Abbott Laboratories
Abbot Park, IL

Adler Planetarium
Chicago, IL

Allstate Insurance Company
Northbrook, IL

Argonne Laboratories
Lemont, IL

AT&T
North America

BNSF Railroad
Chicago, IL

Boeing Company
Chicago, IL

Burlington Northern Santa Fe Railroad
Galesburg, IL

Cambridge Homes
Libertyville, IL

Canadian National Railroad
Elgin, IL

Carrier Building Services
Indianapolis, IN

Caterpillar Incorporated
Montgomery, IL

CB Richard Ellis
Chicago, IL

Central DuPage Hospital
Winfield, IL

Chicago Metro Water Reclamation District
Stickney, IL

Chicago Transit Authority
Evanston, IL

Christopher Burke Engineering
Rosemont, IL

Ciba Geigy
Northfield, IL

Citizens Utilities Storage Tank
Minooka, IL

City of Chicago
Chicago, IL

Clark Oil & Refining Corporation
Blue Island, IL

Commonwealth Edison
Morris, IL

Corps of Engineers
Mississippi River

Del Monte Corporation
DeKalb, IL

FedEx
Memphis, TN

Fermi National Accelerator Laboratory
Batavia, IL

Fifth Third Bank
Midwest

Great Lakes Naval Academy
North Chicago, IL

Illinois Department of Transportation
Illinois

Inland Steel
Gary, IN

JB Swift and Company
Worthington, MN

Kraft General Foods
Northfield, IL

Lennar Homes
Hoffman Estates, IL

Lutheran General Hospital
Park Ridge, IL

Metra Transit
Chicago, IL

Michaels Pipeline
Wisconsin

Michigan Department of Transportation
Michigan

O’Hare Airport
Chicago, IL

Old Castle Precast
Arizona

Pearce Services
Indianapolis, IN

Pepper Construction
Chicago, IL

Construction & Engineering, Inc.
Rolling Meadows, IL

Prologis Properties
Rosemont, IL

Norfolk Southern Railroad
Chesterton, IN

Northern Indiana Power Service
Porter, IN

Northwest Community Hospital
Arlington Heights, IL

NorthWest Suburban Municipal Joint Action Water Agency
Chicago, IL

Northwestern University
Chicago, IL

Pulte Homes
Schaumburg, IL

Ryland Homes
East Dundee, IL

Sabre Integrated Services
Indianapolis, IN

Santa Fe Railroad
Galesburg, IL

Schal & Associates, Incorporated
Chicago, IL

Sheehan Pipeline
Griffith, IN

Six Flags Great America
Gurnee, IL

Social Security Administration Offices 
Chicago, IL

Tappan Zee Bridge
New York

Testing Service Corporation
Carol Stream, IL

Toll Brothers, Inc.
Barrington, IL

U.S. Bank
Midwest

U.S. Corps of Engineers
Saint Louis, MO

U.S. Steel
Gary, IN

Union Pacific Railroad
Lombard, IL

United Parcel Service (UPS)
Memphis, TN & Columbia, SC

University of Chicago
Chicago, IL

Verizon Wireless
Illinois

Viox Services
Cincinnati

Walgreens Corporation
Northbrook, IL

Walmart
Elgin, IL

Weston Solutions – Superfund Site
West Chicago, IL

Wheaton College
Wheaton, IL

Wisconsin Department of Transportation
Wisconsin