| Business | Phone |
| Idea Solution Design 685 Placerville Dr # 412, Placerville 95667 | (530) 622-1572 |
| Sierra Hydrotech 1024 Simon Dr, Placerville 95667 | (530) 622-7155 |
| California Geotechnical 2805 Bud Ln, Placerville 95667 | (530) 344-0644 |
| Frontier Systems 3961 Strickland Mine Rd, Placerville 95667 | (530) 622-4039 |
| Mge Engineering Inc 419 Main St, Placerville 95667 | (530) 621-9593 |