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Safety Memo #4 Trenching & Excavation Safety
Date: September 27, 2018
To: ACI PROJECT DIVISION
<<MANDATORY>>
[ Trenching & Excavation Safety ]
One of the most hazardous operations in construction is trenching and excavation. A trench is defined as “a narrow
underground excavation that is deeper than it is wide, and is no wider than 15 feet”.
Some of the dangers of trenching and excavation:
• Cave-ins.
• Falls into the excavation
• Falling loads
• Hazardous atmospheres
• Incidents involving mobile equipment
Do not enter an unprotected trench!
Trenches 5 feet deep or greater require a protective system.
Trenches 20 feet deep or greater require a protective system that has been designed by a registered professional
engineer.
There are multiple types of protective systems that can be applied for nearly every situation:
• Sloping: Cutting back the trench wall at an angel inclined away from the excavation.
• Shoring: Installation of aluminum hydraulics or other types of supports to prevent soil movement and cave-
ins.
• Shielding: Utilizing a “Trench Box” to protect workers from cave-ins.
According to OSHA, trenches must be inspected daily by a Competent Person AND as conditions change. Only a
Competent Person may inspect the trench to ensure all excavation hazards have been eliminated.
ACI provides training to become a certified Competent Person. If you wish to be certified, please send me a
request by email.
General Trenching and Excavation Rules:
• Trenches 4 feet or greater: ladders, steps, ramps or other safe means of exit shall be installed in the
excavation.
• Keep heavy equipment and surcharge loads at least 2 feet from trench edges.
• Know where underground utilities are located.
• Test for low oxygen, hazardous fumes and toxic gases.
• Inspect trenches daily and/or following a rainstorm.
Please refer to the attachment for further details.
Protect yourself. Protect others. Cave-ins happen in the blink of an eye and are unforgiving!!
Safety is ACI’s number one priority.
Thank you.
