| Business | Phone |
| Creegan & D'Angelo Engineers 2420 Martin Rd # 380, Fairfield 94534 | (707) 429-5300 |
| Csi Engineering 5021 Rowe Dr, Fairfield 94533 | (707) 439-9936 |
| Cunningham Engineering Corp Fairfield 94533 | (707) 422-2018 |
| Johnson's Group Engineering 1954 London Ln, Fairfield 94533 | (707) 864-6629 |
| Robert A Karn & Assoc Inc 707 Beck Ave, Fairfield 94533 | (707) 435-9999 |