EPA UCMR 5 results for 487 public water systems. 128 had at least one PFAS detected; 27 had a highest single PFOA or PFOS result above 4.0 ppt.
UCMR 5 is a one-time EPA monitoring program, not a compliance determination. The values shown are the highest single sample result at any of the system's sampling points; one result above 4.0 ppt does not mean the system violates the PFAS rule, which is judged on running annual averages under separate compliance monitoring. Results describe the public water system, not an individual home.
| Water system | Serves | PFOA max (ppt) | PFOS max (ppt) | PFAS detected |
|---|---|---|---|---|
| Abingdon IL0950050 | Abingdon | 9.4 | 4.8 | 5 |
| Abs Water Coop IL0015350 | Adams County | ND | ND | 0 |
| Addison IL0430050 | Addison | ND | ND | 0 |
| Advocate Christ Medical Center IL3162461 | Cook County | ND | ND | 0 |
| Aledo IL1310050 | Aledo | ND | ND | 0 |
| Alexander Water District IL1370020 | Morgan County | ND | ND | 1 |
| Algonquin IL1110050 | Algonquin | ND | ND | 0 |
| Alsip IL0310030 | Alsip | ND | ND | 0 |
| Altona IL0950100 | Altona | ND | ND | 0 |
| American Water Oper and Maintenance, LLC IL1635237 | St. Clair County | ND | ND | 2 |
| Anna IL1810050 | Anna | ND | ND | 0 |
| Antioch IL0970050 | Antioch | ND | ND | 0 |
| Aqua Illinois-Candlewick DVN IL0075050 | Boone County | ND | ND | 0 |
| Aqua Illinois-Kankakee IL0915030 | Kankakee | ND | ND | 0 |
| Aqua Illinois-North Maine Utilities IL0315350 | Cook County | ND | ND | 0 |
| Aqua Illinois-Peotone IL1970750 | Peotone | ND | ND | 0 |
| Aqua Illinois-University Park IL1975030 | Pk Forest South | ND | ND | 2 |
| Aqua Illinois-Vermilion County IL1835120 | Danville | ND | ND | 1 |
| Aqua Illinois-Willowbrook IL1977870 | Manhattan | ND | ND | 0 |
| Arlington Heights IL0314030 | Arlington Heights | ND | ND | 0 |
| Ashkum IL0750050 | Ashkum | ND | ND | 0 |
| Athens IL1290050 | Athens | ND | ND | 0 |
| Auburn, Il IL1670050 | Auburn | ND | ND | 0 |
| Aurora IL0894070 | Aurora | ND | ND | 4 |
| Barrington IL0974080 | Barrington | ND | ND | 0 |
| Bartlett IL0314120 | Bartlett | ND | ND | 0 |
| Batavia IL0894130 | Batavia | ND | ND | 0 |
| Beach Park IL0970190 | Beach Park | ND | ND | 0 |
| Beardstown IL0170150 | Beardstown | ND | ND | 0 |
| Beecher IL1970050 | Beecher | ND | ND | 0 |
| Bellwood IL0310150 | Bellwood | ND | ND | 0 |
| Belvidere IL0070050 | Belvidere | ND | ND | 1 |
| Bensenville IL0434140 | Bensenville | ND | ND | 0 |
| Benton IL0550050 | Benton | ND | ND | 1 |
| Berkeley IL0310180 | Berkeley | ND | ND | 0 |
| Berwyn IL0310210 | Berwyn | ND | ND | 0 |
| Bethalto IL1190150 | Bethalto | ND | ND | 2 |
| Blandinsville IL1090100 | Blandinsville | ND | ND | 0 |
| Bloomingdale IL0430100 | Weston | ND | ND | 0 |
| Bloomington, Il IL1130200 | Bloomington | ND | ND | 1 |
| Blue Island IL0310240 | Blue Island | ND | ND | 0 |
| Bluffs IL1710100 | Bluffs | ND | ND | 0 |
| Bond/Madison Water Company IL0050020 | Bond County | ND | ND | 3 |
| Bookwalter Woods MHP IL0635125 | Grundy County | ND | ND | 0 |
| Braidwood IL1970150 | Braidwood | ND | ND | 0 |
| Breese IL0270250 | Breese | ND | ND | 0 |
| Bridgeview IL0310270 | Bridgeview | ND | ND | 0 |
| Brighton IL1174160 | Brighton | ND | ND | 3 |
| Broadview IL0310300 | Broadview | ND | ND | 0 |
| Brookfield IL0310330 | Brookfield | ND | ND | 0 |
| Buckley IL0750150 | Buckley | ND | ND | 0 |
| Buda IL0110100 | Buda | ND | ND | 0 |
| Buffalo Grove IL0314180 | Buffalo Grove | ND | ND | 0 |
| Burnham IL0310360 | Burnham | ND | ND | 0 |
| Burr Ridge IL0434190 | Burr Ridge | ND | ND | 0 |
| Bushnell IL1090150 | Bushnell | ND | ND | 0 |
| Byron, Il IL1410100 | Byron | ND | ND | 0 |
| Cahokia Heights IL1635000 | Cahokia | ND | ND | 3 |
| Calhoun County RWD IL0130010 | Calhoun County | ND | ND | 0 |
| Calumet City IL0310390 | Calumet City | ND | ND | 2 |
| Calumet Park IL0310420 | Calumet Park | ND | ND | 0 |
| Canton, Il IL0570250 | Canton | ND | ND | 3 |
| Captain James A Lovell FHCC IL3161232 | Lake County | ND | ND | 0 |
| Carbondale IL0770150 | Carbondale | ND | ND | 0 |
| Carlinville IL1170150 | Carlinville | ND | ND | 0 |
| Carlyle IL0270300 | Carlyle | ND | ND | 0 |
| Carmi IL1930100 | Carmi | ND | ND | 0 |
| Carol Stream IL0430200 | Carol Stream | ND | ND | 1 |
| Carpentersville IL0890200 | Carpentersville | ND | ND | 0 |
| Carrollton, Il IL0610050 | Carrollton | ND | ND | 0 |
| Carterville IL1990150 | Carterville | ND | ND | 1 |
| Cary IL1110100 | Cary | ND | ND | 5 |
| Casey IL0230050 | Casey | ND | ND | 0 |
| Caseyville IL1630250 | Caseyville | ND | ND | 1 |
| Caterpillar Trail PWD IL2035030 | Eureka | ND | ND | 0 |
| Centralia IL1214220 | Centralia | ND | ND | 0 |
| Channahon IL1970200 | Channahon | 4.6 | 5.9 | 6 |
| Charleston IL0290100 | Charleston | ND | ND | 1 |
| Chatham IL1670300 | Chatham | ND | ND | 0 |
| Cherry Valley IL2010050 | Cherry Valley | ND | ND | 0 |
| Chester IL1570100 | Chester | ND | ND | 3 |
| Chicago IL0316000 | Cook County | ND | ND | 0 |
| Chicago Heights IL0310450 | Chicago Heights | ND | ND | 0 |
| Chicago Ridge IL0310480 | Chicago Ridge | ND | ND | 0 |
| Chillicothe IL1430200 | Chillicothe | ND | ND | 3 |
| Cicero IL0310510 | Cicero | ND | ND | 0 |
| Clarendon Hills IL0430250 | Clarendon Hills | ND | ND | 0 |
| Clark-Edgar RWD IL0230010 | Clark County | ND | ND | 0 |
| Clear Water Service Corp IL0295100 | Coles County | ND | ND | 0 |
| Clinton IL0390050 | Clinton | ND | ND | 0 |
| Coal City IL0630200 | Coal City | ND | ND | 0 |
| Coal Valley IL1614260 | Coal Valley | ND | ND | 0 |
| Coal Valley PWD IL1995250 | Williamson County | ND | ND | 0 |
| Collinsville, Il IL1194280 | Collinsville | 18 | 8.9 | 8 |
| Columbia IL1330050 | Columbia | ND | ND | 2 |
| Corinth PWD IL1995120 | Williamson County | ND | ND | 1 |
| Cortland IL0370051 | Cortland | ND | ND | 0 |
| Country Club Hills IL0310540 | Country Club Hills | ND | ND | 0 |
| Countryside IL0310570 | Countryside | ND | ND | 0 |
| Crest Hill IL1970250 | Crest Hill | 13.7 | ND | 7 |
| Crestwood IL0310600 | Crestwood | ND | ND | 0 |
| Crete IL1970300 | Crete | ND | ND | 0 |
| Creve Coeur IL1790100 | Tazewell County | ND | ND | 0 |
| Crystal Lake IL1110150 | Crystal Lake | ND | ND | 2 |
| Crystal Lawns Addition Improvement Assoc IL1975480 | Joliet | ND | ND | 2 |
| Curran-Gardner Township PWD IL1675350 | Springfield | ND | ND | 0 |
| Dallas Rural Water District IL0710010 | Dallas City | ND | ND | 0 |
| Darien IL0430270 | Darien | ND | ND | 0 |
| De Kalb IL0370100 | De Kalb | ND | ND | 0 |
| Decatur IL1150150 | Decatur | ND | ND | 0 |
| Deerfield IL0974340 | Deerfield | ND | ND | 0 |
| Des Plaines IL0310630 | Des Plaines | ND | ND | 0 |
| Dixmoor IL0310660 | Dixmoor | 4.8 | 5.5 | 2 |
| Dixon IL1030200 | Dixon | ND | ND | 0 |
| Dolton IL0310690 | Dolton | ND | ND | 0 |
| Dover IL0110350 | Dover | ND | ND | 0 |
| Downers Grove IL0430300 | Downers Grove | ND | ND | 0 |
| Dupo IL1630350 | Dupo | ND | 5.6 | 3 |
| Duquoin IL1450100 | Du Quoin | ND | ND | 1 |
| Dwight IL1050250 | Dwight | ND | ND | 0 |
| E J Water Coop IL0790010 | Jasper County | ND | ND | 1 |
| East Alton IL1190200 | East Alton | 16 | 17 | 8 |
| East Moline IL1610250 | East Moline | ND | ND | 2 |
| East Peoria IL1790200 | East Peoria | ND | 4.2 | 4 |
| Eastern Illinois University IL0295500 | Charleston | ND | ND | 0 |
| Edwardsville IL1190250 | Edwardsville | ND | ND | 1 |
| Effingham IL0490250 | Effingham | ND | ND | 0 |
| Eisenhower Academy IL3004572 | Will County | ND | ND | 1 |
| Elburn IL0890300 | Elburn | 7.5 | ND | 1 |
| Eldorado IL1655030 | Eldorado | ND | ND | 0 |
| Elgin, Il IL0894380 | Elgin | ND | ND | 3 |
| Elk Grove Village IL0314400 | Elk Grove | ND | ND | 0 |
| Elmhurst IL0430350 | Elmhurst | ND | ND | 1 |
| Elmwood Park IL0310780 | Elmwood Park | ND | ND | 0 |
| Embarras Area Water District IL0290020 | Coles County | ND | ND | 0 |
| Eureka IL2030200 | Eureka | ND | ND | 0 |
| Evanston IL0310810 | Evanston | ND | ND | 0 |
| Evergreen Park IL0310840 | Evergreen Park | ND | ND | 0 |
| Fairbury IL1050350 | Fairbury | ND | ND | 0 |
| Fairfield IL1910100 | Fairfield | ND | ND | 0 |
| Fayette Water Company IL0510010 | Fayette County | ND | ND | 0 |
| Flora IL0250100 | Flora | ND | ND | 0 |
| Flossmoor IL0310870 | Flossmoor | ND | ND | 0 |
| Forest Park IL0310900 | Forest Park | ND | ND | 0 |
| Forsyth, Il IL1150200 | Forsyth | ND | ND | 0 |
| Fort Massac PWD IL1275050 | Joppa | ND | ND | 0 |
| Fosterburg PWD IL1195220 | Madison County | ND | ND | 3 |
| Fountain Water District IL1330020 | Valmeyer | ND | ND | 0 |
| Fox Lake IL0970200 | Fox Lake | ND | 5 | 2 |
| Fox River Grove IL1110200 | Fox River Grove | ND | ND | 4 |
| Frankfort IL1970400 | Frankfort | ND | ND | 0 |
| Franklin Park IL0310960 | Franklin Park | ND | ND | 0 |
| Freeburg IL1630600 | Freeburg | ND | 7 | 1 |
| Freeport IL1770200 | Freeport | ND | 14 | 1 |
| Fulton IL1950250 | Fulton | ND | ND | 1 |
| Galena IL0850200 | Galena | ND | ND | 0 |
| Galesburg IL0950200 | Galesburg | 14 | 4.2 | 5 |
| Geneseo IL0730500 | Geneseo | ND | ND | 1 |
| Geneva IL0890350 | Geneva | ND | ND | 0 |
| Genoa IL0370150 | Genoa | ND | ND | 2 |
| Georgetown IL1830350 | Georgetown | ND | ND | 0 |
| Gibson City IL0530100 | Gibson City | ND | ND | 0 |
| Gilberts IL0890400 | Gilberts | ND | ND | 0 |
| Gillespie IL1170400 | Macoupin County | ND | ND | 0 |
| Glen Carbon IL1190300 | Glen Carbon | ND | ND | 3 |
| Glen Ellyn IL0430450 | Glen Ellyn | ND | ND | 0 |
| Glencoe IL0310990 | Forest Park | ND | ND | 0 |
| Glendale Heights IL0430400 | Glendale Heights | ND | ND | 0 |
| Glenview IL0311020 | Glenview | ND | ND | 0 |
| Glenwood IL0311050 | Glenwood | ND | ND | 0 |
| Grandwood Park Subdivision - Lake Co PW IL0975600 | Lake County | ND | ND | 0 |
| Grayslake IL0970250 | Grays Lake | ND | ND | 0 |
| Great Lakes Naval Training Station IL0975227 | North Chicago | ND | ND | 0 |
| Greenville IL0050050 | Greenville | ND | ND | 0 |
| Gurnee IL0970350 | Gurnee | ND | ND | 0 |
| Hainesville IL0970400 | Hainesville | ND | ND | 0 |
| Hamilton County Water District IL0651000 | Hamilton County | ND | ND | 1 |
| Hampshire IL0890450 | Hampshire | ND | ND | 0 |
| Hanover IL0850250 | Hanover | ND | ND | 0 |
| Hanover Park IL0314480 | Hanover Park | ND | ND | 0 |
| Harrisburg IL1650200 | Harrisburg | ND | ND | 0 |
| Harvard IL1110250 | Harvard | ND | ND | 0 |
| Harvey IL0311110 | Harvey | ND | ND | 0 |
| Harwood Heights IL0311140 | Harwood Heights | ND | ND | 0 |
| Havana IL1250200 | Havana | ND | ND | 0 |
| Hazel Crest IL0311170 | Hazel Crest | ND | ND | 0 |
| Herrin IL1990400 | Herrin | ND | ND | 1 |
| Hickory Hills IL0311200 | Hickory Hills | ND | ND | 0 |
| Highland IL1190550 | Highland | ND | ND | 1 |
| Highland Park, Il IL0970500 | Highland Park | ND | ND | 0 |
| Highwood IL0970550 | Highwood | ND | ND | 0 |
| Hillsboro IL1350300 | Hillsboro | ND | ND | 0 |
| Hillside IL0311230 | Hillside | ND | ND | 0 |
| Hinsdale IL0434520 | Hinsdale | ND | ND | 0 |
| Hoffman Estates IL0311290 | Hoffman Estates | ND | ND | 0 |
| Holiday Shores SD IL1195110 | Madison County | 4 | ND | 2 |
| Hometown IL0311320 | Hometown | ND | ND | 0 |
| Homewood IL0311350 | Homewood | 4.3 | ND | 1 |
| Hoopeston IL1830450 | Hoopeston | ND | ND | 0 |
| Huntley IL1110350 | Huntley | ND | ND | 0 |
| Il American - Lincoln IL1075030 | Lincoln | 5.7 | ND | 5 |
| Il American-Alton IL1195150 | Alton | ND | ND | 3 |
| Il American-Andalusia IL1610050 | Andalusia | ND | ND | 0 |
| Il American-Champaign IL0195300 | Champaign | ND | ND | 0 |
| Il American-Chicago Suburban IL0315150 | Cook County | ND | ND | 0 |
| Il American-Country Club IL0435350 | DuPage County | ND | ND | 0 |
| Il American-East St Louis IL1635040 | East St Louis | ND | ND | 3 |
| Il American-Fernway IL0315030 | Westhaven | ND | ND | 0 |
| Il American-Granite City IL1195030 | Granite City | ND | ND | 3 |
| Il American-Homer Township IL1970100 | Will County | ND | ND | 0 |
| Il American-Liberty Ridge West IL0435650 | DuPage County | ND | ND | 0 |
| Il American-Pekin IL1795040 | Pekin | ND | 4.4 | 7 |
| Il American-Peoria IL1435030 | Peoria | ND | 6.5 | 5 |
| Il American-Pontiac IL1055030 | Pontiac | ND | ND | 1 |
| Il American-South Beloit IL2010450 | South Beloit | ND | ND | 1 |
| Il American-Sterling IL1955040 | Coleta | ND | ND | 0 |
| Il American-Streator IL0995030 | Streator | ND | ND | 4 |
| Il American-Valley View IL0437350 | DuPage County | 7.3 | ND | 1 |
| Il American-West Suburban IL1974151 | Bolingbrook | ND | ND | 0 |
| Illinois State University-Normal IL1135510 | Normal | ND | ND | 0 |
| Island Lake IL0974540 | Island Lake | ND | ND | 0 |
| Itasca IL0430500 | Itasca | ND | ND | 1 |
| Jacksonville IL1370200 | Jacksonville | ND | ND | 1 |
| Jersey RWC IL0835300 | Jersey County | ND | ND | 3 |
| Jerseyville IL0830250 | Jerseyville | ND | ND | 0 |
| Johnston City IL1990500 | Johnston City | ND | ND | 1 |
| Joliet IL1970450 | Joliet | ND | ND | 0 |
| Justice-Willow Springs Water Commission IL0315820 | Justice | ND | ND | 0 |
| Kenilworth IL0311500 | Kenilworth | ND | ND | 0 |
| Kewanee IL0730650 | Kewanee | ND | ND | 0 |
| Kinmundy IL1210300 | Kinmundy | ND | ND | 0 |
| LCPW - Pekara Subdivision IL0975900 | Lake County | ND | ND | 0 |
| La Grange IL0311530 | La Grange | ND | ND | 0 |
| La Grange Highlands Sanitary District IL0315860 | Cook County | ND | ND | 0 |
| La Grange Park IL0311560 | La Grange Park | ND | ND | 0 |
| La Salle IL0990300 | La Salle | ND | ND | 2 |
| Lake Bluff IL0970750 | Lake Bluff | ND | ND | 0 |
| Lake Forest IL0970800 | Lake Forest | ND | ND | 0 |
| Lake In the Hills IL1110400 | Lake In The Hills | ND | ND | 0 |
| Lake Sara Area Water Co-Op, Inc. IL0495150 | Effingham | ND | ND | 1 |
| Lake Villa IL0970840 | Lake Villa | ND | ND | 0 |
| Lake Windermere Estates Subdivision IL1795730 | Tremont | ND | ND | 0 |
| Lake Zurich IL0970850 | Lake Zurich | ND | ND | 2 |
| Lake of Egypt PWD IL1995200 | Marion | ND | ND | 0 |
| Lansing IL0311590 | Lansing | ND | ND | 0 |
| Lawrenceville IL1010150 | Lawrenceville | ND | ND | 0 |
| Le Roy IL1130750 | Le Roy | ND | ND | 0 |
| Lebanon IL1630650 | Lebanon | ND | ND | 0 |
| Lemont IL0311620 | Lemont | ND | ND | 0 |
| Leyden TWSP Water District IL0315880 | Cook County | ND | ND | 0 |
| Libertyville IL0970900 | Libertyville | ND | ND | 1 |
| Lincolnshire IL0970950 | Lincolnshire | ND | ND | 0 |
| Lincolnwood IL0311650 | Lincolnwood | ND | ND | 0 |
| Lindenhurst IL0971000 | Lindenhurst | ND | ND | 0 |
| Lisle IL0430551 | Lisle | ND | ND | 0 |
| Litchfield IL1350400 | Montgomery County | ND | ND | 0 |
| Lockport IL1970500 | Lockport | ND | ND | 4 |
| Lombard IL0430600 | Lombard | ND | ND | 0 |
| Long Creek Township PWS IL1155150 | Long Creek | ND | ND | 0 |
| Loves Park IL2010150 | Loves Park | ND | ND | 0 |
| Low Point Water District IL2035100 | Woodford County | ND | ND | 0 |
| Lutheran General Hospital IL3154633 | Cook County | ND | ND | 0 |
| Lynwood IL0311680 | Lynwood | ND | ND | 0 |
| Lyons, Il IL0311710 | Lyons | ND | ND | 0 |
| Mackinaw IL1790350 | Tazewell County | ND | ND | 0 |
| Macomb IL1090350 | Macomb | ND | ND | 0 |
| Mahomet IL0190450 | Mahomet | ND | ND | 0 |
| Manhattan IL1970550 | Manhattan | ND | ND | 0 |
| Marengo IL1110650 | Marengo | ND | ND | 1 |
| Marion IL1990550 | Marion | ND | ND | 1 |
| Markham IL0311770 | Markham | ND | ND | 1 |
| Marseilles IL0990500 | Marseilles | ND | ND | 0 |
| Marshall IL0230100 | Marshall | ND | ND | 0 |
| Maryville IL1190750 | Maryville | ND | ND | 0 |
| Mascoutah IL1630800 | Mascoutah | ND | ND | 0 |
| Matteson IL0311800 | Matteson | ND | ND | 0 |
| Mattoon IL0290250 | Mattoon | ND | ND | 1 |
| Maywood IL0311830 | Maywood | ND | ND | 0 |
| Mchenry IL1110600 | Mchenry | ND | ND | 1 |
| Melrose Park IL0311860 | Melrose Park | ND | ND | 0 |
| Mendon IL0010500 | Adams County | ND | ND | 0 |
| Mendota IL0990550 | Mendota | ND | ND | 0 |
| Metamora IL2030350 | Metamora | ND | ND | 0 |
| Metropolis IL1270150 | Metropolis | ND | ND | 0 |
| Midlothian IL0311920 | Midlothian | ND | ND | 0 |
| Milan IL1610400 | Milan | ND | ND | 0 |
| Mill Creek PWD IL0015300 | Adams County | ND | ND | 0 |
| Mill Creek Water Reclamation District IL0890120 | Kane County | ND | ND | 0 |
| Millstadt IL1630850 | Millstadt | ND | ND | 4 |
| Millstone PWD IL1515050 | Pope County | ND | ND | 0 |
| Minooka IL0630550 | Minooka | ND | ND | 1 |
| Mitchell PWD IL1195210 | Madison County | ND | ND | 4 |
| Mokena IL1970600 | Mokena | ND | ND | 0 |
| Moline IL1610450 | Moline | ND | ND | 1 |
| Monee IL1970650 | Monee | ND | ND | 0 |
| Monmouth IL1870150 | Monmouth | ND | ND | 0 |
| Montgomery IL0894690 | Montgomery | ND | ND | 0 |
| Monticello IL1470350 | Monticello | ND | ND | 0 |
| Moro PWD IL1195250 | Madison County | ND | ND | 3 |
| Morris, Il IL0630600 | Morris | ND | ND | 0 |
| Morrison IL1950350 | Morrison | ND | ND | 0 |
| Morton IL1790500 | Morton | ND | ND | 0 |
| Morton Grove IL0311950 | Morton Grove | ND | ND | 0 |
| Mount Carmel IL1850200 | Mount Carmel | ND | 4.8 | 2 |
| Mount Olive IL1170700 | Macoupin County | ND | ND | 0 |
| Mount Prospect IL0311980 | Mount Prospect | ND | ND | 0 |
| Mount Vernon IL0810300 | Mount Vernon | ND | ND | 1 |
| Mount Zion IL1150350 | Mount Zion | ND | ND | 1 |
| Mundelein IL0971150 | Mundelein | ND | ND | 0 |
| Murdale PWD IL0775200 | Jackson County | ND | ND | 0 |
| Murphysboro IL0770500 | Murphysboro | ND | ND | 1 |
| Naperville IL0434670 | Naperville | ND | ND | 0 |
| Nashville IL1890300 | Nashville | ND | ND | 0 |
| New Baden IL0274700 | New Baden | ND | 9.4 | 1 |
| New Lenox IL1970700 | New Lenox | ND | ND | 0 |
| Niles, Il IL0312010 | Niles | ND | ND | 0 |
| Normal IL1130900 | Normal | ND | ND | 0 |
| Norridge IL0312040 | Norridge | ND | ND | 0 |
| North Aurora IL0890600 | North Aurora | ND | ND | 0 |
| North Chicago IL0971250 | North Chicago | ND | ND | 0 |
| North East Central PWD IL1195280 | Madison County | 4.1 | 4.1 | 4 |
| North East Marion County Water Cmpny IL1210030 | Marion County | ND | ND | 0 |
| North Park PWD IL2015500 | Machesney Park | 6.2 | 7.3 | 7 |
| North Riverside IL0312160 | North Riverside | ND | ND | 0 |
| North Tazewell PWD IL1795780 | East Peoria | ND | ND | 0 |
| Northbrook IL0312070 | Northbrook | ND | ND | 0 |
| Northeast Mount Vernon Water Company IL0810010 | Jefferson County | ND | ND | 1 |
| Northern Illinois University-Dekalb IL0375500 | DeKalb County | ND | ND | 0 |
| Northfield, Il IL0312100 | Northfield | ND | ND | 0 |
| Northlake IL0314710 | North Lake | ND | ND | 0 |
| Northshore Univ Glenbrook IL3157487 | Cook County | ND | ND | 0 |
| Northshore University Evanston IL3158048 | Cook County | ND | ND | 0 |
| O Fallon IL1631100 | O Fallon | ND | ND | 1 |
| Oak Brook IL0430700 | Oak Brook | ND | ND | 0 |
| Oak Forest IL0312190 | Oak Forest | ND | ND | 1 |
| Oak Lawn IL0312220 | Oak Lawn | ND | ND | 0 |
| Oak Park, Il IL0312250 | Oak Park | ND | ND | 0 |
| Oglesby IL0990700 | Oglesby | ND | ND | 0 |
| Olney IL1590200 | Olney | ND | ND | 0 |
| Olympia Fields IL0312280 | Olympia Fields | ND | ND | 0 |
| Oregon IL1410400 | Oregon | ND | ND | 0 |
| Orland Park IL0312310 | Orland Park | ND | ND | 0 |
| Oswego IL0930150 | Oswego | ND | ND | 0 |
| Ottawa IL0990800 | Ottawa | ND | ND | 0 |
| Palatine IL0312340 | Palatine | ND | ND | 0 |
| Palos Heights IL0312370 | Palos Heights | ND | ND | 0 |
| Palos Hills IL0312400 | Palos Hills | ND | ND | 0 |
| Palos Park IL0311000 | Palos Park | ND | ND | 0 |
| Pana IL0210500 | Pana | ND | ND | 1 |
| Paris IL0450300 | Paris | ND | ND | 0 |
| Park City IL0971400 | Park City | ND | ND | 0 |
| Park Forest IL0314740 | Park Forest | ND | ND | 0 |
| Park Ridge IL0312460 | Park Ridge | ND | ND | 0 |
| Paxton IL0530250 | Paxton | ND | ND | 0 |
| Peoria Heights IL1434750 | Peoria Heights | ND | ND | 5 |
| Peru IL0990850 | Peru | ND | ND | 0 |
| Petersburg IL1290200 | Petersburg | ND | ND | 0 |
| Pike County PWD 1 IL1495000 | Pike County | ND | ND | 0 |
| Pinckneyville IL1450150 | Pinckneyville | ND | ND | 0 |
| Pingree Grove IL0890160 | Hampshire | ND | ND | 0 |
| Pittsfield IL1490750 | Pittsfield | ND | ND | 0 |
| Plainfield IL1970800 | Plainfield | ND | ND | 0 |
| Plano IL0930200 | Plano | ND | ND | 0 |
| Pleasant Valley PWD IL1435470 | Peoria County | ND | ND | 3 |
| Pontoon Beach PWD IL1195300 | Pontoon Beach | ND | ND | 3 |
| Poplar Grove West-Countryside IL0070350 | Poplar Grove | ND | ND | 0 |
| Posen IL0312520 | Posen | ND | ND | 0 |
| Prairie Path Water Co. - Clarendon IL0435300 | DuPage County | ND | ND | 0 |
| Prairie Path Water Co. - Lake Holiday IL0995200 | LaSalle County | ND | ND | 0 |
| Prairie Path Water Co. - Whispering Hills IL1115700 | McHenry County | 8.3 | ND | 7 |
| Princeton IL0110850 | Princeton | ND | ND | 0 |
| Quincy IL0010650 | Quincy | ND | ND | 2 |
| Raccoon Water Company IL1215100 | Marion County | ND | ND | 0 |
| Rantoul IL0190650 | Rantoul | ND | ND | 0 |
| Red Bud IL1570450 | Red Bud | ND | ND | 0 |
| Richton Park IL0312550 | Richton Park | ND | ND | 0 |
| River Forest IL0312610 | River Forest | ND | ND | 0 |
| River Grove IL0312640 | River Grove | ND | ND | 0 |
| Riverdale IL0312580 | Riverdale | ND | ND | 0 |
| Riverside IL0312670 | Riverside | ND | ND | 0 |
| Riverton IL1670950 | Riverton | ND | ND | 0 |
| Riverwoods IL0971450 | Riverwoods | ND | ND | 0 |
| Robbins IL0312700 | Robbins | ND | ND | 0 |
| Robinson-Palestine Water Commission IL0335030 | Crawford County | ND | 4.6 | 2 |
| Rochelle IL1410500 | Rochelle | ND | ND | 0 |
| Rochester IL1671000 | Rochester | ND | ND | 0 |
| Rock Falls IL1950450 | Rock Falls | ND | ND | 1 |
| Rock Island IL1610650 | Rock Island | ND | ND | 1 |
| Rock Island Arsenal, Us Army IL1615387 | Rock Island County | 4.6 | ND | 2 |
| Rockford, Il IL2010300 | Rockford | ND | ND | 2 |
| Rockton IL2010350 | Rockton | ND | ND | 1 |
| Rolling Meadows IL0312730 | Rolling Meadows | ND | ND | 0 |
| Romeoville IL1970900 | Romeoville | ND | ND | 3 |
| Roselle IL0434820 | Roselle | ND | ND | 0 |
| Rosemont IL0312760 | Rosemont | ND | ND | 0 |
| Round Lake IL0971500 | Round Lake | ND | ND | 0 |
| Round Lake Beach IL0971550 | Round Lake Beach | ND | ND | 0 |
| Round Lake Park IL0971600 | Round Lake Park | ND | ND | 0 |
| Salem IL1210450 | Salem | ND | ND | 0 |
| Saline Valley Conservancy District IL1655300 | Eldorado | ND | ND | 0 |
| Sandwich IL0374850 | Sandwich | ND | ND | 0 |
| Sangamon Valley PWD IL0195150 | Champaign County | ND | ND | 0 |
| Sauk IL0312790 | Sauk | ND | ND | 1 |
| Schaumburg IL0314890 | Schaumburg | ND | ND | 0 |
| Schiller Park IL0312850 | Schiller Park | ND | ND | 0 |
| Shady Oaks MHP IL0635225 | Grundy County | ND | ND | 0 |
| Shelbyville IL1730300 | Shelbyville | ND | ND | 0 |
| Sherrard JR/SR High School IL3090290 | Rock Island County | ND | ND | 0 |
| Shorewood, Il IL1975080 | Shorewood | ND | ND | 1 |
| Silvis IL1610700 | Silvis | ND | ND | 0 |
| Skokie IL0312880 | Skokie | ND | ND | 0 |
| South Chicago Heights IL0312940 | South Chicago Heights | ND | ND | 0 |
| South Elgin IL0890800 | South Elgin | 5.7 | ND | 5 |
| South Highway PWD IL0775400 | Jackson County | ND | ND | 0 |
| South Holland IL0312970 | South Holland | ND | ND | 1 |
| South Jacksonville IL1370400 | South Jacksonville | ND | ND | 3 |
| South Stickny SD IL0317370 | Burbank (South Stickney) | ND | ND | 0 |
| Southeast Regional Water Facility IL0430060 | DuPage County | ND | ND | 0 |
| Southern Il University-Edwardsville IL1195550 | Madison County | ND | ND | 2 |
| Sparta IL1570600 | Sparta | ND | ND | 1 |
| Spring Valley IL0111000 | Spring Valley | ND | ND | 0 |
| Springfield, Il IL1671200 | Springfield | ND | ND | 1 |
| St Charles IL0894830 | Saint Charles | ND | ND | 3 |
| Staunton IL1171050 | Staunton | ND | ND | 1 |
| Steger IL0314860 | Steger | ND | ND | 0 |
| Stickney IL0313000 | Stickney | ND | ND | 0 |
| Stone Park IL0313030 | Stone Park | ND | ND | 0 |
| Streamwood IL0313060 | Streamwood | ND | ND | 0 |
| Sugar Grove IL0890850 | Sugar Grove | ND | ND | 1 |
| Sullivan IL1390300 | Sullivan | ND | ND | 0 |
| Summit IL0310060 | Summit | ND | ND | 1 |
| Sycamore IL0370550 | Sycamore | ND | ND | 0 |
| Taylorville IL0210600 | Taylorville | ND | ND | 0 |
| Tinley Park IL0314910 | Tinley Park | ND | ND | 0 |
| Tritownship Water District IL1190080 | Highland | ND | ND | 0 |
| Troy, Il IL1191000 | Troy | ND | ND | 1 |
| Tuscola IL0415030 | Tuscola | ND | ND | 0 |
| U of I Chicago Medical Center IL3155606 | Cook County | ND | ND | 0 |
| U of I-Champaign IL0195500 | Urbana | ND | ND | 0 |
| Utl Inc-Galena Territory IL0855050 | Jo Daviess County | ND | ND | 0 |
| Valmeyer IL1330250 | Valmeyer | ND | ND | 0 |
| Vandalia IL0510350 | Vandalia | ND | ND | 0 |
| Vandalia Correctional Center IL0515500 | Fayette County | ND | ND | 0 |
| Vernon Hills - Lake Co PW IL0971750 | Vernon Hills | ND | ND | 0 |
| Villa Park IL0430800 | Villa Park | ND | ND | 0 |
| Virden IL1171100 | Virden | ND | ND | 0 |
| Volo IL0971770 | Volo | ND | ND | 0 |
| Warrenville IL0430833 | Warrenville | ND | ND | 0 |
| Wasco SD IL0890110 | Kane County | ND | ND | 0 |
| Washington County Water Company IL1895600 | Nashville | ND | ND | 1 |
| Washington, Il IL1790750 | Washington | ND | ND | 0 |
| Waterloo IL1330300 | Waterloo | ND | ND | 2 |
| Watseka IL0750900 | Watseka | ND | ND | 0 |
| Wauconda IL0971850 | Wauconda | ND | ND | 0 |
| Waukegan IL0971900 | Waukegan | ND | ND | 0 |
| Wee-MA-Tuk Water District IL0570040 | Fulton County | ND | ND | 3 |
| West Chicago IL0430900 | West Chicago | ND | ND | 0 |
| West Dundee IL0890950 | West Dundee | ND | ND | 0 |
| West Frankfort IL0550700 | West Frankfort | ND | ND | 0 |
| West Liberty-Dundas Water District IL1595050 | Richland County | ND | ND | 0 |
| Westchester IL0313150 | Westchester | ND | ND | 0 |
| Western Illinois University IL1095510 | McDonough County | ND | ND | 0 |
| Western Springs IL0313180 | Western Springs | ND | ND | 0 |
| Westmont IL0430950 | Westmont | ND | ND | 0 |
| Westville IL1830950 | Westville | ND | ND | 0 |
| Wheaton IL0431050 | Wheaton | ND | ND | 0 |
| Wheeling IL0314970 | Wheeling | ND | ND | 0 |
| Wildwood Subdivision - Lake Co PW IL0977350 | Lake County | ND | ND | 0 |
| Williamsville IL1671300 | Williamsville | ND | ND | 0 |
| Willow Lake Estates MHP IL0894400 | Elgin | ND | ND | 3 |
| Willowbrook IL0431100 | Willowbrook | ND | ND | 0 |
| Wilmette IL0313300 | Wilmette | ND | ND | 0 |
| Wilmington IL1971100 | Wilmington | ND | ND | 4 |
| Winfield IL0431150 | Winfield | ND | ND | 0 |
| Winnetka IL0313330 | Winnetka | ND | ND | 0 |
| Winthrop Harbor IL0971950 | Winthrop Harbor | ND | ND | 0 |
| Wonder Lake IL1115750 | McHenry County | ND | ND | 0 |
| Wood Dale IL0431200 | Wood Dale | ND | ND | 0 |
| Wood River IL1191150 | Wood River | ND | 4.1 | 3 |
| Woodhaven, Il IL1035100 | Lee County | ND | ND | 0 |
| Woodlawn IL0810450 | Woodlawn | ND | ND | 1 |
| Woodridge IL0431250 | Woodridge | ND | ND | 0 |
| Woodstock, Il IL1110950 | Woodstock | ND | ND | 0 |
| Worth IL0313360 | Worth | ND | ND | 0 |
| Xenia IL0250300 | Xenia | ND | ND | 0 |
| Yorkville IL0930250 | Yorkville | ND | ND | 0 |
| Zion IL0972000 | Zion | ND | ND | 0 |
ND = not detected (below the 4 ppt UCMR 5 reporting level). Values are the highest single sample result, not an annual average.