| Business | Phone |
| C C Hooks & Assoc 3200 Industrial Hwy, Gary 46406 | (219) 949-2331 |
| Core Engineering 8047 Hemlock Ave, Gary 46403 | (219) 938-4677 |
| E B Advanced 201 E 5th Ave, Gary 46402 | (219) 882-3034 |
| General Energy Corp 504 Broadway, Gary 46402 | (219) 886-7745 |
| Greeley & Hansen 567 S Lake St, Gary 46403 | (219) 938-8354 |
| Mark J Stern & Assocs 860 Maryland St, Gary 46402 | (219) 882-6072 |
| North-West Engineering 504 Broadway # 1028, Gary 46402 | (219) 882-6856 |
| Robinson Engineering Ltd 607 S Lake St, Gary 46403 | (219) 938-7000 |