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National Pollutant Discharge Elimination System (NPDES)

Combined Sewer Overflows in the Great Lakes Basin-Illinois

There are 152 NPDES permits which authorize discharges from combined sewer overflows (CSOs) to the Great Lakes Basin. Select the state in the right-side box for the list of CSO permits in the Great Lakes Basin in that state.

There are 42 NPDES permits for CSO discharges in the Great Lakes Basin in Illinois. All 42 of these NPDES CSO permits are in the Chicago metropolitan area and are part of the Tunnel and Reservoir Plan (TARP). The Metropolitan Water Reclamation District of Greater Chicago provides information on CSO discharges from the TARP system and has developed a program where reaches of the Chicagoland waterway map are color coded based on CSO data compiled by staff. The geographical boundaries of the segments are listed in the District's CSO Notification Plan. The Metropolitan Water Reclamation District's website can be queried for CSO Event Synopsis Reports.Exit

Map of CSO communities in Illinois that drain to the Great Lakes Basin

Municipal Operator of CSO NPDES Permit Number Water Body Directly Discharged Into
Brookfield CSO - TARP ILM580032 Salt Creek
Chicago CSO - TARP IL0045012 Chicago CSO -  North Shore Channel, North Branch Chicago River, Little Calumet River, Calumet River, Chicago River, South Branch of Chicago River (SBCR), South Fork of SBCR, Chicago Sanitary and Ship Canal, Collateral Channel and Des Plaines River
City of Blue Island CSO - TARP ILM580031 Cal-Sag Channel
City of Calumet City CSO - TARP ILM580025 Little Calumet River
City of Evanston CSO - TARP ILM580002 North Shore Channel
City of Harvey - TARP ILM580020 Little Calumet River
Des Plaines - TARP ILM580026 Des Plaines River
Dixmoor CSO - TARP ILM580011 Little Calumet River
Franklin Park CSO - TARP ILM580029 Des Plaines River
Golf CSO - TARP IL0072389 North Branch Chicago River
LaGrange Park CSO - TARP ILM580008 Salt Creek
Lansing CSO - TARP ILM580027 Little Calumet River
Lincolnwood CSO - TARP ILM580034 North Shore Channel
MWRDGC  IL0028061,
IL0047741, IL0028053, IL0028088
Little Calumet River, Weller's Creek, Chicago Sanitary and Ship Canal, North Shore Channel
Park Ridge CSO - TARP ILM580014 Des Plaines River
Phoenix CSO - TARP IL0072834 Little Calumet River
Posen CSO - TARP ILM580037 Cal-Sag Channel
Riverside CSO - TARP ILM580015 Des Plaines River
Skokie CSO - TARP ILM580036 North Shore Channel
Summit CSO - TARP ILM580033 Chicago Sanitary and Ship Canal
Village of Arlington Heights CSO - TARP ILM580006 Weller's Creek
Village of Burnham CSO - TARP ILM580018 Grand Calumet River
Village of Calumet Park CSO - TARP ILM580016 Cal-Sag Channel
Village of Dolton CSO - TARP IL0052426 Little Calumet River
Village of Forest Park CSO - TARP ILM580019 Des Plaines River
Village of LaGrange CSO - TARP ILM580009 Salt Creek
Village of Lyons CSO - TARP ILM580004 Des Plaines River
Village of Maywood CSO - TARP ILM580022 Des Plaines River
Village of Melrose Park CSO - TARP ILM580003 Des Plaines River
Village of Morton Grove CSO - TARP ILM580005 North Branch Chicago River
Village of Niles CSO - TARP ILM580035 North Branch Chicago River
Village of North Riverside - TARP ILM580030 Des Plaines River
Village of River Forest CSO - TARP ILM580024 Des Plaines River
Village of River Grove CSO - TARP ILM580021 Des Plaines River
Village of Riverdale CSO - TARP ILM580007 Little Calumet River
Village of Schiller CSO - TARP ILM580013 Des Plaines River
Village of South Holland CSO - TARP ILM580010 Little Calumet River
Village of Stickney CSO - TARP ILM580023 Chicago Sanitary and Ship Canal
Village of Wilmette CSO - TARP ILM580012 North Shore Channel

EPA’s Enforcement and Compliance History Online (ECHO) database has additional information on NPDES discharges, including CSO discharges for some facilities.

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