| Vendor Name |
| ABNA of Illinois, Inc. |
| AES Services, Inc. |
| Alfred Benesch & Company |
| Apex Consulting Engineerings, LLC |
| APS Consulting, Inc. |
| Baxter & Woodman, Inc. |
| Camp Dresser McKee, Inc. |
| Christopher B. Burke Engineering, Ltd. |
| Civiltech Engineering |
| Collins Engineers, Inc. |
| Crawford Murphy and Tilly, Inc. |
| David Mason & Associates of Illinois, Ltd. |
| DB Sterlin Consultants, Inc. |
| Delta Engineering Group, LLC |
| DuSable, Inc. |
| Dynasty Group, Inc. |
| Edgewater Resources, LLC |
| Environmental Design International, Inc. |
| Environmental Protection Industries, Inc. |
| ESI Consultants, Ltd. |
| exp. US Services, Inc. |
| Gewalt Hamilton Associates, Inc. |
| Ghafari Associates, LLC |
| Globetrotters Engineering Corporation |
| GRAEF-USA, Inc. |
| GSG Consultants, Inc. |
| HBM Engineering Group, LLC |
| Henneman Engineering, Inc. |
| Hey and Associates Inc. |
| HOH Architects, Inc. |
| Infrastructure Engineering, Inc. |
| Kaltsouni Mehdi, Inc. |
| Knight E/A Inc. |
| McDonough Associates, Inc. |
| Milhouse Engineering and Construction, Inc. |
| Primera Engineers, Ltd. |
| RME (Rubinos & Mesia Engineers, Inc.) |
| SPAAN Tech, Inc. |
| Techma Associates, Inc. |
| Terra Engineering, Ltd. |
| URS Corporation |
| V3 Companies of Illinois, Inc. |
| Wight & Company |
| Wiss, Janney, Elstner Associates, Inc. |
| WRD Environmental |
| W-T Civil Engineering, LLC |