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Illinois Water Quality
5,117 public water systems serving 12,576,876 people.
Water Systems
5,117
Total Violations
355,322
Violation Rate
80.8%
PFAS Detection
40.9%
199 of 487 tested
Largest Water Systems
CHICAGO
CHICAGO, IL · 2,746,388 served
AURORA
AURORA, IL · 183,000 served
JOLIET
JOLIET, IL · 160,000 served
NAPERVILLE
NAPERVILLE, IL · 156,406 served
IL AMERICAN-CHAMPAIGN
GODFREY, IL · 150,000 served
ROCKFORD
ROCKFORD, IL · 147,051 served
IL AMERICAN-PEORIA
GODFREY, IL · 137,575 served
IL AMERICAN-EAST ST LOUIS
GODFREY, IL · 131,368 served
SPRINGFIELD
SPRINGFIELD, IL · 117,444 served
ELGIN
ELGIN, IL · 114,797 served
WAUKEGAN
WAUKEGAN, IL · 87,149 served
CICERO
CICERO, IL · 83,000 served
AQUA ILLINOIS-KANKAKEE
KANKAKEE, IL · 80,000 served
BLOOMINGTON
BLOOMINGTON, IL · 77,610 served
DECATUR
DECATUR, IL · 76,122 served
SCHAUMBURG
SCHAUMBURG, IL · 75,750 served
EVANSTON
EVANSTON, IL · 74,486 served
IL AMERICAN-WEST SUBURBAN
GODFREY, IL · 73,978 served
ARLINGTON HEIGHTS
ARLINGTON HEIGHTS, IL · 73,320 served
PALATINE
PALATINE, IL · 70,875 served
Most Violations
#1 SKYVIEW ESTATES MOMENCE
7,512 #2 WINDMILL ESTATES MOMENCE
5,042 #3 CARMEL MONTESSORI ACADEMY WARRENVILLE
4,386 #4 CRISWELL COURT MHP JOLIET
3,770 #5 CONGREGATION BETH JUDEA WAUKEGAN
3,204 #6 CHRIST MISSION LUTHERAN CHURCH MANHATTAN
3,123 #7 SAVE A PET WAUKEGAN
2,953 #8 AMERICAN PRECISION ELCTRONICS CAROL STREAM
2,881 #9 FORMING AMERICA LTD WEST CHICAGO
2,507 #10 MOTHER TERESA CATHOLIC ACADEMY CRETE
2,381 #11 TALEEM UL HAQ PLAINFIELD
2,193 #12 BOLEY TOOL AND MACHINE WORKS PEORIA
2,188 #13 COG HILL COUNTRY CLUB LEMONT
1,849 #14 GAME DAY GRILL DOWNS
1,797 #15 NORTHFIELD BLOCK COMPANY 1 MORRIS
1,774 Counties in Illinois
Cook
427 systems · 5,304,996 served
· 21,728 violations
DuPage
207 systems · 861,775 served
· 15,779 violations
Lake
540 systems · 719,035 served
· 33,311 violations
Will
330 systems · 622,572 served
· 37,818 violations
Kane
191 systems · 592,544 served
· 12,844 violations
McHenry
307 systems · 271,051 served
· 11,554 violations
Madison
68 systems · 268,778 served
· 1,940 violations
St. Clair
54 systems · 258,141 served
· 3,100 violations
Winnebago
196 systems · 255,966 served
· 12,949 violations
Champaign
81 systems · 209,446 served
· 2,997 violations
Peoria
83 systems · 188,814 served
· 7,041 violations
Sangamon
68 systems · 183,628 served
· 1,245 violations
McLean
90 systems · 171,235 served
· 10,265 violations
Rock Island
120 systems · 164,178 served
· 6,591 violations
Tazewell
100 systems · 131,500 served
· 7,258 violations
LaSalle
174 systems · 112,392 served
· 13,172 violations
Macon
25 systems · 104,510 served
· 886 violations
DeKalb
57 systems · 100,590 served
· 2,730 violations
Kankakee
65 systems · 95,216 served
· 17,039 violations
Kendall
64 systems · 84,307 served
· 6,782 violations
Williamson
26 systems · 75,426 served
· 1,069 violations
Adams
25 systems · 67,920 served
· 2,040 violations
Vermilion
41 systems · 58,420 served
· 3,428 violations
Coles
16 systems · 57,953 served
· 520 violations
Jackson
24 systems · 56,580 served
· 761 violations
Grundy
63 systems · 52,209 served
· 12,515 violations
Knox
45 systems · 49,636 served
· 2,317 violations
Ogle
112 systems · 45,754 served
· 8,348 violations
Boone
56 systems · 45,698 served
· 2,853 violations
Macoupin
37 systems · 45,357 served
· 3,529 violations
Showing top 30 of 102 counties.