Illinois
Cook County drinking water quality
423 active public water systems serve 5,279,874 people in Cook County. 203 are compliant, 220 had at least one EPA violation in the past three years, 43 are designated serious violators, and 5 carry a health flag.
Active systems
423
163 community systems
People served
5.3M
by public water systems
Systems with violations
220
52% of active systems, past 3 years
Serious violators
43
5 systems carry a health flag
Needs attention
Richton Park
IL0312550 · Richton Park · Community water system · Serves 12,504
5 rules violated in the past three years. Unresolved: Consumer Confidence Rule (CCR), Lead and Copper Rule (LCR), and Public Notification Rule.
Robbins
IL0312700 · Robbins · Community water system · Serves 5,415
6 rules violated in the past three years. Unresolved: Consumer Confidence Rule (CCR), Lead and Copper Rule (LCR), and Public Notification Rule.
Lutheran General Hospital
IL3154633 · Non-Transient non-community system · Serves 3,400
6 rules violated in the past three years. Unresolved: Chlorine (MRDL) and Public Notification Rule.
Dixmoor
IL0310660 · Dixmoor · Community water system · Serves 2,973
5 rules violated in the past three years. Unresolved: Consumer Confidence Rule (CCR), Lead and Copper Rule (LCR), Lead and Copper Rule Revisions (LCRR), Public Notification Rule, TTHM (Total Trihalomethanes), and Total Haloacetic Acids (HAA5).
Prospect Heights Plaza
IL3161463 · Non-Transient non-community system · Serves 1,240
6 rules violated in the past three years. Unresolved: 1,1,1-Trichloroethane, 1,1,2-Trichloroethane, 1,1-Dichloroethylene, 1,2,4-Trichlorobenzene, 1,2-Dibromo-3-Chloropropane (DBCP), 1,2-Dichloroethane, 1,2-Dichloropropane, 2,4,5-TP (Silvex), 2,4-D, Alachlor (Lasso), Atrazine, BHC-Gamma (Lindane), Benzene, Benzo(a)pyrene, Carbofuran, Carbon Tetrachloride, Chlordane, Chlorobenzene, Dalapon, Di(2-ethylhexyl) Adipate, Di(2-ethylhexyl) Phthalate, Dichloromethane (Methylene Chloride), Dinoseb, Diquat, Endothall, Endrin, Ethylbenzene, Ethylene Dibromide (EDB), Glyphosate, Heptachlor, Heptachlor Epoxide, Hexachlorobenzene, Hexachlorocyclopentadiene, Lead and Copper Rule (LCR), Methoxychlor, Oxamyl (Vydate), Pentachlorophenol, Picloram, Polychlorinated Biphenyls (PCBs), Public Notification Rule, Simazine, Styrene, Tetrachloroethylene (PCE), Toluene, Toxaphene, Trichloroethylene (TCE), Vinyl Chloride, Xylenes, Total, cis-1,2-Dichloroethylene, o-Dichlorobenzene, p-Dichlorobenzene, and trans-1,2-Dichloroethylene.
Swedish Covenant Hospital
IL3162651 · Non-Transient non-community system · Serves 1,200
6 rules violated in the past three years. Unresolved: Public Notification Rule, Revised Total Coliform Rule (RTCR), TTHM (Total Trihalomethanes), and Total Haloacetic Acids (HAA5).
JW Marriot Hotel
IL3156836 · Non-Transient non-community system · Serves 700
4 rules violated in the past three years. Unresolved: Lead and Copper Rule (LCR), Public Notification Rule, TTHM (Total Trihalomethanes), and Total Haloacetic Acids (HAA5).
Schiller Woods W 3072
IL3074484 · Transient non-community system · Serves 400
3 rules violated in the past three years. Unresolved: Public Notification Rule.
Crabtree Nature Center
IL3100354 · Transient non-community system · Serves 273
3 rules violated in the past three years. Unresolved: Public Notification Rule.
Swallow Cliff Stairs Pavillion 5022
IL3101980 · Transient non-community system · Serves 200
3 rules violated in the past three years. Unresolved: Public Notification Rule.
37 more systems with a serious violator or health flag designation are in the lists below.
Community water systems
163 systems, largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Chicago |
2,721,308 | 4 | 0 | |
|
Cicero Cicero |
83,000 | 4 | 1 | |
|
Schaumburg Schaumburg |
75,750 | 1 | 0 | |
|
Evanston Evanston |
74,486 | 0 | 0 | |
|
Arlington Heights Arlington Heights |
73,320 | 3 | 2 | |
|
Palatine Palatine |
70,875 | 0 | 0 | |
|
Skokie Skokie |
66,422 | 4 | 1 | |
|
Des Plaines Des Plaines |
60,675 | 3 | 2 | |
|
Oak Lawn Oak Lawn |
58,362 | 1 | 1 | |
|
Orland Park Orland Park |
58,020 | 1 | 1 | |
|
Berwyn Berwyn |
57,250 | 3 | 0 | |
|
Tinley Park Tinley Park |
56,703 | 3 | 1 | |
|
Oak Park Oak Park |
54,583 | 0 | 0 | |
|
Hoffman Estates Hoffman Estates |
50,179 | 0 | 0 | |
|
Glenview Glenview |
47,856 | 2 | 0 | |
|
Buffalo Grove Buffalo Grove |
43,212 | 2 | 0 | |
|
Bartlett Bartlett |
41,500 | 1 | 0 | |
|
Mount Prospect Mount Prospect |
41,000 | 3 | 1 | |
|
Park Ridge Park Ridge |
39,800 | 1 | 1 | |
|
Wheeling Wheeling |
39,725 | 0 | 0 | |
|
Streamwood Streamwood |
38,360 | 0 | 0 | |
|
Hanover Park Hanover Park |
37,470 | 2 | 1 | |
|
Calumet City Calumet City |
37,000 | 4 | 1 | |
|
Northbrook Northbrook |
34,200 | 2 | 0 | |
|
Elk Grove Village Elk Grove |
31,802 | 4 | 1 | |
|
Aqua Illinois-North Maine Utilities |
30,043 | 1 | 0 | |
|
South Stickny SD Burbank (south Stickney) |
30,000 | 3 | 1 | |
|
Niles Niles |
29,350 | 1 | 1 | |
|
Lansing Lansing |
29,076 | 4 | 3 | |
|
Wilmette Wilmette |
27,650 | 2 | 1 | |
|
Oak Forest Oak Forest |
27,478 | 2 | 1 | |
|
Chicago Heights Chicago Heights |
26,184 | 2 | 0 | |
|
Morton Grove Morton Grove |
25,297 | 3 | 2 | |
|
Elmwood Park Elmwood Park |
25,000 | 2 | 1 | |
|
Harvey Harvey |
25,000 | 2 | 1 | |
|
Melrose Park Melrose Park |
24,206 | 0 | 0 | |
|
Maywood Maywood |
24,090 | 4 | 2 | |
|
Rolling Meadows Rolling Meadows |
23,329 | 3 | 1 | |
|
South Holland South Holland |
22,000 | 1 | 1 | |
|
Park Forest Park Forest |
21,687 | 1 | 0 | |
|
Blue Island Blue Island |
21,494 | 1 | 0 | |
|
Dolton Dolton |
20,510 | 5 | 2 | |
|
Evergreen Park Evergreen Park |
19,943 | 0 | 0 | |
|
Homewood Homewood |
19,463 | 2 | 1 | |
|
Bellwood Bellwood |
19,156 | 4 | 2 | |
|
Alsip Alsip |
19,063 | 1 | 0 | |
|
Brookfield Brookfield |
18,776 | 0 | 0 | |
|
Palos Hills Palos Hills |
18,530 | 0 | 0 | |
|
Lemont Lemont |
18,513 | 1 | 1 | |
|
Franklin Park Franklin Park |
18,467 | 4 | 1 |
Non-community systems (260: schools, campgrounds, workplaces, restaurants)
These systems serve places people visit rather than homes.
Inactive systems (2,682, no longer operating or reporting)
Kept for the record and excluded from the county totals above. Browse inactive systems.
About this data
Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Illinois records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.