EPA EXPORT · 13 SEP 2026FEDERAL COMPLIANCE RECORDS · NOT A HOME WATER TEST
TAP WATERLEDGERPublic system compliance records

COUNTY WATER-SYSTEM LEDGER

Cook, Illinois

Compare active community water systems serving this county in EPA's public export. Systems can serve multiple places, so population totals may overlap.

Systems113active CWS · pop. 2,500+
Population served5,180,585reported total; may overlap
Current violation flag57.5%65 systems
Serious-violator flag0.9%1 systems

01 / SYSTEMS

Water systems serving Cook

Ordered by reported population served. Open any record for separate health, monitoring, notice, other, and serious-violator flags.

Water systemPopulation servedPrimary sourceCurrent export status
ChicagoIL03160002,721,308Surface waterNo current violation flagged
CiceroIL031051083,000Surface water purchasedCurrent monitoring/reporting flag
SchaumburgIL031489075,750Surface water purchasedNo current violation flagged
EvanstonIL031081074,486Surface waterNo current violation flagged
Arlington HeightsIL031403073,320Surface water purchasedOther current violation flag
PalatineIL031234070,875Surface water purchasedNo current violation flagged
SkokieIL031288066,422Surface water purchasedCurrent monitoring/reporting flag
Des PlainesIL031063060,675Surface water purchasedCurrent monitoring/reporting flag
Oak LawnIL031222058,362Surface water purchasedOther current violation flag
Orland ParkIL031231058,020Surface water purchasedOther current violation flag
BerwynIL031021057,250Surface water purchasedCurrent monitoring/reporting flag
Tinley ParkIL031491056,703Surface water purchasedOther current violation flag
Oak ParkIL031225054,583Surface water purchasedNo current violation flagged
Hoffman EstatesIL031129050,179Surface water purchasedNo current violation flagged
GlenviewIL031102047,856Surface water purchasedOther current violation flag
Buffalo GroveIL031418043,212Surface water purchasedNo current violation flagged
BartlettIL031412041,500Surface water purchasedNo current violation flagged
Mount ProspectIL031198041,000Surface water purchasedOther current violation flag
Park RidgeIL031246039,800Surface water purchasedOther current violation flag
WheelingIL031497039,725Surface water purchasedNo current violation flagged
StreamwoodIL031306039,577Surface water purchasedNo current violation flagged
Hanover ParkIL031448037,470Surface water purchasedOther current violation flag
Calumet CityIL031039037,000Surface water purchasedCurrent health-based flag
NorthbrookIL031207034,407Surface waterNo current violation flagged
Elk Grove VillageIL031440031,802Surface water purchasedOther current violation flag
Aqua Illinois-North Maine UtilitiesIL031535030,043Surface water purchasedNo current violation flagged
South Stickny SdIL031737030,000Surface water purchasedOther current violation flag
NilesIL031201029,350Surface water purchasedOther current violation flag
LansingIL031159029,076Surface water purchasedCurrent monitoring/reporting flag
Oak ForestIL031219027,478Surface water purchasedCurrent monitoring/reporting flag
WilmetteIL031330027,087Surface waterOther current violation flag
Chicago HeightsIL031045026,184Surface water purchasedCurrent monitoring/reporting flag
Morton GroveIL031195025,297Surface water purchasedOther current violation flag
Elmwood ParkIL031078025,000Surface water purchasedOther current violation flag
HarveyIL031111025,000Surface water purchasedCurrent monitoring/reporting flag
Melrose ParkIL031186024,206Surface water purchasedNo current violation flagged
MaywoodIL031183024,090Surface water purchasedCurrent health-based flag
Rolling MeadowsIL031273023,329Surface water purchasedOther current violation flag
South HollandIL031297022,000Surface water purchasedOther current violation flag
Park ForestIL031474021,687Ground waterNo current violation flagged
Blue IslandIL031024021,494Surface water purchasedNo current violation flagged
DoltonIL031069020,510Surface water purchasedCurrent monitoring/reporting flag
Evergreen ParkIL031084019,943Surface water purchasedNo current violation flagged
HomewoodIL031135019,463Surface water purchasedOther current violation flag
BellwoodIL031015019,156Surface water purchasedOther current violation flag
AlsipIL031003019,063Surface water purchasedNo current violation flagged
BrookfieldIL031033018,776Surface water purchasedNo current violation flagged
Palos HillsIL031240018,530Surface water purchasedNo current violation flagged
Franklin ParkIL031096018,467Surface water purchasedCurrent monitoring/reporting flag
Justice-Willow Springs Water CommissionIL031582018,450Surface water purchasedNo current violation flagged
MattesonIL031180018,293Surface water purchasedCurrent monitoring/reporting flag
LemontIL031162017,500Ground waterNo current violation flagged
Country Club HillsIL031054016,500Surface water purchasedOther current violation flag
BridgeviewIL031027016,467Surface water purchasedNo current violation flagged
WestchesterIL031315016,241Surface water purchasedCurrent monitoring/reporting flag
La GrangeIL031153016,200Surface water purchasedCurrent monitoring/reporting flag
Palos HeightsIL031237015,500Surface water purchasedOther current violation flag
NorridgeIL031204015,251Surface water purchasedNo current violation flagged
MidlothianIL031192014,819Surface water purchasedCurrent monitoring/reporting flag
Hickory HillsIL031120014,505Surface water purchasedNo current violation flagged

Showing the 60 largest systems by reported population served.

02 / SOURCE MIX

Surface water6 systems · 2,878,612 served
Surface water purchased100 systems · 2,214,387 served
Ground water7 systems · 87,586 served
How to read the population total

It is the sum of each listed system's reported population served, not a census estimate. Service areas can overlap and some systems list multiple cities or counties.