Special Pipeline Issue
Volume 3, Issue 2
Protecting Mississippi’s vital flow...one call at a time
quiet neighbor page 14
Are you hiring the right person?
Bite off more than you can
chew, then chew it
Trenching and excavation safety
Part two: The importance of OSHA’s general requirements
By David V. Dow
As discussed in Part 1 of the series, working in trenches and excavations is potentially one of the most hazardous
types of work in the construction and utility industry. Each year, as many as 400 workers are killed, and several
thousand are injured in the U.S. Most of these workers have received no training, and the trenches and excavations in which
mishaps occur are relatively shallow (five to 15 feet deep).
The General Requirements section of OSHA’s 29 CFR 1926, Subpart P – Excavations, addresses a number of “common
sense items” related to trenches and excavations.
These are described as telephone
poles, trees, fire hydrants, street signs,
sidewalks, curbs and gutters, and similar
objects adjacent to an excavation.
They should be removed or supported
to ensure their stability and safeguard
These include underground utilities
such as sewer, gas, water, telephone
and electric lines. Utility companies
must be contacted within established
or customary local lead times, advised
of the proposed work, and asked to
establish the location of the utilities
prior to the start of actual excavation.
All underground utilities must be
protected, supported, or removed to
ACCESS & EGRESS
These are just fancy words for getting
in or out of an excavation. Trenches
and excavations deeper than four feet
require a means of access and egress.
Each worker must be within 25 feet
ACCESS & EGRESS
of a ladder, ramp or stair. The means
of access and egress must be within a
FALLING LOADS Workers are not
permitted underneath overhead loads.
In addition, employees must stand
away from equipment being loaded or
unloaded from vehicles.
WARNING SYSTEMS FOR
When equipment is operated near the
edge of an excavation, and the operator
does not have a clear and direct view of
that edge, warning systems — such as
barricades, spotters or stop logs — are
This section of the OSHA Standard
is designed to protect workers from
so-called “bad air.” Concerns include
too little oxygen, too much oxygen,
flammable gases such as methane and
natural gas, and toxic gases such as
hydrogen sulfide or carbon monoxide.
Testing and the use of ventilation
equipment are two of the most common,
and important, methods of addressing
hazardous or potentially hazardous
Employees must not work in trenches or
excavations where there is accumulated
water, or where water is accumulating,
unless adequate precautions are taken.
If the excavation work interrupts the
natural flow of surface water, then
diversion ditches, dikes or other means
may be required to keep water out.
The stability of sidewalks, streets,
adjoining buildings, walls and other
structures can be endangered by
excavation operations. Specialized
shoring systems, bracing, or
underpinning may be required to ensure
the stability of these structures and
LOOSE SOIL OR ROCK
Spoils and equipment must be set back
at least two feet from the edge of the
trench or excavation.
A properly trained and authorized
“Competent Person” must inspect
the excavation daily, prior to the start
of work, as needed throughout the
shift, after rainstorms, and following
other hazard-increasing occurrences.
The “Competent Person” must check
adjacent areas, protective systems
(before and during use), for indications
of possible cave-ins, and hazardous or
potentially hazardous conditions.
continued on page 26
Vol. 3, Issue 2
continued from page 13
Workers exposed to traffic must be
provided with, and must wear, warning
vests or other highly visible garments.
Signs, signals, barricades and/or
flagmen may also be required.
Walkways with standard guardrails are
required when employees or equipment
cross over excavations. Wells, pits,
shafts, etc., must be barricaded or
Paying close attention to each
of these important potential dangerous
circumstances will help insure worker
safety, as well as help contractors and
utilities “stay legal” with OSHA.
Editor’s Note: This is the second
of four articles in this series that
discusses specific steps that contractors
and utilities can take to help insure the
safety of their personnel. Obviously,
this is an overview of the subject. It is
impossible to properly cover the topic
in just four relatively short articles.
Contractors and utilities involved in
underground work will need additional
training to insure worker safety.
Coming in the next issue
David V. Dow is co-founder and Vice-
President of TrenchSafety and Supply,
Inc. Learn more about his company at
Traffic control cones and signs must be clearly visible, clean, and in good repair.
26 Vol. 3, Issue 2