| Business | Phone |
| Del-Tec Surveying & Engrg 5800 E 12 Mile Rd, Warren 48092 | (586) 573-8288 |
| Northstar Engineering Llc 11341 Meadowbrook Dr, Warren 48093 | (586) 558-4064 |
| Metco Services Inc 12504 Stephens Rd, Warren 48089 | (586) 755-5770 |
| Landwehr & Assoc 30050 Moulin Ave, Warren 48088 | (586) 751-0274 |