Excavation and Trenching — Construction Safety

An excavation is a cut, cavity, trench or depression made by removing earth. A trench is a narrow excavation, generally deeper than it is wide, with a bottom width no greater than 15 feet. Forms or other structures can also make the space between a structure and the earth a trench when that bottom dimension is 15 feet or less. A wide excavation still has hazards and protective requirements.

This course covers OSHA construction Subpart P. It applies to open excavations in the earth, including trenches. The employer must also identify other rules for the actual work, equipment and jurisdiction. Underground construction and entry into a sewer, manhole or other separate structure need their own applicability review. Construction work regulated by Subpart P is excluded from Subpart AA; that exclusion does not remove atmospheric hazards or automatically cover entry into a separate confined space.

A cave-in can trap or bury a person when soil or rock separates from the face, or when soil is lost beneath a shield or support system. Other hazards include utilities, falling loads, equipment movement, falls, water, unsafe air and collapse of nearby structures. A hard hat, short task or experienced crew does not replace control of these hazards.

A competent person must be able to identify existing and predictable hazardous conditions and must have authority to take prompt corrective measures. That role includes the inspections and decisions assigned by Subpart P. A title, course certificate or ability to complete a form does not establish the needed knowledge and authority. Workers need to know who fills this role and how to report a change.

Registered professional engineers approve designs or data where the selected design route requires them. A competent person is not automatically an engineer. The employer must assign competent personnel, obtain the required design basis, train workers and provide protective arrangements before exposure. This course develops core knowledge; actual soil testing, system selection, installation and task performance need workplace instruction and verification.