| Business | Phone |
| Amtec Engineering Corp 2749 Saturn St, Brea 92821 | (562) 691-7736 |
| Baytech Engineering Co 510 W Central Ave # A, Brea 92821 | (714) 257-1680 |
| Fero Environmental Engineering 431 W Lambert Rd # 305, Brea 92821 | (714) 256-2737 |
| Amtec Engineering Corp 2749 Saturn St, Brea 92821 | (714) 993-1900 |