Illinois NPDES Permits
Pretreatment: EPA and authorized NPDES state pretreatment programs approve local municipalities to perform permitting, administrative and enforcement tasks for discharges into the municipalities. This spreadsheet explains the limits for Illinois. Region 5 Pretreatment Limit Spreadsheet Illinois/Indiana (xls) Information about the National Pretreatment Program.
For state-issued permits, visit Illinois EPA Wastewater Permit Programs.