PROTECTIVE SYSTEM REQUIREMENTS IN SHALLOW TRENCHES

When making the decision if a protective system is required in a shallow trench, the thinking is often misguided. Common practice seems to be based only on whether or not the trench is five feet deep or deeper.

The Federal Excavation Safety Standard states the following:

“Each employee in an excavation shall be protected from cave-ins by an adequate protective system designed in accordance with paragraph (b) or (c) of this section except when: (1) Excavations are made entirely in stable rock; or (2) Excavations are less than 5 feet in depth and examination of the ground by a competent person provides no indication of a potential cave-in.

In a lengthy discussion beginning on page 45926 of the federal register, the narrative that leads up to this regulation reveals a different perspective.

“The proposal clarified that inspections must first be conducted before an employer could use the exception of not providing cave-in protection in excavations less than 5 feet in depth.?There would be a presumption that excavations less than 5 feet deep need to be protected unless there is a determination by a competent person that such protection is not needed.”

Based on this, any excavation less than five feet deep NEEDS a protective system unless the competent person determines it DOES NOT need one. NOT because it is less than five feet deep. Rather, it is because of the hazards related to cave-ins. See the difference?

This difference might be subtle, but according to the above from the federal register, that is the true intent of this regulation.

Before going further, let’s add to the discussion that it is the employer’s “general duty” to provide a safe workplace. Any time an employee is exposed to being struck by soil or by something else that might be in the adjacent area, a protective system is required, regardless of the trench depth.

There are reports where employees have been killed or seriously injured in cave-ins in trenches that were only four feet deep, three feet deep, and even one that was a two-foot-eight-inch-deep trench.

To better illustrate the difference in these two perspectives, let’s show how they would play out on the jobsite in two different scenarios:

Scenario “A”

Competent Person Chuck on the phone: “Hey boss, we got the trench dug and are fixing the pipe”.

Boss Bob: “You guys using the shoring?”

Competent Person Chuck: “Didn’t have to boss. It’s only four foot-ten inches deep”.

Boss Bob: “OK. That’s good. Just don’t dig it any deeper, you know the rule.”

Contrast that scenario with the following:

Scenario “B”

Competent Person Chuck on the phone: “Hey boss, we got the trench dug and are fixing the pipe”.

Boss Bob: “You guys using the shoring?”

Competent Person Chuck: “Yessir! It’s only four foot-ten inches deep, but if this thing caves in its gonna hit somebody, so we got it shored to be safe.”

Boss Bob: “Good deal Chuck!”

?Which scenario you would feel more comfortable with, either as the employer or the employee? The intent of the rule is safety, which the soil is not subject to. Soil is subject only to forces of nature. The following is also an excerpt from the federal register found on page 45930.

“Soil is a difficult material to work with because there is no control over its structural quality. In addition, its properties vary from place to place, and they change with the passage of time due to environmental exposure. There is an infinite number of combinations of conditions and factors that can affect soil stability.”

The requirement to protect employees from cave-ins applies to shallow trenches as well as the deeper ones. OSHA believes that there is?a potential for a cave-in in virtually all excavations.?Remember, there would be a presumption that excavations less than 5 feet deep need to be protected unless there is a determination by a competent person that such protection is not needed.

A decision not to use a protective system in an excavation less than five feet deep should be based on safety concerns such as the following:

·??????The excavation face is far enough away from the employees so that if (when) it fails, no one is hit.

·??????Employees would not be struck by any structure or by any object in the adjacent area that could fall into the excavation if (when) the excavation walls fail. (Sidewalks, pavement, walls, etc.)

·??????Any utilities in the excavation or in the adjacent area need to be protected so as not to present a danger to anyone working in the excavation. A cave-in could dislodge or cause damage to utilities, resulting in serious safety problems.

·??????Employees would not be struck by any structure within the excavation that could be displaced by moving soil should a cave-in occur.

·??????Any other issue determined to present a safety concern to those working either within or around the excavation.

In conclusion, OSHA requires that employees be trained in hazard recognition and avoidance, which means that they are to be informed as to how they are being protected against cave-ins, regardless of depth.

The competent person is to be trained and knowledgeable about soils, protective systems, and in the requirements of the excavation standard. The competent person must be able to recognize existing and predictable hazards and have the authority to correct them.

A cave-in is a predictable hazard. At any depth.