| Business | Phone |
| Allard Engineering 8253 Sierra Ave # 2, Fontana 92335 | (909) 356-1815 |
| Banning & Assoc 7550 Lily Ct, Fontana 92336 | (951) 776-1515 |
| Brutoco Engineering 14801 Slover Ave, Fontana 92337 | (909) 350-3535 |
| Hall & Foreman Inc 6101 Cherry Ave, Fontana 92336 | (909) 484-9090 |
| T W Cooper Inc Fontana 92335 | (909) 427-0151 |