Illinois Drinking Water Compliance Records
1,787 water systems serving 12,093,685 people. 37,113 historical EPA violation records in the Q2 2026 snapshot.
TapScore Compliance-History Grades
A
722
40%
B
460
26%
C
450
25%
D
142
8%
F
13
1%
1,787
Water Systems
12,093,685
Population Served
37,113
Historical Records
7,178
Health-Based (All Years)
Systems With the Most Recent EPA Records
CRISWELL COURT MHP
94 served1,048 historical records538 recent
C
WALNUT GROVE MHC
40 served164 historical records161 recent
C
CORTLAND CORNERS MHP
205 served148 historical records106 recent
D
SAUK
9,921 served193 historical records102 recent
C
BONE GAP
207 served133 historical records102 recent
C
FIELDS HILL IMPROVEMENT ASSOCIATION
312 served102 historical records88 recent
D
FORGE AT THE LAKE
387 served95 historical records78 recent
C
MENARD CORRECTIONAL CENTER
2,950 served81 historical records69 recent
C
DAWSON
2,375 served77 historical records67 recent
C
PRAIRIE PATH WATER CO-WHISPERING HILLS
8,300 served61 historical records53 recent
D
Large Systems With No Recent Records
AURORA
183,000 served7 historical records
A
IL AMERICAN-CHAMPAIGN
150,000 served2 historical records
A
IL AMERICAN-PEORIA
137,575 served8 historical records
A
IL AMERICAN-EAST ST LOUIS
131,368 served4 historical records
A
BLOOMINGTON
77,610 served14 historical records
A
EVANSTON
74,486 served33 historical records
A
IL AMERICAN-WEST SUBURBAN
73,978 served6 historical records
A
PALATINE
70,875 served2 historical records
A
OAK PARK
54,583 served7 historical records
A
NORMAL
52,736 served3 historical records
A
Largest Water Systems in Illinois
| Water System | Grade | Population | Historical Records |
|---|---|---|---|
| CHICAGO | C | 2,721,308 | 53 |
| AURORA | A | 183,000 | 7 |
| JOLIET | D | 160,000 | 55 |
| NAPERVILLE | C | 156,406 | 17 |
| IL AMERICAN-CHAMPAIGN | A | 150,000 | 2 |
| ROCKFORD | C | 147,051 | 39 |
| IL AMERICAN-PEORIA | A | 137,575 | 8 |
| IL AMERICAN-EAST ST LOUIS | A | 131,368 | 4 |
| SPRINGFIELD | C | 117,444 | 6 |
| ELGIN | C | 114,797 | 17 |
| WAUKEGAN | C | 87,149 | 27 |
| CICERO | C | 83,000 | 11 |
| AQUA ILLINOIS-KANKAKEE | C | 80,000 | 8 |
| BLOOMINGTON | A | 77,610 | 14 |
| DECATUR | B | 76,122 | 29 |
| SCHAUMBURG | C | 75,750 | 7 |
| EVANSTON | A | 74,486 | 33 |
| IL AMERICAN-WEST SUBURBAN | A | 73,978 | 6 |
| ARLINGTON HEIGHTS | C | 73,320 | 29 |
| PALATINE | A | 70,875 | 2 |
Contaminants in Illinois
Lead in IllinoisArsenic in IllinoisNitrate in IllinoisFluoride in IllinoisPFOS in IllinoisPFOA in IllinoisTHMs in IllinoisHAA5 in Illinois
Cities in Illinois
CHICAGO(11)GODFREY(53)GLENVIEW(34)AURORA(6)JOLIET(14)CHAMPAIGN(3)NAPERVILLE(1)ROCKFORD(8)PEORIA(3)SPRINGFIELD(25)EAST ST LOUIS(2)ELGIN(4)WAUKEGAN(1)DECATUR(5)CICERO(1)BLOOMINGTON(7)KANKAKEE(1)SCHAUMBURG(4)EVANSTON(1)BOLINGBROOK(1)ARLINGTON HEIGHTS(2)PALATINE(1)SKOKIE(1)DES PLAINES(3)NORMAL(3)OAK LAWN(1)ORLAND PARK(1)BERWYN(1)TINLEY PARK(1)ALTON(4)WHEATON(5)OAK PARK(1)MOLINE(7)ROMEOVILLE(1)PLAINFIELD(2)HOFFMAN ESTATES(1)DOWNERS GROVE(1)QUINCY(4)O FALLON(2)DEKALB(3)ROCK ISLAND(2)O'FALLON(1)LOMBARD(2)ELMHURST(2)NORTHBROOK(8)BUFFALO GROVE(1)ST. CHARLES(10)GRANITE CITY(3)BARTLETT(1)DIETERICH(15)MOUNT PROSPECT(1)VERNON HILLS(6)CRYSTAL LAKE(1)DE KALB(1)CAROL STREAM(1)NORTH CHICAGO(2)PARK RIDGE(1)WHEELING(1)STREAMWOOD(1)OSWEGO(1)ADDISON(1)CARPENTERSVILLE(1)CALUMET CITY(2)HANOVER PARK(1)EDWARDSVILLE(6)MARION(9)MACHESNEY PARK(2)EAST PEORIA(9)DARIEN(7)PEKIN(3)WOODRIDGE(1)MUNDELEIN(8)GLENDALE HEIGHTS(1)SAINT CHARLES(1)BURBANK(2)ROUND LAKE BEACH(2)GENEVA(4)GALESBURG(2)ELK GROVE VILLAGE(2)ELK GROVE(1)COLLINSVILLE(2)ALGONQUIN(1)CENTRALIA(13)GURNEE(1)HIGHLAND PARK(1)DANVILLE(1)BURBANK (SOUTH STICKNEY)(1)NEW LENOX(3)WEST CHICAGO(2)NILES(2)LANSING(1)MONTGOMERY(1)GLEN ELLYN(1)LAKE IN THE HILLS(1)HUNTLEY(1)FRANKLIN PARK(2)CARBONDALE(7)LOVES PARK(4)OAK FOREST(1)MCHENRY(9)