OSHA 29 CFR Part 1926.650-.652 Subpart P-Excavations:
OSHA's excavation standard contains many different requirements as well as several appendices that can be confusing at first glance. The following information summarizes the main requirements in order to help contractors prepare the job site for OSHA inspections.
- Prior to digging, the contractor shall locate and identify all underground utilities such as sewer, telephone, fuel, electric, water lines, etc. that may be encountered during the excavation.
- The contractor must designate a competent person or qualified person to assess the excavation and determine that it is safe for project personnel to enter and work.
- All surface encumbrances such as signs, trees, fences, poles, sidewalks, etc. that create a hazard to employees must be removed or supported during the excavation.
- All excavating must maintain a minimum of 10 ft. from overhead power lines rated 50 kV or less, with 0.4 inches of clearance added for every kV over 50.
- Support systems shall be provided to ensure the stability of adjacent structures endangered by excavation operations.
- If excavation is over 5 ft. deep, a protective system such as a trench shield shall be used to prevent a cave-in.
- The contractor must provide a safe means of entering or exiting any excavation over 4 ft. deep.
- A means of egress from a trench such as a ladder, ramp, or stairway shall be located within 25 ft. of workers.
- In excavations over 4 ft. in depth, the potential for the accumulation of hazardous gases or vapors must be realized.
- Shielding systems shall be installed and removed in a manner that protects employees from cave-ins, structural collapses, or from being struck by members of the support system.
- Shielding systems shall be installed in a manner to restrict lateral or other hazardous movement of the shield in the event of a sudden collapse.
- The bottom of the shielding system can not be positioned greater than 2 ft. above the bottom of the excavation.
- Shielding systems and their components shall not be subjected to loads which they are not designed to withstand.
- Shielding systems and their components shall be securely connected to prevent predictable failures.
- The removed spoil shall not be stockpiled closer than 2 ft. from the excavation's edge.
- Backfilling shall progress together with the removal of support systems from excavations.
- Any excavation left unattended must be barricaded, fenced or otherwise protected against accidental entry by pedestrians.
- Employees exposed to vehicular traffic must wear a high-visibility vest, and the excavation must be protected from traffic.
- If employees must cross over an open excavation a safe means must be provided so that the employees do not have to jump across the trench.
- No workers shall enter or work in excavations where standing water is visible unless adequate protection is used.
- No employee shall be permitted underneath loads handled by lifting or digging equipment.
- If the competent person finds evidence of a hazardous situation that may result in a cave-in, protective system failure, a hazardous atmosphere, or other hazardous conditions, exposed employees shall be removed from the hazardous area until the necessary precautions have been taken to ensure safety.