ILLINOIS EPA (IEPA)
File online https://www2.illinois.gov/epa/pollution-complaint/Pages/submit-a-complaint.aspx
Download a paper log you can mail in: http://bit.ly/OdorLog

311 / CHICAGO DEPT OF PUBLIC HEALTH  (CDPH)
https://311.chicago.gov/s/new-service-request?typecodeid=a1Pt0000000LwZwEAK&language=en_US

You can also call 311 or download the CHI311 app:
Android: https://311.chicago.gov/resource/1550684770000/mobileAppDownloadGoogle
iPhone: https://apps.apple.com/us/app/chi311/id1441580123