Oregon OSHA Standards (Partial list taken from the Specific Excavation Requirements)

1926.651(b)(1) The estimated location of utility installations, such as sewer, telephone, fuel, electric, water lines, or any other underground installations that reasonably may be expected to be encountered during excavation work, shall be determined prior to opening an excavation.

OAR 437-003-0096 Underground Installations. In addition to and not in lieu of any rules relating to “underground installations” adopted in Oregon Administrative Rules, Chapter 437, the following Oregon Revised Statutes and Oregon Administrative Rules administered by the Oregon Public Utility Commission (PUC) shall apply:

1. ORS 757.541 through 757.571; and
2. OAR 860-24-006 and OAR 860-24-007.

1926.651(b)(3) When excavation operations approach the estimated location of underground installations, the exact location of the installations shall be determined by safe and acceptable means.

1926.651(b)(4) While the excavation is open, underground installations shall be protected, supported or removed to safeguard employees.