| Business | Phone |
| Alstom Power 1245 E Diehl Rd 304, Naperville 60563 | (630) 505-2440 |
| Assoc Enapplied Soil Mechanics 4s100 N State Route 59 10, Naperville 60563 | (630) 420-8300 |
| Automated Engineering Svc Corp 387 Shuman Blvd 230w, Naperville 60563 | (630) 357-8880 |
| Babic Engineering & Tool Co 5s660 Buttonwood Ct, Naperville 60540 | (630) 717-1696 |
| G R Bach & Assoc Naperville 60540 | (630) 416-0024 |
| Building Systems Engineering 1755 Park St, Naperville 60563 | (630) 753-0800 |
| Carollo Engineers 2948 Artesian Rd, Naperville 60564 | (630) 717-7247 |
| Engineered Product Svc Inc 1952 Mc Dowell Rd, Naperville 60563 | (630) 778-7773 |
| Diversified Services Network 354 Meadow Green Dr, Naperville 60565 | (630) 983-9819 |
| Civil Design Group Inc 1754 N Washington St 120, Naperville 60563 | (630) 577-1500 |
| Golder Associates Inc 1809 N Mill St, Naperville 60563 | (630) 357-2066 |