Archive Notice - OSHA Archive

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at

June 4, 1979

Mr. Victor J. Greco
Regional Supervisor
Maryland Occupational
Safety and Health
4321 Hartwich Road #418
College Park, Maryland 20740

Dear Mr. Greco:

This is in response to your recent inquiry requesting an interpretation of our trenching requirements.

29 CFR 1926.653(c) defines "Bank" as a mass of soil rising above a digging level. This area was addressed to take into consideration trenches passing close to a side of a hill or a vertical face that would have a direct bearing on the sides of the trench being excavated. The digging level could be considered as grade.

29 CFR 1926.651(i)(1) and (2) requires that excavated or other material shall be effectively shored and retained. If a compliance officer observed an employee working below grade (digging level) in a trench 6 feet in depth, 10 feet in length and 4 feet in width in unstable or soft material with a soil bank rising 6 feet above grade, he would cite 29 CFR 1926.652(b) for the trench violation, 29 CFR 1926.651(i)(1) or (2) for an excavated material violation and 29 CFR 1926.652(a) for a bank violation.

I hope this information will be helpful to you. If I may be of any further assistance, please feel free to contact me.


Grover C. Wrenn Director,
Federal Compliance
and State Programs