Fields
- Orland Park
- Palatine
- Palos Heights
- Palos Hills
- Palos Park
- Park Forest
- Park Ridge
- Posen
- Prospect Heights
- Richton Park
- River Forest
- River Grove
- Riverdale
- Riverside
- Robbins
- Rolling Meadows
- Schaumburg
- Schiller Park
- Skokie
- South Holland
- Steger
- Stone Park
- Streamwood
- Summit
- Thornton
- Tinley Park
- Westchester
- Western Springs
- Wheeling
- Willow Springs
- Wilmette
- Winnetka
- Worth
View ZIP areas and understand coverage
- 60004Arlington Heights
- 60005Arlington Heights
- 60007Elk Grove Village
- 60008Rolling Meadows
- 60010Barrington Hills
- 60016Des Plaines
- 60018Chicago
- 60022Glencoe
- 60025Glenview
- 60026Glenview
- 60029Golf
- 60043Kenilworth
- 60053Morton Grove
- 60056Mount Prospect
- 60062Northbrook
- 60067Palatine
- 60068Park Ridge
- 60070Prospect Heights
- 60074Palatine
- 60076Skokie
- 60077Skokie
- 60090Wheeling
- 60091Wilmette
- 60093Winnetka
- 60104Bellwood
- 60107Streamwood
- 60120Elgin
- 60130Forest Park
- 60131Franklin Park
- 60141
- 60153Maywood
- 60154Westchester
- 60155Broadview
- 60160Melrose Park
- 60162Hillside
- 60163Berkeley
- 60164Northlake
- 60165Stone Park
- 60169Hoffman Estates
- 60171River Grove
- 60173Schaumburg
- 60176Schiller Park
- 60192Hoffman Estates
- 60193Schaumburg
- 60194Schaumburg
- 60195Schaumburg
- 60201Evanston
- 60202Evanston
- 60203Skokie
- 60208Evanston
- 60301Oak Park
- 60302Oak Park
- 60304Oak Park
- 60305River Forest
- 60402Berwyn
- 60406Blue Island
- 60409Calumet City
- 60411Chicago Heights
- 60415Chicago Ridge
- 60418Crestwood
- 60419Dolton
- 60422Flossmoor
- 60425Glenwood
- 60426Harvey
- 60428Markham
- 60429Hazel Crest
- 60430Homewood
- 60438Lansing
- 60439Lemont
- 60443Matteson
- 60445Midlothian
- 60452Oak Forest
- 60453Oak Lawn
- 60455Bridgeview
- 60456Hometown
- 60457Hickory Hills
- 60458Justice
- 60459Burbank
- 60461Olympia Fields
- 60462Orland Park
- 60463Palos Heights
- 60464Palos Park
- 60465Palos Hills
- 60466Park Forest
- 60467Orland Park
- 60469Posen
- 60471Richton Park
- 60472Robbins
- 60473South Holland
- 60475Steger
- 60476Thornton
- 60477Tinley Park
- 60478Country Club Hills
- 60480Willow Springs
- 60482Worth
- 60487Tinley Park
- 60501Summit
- 60513Brookfield
- 60525Countryside
- 60526La Grange Park
- 60534Lyons
- 60546Riverside
- 60558Western Springs
- 60601Chicago
- 60602Chicago
- 60603Chicago
- 60604Chicago
- 60605Chicago
- 60606Chicago
- 60607Chicago
- 60608Chicago
- 60609Chicago
- 60610Chicago
- 60611Chicago
- 60612Chicago
- 60613Chicago
- 60614Chicago
- 60615Chicago
- 60616Chicago
- 60617Chicago
- 60618Chicago
- 60619Chicago
- 60620Chicago
- 60621Chicago
- 60622Chicago
- 60623Chicago
- 60624Chicago
- 60625Chicago
- 60626Chicago
- 60628Chicago
- 60629Chicago
- 60630Chicago
- 60631Chicago
- 60632Chicago
- 60633Chicago
- 60634Chicago
- 60636Chicago
- 60637Chicago
- 60638Chicago
- 60639Chicago
- 60640Chicago
- 60641Chicago
- 60642Chicago
- 60643Chicago
- 60644Chicago
- 60645Chicago
- 60646Chicago
- 60647Chicago
- 60649Chicago
- 60651Chicago
- 60652Chicago
- 60653Chicago
- 60654Chicago
- 60655Chicago
- 60656Chicago
- 60657Chicago
- 60659Chicago
- 60660Chicago
- 60661Chicago
- 60706Norridge
- 60707Elmwood Park
- 60712Lincolnwood
- 60714Niles
- 60803Alsip
- 60804Cicero
- 60805Evergreen Park
- 60827Riverdale
These Census ZIP Code Tabulation Areas are grouped here by their largest county overlap. A ZIP area can cross county lines and contain several water suppliers or private wells. Place labels reflect Census geography, not verified postal city names or utility service boundaries.
Records for these areas are currently presented in this county overview rather than individual ZIP reports. An unpublished report does not mean there are no water records. Confirm your supplier on your water bill; if you use a private well, testing your own well is the relevant next step.
Sources and scope
EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Database prepared 2026-09-03.
Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.
Compiled by Tap Water Lookup from the sources identified on this page. Read the methodology and review process.