| Business | Phone |
| Alexander Engineers Inc 502 W Route 66 # 17, Glendora 91740 | (626) 914-1244 |
| Pacific Consulting Engineers 345 W Foothill Blvd # D, Glendora 91741 | (626) 968-0945 |
| Phb & Assoc 1620 S Grand Ave, Glendora 91740 | (626) 914-6256 |
| H2or2 Consultants 2030 E Route 66 # 200, Glendora 91740 | (626) 852-1235 |
| Kjelstrom & Assoc 150 E Meda Ave # 130, Glendora 91741 | (626) 963-6320 |