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AquaCensus

Illinois public water systems

3,872 active systems regulated under the Safe Drinking Water Act, serving a reported 12.4M people across 149 counties.

Dataset updated . Source: EPA SDWIS/ECHO, refreshed quarterly.

Active systems

3,872

Population served

12.4M

Community systems

1,773

Groundwater share

81.7%

System types in Illinois

1,773

Community water system

396

Non-transient non-community water system

1,703

Transient non-community water system

Largest water systems in Illinois

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The largest active public water systems in Illinois by population served
#Water systemCountyPopulation servedTypeSource
1ChicagoCook2,721,308CommunitySurface water
2AuroraKane183,000CommunitySurface water
3JolietWill160,000CommunityGroundwater
4NapervilleDuPage156,406CommunityPurchased surface water
5Il American-ChampaignChampaign150,000CommunityGroundwater
6RockfordWinnebago147,051CommunityGroundwater
7Il American-PeoriaPeoria137,575CommunitySurface water
8Il American-East St LouisSt. Clair131,368CommunitySurface water
9SpringfieldSangamon117,444CommunitySurface water
10ElginKane114,797CommunitySurface water
11WaukeganLake87,149CommunitySurface water
12CiceroCook83,000CommunityPurchased surface water
13Aqua Illinois-KankakeeKankakee80,000CommunitySurface water
14BloomingtonMcLean77,610CommunitySurface water
15DecaturMacon76,122CommunitySurface water
16SchaumburgCook75,750CommunityPurchased surface water
17EvanstonCook74,486CommunitySurface water
18Il American-West SuburbanWill73,978CommunityPurchased surface water
19Arlington HeightsCook73,320CommunityPurchased surface water
20PalatineCook70,875CommunityPurchased surface water
21SkokieCook66,422CommunityPurchased surface water
22Des PlainesCook60,675CommunityPurchased surface water
23Oak LawnCook58,362CommunityPurchased surface water
24Orland ParkCook58,020CommunityPurchased surface water
25BerwynCook57,250CommunityPurchased surface water

By county

Lake266 systemsCook251 systemsWill236 systemsMcHenry192 systemsWinnebago137 systemsLaSalle129 systemsDuPage125 systemsKane118 systemsOgle102 systemsRock Island102 systemsTazewell83 systemsMcLean79 systemsHenry72 systemsChampaign66 systemsPeoria66 systemsWhiteside59 systemsWoodford58 systemsIroquois56 systemsLee55 systemsMadison54 systemsBureau52 systemsGrundy51 systemsKankakee50 systemsBoone47 systemsKendall47 systemsDeKalb43 systemsSangamon43 systemsSt. Clair42 systemsStephenson42 systemsJo Daviess41 systemsCarroll35 systemsVermilion35 systemsKnox34 systemsMacoupin32 systemsFulton30 systemsLivingston29 systemsMercer27 systemsHenderson26 systemsJackson25 systemsWilliamson25 systemsClinton24 systemsMason24 systemsMontgomery24 systemsFranklin23 systemsAdams22 systemsMcDonough21 systemsRandolph21 systemsLogan20 systemsMarshall20 systemsPutnam20 systemsChristian18 systemsMacon18 systemsMarion18 systemsMorgan17 systemsCass15 systemsFord15 systemsWarren15 systemsWashington15 systemsDe Witt14 systemsEffingham14 systemsJefferson14 systemsLawrence14 systemsPiatt14 systemsBond13 systemsDouglas13 systemsMonroe13 systemsPike13 systemsSaline12 systemsShelby12 systemsStark12 systemsUnion12 systemsWayne12 systemsFayette11 systemsHancock11 systemsEdgar10 systemsGreene10 systemsMenard10 systemsWhite10 systemsClark9 systemsColes9 systemsPerry9 systemsRichland9 systemsVan Buren9 systemsClay8 systemsCrawford8 systemsGallatin7 systemsJohnson7 systemsMoultrie7 systemsSchuyler7 systemsScott7 systemsAlexander6 systemsCalhoun6 systemsJersey6 systemsPulaski6 systemsBrown5 systemsHardin5 systemsJasper5 systemsMassac5 systemsWabash5 systemsCumberland4 systemsEdwards4 systemsHamilton4 systemsPope3 systemsHarris3 systems
Calcasieu Parish2 systems
Berrien2 systems
Grand Traverse2 systems
St. Joseph2 systems
Emmet2 systems
Hillsdale2 systems
St. Louis2 systems
Buchanan2 systems
Madera1 systems
Sonoma1 systems
Pitkin1 systems
Gunnison1 systems
Baltimore1 systems
Eaton1 systems
Kalamazoo1 systems
Washtenaw1 systems
Mecosta1 systems
Kalkaska1 systems
Otsego1 systems
Shiawassee1 systems
Newaygo1 systems
Hennepin1 systems
Olmsted1 systems
Ramsey1 systems
Anoka1 systems
Mille Lacs1 systems
Miller1 systems
Camden1 systems
Stone1 systems
Medina1 systems
Portage1 systems
Oklahoma1 systems
Lane1 systems
Berks1 systems
Lehigh1 systems
Bandera1 systems
Brazoria1 systems
Colorado1 systems
Frio1 systems
Guadalupe1 systems
Hidalgo1 systems
Howard1 systems
La Salle1 systems
Llano1 systems
Wise1 systems