City of Aurora

City of Chicago

City of Chicago Park District

City of Chicago Public Building Commission

City of Elmhurst

City of Northlake

Cook County Highway Department

DuPage County Department of Environmental Concerns

DuPage County Forest Preserve

DuPage Water Commission

Elk Grove Village

Federal Aviation Administration

Illinois Department of Transportation

Illinois State Toll Highway Authority

METRA

Metropolitan Pier and Exposition Authority

Metropolitan Water Reclamation District of Greater Chicago

Northwest Suburban Municipal Joint Action Water Agency

O'Hare Airport Transit System Inc.

United States Postal Service

Veteran's Administration, Hines Hospital

Village of Addison

Village of Bensenville

Village of Franklin Park

Village of Glen Ellyn

Village of Hillside

Village of Maywood

Village of Riverdale

West Chicago Community High School District 94