| Business | Phone |
| Carone & Co Inc 5009 Forni Dr # A, Concord 94520 | (925) 602-8800 |
| Diablo General Engineering 2179 Kirker Pass Rd, Concord 94521 | (925) 676-9211 |
| Dig This Inc 5206 Valmar Dr, Concord 94521 | (925) 246-7993 |
| Dunn Co Inc 4425c Treat Blvd # 235, Concord 94521 | (925) 680-7846 |
| Reitz Bros Excavating Concord 94520 | (925) 682-2802 |
| Scharmer Co 1929 Arnold Industrial Way # B, Concord 94520 | (925) 680-1121 |
| Steve Cox Backhoe 1845 Clayton Way, Concord 94519 | (925) 798-8288 |