Systems with a yearly average above an EPA comparison level
2.7%13 of 477 active community water systems
All 477 systems met the sampling requirement for a yearly average. Of those systems, 13 had at least one yearly average above an EPA comparison level and 464 did not.
EPA-based study benchmark: a fixed, unrounded research cutoff used to reproduce EPA’s final UCMR 5 technical-assistance classification based on the April 2024 federal levels. It is not a current federal or state standard. The label does not determine compliance, household exposure, or health risk.
State rules: The labels on this page use fixed research cutoffs based on the April 2024 federal levels. Illinois may use different current standards or guidance. These UCMR 5 results do not determine current federal or state compliance. Find the official Illinois drinking-water program →
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Find your water system
A ZIP code finds possible public water systems for an area; it cannot identify the supplier for a specific home. Confirm the provider using a water bill or utility record.
Compound summary
System counts in Illinois
Each count shows how many included water systems had a yearly average above the named EPA comparison level.
| EPA rounding cutoff | Systems above comparison level | Water systems included | Percent |
|---|---|---|---|
| PFOA: 4 ppt level; unrounded average ≥4.05 ppt after applying EPA rounding | 9 | 477 | 1.9% |
| PFOS: 4 ppt level; unrounded average ≥4.05 ppt after applying EPA rounding | 7 | 477 | 1.5% |
| PFHxS: 10 ppt level; unrounded average ≥15 ppt after applying EPA rounding | 1 | 477 | 0.2% |
| PFNA: 10 ppt level; unrounded average ≥15 ppt after applying EPA rounding | 0 | 477 | 0.0% |
| HFPO-DA: 10 ppt level; unrounded average ≥15 ppt after applying EPA rounding | 0 | 477 | 0.0% |
| Hazard Index: 1 level; unrounded index ≥1.5 and at least two detected components | 1 | 477 | 0.2% |
System directory
Community water systems with complete monitoring
“Complete monitoring” means at least one sampling location had every required sample needed to calculate a yearly average. It does not mean every location or home was tested. Each PWSID appears once, preventing double counting across ZIP associations.
| Public water system | PWSID | Population served | Primary source | Sampling locations | EPA comparison result |
|---|---|---|---|---|---|
| ABINGDON | IL0950050 | 3,275 | Ground water purchased | 1 | Above an EPA comparison level |
| ABS WATER COOP | IL0015350 | 6,858 | Ground water purchased | 5 | No available average above comparison levels |
| ADDISON | IL0430050 | 38,017 | Surface water purchased | 1 | No available average above comparison levels |
| ALEDO | IL1310050 | 3,470 | Ground water | 1 | No available average above comparison levels |
| ALEXANDER WATER DISTRICT | IL1370020 | 442 | Surface water purchased | 1 | No available average above comparison levels |
| ALGONQUIN | IL1110050 | 30,700 | Ground water | 4 | No available average above comparison levels |
| ALSIP | IL0310030 | 19,063 | Surface water purchased | 1 | No available average above comparison levels |
| ALTONA | IL0950100 | 483 | Ground water | 1 | No available average above comparison levels |
| AMERICAN WATER OPER AND MAINTENANCE, LLC | IL1635237 | 6,779 | Surface water purchased | 1 | No available average above comparison levels |
| ANNA | IL1810050 | 4,910 | Ground water purchased | 1 | No available average above comparison levels |
| ANTIOCH | IL0970050 | 14,175 | Ground water | 7 | No available average above comparison levels |
| AQUA ILLINOIS-CANDLEWICK DVN | IL0075050 | 6,426 | Ground water | 1 | No available average above comparison levels |
| AQUA ILLINOIS-KANKAKEE | IL0915030 | 80,000 | Surface water | 1 | No available average above comparison levels |
| AQUA ILLINOIS-NORTH MAINE UTILITIES | IL0315350 | 30,043 | Surface water purchased | 2 | No available average above comparison levels |
| AQUA ILLINOIS-PEOTONE | IL1970750 | 4,182 | Surface water purchased | 2 | No available average above comparison levels |
| AQUA ILLINOIS-UNIVERSITY PARK | IL1975030 | 7,002 | Surface water purchased | 1 | No available average above comparison levels |
| AQUA ILLINOIS-VERMILION COUNTY | IL1835120 | 30,106 | Surface water | 1 | No available average above comparison levels |
| AQUA ILLINOIS-WILLOWBROOK | IL1977870 | 5,100 | Ground water | 3 | No available average above comparison levels |
| ARLINGTON HEIGHTS | IL0314030 | 73,320 | Surface water purchased | 1 | No available average above comparison levels |
| ASHKUM | IL0750050 | 724 | Ground water | 2 | No available average above comparison levels |
| ATHENS | IL1290050 | 4,575 | Ground water | 1 | No available average above comparison levels |
| AUBURN, IL | IL1670050 | 4,574 | Surface water purchased | 1 | No available average above comparison levels |
| AURORA | IL0894070 | 183,000 | Surface water | 1 | No available average above comparison levels |
| BARRINGTON | IL0974080 | 10,327 | Ground water | 2 | No available average above comparison levels |
| BARTLETT | IL0314120 | 41,500 | Surface water purchased | 1 | No available average above comparison levels |
| BATAVIA | IL0894130 | 26,098 | Ground water | 1 | No available average above comparison levels |
| BEACH PARK | IL0970190 | 8,710 | Surface water purchased | 1 | No available average above comparison levels |
| BEARDSTOWN | IL0170150 | 5,951 | Ground water | 1 | No available average above comparison levels |
| BEECHER | IL1970050 | 4,713 | Ground water | 3 | No available average above comparison levels |
| BELLWOOD | IL0310150 | 19,156 | Surface water purchased | 1 | No available average above comparison levels |
| BELVIDERE | IL0070050 | 25,339 | Ground water | 5 | No available average above comparison levels |
| BENSENVILLE | IL0434140 | 18,537 | Surface water purchased | 1 | No available average above comparison levels |
| BENTON | IL0550050 | 8,104 | Surface water purchased | 1 | No available average above comparison levels |
| BERKELEY | IL0310180 | 5,214 | Surface water purchased | 1 | No available average above comparison levels |
| BETHALTO | IL1190150 | 15,210 | Ground water | 1 | No available average above comparison levels |
| BLANDINSVILLE | IL1090100 | 569 | Surface water | 1 | No available average above comparison levels |
| BLOOMINGDALE | IL0430100 | 22,018 | Surface water purchased | 1 | No available average above comparison levels |
| BLOOMINGTON, IL | IL1130200 | 77,610 | Surface water | 1 | No available average above comparison levels |
| BLUE ISLAND | IL0310240 | 21,494 | Surface water purchased | 1 | No available average above comparison levels |
| BLUFFS | IL1710100 | 748 | Ground water | 1 | No available average above comparison levels |
| BOND/MADISON WATER COMPANY | IL0050020 | 6,645 | Surface water purchased | 1 | No available average above comparison levels |
| BOOKWALTER WOODS MHP | IL0635125 | 389 | Ground water | 1 | No available average above comparison levels |
| BRAIDWOOD | IL1970150 | 6,194 | Ground water | 1 | No available average above comparison levels |
| BREESE | IL0270250 | 4,772 | Surface water | 1 | No available average above comparison levels |
| BRIDGEVIEW | IL0310270 | 16,467 | Surface water purchased | 1 | No available average above comparison levels |
| BRIGHTON | IL1174160 | 5,041 | Surface water purchased | 1 | No available average above comparison levels |
| BROADVIEW | IL0310300 | 7,847 | Surface water purchased | 1 | No available average above comparison levels |
| BROOKFIELD | IL0310330 | 18,776 | Surface water purchased | 1 | No available average above comparison levels |
| BUCKLEY | IL0750150 | 500 | Ground water | 1 | No available average above comparison levels |
| BUDA | IL0110100 | 482 | Ground water | 1 | No available average above comparison levels |
| BUFFALO GROVE | IL0314180 | 43,212 | Surface water purchased | 1 | No available average above comparison levels |
| BURNHAM | IL0310360 | 3,989 | Surface water purchased | 2 | No available average above comparison levels |
| BURR RIDGE | IL0434190 | 11,192 | Surface water purchased | 1 | No available average above comparison levels |
| BUSHNELL | IL1090150 | 2,972 | Ground water | 1 | No available average above comparison levels |
| BYRON, IL | IL1410100 | 3,784 | Ground water | 3 | No available average above comparison levels |
| CAHOKIA HEIGHTS | IL1635000 | 12,528 | Surface water purchased | 1 | No available average above comparison levels |
| CALHOUN COUNTY RWD | IL0130010 | 4,675 | Ground water | 1 | No available average above comparison levels |
| CALUMET CITY | IL0310390 | 37,000 | Surface water purchased | 2 | No available average above comparison levels |
| CALUMET PARK | IL0310420 | 8,442 | Surface water purchased | 1 | No available average above comparison levels |
| CANTON, IL | IL0570250 | 16,748 | Groundwater under influence of surface water | 1 | No available average above comparison levels |
| CARBONDALE | IL0770150 | 22,107 | Surface water | 1 | No available average above comparison levels |
| CARLINVILLE | IL1170150 | 6,598 | Surface water | 1 | No available average above comparison levels |
| CARLYLE | IL0270300 | 3,373 | Surface water | 1 | No available average above comparison levels |
| CARMI | IL1930100 | 6,307 | Ground water | 1 | No available average above comparison levels |
| CAROL STREAM | IL0430200 | 39,854 | Surface water purchased | 2 | No available average above comparison levels |
| CARPENTERSVILLE | IL0890200 | 37,983 | Ground water | 1 | No available average above comparison levels |
| CARROLLTON, IL | IL0610050 | 2,513 | Ground water | 1 | No available average above comparison levels |
| CARTERVILLE | IL1990150 | 6,528 | Surface water purchased | 1 | No available average above comparison levels |
| CARY | IL1110100 | 17,826 | Ground water | 6 | No available average above comparison levels |
| CASEY | IL0230050 | 3,274 | Ground water purchased | 1 | No available average above comparison levels |
| CASEYVILLE | IL1630250 | 13,798 | Surface water purchased | 1 | No available average above comparison levels |
| CATERPILLAR TRAIL PWD | IL2035030 | 5,125 | Ground water | 1 | No available average above comparison levels |
| CENTRALIA | IL1214220 | 12,182 | Surface water | 1 | No available average above comparison levels |
| CHANNAHON | IL1970200 | 13,380 | Ground water | 3 | Above an EPA comparison level |
| CHARLESTON | IL0290100 | 17,286 | Surface water | 1 | No available average above comparison levels |
| CHATHAM | IL1670300 | 16,423 | Ground water purchased | 1 | No available average above comparison levels |
| CHERRY VALLEY | IL2010050 | 4,731 | Ground water | 4 | No available average above comparison levels |
| CHESTER | IL1570100 | 8,407 | Surface water | 1 | No available average above comparison levels |
| CHICAGO | IL0316000 | 2,721,308 | Surface water | 2 | No available average above comparison levels |
| CHICAGO HEIGHTS | IL0310450 | 26,184 | Surface water purchased | 1 | No available average above comparison levels |
| CHICAGO RIDGE | IL0310480 | 14,130 | Surface water purchased | 1 | No available average above comparison levels |
| CHILLICOTHE | IL1430200 | 6,660 | Ground water | 7 | No available average above comparison levels |
| CICERO | IL0310510 | 83,000 | Surface water purchased | 1 | No available average above comparison levels |
| CLARENDON HILLS | IL0430250 | 8,702 | Surface water purchased | 1 | No available average above comparison levels |
| CLARK-EDGAR RWD | IL0230010 | 9,657 | Ground water | 1 | No available average above comparison levels |
| CLEAR WATER SERVICE CORP | IL0295100 | 8,900 | Ground water | 2 | No available average above comparison levels |
| CLINTON | IL0390050 | 7,200 | Ground water | 1 | No available average above comparison levels |
| COAL CITY | IL0630200 | 5,749 | Ground water | 1 | No available average above comparison levels |
| COAL VALLEY | IL1614260 | 3,873 | Ground water | 3 | No available average above comparison levels |
| COAL VALLEY PWD | IL1995250 | 4,023 | Surface water purchased | 1 | No available average above comparison levels |
| COLLINSVILLE, IL | IL1194280 | 29,500 | Ground water | 1 | Above an EPA comparison level |
| COLUMBIA | IL1330050 | 11,129 | Surface water purchased | 1 | No available average above comparison levels |
| CORINTH PWD | IL1995120 | 3,927 | Surface water purchased | 1 | No available average above comparison levels |
| CORTLAND | IL0370051 | 4,398 | Ground water | 4 | No available average above comparison levels |
| COUNTRY CLUB HILLS | IL0310540 | 16,500 | Surface water purchased | 1 | No available average above comparison levels |
| COUNTRYSIDE | IL0310570 | 6,420 | Surface water purchased | 1 | No available average above comparison levels |
| CREST HILL | IL1970250 | 21,169 | Ground water | 7 | Above an EPA comparison level |
| CRESTWOOD | IL0310600 | 10,826 | Surface water purchased | 1 | No available average above comparison levels |
| CRETE | IL1970300 | 8,275 | Ground water | 5 | No available average above comparison levels |
| CREVE COEUR | IL1790100 | 4,934 | Ground water | 1 | No available average above comparison levels |
| CRYSTAL LAKE | IL1110150 | 40,661 | Ground water | 5 | No available average above comparison levels |
| CRYSTAL LAWNS ADDITION IMPROVEMENT ASSOC | IL1975480 | 1,435 | Ground water | 5 | No available average above comparison levels |
| CURRAN-GARDNER TOWNSHIP PWD | IL1675350 | 6,651 | Ground water | 1 | No available average above comparison levels |
| DALLAS RURAL WATER DISTRICT | IL0710010 | 6,370 | Ground water | 2 | No available average above comparison levels |
| DARIEN | IL0430270 | 21,751 | Surface water purchased | 1 | No available average above comparison levels |
| DE KALB | IL0370100 | 40,290 | Ground water | 5 | No available average above comparison levels |
| DECATUR | IL1150150 | 76,122 | Surface water | 1 | No available average above comparison levels |
| DEERFIELD | IL0974340 | 19,196 | Surface water purchased | 1 | No available average above comparison levels |
| DES PLAINES | IL0310630 | 60,675 | Surface water purchased | 2 | No available average above comparison levels |
| DIXMOOR | IL0310660 | 2,973 | Surface water purchased | 1 | No available average above comparison levels |
| DIXON | IL1030200 | 15,096 | Ground water | 6 | No available average above comparison levels |
| DOLTON | IL0310690 | 20,510 | Surface water purchased | 1 | No available average above comparison levels |
| DOVER | IL0110350 | 200 | Ground water | 1 | No available average above comparison levels |
| DOWNERS GROVE | IL0430300 | 49,425 | Surface water purchased | 1 | No available average above comparison levels |
| DUPO | IL1630350 | 4,684 | Ground water | 1 | Above an EPA comparison level |
| DUQUOIN | IL1450100 | 7,169 | Surface water purchased | 1 | No available average above comparison levels |
| DWIGHT | IL1050250 | 4,400 | Ground water | 1 | No available average above comparison levels |
| E J WATER COOP | IL0790010 | 29,720 | Surface water | 6 | No available average above comparison levels |
| EAST ALTON | IL1190200 | 5,786 | Ground water | 1 | Above an EPA comparison level |
| EAST MOLINE | IL1610250 | 21,374 | Surface water | 1 | No available average above comparison levels |
| EAST PEORIA | IL1790200 | 22,284 | Ground water | 6 | No available average above comparison levels |
| EASTERN ILLINOIS UNIVERSITY | IL0295500 | 5,500 | Surface water purchased | 1 | No available average above comparison levels |
| EDWARDSVILLE | IL1190250 | 26,808 | Ground water | 1 | No available average above comparison levels |
| EFFINGHAM | IL0490250 | 12,252 | Surface water | 1 | No available average above comparison levels |
| ELBURN | IL0890300 | 6,559 | Ground water | 3 | No available average above comparison levels |
| ELDORADO | IL1655030 | 4,715 | Ground water purchased | 1 | No available average above comparison levels |
| ELGIN, IL | IL0894380 | 114,797 | Surface water | 2 | No available average above comparison levels |
| ELK GROVE VILLAGE | IL0314400 | 31,802 | Surface water purchased | 1 | No available average above comparison levels |
| ELMHURST | IL0430350 | 45,000 | Surface water purchased | 1 | No available average above comparison levels |
| ELMWOOD PARK | IL0310780 | 25,000 | Surface water purchased | 1 | No available average above comparison levels |
| EMBARRAS AREA WATER DISTRICT | IL0290020 | 3,750 | Ground water purchased | 1 | No available average above comparison levels |
| EUREKA | IL2030200 | 5,216 | Ground water | 1 | No available average above comparison levels |
| EVANSTON | IL0310810 | 74,486 | Surface water | 1 | No available average above comparison levels |
| EVERGREEN PARK | IL0310840 | 19,943 | Surface water purchased | 1 | No available average above comparison levels |
| FAIRBURY | IL1050350 | 3,633 | Ground water | 1 | No available average above comparison levels |
| FAIRFIELD | IL1910100 | 6,202 | Surface water | 1 | No available average above comparison levels |
| FAYETTE WATER COMPANY | IL0510010 | 5,608 | Surface water purchased | 3 | No available average above comparison levels |
| FLORA | IL0250100 | 5,233 | Surface water purchased | 1 | No available average above comparison levels |
| FLOSSMOOR | IL0310870 | 9,371 | Surface water purchased | 1 | No available average above comparison levels |
| FOREST PARK | IL0310900 | 14,340 | Surface water purchased | 1 | No available average above comparison levels |
| FORSYTH, IL | IL1150200 | 3,490 | Ground water | 1 | No available average above comparison levels |
| FORT MASSAC PWD | IL1275050 | 6,290 | Ground water purchased | 1 | No available average above comparison levels |
| FOSTERBURG PWD | IL1195220 | 7,940 | Surface water purchased | 1 | No available average above comparison levels |
| FOUNTAIN WATER DISTRICT | IL1330020 | 3,650 | Ground water | 1 | No available average above comparison levels |
| FOX LAKE | IL0970200 | 11,780 | Ground water | 4 | No available average above comparison levels |
| FOX RIVER GROVE | IL1110200 | 4,702 | Ground water | 2 | No available average above comparison levels |
| FRANKFORT | IL1970400 | 24,000 | Ground water | 6 | No available average above comparison levels |
| FRANKLIN PARK | IL0310960 | 18,467 | Surface water purchased | 1 | No available average above comparison levels |
| FREEBURG | IL1630600 | 4,707 | Surface water purchased | 2 | No available average above comparison levels |
| FREEPORT | IL1770200 | 23,930 | Ground water | 4 | Above an EPA comparison level |
| FULTON | IL1950250 | 3,346 | Ground water | 2 | No available average above comparison levels |
| GALENA | IL0850200 | 3,308 | Ground water | 3 | No available average above comparison levels |
| GALESBURG | IL0950200 | 31,620 | Ground water | 1 | Above an EPA comparison level |
| GENESEO | IL0730500 | 6,539 | Ground water | 1 | No available average above comparison levels |
| GENEVA | IL0890350 | 21,247 | Ground water | 1 | No available average above comparison levels |
| GENOA | IL0370150 | 5,298 | Ground water | 3 | No available average above comparison levels |
| GEORGETOWN | IL1830350 | 4,200 | Ground water | 1 | No available average above comparison levels |
| GIBSON CITY | IL0530100 | 3,500 | Ground water | 1 | No available average above comparison levels |
| GILBERTS | IL0890400 | 8,366 | Ground water | 1 | No available average above comparison levels |
| GILLESPIE | IL1170400 | 3,737 | Surface water | 1 | No available average above comparison levels |
| GLEN CARBON | IL1190300 | 12,618 | Surface water purchased | 1 | No available average above comparison levels |
| GLEN ELLYN | IL0430450 | 28,850 | Surface water purchased | 1 | No available average above comparison levels |
| GLENCOE | IL0310990 | 8,849 | Surface water | 1 | No available average above comparison levels |
| GLENDALE HEIGHTS | IL0430400 | 33,176 | Surface water purchased | 1 | No available average above comparison levels |
| GLENVIEW | IL0311020 | 47,856 | Surface water purchased | 1 | No available average above comparison levels |
| GLENWOOD | IL0311050 | 8,956 | Surface water purchased | 1 | No available average above comparison levels |
| GRANDWOOD PARK SUBDIVISION - LAKE CO PW | IL0975600 | 5,751 | Surface water purchased | 1 | No available average above comparison levels |
| GRAYSLAKE | IL0970250 | 21,248 | Surface water purchased | 1 | No available average above comparison levels |
| GREAT LAKES NAVAL TRAINING STATION | IL0975227 | 23,000 | Surface water | 1 | No available average above comparison levels |
| GREENVILLE | IL0050050 | 8,310 | Surface water | 1 | No available average above comparison levels |
| GURNEE | IL0970350 | 30,193 | Surface water purchased | 1 | No available average above comparison levels |
| HAINESVILLE | IL0970400 | 3,528 | Ground water | 2 | No available average above comparison levels |
| HAMILTON COUNTY WATER DISTRICT | IL0651000 | 3,958 | Surface water purchased | 1 | No available average above comparison levels |
| HAMPSHIRE | IL0890450 | 7,758 | Ground water | 2 | No available average above comparison levels |
| HANOVER | IL0850250 | 863 | Ground water | 2 | No available average above comparison levels |
| HANOVER PARK | IL0314480 | 37,470 | Surface water purchased | 1 | No available average above comparison levels |
| HARRISBURG | IL1650200 | 8,524 | Ground water purchased | 1 | No available average above comparison levels |
| HARVARD | IL1110250 | 9,469 | Ground water | 3 | No available average above comparison levels |
| HARVEY | IL0311110 | 25,000 | Surface water purchased | 1 | No available average above comparison levels |
| HARWOOD HEIGHTS | IL0311140 | 9,065 | Surface water purchased | 1 | No available average above comparison levels |
| HAVANA | IL1250200 | 2,963 | Ground water | 1 | No available average above comparison levels |
| HAZEL CREST | IL0311170 | 13,792 | Surface water purchased | 1 | No available average above comparison levels |
| HERRIN | IL1990400 | 12,747 | Surface water purchased | 1 | No available average above comparison levels |
| HICKORY HILLS | IL0311200 | 14,505 | Surface water purchased | 1 | No available average above comparison levels |
| HIGHLAND | IL1190550 | 10,674 | Surface water | 1 | No available average above comparison levels |
| HIGHLAND PARK, IL | IL0970500 | 30,176 | Surface water | 1 | No available average above comparison levels |
| HIGHWOOD | IL0970550 | 5,335 | Surface water | 1 | No available average above comparison levels |
| HILLSBORO | IL1350300 | 4,402 | Surface water | 1 | No available average above comparison levels |
| HILLSIDE | IL0311230 | 8,200 | Surface water purchased | 1 | No available average above comparison levels |
| HINSDALE | IL0434520 | 17,900 | Surface water purchased | 1 | No available average above comparison levels |
| HOFFMAN ESTATES | IL0311290 | 50,179 | Surface water purchased | 1 | No available average above comparison levels |
| HOLIDAY SHORES SD | IL1195110 | 2,840 | Surface water | 1 | No available average above comparison levels |
| HOMETOWN | IL0311320 | 4,240 | Surface water purchased | 1 | No available average above comparison levels |
| HOMEWOOD | IL0311350 | 19,463 | Surface water purchased | 1 | No available average above comparison levels |
| HOOPESTON | IL1830450 | 5,802 | Ground water | 1 | No available average above comparison levels |
| HUNTLEY | IL1110350 | 28,495 | Ground water | 5 | No available average above comparison levels |
| IL AMERICAN-ALTON | IL1195150 | 46,127 | Surface water | 1 | No available average above comparison levels |
| IL AMERICAN-ANDALUSIA | IL1610050 | 1,184 | Ground water | 1 | No available average above comparison levels |
| IL AMERICAN-CHAMPAIGN | IL0195300 | 150,000 | Ground water | 2 | No available average above comparison levels |
| IL AMERICAN-CHICAGO SUBURBAN | IL0315150 | 11,187 | Surface water purchased | 1 | No available average above comparison levels |
| IL AMERICAN-COUNTRY CLUB | IL0435350 | 1,014 | Surface water purchased | 1 | No available average above comparison levels |
| IL AMERICAN-EAST ST LOUIS | IL1635040 | 131,368 | Surface water | 1 | No available average above comparison levels |
| IL AMERICAN-FERNWAY | IL0315030 | 5,521 | Surface water purchased | 1 | No available average above comparison levels |
| IL AMERICAN-GRANITE CITY | IL1195030 | 33,572 | Surface water | 1 | No available average above comparison levels |
| IL AMERICAN-HOMER TOWNSHIP | IL1970100 | 24,543 | Surface water purchased | 1 | No available average above comparison levels |
| IL AMERICAN-LIBERTY RIDGE WEST | IL0435650 | 3,307 | Surface water purchased | 1 | No available average above comparison levels |
| IL AMERICAN-PEKIN | IL1795040 | 31,731 | Ground water | 7 | No available average above comparison levels |
| IL AMERICAN-PEORIA | IL1435030 | 137,575 | Surface water | 4 | Above an EPA comparison level |
| IL AMERICAN-PONTIAC | IL1055030 | 11,864 | Surface water | 1 | No available average above comparison levels |
| IL AMERICAN-SOUTH BELOIT | IL2010450 | 7,893 | Ground water purchased | 1 | No available average above comparison levels |
| IL AMERICAN-STERLING | IL1955040 | 14,782 | Ground water | 2 | No available average above comparison levels |
| IL AMERICAN-STREATOR | IL0995030 | 19,000 | Surface water | 1 | No available average above comparison levels |
| IL AMERICAN-VALLEY VIEW | IL0437350 | 6,721 | Surface water purchased | 1 | No available average above comparison levels |
| IL AMERICAN-WEST SUBURBAN | IL1974151 | 73,978 | Surface water purchased | 1 | No available average above comparison levels |
| IL American - Lincoln | IL1075030 | 15,200 | Groundwater under influence of surface water | 3 | Above an EPA comparison level |
| ILLINOIS STATE UNIVERSITY-NORMAL | IL1135510 | 6,600 | Ground water purchased | 1 | No available average above comparison levels |
| ISLAND LAKE | IL0974540 | 8,066 | Ground water | 2 | No available average above comparison levels |
| ITASCA | IL0430500 | 9,506 | Surface water purchased | 3 | No available average above comparison levels |
| JACKSONVILLE | IL1370200 | 19,903 | Surface water | 1 | No available average above comparison levels |
| JERSEY RWC | IL0835300 | 12,750 | Surface water purchased | 1 | No available average above comparison levels |
| JERSEYVILLE | IL0830250 | 8,412 | Ground water | 1 | No available average above comparison levels |
| JOHNSTON CITY | IL1990500 | 3,509 | Surface water purchased | 1 | No available average above comparison levels |
| JOLIET | IL1970450 | 160,000 | Ground water | 11 | No available average above comparison levels |
| JUSTICE-WILLOW SPRINGS WATER COMMISSION | IL0315820 | 18,450 | Surface water purchased | 1 | No available average above comparison levels |
| KENILWORTH | IL0311500 | 2,514 | Surface water purchased | 1 | No available average above comparison levels |
| KEWANEE | IL0730650 | 12,509 | Ground water | 2 | No available average above comparison levels |
| KINMUNDY | IL1210300 | 940 | Surface water purchased | 1 | No available average above comparison levels |
| LA GRANGE | IL0311530 | 16,200 | Surface water purchased | 1 | No available average above comparison levels |
| LA GRANGE HIGHLANDS SANITARY DISTRICT | IL0315860 | 6,600 | Surface water purchased | 1 | No available average above comparison levels |
| LA GRANGE PARK | IL0311560 | 13,011 | Surface water purchased | 1 | No available average above comparison levels |
| LA SALLE | IL0990300 | 9,700 | Ground water | 1 | No available average above comparison levels |
| LAKE BLUFF | IL0970750 | 5,600 | Surface water purchased | 1 | No available average above comparison levels |
| LAKE FOREST | IL0970800 | 19,642 | Surface water | 1 | No available average above comparison levels |
| LAKE IN THE HILLS | IL1110400 | 28,661 | Ground water | 8 | No available average above comparison levels |
| LAKE OF EGYPT PWD | IL1995200 | 11,368 | Surface water | 1 | No available average above comparison levels |
| LAKE SARA AREA WATER CO-OP, INC. | IL0495150 | 3,352 | Surface water purchased | 1 | No available average above comparison levels |
| LAKE VILLA | IL0970840 | 8,829 | Surface water purchased | 1 | No available average above comparison levels |
| LAKE WINDERMERE ESTATES SUBDIVISION | IL1795730 | 300 | Ground water | 2 | No available average above comparison levels |
| LAKE ZURICH | IL0970850 | 19,759 | Ground water | 5 | No available average above comparison levels |
| LANSING | IL0311590 | 29,076 | Surface water purchased | 1 | No available average above comparison levels |
| LAWRENCEVILLE | IL1010150 | 4,524 | Ground water | 1 | No available average above comparison levels |
| LCPW - PEKARA SUBDIVISION | IL0975900 | 3,711 | Surface water purchased | 5 | No available average above comparison levels |
| LE ROY | IL1130750 | 3,498 | Ground water | 1 | No available average above comparison levels |
| LEBANON | IL1630650 | 4,714 | Surface water purchased | 1 | No available average above comparison levels |
| LEMONT | IL0311620 | 17,500 | Ground water | 4 | No available average above comparison levels |
| LEYDEN TWSP WATER DISTRICT | IL0315880 | 10,000 | Surface water purchased | 1 | No available average above comparison levels |
| LIBERTYVILLE | IL0970900 | 20,500 | Surface water purchased | 1 | No available average above comparison levels |
| LINCOLNSHIRE | IL0970950 | 7,940 | Surface water purchased | 1 | No available average above comparison levels |
| LINCOLNWOOD | IL0311650 | 13,463 | Surface water purchased | 1 | No available average above comparison levels |
| LINDENHURST | IL0971000 | 14,500 | Surface water purchased | 1 | No available average above comparison levels |
| LISLE | IL0430551 | 24,223 | Surface water purchased | 1 | No available average above comparison levels |
| LITCHFIELD | IL1350400 | 6,648 | Surface water | 1 | No available average above comparison levels |
| LOCKPORT | IL1970500 | 23,100 | Ground water | 7 | No available average above comparison levels |
| LOMBARD | IL0430600 | 44,476 | Surface water purchased | 1 | No available average above comparison levels |
| LONG CREEK TOWNSHIP PWS | IL1155150 | 7,850 | Ground water | 1 | No available average above comparison levels |
| LOVES PARK | IL2010150 | 23,335 | Ground water | 4 | No available average above comparison levels |
| LOW POINT WATER DISTRICT | IL2035100 | 200 | Ground water | 1 | No available average above comparison levels |
| LYNWOOD | IL0311680 | 9,149 | Surface water purchased | 1 | No available average above comparison levels |
| LYONS, IL | IL0311710 | 10,304 | Surface water purchased | 1 | No available average above comparison levels |
| MACKINAW | IL1790350 | 3,399 | Ground water | 1 | No available average above comparison levels |
| MACOMB | IL1090350 | 15,051 | Surface water | 1 | No available average above comparison levels |
| MAHOMET | IL0190450 | 6,580 | Ground water | 1 | No available average above comparison levels |
| MANHATTAN | IL1970550 | 10,340 | Ground water | 2 | No available average above comparison levels |
| MARENGO | IL1110650 | 7,572 | Ground water | 2 | No available average above comparison levels |
| MARION | IL1990550 | 16,855 | Surface water purchased | 1 | No available average above comparison levels |
| MARKHAM | IL0311770 | 12,500 | Surface water purchased | 1 | No available average above comparison levels |
| MARSEILLES | IL0990500 | 5,061 | Ground water | 2 | No available average above comparison levels |
| MARSHALL | IL0230100 | 3,947 | Ground water | 1 | No available average above comparison levels |
| MARYVILLE | IL1190750 | 10,150 | Ground water | 1 | No available average above comparison levels |
| MASCOUTAH | IL1630800 | 8,759 | Surface water purchased | 1 | No available average above comparison levels |
| MATTESON | IL0311800 | 18,293 | Surface water purchased | 1 | No available average above comparison levels |
| MATTOON | IL0290250 | 19,500 | Surface water | 1 | No available average above comparison levels |
| MAYWOOD | IL0311830 | 24,090 | Surface water purchased | 1 | No available average above comparison levels |
| MCHENRY | IL1110600 | 22,335 | Ground water | 4 | No available average above comparison levels |
| MELROSE PARK | IL0311860 | 24,206 | Surface water purchased | 1 | No available average above comparison levels |
| MENDON | IL0010500 | 953 | Ground water purchased | 1 | No available average above comparison levels |
| MENDOTA | IL0990550 | 7,100 | Ground water | 3 | No available average above comparison levels |
| METAMORA | IL2030350 | 3,895 | Ground water | 1 | No available average above comparison levels |
| METROPOLIS | IL1270150 | 6,309 | Ground water | 1 | No available average above comparison levels |
| MIDLOTHIAN | IL0311920 | 14,819 | Surface water purchased | 1 | No available average above comparison levels |
| MILAN | IL1610400 | 4,945 | Ground water | 2 | No available average above comparison levels |
| MILL CREEK PWD | IL0015300 | 5,755 | Ground water | 1 | No available average above comparison levels |
| MILL CREEK WATER RECLAMATION DISTRICT | IL0890120 | 8,000 | Ground water | 1 | No available average above comparison levels |
| MILLSTADT | IL1630850 | 4,071 | Surface water purchased | 1 | No available average above comparison levels |
| MILLSTONE PWD | IL1515050 | 5,565 | Ground water | 1 | No available average above comparison levels |
| MINOOKA | IL0630550 | 12,800 | Ground water | 3 | No available average above comparison levels |
| MITCHELL PWD | IL1195210 | 5,253 | Surface water purchased | 1 | No available average above comparison levels |
| MOKENA | IL1970600 | 19,887 | Surface water purchased | 1 | No available average above comparison levels |
| MOLINE | IL1610450 | 44,500 | Surface water | 1 | No available average above comparison levels |
| MONEE | IL1970650 | 5,148 | Ground water | 3 | No available average above comparison levels |
| MONMOUTH | IL1870150 | 8,902 | Ground water | 2 | No available average above comparison levels |
| MONTGOMERY | IL0894690 | 28,956 | Ground water | 3 | No available average above comparison levels |
| MONTICELLO | IL1470350 | 5,548 | Ground water | 1 | No available average above comparison levels |
| MORO PWD | IL1195250 | 723 | Ground water purchased | 1 | No available average above comparison levels |
| MORRIS, IL | IL0630600 | 14,775 | Ground water | 1 | No available average above comparison levels |
| MORRISON | IL1950350 | 4,188 | Ground water | 2 | No available average above comparison levels |
| MORTON | IL1790500 | 17,111 | Ground water | 3 | No available average above comparison levels |
| MORTON GROVE | IL0311950 | 25,297 | Surface water purchased | 1 | No available average above comparison levels |
| MOUNT CARMEL | IL1850200 | 7,015 | Groundwater under influence of surface water | 1 | No available average above comparison levels |
| MOUNT OLIVE | IL1170700 | 2,193 | Surface water purchased | 1 | No available average above comparison levels |
| MOUNT PROSPECT | IL0311980 | 41,000 | Surface water purchased | 1 | No available average above comparison levels |
| MOUNT VERNON | IL0810300 | 15,793 | Surface water purchased | 1 | No available average above comparison levels |
| MOUNT ZION | IL1150350 | 5,833 | Surface water purchased | 1 | No available average above comparison levels |
| MUNDELEIN | IL0971150 | 31,500 | Surface water purchased | 1 | No available average above comparison levels |
| MURDALE PWD | IL0775200 | 4,963 | Surface water purchased | 1 | No available average above comparison levels |
| NAPERVILLE | IL0434670 | 156,406 | Surface water purchased | 1 | No available average above comparison levels |
| NASHVILLE | IL1890300 | 3,230 | Surface water | 1 | No available average above comparison levels |
| NEW BADEN | IL0274700 | 4,178 | Surface water purchased | 1 | No available average above comparison levels |
| NEW LENOX | IL1970700 | 27,690 | Surface water purchased | 1 | No available average above comparison levels |
| NILES, IL | IL0312010 | 29,350 | Surface water purchased | 1 | No available average above comparison levels |
| NORMAL | IL1130900 | 52,736 | Ground water | 1 | No available average above comparison levels |
| NORRIDGE | IL0312040 | 15,251 | Surface water purchased | 1 | No available average above comparison levels |
| NORTH AURORA | IL0890600 | 18,261 | Ground water | 2 | No available average above comparison levels |
| NORTH CHICAGO | IL0971250 | 16,813 | Surface water | 1 | No available average above comparison levels |
| NORTH EAST CENTRAL PWD | IL1195280 | 3,975 | Ground water purchased | 1 | No available average above comparison levels |
| NORTH EAST MARION COUNTY WATER CMPNY | IL1210030 | 3,220 | Surface water purchased | 1 | No available average above comparison levels |
| NORTH PARK PWD | IL2015500 | 35,580 | Ground water | 3 | Above an EPA comparison level |
| NORTH RIVERSIDE | IL0312160 | 7,071 | Surface water purchased | 1 | No available average above comparison levels |
| NORTH TAZEWELL PWD | IL1795780 | 7,625 | Ground water | 1 | No available average above comparison levels |
| NORTHBROOK | IL0312070 | 34,407 | Surface water | 1 | No available average above comparison levels |
| NORTHEAST MOUNT VERNON WATER COMPANY | IL0810010 | 5,483 | Surface water purchased | 1 | No available average above comparison levels |
| NORTHERN ILLINOIS UNIVERSITY-DEKALB | IL0375500 | 6,500 | Ground water purchased | 3 | No available average above comparison levels |
| NORTHFIELD, IL | IL0312100 | 5,470 | Surface water purchased | 1 | No available average above comparison levels |
| NORTHLAKE | IL0314710 | 12,840 | Surface water purchased | 1 | No available average above comparison levels |
| O FALLON | IL1631100 | 46,603 | Surface water purchased | 1 | No available average above comparison levels |
| OAK BROOK | IL0430700 | 9,400 | Surface water purchased | 1 | No available average above comparison levels |
| OAK FOREST | IL0312190 | 27,478 | Surface water purchased | 1 | No available average above comparison levels |
| OAK LAWN | IL0312220 | 58,362 | Surface water purchased | 1 | No available average above comparison levels |
| OAK PARK, IL | IL0312250 | 54,583 | Surface water purchased | 1 | No available average above comparison levels |
| OGLESBY | IL0990700 | 4,500 | Ground water | 1 | No available average above comparison levels |
| OLNEY | IL1590200 | 8,877 | Surface water | 1 | No available average above comparison levels |
| OLYMPIA FIELDS | IL0312280 | 4,922 | Surface water purchased | 1 | No available average above comparison levels |
| OREGON | IL1410400 | 3,449 | Ground water | 4 | No available average above comparison levels |
| ORLAND PARK | IL0312310 | 58,020 | Surface water purchased | 1 | No available average above comparison levels |
| OSWEGO | IL0930150 | 38,169 | Ground water | 8 | No available average above comparison levels |
| OTTAWA | IL0990800 | 18,097 | Ground water | 2 | No available average above comparison levels |
| PALATINE | IL0312340 | 70,875 | Surface water purchased | 1 | No available average above comparison levels |
| PALOS HEIGHTS | IL0312370 | 15,500 | Surface water purchased | 1 | No available average above comparison levels |
| PALOS HILLS | IL0312400 | 18,530 | Surface water purchased | 1 | No available average above comparison levels |
| PALOS PARK | IL0311000 | 4,873 | Surface water purchased | 1 | No available average above comparison levels |
| PANA | IL0210500 | 5,800 | Surface water | 1 | No available average above comparison levels |
| PARIS | IL0450300 | 9,100 | Ground water | 1 | No available average above comparison levels |
| PARK CITY | IL0971400 | 5,425 | Surface water purchased | 1 | No available average above comparison levels |
| PARK FOREST | IL0314740 | 21,687 | Ground water | 1 | No available average above comparison levels |
| PARK RIDGE | IL0312460 | 39,800 | Surface water purchased | 1 | No available average above comparison levels |
| PAXTON | IL0530250 | 4,200 | Ground water | 1 | No available average above comparison levels |
| PEORIA HEIGHTS | IL1434750 | 5,908 | Ground water | 1 | No available average above comparison levels |
| PERU | IL0990850 | 10,300 | Ground water | 1 | No available average above comparison levels |
| PETERSBURG | IL1290200 | 4,725 | Ground water | 1 | No available average above comparison levels |
| PIKE COUNTY PWD 1 | IL1495000 | 5,375 | Ground water | 2 | No available average above comparison levels |
| PINCKNEYVILLE | IL1450150 | 5,804 | Surface water | 1 | No available average above comparison levels |
| PINGREE GROVE | IL0890160 | 10,365 | Ground water | 1 | No available average above comparison levels |
| PITTSFIELD | IL1490750 | 4,697 | Ground water | 1 | No available average above comparison levels |
| PLAINFIELD | IL1970800 | 50,000 | Surface water purchased | 1 | No available average above comparison levels |
| PLANO | IL0930200 | 12,600 | Ground water | 3 | No available average above comparison levels |
| PLEASANT VALLEY PWD | IL1435470 | 3,783 | Ground water | 3 | No available average above comparison levels |
| PONTOON BEACH PWD | IL1195300 | 3,325 | Surface water purchased | 1 | No available average above comparison levels |
| POPLAR GROVE WEST-COUNTRYSIDE | IL0070350 | 790 | Ground water | 1 | No available average above comparison levels |
| POSEN | IL0312520 | 5,331 | Surface water purchased | 1 | No available average above comparison levels |
| PRINCETON | IL0110850 | 7,832 | Ground water | 1 | No available average above comparison levels |
| Prairie Path Water Co. - Clarendon | IL0435300 | 625 | Ground water | 1 | No available average above comparison levels |
| Prairie Path Water Co. - Lake Holiday | IL0995200 | 4,750 | Ground water | 1 | No available average above comparison levels |
| Prairie Path Water Co. - Whispering Hills | IL1115700 | 8,300 | Ground water | 5 | Above an EPA comparison level |
| QUINCY | IL0010650 | 42,000 | Surface water | 1 | No available average above comparison levels |
| RACCOON WATER COMPANY | IL1215100 | 7,080 | Surface water purchased | 3 | No available average above comparison levels |
| RANTOUL | IL0190650 | 13,000 | Ground water | 1 | No available average above comparison levels |
| RED BUD | IL1570450 | 3,804 | Ground water | 1 | No available average above comparison levels |
| RICHTON PARK | IL0312550 | 12,504 | Ground water | 3 | No available average above comparison levels |
| RIVER FOREST | IL0312610 | 11,717 | Surface water purchased | 1 | No available average above comparison levels |
| RIVER GROVE | IL0312640 | 10,282 | Surface water purchased | 1 | No available average above comparison levels |
| RIVERDALE | IL0312580 | 10,266 | Surface water purchased | 1 | No available average above comparison levels |
| RIVERSIDE | IL0312670 | 9,298 | Surface water purchased | 1 | No available average above comparison levels |
| RIVERTON | IL1670950 | 4,279 | Ground water | 1 | No available average above comparison levels |
| RIVERWOODS | IL0971450 | 3,618 | Surface water purchased | 1 | No available average above comparison levels |
| ROBBINS | IL0312700 | 5,415 | Surface water purchased | 1 | No available average above comparison levels |
| ROBINSON-PALESTINE WATER COMMISSION | IL0335030 | 11,331 | Ground water | 1 | No available average above comparison levels |
| ROCHELLE | IL1410500 | 9,446 | Ground water | 5 | No available average above comparison levels |
| ROCHESTER | IL1671000 | 3,856 | Surface water purchased | 1 | No available average above comparison levels |
| ROCK FALLS | IL1950450 | 8,620 | Ground water | 1 | No available average above comparison levels |
| ROCK ISLAND | IL1610650 | 39,018 | Surface water | 1 | No available average above comparison levels |
| ROCK ISLAND ARSENAL, US ARMY | IL1615387 | 7,800 | Surface water | 1 | No available average above comparison levels |
| ROCKFORD, IL | IL2010300 | 147,051 | Ground water | 23 | No available average above comparison levels |
| ROCKTON | IL2010350 | 7,685 | Ground water | 4 | No available average above comparison levels |
| ROLLING MEADOWS | IL0312730 | 23,329 | Surface water purchased | 1 | No available average above comparison levels |
| ROMEOVILLE | IL1970900 | 50,458 | Ground water | 8 | No available average above comparison levels |
| ROSELLE | IL0434820 | 22,897 | Surface water purchased | 1 | No available average above comparison levels |
| ROSEMONT | IL0312760 | 3,952 | Surface water purchased | 1 | No available average above comparison levels |
| ROUND LAKE | IL0971500 | 18,430 | Surface water purchased | 1 | No available average above comparison levels |
| ROUND LAKE BEACH | IL0971550 | 27,200 | Surface water purchased | 1 | No available average above comparison levels |
| ROUND LAKE PARK | IL0971600 | 4,900 | Surface water purchased | 2 | No available average above comparison levels |
| SALEM | IL1210450 | 7,905 | Surface water | 1 | No available average above comparison levels |
| SALINE VALLEY CONSERVANCY DISTRICT | IL1655300 | 3,921 | Ground water | 2 | No available average above comparison levels |
| SANDWICH | IL0374850 | 7,156 | Ground water | 2 | No available average above comparison levels |
| SANGAMON VALLEY PWD | IL0195150 | 5,300 | Ground water | 1 | No available average above comparison levels |
| SAUK | IL0312790 | 9,921 | Ground water | 2 | No available average above comparison levels |
| SCHAUMBURG | IL0314890 | 75,750 | Surface water purchased | 1 | No available average above comparison levels |
| SCHILLER PARK | IL0312850 | 11,709 | Surface water purchased | 1 | No available average above comparison levels |
| SHADY OAKS MHP | IL0635225 | 912 | Ground water | 1 | No available average above comparison levels |
| SHELBYVILLE | IL1730300 | 5,600 | Ground water | 1 | No available average above comparison levels |
| SHOREWOOD, IL | IL1975080 | 18,645 | Ground water | 5 | No available average above comparison levels |
| SILVIS | IL1610700 | 7,473 | Surface water purchased | 1 | No available average above comparison levels |
| SKOKIE | IL0312880 | 66,422 | Surface water purchased | 1 | No available average above comparison levels |
| SOUTH CHICAGO HEIGHTS | IL0312940 | 3,924 | Surface water purchased | 1 | No available average above comparison levels |
| SOUTH ELGIN | IL0890800 | 23,648 | Ground water | 8 | Above an EPA comparison level |
| SOUTH HIGHWAY PWD | IL0775400 | 4,972 | Surface water purchased | 1 | No available average above comparison levels |
| SOUTH HOLLAND | IL0312970 | 22,000 | Surface water purchased | 2 | No available average above comparison levels |
| SOUTH JACKSONVILLE | IL1370400 | 3,501 | Ground water | 2 | No available average above comparison levels |
| SOUTH STICKNY SD | IL0317370 | 30,000 | Surface water purchased | 1 | No available average above comparison levels |
| SOUTHEAST REGIONAL WATER FACILITY | IL0430060 | 6,940 | Surface water purchased | 1 | No available average above comparison levels |
| SOUTHERN IL UNIVERSITY-EDWARDSVILLE | IL1195550 | 2,817 | Ground water purchased | 1 | No available average above comparison levels |
| SPARTA | IL1570600 | 4,395 | Surface water | 1 | No available average above comparison levels |
| SPRING VALLEY | IL0111000 | 5,582 | Ground water | 1 | No available average above comparison levels |
| SPRINGFIELD, IL | IL1671200 | 117,444 | Surface water | 1 | No available average above comparison levels |
| ST CHARLES | IL0894830 | 33,103 | Ground water | 5 | No available average above comparison levels |
| STAUNTON | IL1171050 | 5,756 | Surface water | 1 | No available average above comparison levels |
| STEGER | IL0314860 | 9,700 | Ground water | 2 | No available average above comparison levels |
| STICKNEY | IL0313000 | 6,902 | Surface water purchased | 1 | No available average above comparison levels |
| STONE PARK | IL0313030 | 4,576 | Surface water purchased | 1 | No available average above comparison levels |
| STREAMWOOD | IL0313060 | 39,577 | Surface water purchased | 1 | No available average above comparison levels |
| SUGAR GROVE | IL0890850 | 11,243 | Ground water | 5 | No available average above comparison levels |
| SULLIVAN | IL1390300 | 4,729 | Ground water | 1 | No available average above comparison levels |
| SUMMIT | IL0310060 | 11,161 | Surface water purchased | 1 | No available average above comparison levels |
| SYCAMORE | IL0370550 | 18,500 | Ground water | 5 | No available average above comparison levels |
| TAYLORVILLE | IL0210600 | 12,806 | Surface water | 1 | No available average above comparison levels |
| TINLEY PARK | IL0314910 | 56,703 | Surface water purchased | 1 | No available average above comparison levels |
| TRITOWNSHIP WATER DISTRICT | IL1190080 | 3,470 | Surface water purchased | 1 | No available average above comparison levels |
| TROY, IL | IL1191000 | 16,962 | Ground water | 1 | No available average above comparison levels |
| TUSCOLA | IL0415030 | 4,875 | Ground water purchased | 1 | No available average above comparison levels |
| U OF I-CHAMPAIGN | IL0195500 | 13,000 | Ground water purchased | 1 | No available average above comparison levels |
| UTL INC-GALENA TERRITORY | IL0855050 | 2,294 | Ground water | 6 | No available average above comparison levels |
| VALMEYER | IL1330250 | 1,263 | Ground water purchased | 1 | No available average above comparison levels |
| VANDALIA | IL0510350 | 7,616 | Surface water | 1 | No available average above comparison levels |
| VANDALIA CORRECTIONAL CENTER | IL0515500 | 700 | Surface water purchased | 1 | No available average above comparison levels |
| VERNON HILLS - LAKE CO PW | IL0971750 | 33,207 | Surface water purchased | 1 | No available average above comparison levels |
| VILLA PARK | IL0430800 | 22,263 | Surface water purchased | 1 | No available average above comparison levels |
| VIRDEN | IL1171100 | 3,274 | Surface water purchased | 1 | No available average above comparison levels |
| VOLO | IL0971770 | 6,629 | Surface water purchased | 1 | No available average above comparison levels |
| WARRENVILLE | IL0430833 | 12,350 | Ground water | 4 | No available average above comparison levels |
| WASCO SD | IL0890110 | 4,000 | Ground water | 1 | No available average above comparison levels |
| WASHINGTON COUNTY WATER COMPANY | IL1895600 | 11,374 | Surface water purchased | 4 | No available average above comparison levels |
| WASHINGTON, IL | IL1790750 | 14,793 | Ground water | 2 | No available average above comparison levels |
| WATERLOO | IL1330300 | 10,190 | Ground water | 1 | No available average above comparison levels |
| WATSEKA | IL0750900 | 5,500 | Ground water | 2 | No available average above comparison levels |
| WAUCONDA | IL0971850 | 15,349 | Surface water purchased | 1 | No available average above comparison levels |
| WAUKEGAN | IL0971900 | 87,149 | Surface water | 1 | No available average above comparison levels |
| WEE-MA-TUK WATER DISTRICT | IL0570040 | 863 | Purchased ground water under influence of surface water source | 1 | No available average above comparison levels |
| WEST CHICAGO | IL0430900 | 25,166 | Ground water | 1 | No available average above comparison levels |
| WEST DUNDEE | IL0890950 | 7,845 | Ground water | 2 | No available average above comparison levels |
| WEST FRANKFORT | IL0550700 | 8,650 | Surface water purchased | 1 | No available average above comparison levels |
| WEST LIBERTY-DUNDAS WATER DISTRICT | IL1595050 | 563 | Surface water purchased | 1 | No available average above comparison levels |
| WESTCHESTER | IL0313150 | 16,241 | Surface water purchased | 1 | No available average above comparison levels |
| WESTERN ILLINOIS UNIVERSITY | IL1095510 | 8,000 | Surface water purchased | 1 | No available average above comparison levels |
| WESTERN SPRINGS | IL0313180 | 13,274 | Ground water | 1 | No available average above comparison levels |
| WESTMONT | IL0430950 | 24,161 | Surface water purchased | 1 | No available average above comparison levels |
| WESTVILLE | IL1830950 | 3,917 | Surface water purchased | 1 | No available average above comparison levels |
| WHEATON | IL0431050 | 53,970 | Surface water purchased | 1 | No available average above comparison levels |
| WHEELING | IL0314970 | 39,725 | Surface water purchased | 1 | No available average above comparison levels |
| WILDWOOD SUBDIVISION - LAKE CO PW | IL0977350 | 14,832 | Surface water purchased | 1 | No available average above comparison levels |
| WILLIAMSVILLE | IL1671300 | 6,198 | Surface water purchased | 1 | No available average above comparison levels |
| WILLOW LAKE ESTATES MHP | IL0894400 | 920 | Surface water purchased | 1 | No available average above comparison levels |
| WILLOWBROOK | IL0431100 | 9,000 | Surface water purchased | 1 | No available average above comparison levels |
| WILMETTE | IL0313300 | 27,087 | Surface water | 1 | No available average above comparison levels |
| WILMINGTON | IL1971100 | 5,700 | Surface water | 1 | No available average above comparison levels |
| WINFIELD | IL0431150 | 9,835 | Surface water purchased | 1 | No available average above comparison levels |
| WINNETKA | IL0313330 | 12,475 | Surface water | 1 | No available average above comparison levels |
| WINTHROP HARBOR | IL0971950 | 6,565 | Surface water purchased | 1 | No available average above comparison levels |
| WONDER LAKE | IL1115750 | 3,870 | Ground water | 3 | No available average above comparison levels |
| WOOD DALE | IL0431200 | 14,012 | Surface water purchased | 1 | No available average above comparison levels |
| WOOD RIVER | IL1191150 | 10,464 | Ground water | 1 | No available average above comparison levels |
| WOODHAVEN, IL | IL1035100 | 4,100 | Ground water | 1 | No available average above comparison levels |
| WOODLAWN | IL0810450 | 3,587 | Surface water purchased | 1 | No available average above comparison levels |
| WOODRIDGE | IL0431250 | 33,566 | Surface water purchased | 1 | No available average above comparison levels |
| WOODSTOCK, IL | IL1110950 | 25,630 | Ground water | 2 | No available average above comparison levels |
| WORTH | IL0313360 | 10,970 | Surface water purchased | 1 | No available average above comparison levels |
| XENIA | IL0250300 | 542 | Surface water purchased | 1 | No available average above comparison levels |
| YORKVILLE | IL0930250 | 23,000 | Ground water | 3 | No available average above comparison levels |
| ZION | IL0972000 | 24,442 | Surface water purchased | 1 | No available average above comparison levels |
How the count works
What is included
Each active community water system with enough required samples for a yearly average is counted once, even if it is linked with several ZIP codes. Private wells are excluded, and UCMR 5 did not comprehensively monitor every small system.