EXCAVATING WITH

HYDROVACS IN THE
VICINITY OF
UNDERGROUND
ELECTRICAL PLANT 
Safe Practice Guide

Rev. Sep 2013 ihsa.ca

 Infrastructure Health & Safety Association

Safe Practice Guide

Excavating with Hydrovacs in the Vicinity
of Underground Electrical Plant

Foreword
This Guide designates the practices that should be
followed by the member firms of the Infrastructure Health
& Safety Association (IHSA) when using hydrovacuum
excavation equipment in the vicinity of underground
electrical plant. This Guide is not designed as a training
manual, but contains information, best practices and
general recommendations deemed appropriate to
perform a job in a responsible and safe manner.
The contents of this Safe Practice Guide, including all
advice, recommendations and procedures, are provided
as a service by the Infrastructure Health & Safety
Association. No representation of any kind is made to
any persons whatsoever with regard to the accuracy,
completeness or sufficiency of the information contained
herein. Any and all use of or reliance on this Safe
Practice Guide and the information contained herein
is solely and entirely at the user’s risk. The user also
acknowledges that the safe practices described herein
may not satisfy all requirements of Ontario law.
The Infrastructure Health & Safety Association wishes
to express its appreciation to those who assisted in the
preparation of this Guide.
©Infrastructure Health and Safety Association, 2011
All rights reserved. This publication may not be reproduced, in whole or in part, without
express written permission of the copyright owner.

Revised, September 2013

ISBN 978-1-894761-25-3

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The Infrastructure Health & Safety Association wishes to
express its appreciation to the following for individuals
their assistance in the preparation of this guide:

Bruce Proctor Best Practice & Safety

Compliance Ltd.
Malcolm Robertson Ontario Excavac Inc.
Phil Lafleche Ontario Excavac Inc.
Paul Kelly Super Sucker
Dan Bartels Super Sucker
Pat Forbes Badger Daylighting
Paul Maysuik Badger Daylighting
Don Gilbert FortisOntario

September, 2013

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 Table of Contents
Introduction 5
Purpose 5
Definitions 6
Section I
General
100 Hydro Excavation in Lieu of Hand Digging 12
101 Hydrovac Operator Competency and Training
Requirements 13

Section II
Health and Safety Policy
200 Safety Policy and Program 18
201 Personal Protective Equipment 18
202 Job Planning 18
203 Public and Worker Protection 20

Section III
Protection
300 Isolated or Isolated and De-Energized 23
301 Hold-off Protection 23
302 Equipotential Bonding 24
303 Equipotential Bonded Work Zones 24
304 Equipotential Bonding with Use of 32
Temporary Grounds
305 Energized Overhead Conductors 36
– Safe Limits of Approach

3
 Section IV
Locates
400 Locating Buried Utilities 40

Section V
System
500 Hydrovac Operating Requirements 42

4
Introduction
This Guide has been compiled to familiarize personnel
with the specialized techniques, work practices,
and equipment to work safely while using hydrovac
equipment in the vicinity of underground electrical plant.

Purpose
The purpose of this guide is to:
1. Educate workers on general hazard recognition,
assessment, and control practices.
2. Assist in providing a safe work zone for workers in
vicinity of energized underground electrical plant.
3. Transfer knowledge regarding these procedures to
workers, employers, and contractors.

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Definitions
Alive – See Energized
Approved: A device or method that has been evaluated
and selected from alternatives that meet the specific
requirements of the job.
Approved Work Procedure: An approved,
documented, step-by-step method that ensures the task
can be performed safely.
Apparatus: All equipment pertaining to the generation,
transmission, distribution, and use of electricity.
Arc Rating/Flame Resistant: The value attributed to
materials that describes their performance on exposure
to an electrical arc discharge.
Bond: Electrical connection that causes conductive
parts to be at an equal potential.
Bonding: (electrical) Making a mechanically secure
connection between two or more objects to ensure they
are at the same potential
Competent Person: A person who is,
a) qualified because of knowledge, training and
experience to organize work and its performance
b) familiar with the provisions of the Occupational
Health and Safety Act and the Regulations that
apply to the work
c) knowledgeable of any potential or actual danger to
health or safety in the workplace.
Competent Worker: In relation to specific work, means
a worker who is,
a) is qualified because of knowledge, training and
experience to perform the work
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b) is familiar with the provisions of the Occupational
Health and Safety Act and the Regulations that
apply to the work
c) knowledgeable of any potential or actual danger to
health or safety in the work.
Conductor: That part of a cable, overhead line, or
apparatus intended to conduct the flow of electrical
energy.
Confined Space: A fully or partially enclosed space
a) that is not both designed and constructed for
continuous human occupancy, and
b) in which atmospheric hazards may occur because of
its construction, location or contents or because of
work that is done in it;

Controlling Authority: The person(s) who occupies

a position responsible for performing, directing or
authorizing changes in conditions or position of the
specific apparatus or devices.
De-energized: Where electrical energy has been
discharged through a mechanically secure connection to
an effective ground potential.
Energized: Capable of delivering energy by reason of
being dynamically alive or charged.
Electrical Plant: Includes all components that are part
of an Electrical Distribution System both overhead and
underground that are part of the delivery and supply of
electricity. Examples of Electrical Plant Components
would be poles, guy wires, anchor rods, overhead
and underground cables/conductors, meter bases,
transformers, switch gear, pedestals, handholes, and
transformer vaults.

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Equipotential: The state of having all objects in a work
area at the same potential.
Equipotential Bonding: Provision of electrical
connections between conductive parts, intended to
ensure they are equipotential.
Equipotential Zone: A work area, the bounds of which
are set by the outermost point of conductive parts that
are connected by an equipotential bonding or grounding
system.
Flame Resistant: The property of a material whereby
combustion is prevented, terminated, or inhibited
following the application of a flaming or non-flaming
source of ignition, with or without subsequent removal of
the ignition source. Flame resistance can be an inherent
property of a material, or it can be imparted by a specific
treatment applied to the material.
Ground: Reference for zero potential, also referred to as
"earth" potential.
Grounding:
Provision of a continuous conductive path to the earth that
1. has sufficient ampacity to carry any fault current that
may be imposed on it
2. has a sufficiently low impedance to limit the voltage
rise above ground potential
3. facilitates the operation of the protective devices in
the circuit as quickly as possible
4. bleeds any excess energies induced by electric and
magnetic fields or static sources.
Ground Rod: A metallic electrode (rod or plate) inserted
into the earth that, based on its resistance, effectively
allows the flow of electrons into the surrounding soil.
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Hazard: Potential source of harm.
NOTE: The term hazard can be qualified in order to
define its origin or the nature of the expected harm
(i.e., electric shock hazard, arc-flash hazard, crushing
hazard, cutting hazard, toxic hazard, fire hazard,
downing hazard).
Hazardous Energy: Any electrical, mechanical,
hydraulic, pneumatic, chemical, or thermal energy, or
force such as gravity, that could potentially harm workers.
Hold-off: A device having its operation restricted to
previously agreed limits by the placement of a hold off
tag. Hold offs are most commonly used to block the
auto reclosing and the manual re-energization of a line
following an automatic trip.
Hydrovac: Equipment that has been originally designed
and built for the function of excavating near or exposing
underground utilities.
Isolated: Separated from all sources of dynamic energy.
Job Plan: A work plan agreed to by all workers involved,
that identifies all known hazards, the associated barrier(s)
to control each hazard, and identifies each worker’s
responsibilities in the performance of the work.
Personal Protective Equipment: Safety equipment
worn and used to reduce risk of personal injury.
Portable Bond Mat: A mat that creates an equipotential
zone for the worker to stand on during various energized
and de-energized work practices.
Rated: A qualifying term that is applied to an operating
characteristic to indicate the designated limit or limits
of the characteristic for an application under specified
conditions.

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Risk: Combination of the probability of occurrence of
harm and severity of that harm.
Safe Work Area: A specifically identified area for work
where all known hazards have been eliminated or are
controlled.
TSSA: Technical Standards & Safety Authority.
Utility Work Protection Code: The written procedures
to establish an isolated tagged and/or locked out condition
for work. The Utility Work Protection Code has been
approved and adopted by the Infrastructure Health &
Safety Association and Hydro One Inc.

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 SECTION I
General

100 Hydro Excavation Equipment

in Lieu of Hand Digging

101 Hydrovac Operator Competency

and Training Requirements

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 SECTION I
General

100 Hydro Excavation Equipment

in Lieu of Hand Digging
Many utilities use hydrovac equipment in place of hand-
digging due to restrictions in certain work environments.
For example, when excavating within one metre of
energized underground conductors, utilities require that
further excavations to expose these conductors be done
by hand only.
Hydrovac equipment can be used as an alternate
method to hand digging provided that the following
requirements have been met:
• Hydrovac equipment/vehicles used in lieu of hand
digging have been originally designed and built
for the function of excavating near or exposing
underground utilities. If this is not the case, the
owner of the equipment should seek engineering
consultation in order to determine that the equipment
in question can be used for this purpose.
• The equipment/vehicle is used only for its designed
purpose using manufacturer’s recommended
practices. If practices are unavailable, the owner of
the equipment/vehicle should develop practices in
accordance with current regulations, manufacturer’s
recommendations and this guideline. These practices
should be documented and communicated to all
workers involved in the work and be readily available
at the worksite.

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• Workers using the hydrovac equipment/vehicle are
competent to operate it safely and have received
written and oral instructions for any new or modified
equipment and/or work procedures.

• Safe work practices for working within one metre

of energized underground conductors are
documented and all workers involved understand
them. Instructions (both written and oral) should be
provided by a competent person for new workers or
for those who do not perform the work on a regular
basis.

• Additional safe work practices involving hydrovac

equipment/vehicles are documented.

101 Hydrovac Operator Competency
and Training Requirements
Every worker should have a basic understanding of
electrical theory, energy flow and barriers, grounding,
bonding, induction, effects of electricity on the human
body, system protection, step and touch potential, and
safe limits of approach.

Any worker operating hydrovac equipment should

be trained on how to use the equipment and how to
excavate safely. All hydrovac equipment should be used
in accordance with any operating manuals issued by the
manufacturer.

Knowledge of any potential or actual danger to health

and safety is part of being a competent worker or
competent person. Hazards should be identified during
the pre-start hazard assessment. Hazards can include

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working around trenches and excavations, falls, traffic,
electricity, and confined spaces. Hydrovac tanks should
be considered a confined space. A person with adequate
knowledge, training, and experience should test and
evaluate a confined space before a worker enters it.

Workers should be properly trained to use and inspect

all equipment required to perform the work, including the
hydrovac equipment, personal protective equipment, fall
protection equipment, and equipotential bonding and
grounding system.

The minimum training courses to be considered should

include:
1. The Occupational Health and Safety Act (OHSA) and
applicable Regulations – Workers should be aware
of their duties and safety responsibilities.
2. First Aid and CPR – All employers covered by the
Workplace Safety and Insurance Act are required
to have first aid equipment, facilities, and trained
personnel in all workplaces.
3. WHMIS – WHMIS training is required in all
workplaces that may have controlled products.
4. Traffic Control – For workers required to set up or
remove traffic control measures. It should include
training on using the Ontario Traffic Manual (Book 7)
– Temporary Conditions.
5. Fall Protection – For workers exposed to a fall of
three metres or any situation that could reasonably
cause injury to a worker, including falls from the top
of the vehicle and dangerous excavations.
6. Electrical Safety and Awareness for Hydrovac
Operators – For personnel who perform work using
hydrovac equipment.
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7. Confined Spaces – For any worker entering a
confined space.
8. Hydrovac Operation and Equipment Training – All
operators and personnel using hydrovac equipment
must be trained in the operation of the equipment.
9. Personal Protective Equipment – For workers who
are required to wear personal protective equipment.
10. Trenching Safety – For workers and supervisors who
are involved trenching or shoring.

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16
 Section II
Health and Safety Policy

200 Safety Policy and Program

201 Personal Protective Equipment

202 Job Planning

203 Public and Worker Protection

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 SECTION II
Health and Safety POLICY

200 Safety Policy and Program

Every hydrovac company should have a comprehensive
health and safety policy and program. The program
should explain how the supervisors and workers will be
properly trained to use the equipment. Job procedures
should be developed for excavating any type of
utility expected to be encountered so that all hazards
associated with the work are taken into account.

201 Personal Protective Equipment

The minimum requirement for safety equipment to be
used by workers should include:

• CSA-approved head protection

• CSA-approved foot protection
• CSA-approved eye protection
• CSA-approved hearing protection
• Approved arc-rated/flame-resistant clothing
• Suitable hand protection

202 Job Planning

1. Communication of Hazards
Establish and document communication protocols
prior to the start of any vacuum excavation projects.
These protocols should be communicated again (and
documented again if altered) whenever changes occur
with work procedures and whenever new workers are

18
receiving orientation at the jobsite. Do not begin work
until all workers at the jobsite have agreed to and have
signed this documentation.

Additions to these minimum guidelines for communication

can be made when necessary by the facility owner.

2. Hazard Identification – Risk Assessment

Establish and maintain procedures and safe work
practices for ongoing hazard identification, risk
assessment, and implementation of controls. The
procedures and practices should include considerations
for routine and non-routine activities for all personnel with
access to the workplace. They should be communicated
to all interested parties and reviewed/updated
periodically.

3. Work Interruption
All excavation activities should stop immediately if
damaged underground plant is seen or suspected.
Perform a worker reassessment and notify the employer
or supervisor if it is outside the scope of the worker.
This work restriction should be carried out under the
communications and emergency protocols previously
determined and agreed to by both the excavator and
facility owner.

In the event of a work restriction, the facility owner should

be notified and work should not continue until facility
personnel have inspected the worksite and approved
continuation of the work.

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203 Public and Worker Protection
Hydrovac excavation operations may be carried out
along busy thoroughfares. Personnel and equipment
may be situated in various locations along the route
and require adequate work area protection for the safe
execution of the job.
Work area protection legislation is found in the Ontario
Traffic Manual (Book 7) or the Ontario Highway Traffic
Act and local bylaws. Follow the legislation whenever
you are working near traffic.
Barricades should be placed so that the public cannot
inadvertently come into contact with the established
equipotential work environment. A non-conductive
perimeter barrier that is sufficient to protect the public
should be installed. This barrier should be designed and
installed in such a way as to prohibit public entry into the
work area. The public should be protected from touching
or approaching equipment inside the barriers to avoid
touch potential situations.
Appropriate warning signs should be conspicuously
displayed on this outer barrier.
Hydrovac equipment is used in a variety of work
settings, so the arrangements of the barriers, mats, etc.,
should be determined by the specific needs of the work
environment.

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 Section III
Protection

300 Isolated or Isolated and

De-Energized

301 Hold-Off Protection

302 Equipotential Bonding

303 Equipotential Bonded Work Zones

304 Equipotential Bonding with Use of

Temporary Grounds

305 Energized Overhead Conductors

– Safe Limits of Approach

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22
 SECTION III
PROTECTION

300 Isolated or Isolated and

De-Energized
The preferred work method when using hydrovac
equipment in the vicinity of an electrical plant is to work
with the plant isolated or isolated and de-energized.

Damaged or Suspect Cables:

When the electrical plant is damaged or suspected to
be damaged, the plant in the vicinity of the excavation
should be isolated and de-energized prior to the
excavation process.
Any damage to the electrical plant from the excavation
process or discovered during the process shall be
reported to the owner prior to any backfilling.

Working in the Vicinity of
Energized Plant
301 Hold-Off Protection
Where isolated or isolated and de-energized is not
practical and work is being performed in the vicinity of an
overhead conductor and/or an underground energized
electrical apparatus, a hold-off should be established when
deemed necessary by the controlling authority or worker(s).
Hold-off devices are primarily designed for system
protection in the event of inadvertent electrical contact
and are not designed to protect workers from electrical
contact. The controlling authority determines the
availability of hold-off protection.

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302 Equipotential Bonding
When working with an energized electrical apparatus,
equipotential bonding is the preferred method of
protecting workers from injuries due to electrical contact.
Equipotential bonding is intended to keep all bonded
equipment and personnel at the same potential to
mitigate the risk of current flow.

303 Equipotential Bonded Work

Zones
The equipotential bonded work zone incorporates a
system of conductive bonding clamps and conductors
capable of maintaining the work zone at an equalized
potential at all times. These connections include but are
not limited to the bonding of all conductive objects or
equipment such as the gun/wand, the dig tube, the truck
chassis, and the ground gradient control mat(s).

Before moving out of the equipotential work zone, water

must be turned off and any conductive equipment and/or
bonded parts of the equipotential system removed from
the excavation leaving the end of the dig tube and the
gun/wand visible. This is required when repositioning the
mats or when one of the operators needs to step off the
mat; hydrovac personnel must stay on the mats during
the work procedure.

Do not touch other non-bonded objects in the immediate

work area when the dig tube or gun/wand is in the
excavation because they are considered to be at a
different potential. Examples include a spud bar in the
excavation or a nearby hydro pole or similar equipment.
Communication between operators is an essential safety
component.

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Equipotential Set-Ups

This guide is not intended to provide specific

equipotential set-ups but may help to ensure that
essential pieces of equipment are properly bonded
together. The cables and connecters/clamps used
to create the equipotential zone are not considered
to be grounding components and as a result,
various-sized cables and approved clamps may be
used. As a minimum, #2-type grounding cable with
approved connecters rated for continuous current are
recommended for bonding cables.

The key points to remember are that all bonded

equipment be properly inspected and that personnel
involved with the hydrovac operation stay on the
mats when work is taking place.

Diagrams 1, 2, and 3 are recommended set-ups using

equipotential bonding equipment based on the hazard
of energized apparatus in or near the dig area. In
the diagrams, individual bonding cables are used to
create the equipotential zone, but there are other cable
systems that incorporate a splitter. A single mat may be
used instead of the two mats shown in the diagrams.
Whatever set-up is used, ensure that the equipment that
is part of the equipotential zone is properly bonded.

25
26
PG

A touch potential hazard exists if contact is made with an

energized conductor and one of the operators on the mats
makes contact with the truck.
Diagram 1: This set-up has the excavation work or mats
within 2 metres of the truck. The following pieces of
equipment should be bonded:
1. the mat(s) 3. the dig tube
2. the gun/wand 4. the truck.
This is based on a truck bin that may be open or there is
some form of inadvertent contact with the truck. The gun/
wand is connected to the truck by means of the metal braid
in the high-pressure water hose. However, since there is no
means of properly proving or testing this as a conductive
path, a separate bonding cable is recommended for any
set-up requiring the truck to be part of the bonded zone.

PG

27
28
PG

A different potential hazard exists if electrical contact is made and the cord-
connected light or wired pendant was not part of the Bonded Equipment,
potentially allowing for current to flow through the operator back to the truck.
Diagram 2: Similar to Diagram 1, except that this set-up
requires the mat(s), the gun/wand, the dig tube, and the
truck to be part of the bonded system. This equipotential
set-up is required when there is some form of conductive
connection between the bonded work area and the truck.
Primarily, this would include a hard-wired light being used
during the excavation activity or the use of a wired pendant.
In both cases, the cord connected to the equipment provides
a possible current path through the operator and back to
the truck if electrical contact is made. Another consideration
could be the use of a conductive “connecting device/lanyard”
if the truck is being used as an anchor point for fall protection.

PG

29
30
PG

A hazard exists if electrical contact is made with an

energized apparatus. Using this work method keeps the
operators at the same potential.
Diagram 3: Similar to Diagram 1, except that the truck
is not required to be a bonded component. This set-up is
used when the following criteria are met:
1) the truck is greater than 2 metres from the bonded
work area
2) there is no conductive connection back to the truck
such as a light or pendant. This does not include the
water hose with a metal braid as it is already part of
the bonded system.

PG

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Diagram 3: This set-up allows for situations where the
distance from the truck to the bonded work area would
make it difficult to have a cable long enough to connect
the truck to the bonded work zone. The key point is to
ensure that there is an equipotential bonded zone for all
equipment used in the immediate hydrovac area.

304 EQUIPOTENTIAL BONDING WITH THE

USE OF TEMPORARY GROUNDS
Equipotential bonding in conjunction with maintaining
safe limits of approach is the recommended method for
protecting workers from injuries due to electrical contact with
an energized electrical apparatus. As a result, temporary
grounding should only be used for specific situations.

Equipment grounding is the process of mechanically

connecting electrical equipment to the earth or system
neutral to allow current flow to ground or earth potential.
When grounding for worker protection, the capacity of
such grounding equipment should be capable of carrying
available fault current levels of the particular electrical
system.

There have been requests (primarily by Hydro Utilities) to

ground the bonded mats and equipment to some form of
ground connection. There are two major concerns with that.

First is that connecting equipment to an effective ground

will cause current to flow should contact be made
with an energized conductor. Equipotential bonding
is intended to equalize voltage, not to support any
significant amount of current flow. Unless it can be
proven that the ground connection is indeed an effective
ground, a false sense of security is could be created. An
example is using a driven or screwed-in ground probe

32
and connecting the equipotential bonding equipment to
it. Second is that a possible step potential hazard has
now been created for anyone standing near the probe if
the ground probe becomes energized.

It is NOT RECOMMENDED that temporary ground

probes be used because they are extremely difficult
to properly test and verify as an effective ground.

Grounding the truck may sometimes be a requirement if

it is requested by the Hydro Utility (Controlling Authority)
or based on the hazards identified during the job planning
process. Because temporary grounding allows a low
impedance current path through the grounding equipment
significant enough to clear a circuit, the resistance rating
of the grounding component becomes key. The system
neutral is the preferred location because the multi-
grounded system offers the best method of clearing a
circuit by either blowing a fuse or tripping a breaker should
electrical contact be made. This would most likely occur
due to contact with an overhead powerline.

Grounding the truck will be done in conjunction with

the use of equipotential bonding regardless of the work
activity. If there is electrical contact, especially with a
high-voltage powerline, ensure there is a path for the
current to flow from the truck to the ground connection,
which is intended to cause the circuit to clear.

Hydrovac operators are not qualified to connect any

form of bonding or grounding cables to the system
neutral. If grounding becomes a requirement, it must
be done in conjunction with the Controlling Authority.

33
34
PG

If this set-up meets the criteria covered in Diagram 1 or 2, a bonding

cable should be connected from the bonded work area to the truck.
Diagram 4: This set-up shows an equipotential-bonded
system with an additional grounding cable connected
from the truck to an effective ground. This grounding
component needs to be sized accordingly with properly
rated grounding clamps. A 1/0 grounding cable is the
recommended minimum. If there is a need to ground the
truck, it must be connected to an effective ground with
the ability to clear the circuit should electrical contact be
made. This work method should be used at the request
of the Controlling Authority or based on the hazards
identified during job planning. If temporary grounding
of the truck or equipment is required, it should be
connected to the system neutral or equivalent.

PG

35
305 ENERGIZED OVERHEAD CONDUCTORS
– SAFE LIMITS OF APPROACH
The table below sets out the minimum distance objects
can come to an energized overhead electrical conductor
on the nominal phase-to-phase voltage rating.

Nominal phase-to-phase
Minimum distance
voltage rating
750 or more volts, but no more
3 metres
than 150,000 volts

more than 150,000 volts, but no

4.5 metres
more than 250,000 volts

more than 250,000 volts 6 metres

EQUIPMENT AND OVERHEAD POWERLINES

Boom Movement and Maintaining Safe Limits from

Powerlines
Boom movement must be monitored to ensure that
safe distances are maintained as required by the
Occupational Health & Safety Act (O.Reg. 213/91, s.
188). It is the responsibility of all those involved with
hydrovac operations to communicate with one another
when any boom movement is required in the vicinity of
overhead powerlines. This includes during initial set-up
or to reposition the boom.

Boom Position when Setting Up or Moving the Truck

Take special care to ensure that the boom has been
properly stored in the cradle. The boom may not need
to be stored when moving the truck very short distances

36
or removing the boom from the cradle prior to getting
the truck into a working position. Take all necessary
precautions such as inspecting the surrounding area
prior to moving the truck and positioning the boom so
that its height is equal to or lower than it would be if it
was in the stored position.
Communication between the person moving the truck and
the signaller must be established and the signaller needs
to be in the best position possible to monitor the truck and
boom while maintaining visual contact with the driver.

Blockages or Removing the Dig Tube

Periodically, rocks or other pieces of debris can become
lodged in the dig tube and need to be removed to allow
for a proper vacuum. Take special care if the dig tube
needs to be elevated for removal of the blockage.
Remove sections of the dig tube if required, but in all
cases, have the signaller observe the boom movement,
giving consideration to safe limits of approach.
This same consideration needs to be taken when removing
the dig tube from the excavation, especially when
additional sections have been added because of the depth.

Induction Hazards
Energized electrical conductors generate electrostatic
and electromagnetic fields. As result, working under
some high-voltage lines can cause vehicles and metal
objects to become electrically energized to a voltage
greater than ground/earth.

Review this hazard during the job planning process and

establish a means to control induction. This could be by
using bonding techniques or combining bonding with
a method of draining the induced voltage by using a
connection to an effective ground.

37
38
 SECTION IV
LOCATES
400 LOCATING BURIED UTILITIES

39
 SECTION IV
LOCATES
400 LOCATING BURIED UTILITIES

400 Locate Requirements

Section 228(1) (a) of the Regulations for Construction

Projects 213/91 requires an employer, prior to starting
an excavation, to “ensure that all gas, electrical and
other services in and near the area to be excavated are
located and marked.

However, instead of waiting for traditional locates and

markings, a service owner and excavation contractor
can enter into an “Alternate Locate Agreement”. ALAs,
as referred to in clause 3-19 of the Ontario Regional
Common Ground Alliance’s (ORCGA) Best Practices,
allows a service owner to set terms and conditions for
the excavation contractor to follow. ALAs must provide
the same level of protection as traditional locates for the
health and safety of the workers involved in or around
the excavation.

When an ALA agreement is in place and when permitted

by a utility service owner, the employer/excavator will
be deemed to have fulfilled the requirements of section
228(1) (a) of the construction regulations.

Prior to starting the work, the excavator must have

accurate locates and markings from all other service
owners in the area being excavated. More than one ALA
may be permitted to be used on any project.

40
 SECTION V
SYSTEM
500 HYDROVAC OPERATING REQUIREMENTS

41
 SECTION V
SYSTEM
500 HYDROVAC OPERATING REQUIREMENTS

Follow these procedures when excavating with hydro-

excavation technology within 1 metre of underground
electrical plant.

1. Have a documented company safety and

maintenance program in place that is available for
review by a facility owner representative.

2. Have vacuum excavation job procedures in place

that meet or exceed the manufacturer’s equipment
specifications and are available for review by a
facility owner representative.

3. Develop additional job procedures in conjunction

with facility owners and hydro-excavators to establish
minimum standards relating to safe work performed
in the vicinity of their plant. This may include,
standards relating to water pressure, water volume,
water temperature controls, and specific personal
protective equipment minimums.

4. Document operator competencies including operator

training certificates. These may be requested by a
facility owner representative.

5. Use approved equipotential bonding equipment

and procedures when excavating within 1 metre of
underground electrical plant.

6. Have a valid locate on site before starting the

excavation.

42
7. The gun/wand should always be in motion while
excavating. Avoid aiming directly at the plant.

8. Only use hydro-excavation equipment and nozzles

specifically engineered and designed for use around
buried lines or other underground plant that is
reasonably expected to be on site.

9. Have a way to shut off the water at the excavation.

10. Have a way to measure temperatures and

pressuresat all times (e.g., calibrated gauges)

11. Be aware that the excavator must contact the utility if

damage to underground electrical plant occurs while
hydro-excavating.

43
44
 Available Safe Practice Guides
• Bare Hand Live Line • Ladder Safety
Techniques • Line Clearing Operations
• Conductor Stringing • Live Line Tool Techniques
• Entry and Work in a • Low Voltage Applications
Confined Space
• Pole Handling
• Excavating with
• Ropes, Rigging and
Hydrovacs in the
Slinging Hardware
Vicinity of Underground
Electrical Plant • Temporary Grounding
and Bonding Techniques
• High Voltage Rubber
Techniques up to 36 kV • Underground Electrical
Systems
• Hydraulics

T  905-625-0100  •  T  1-800-263-5024  •  F  905-625-8998 

info@ihsa.ca  •  ihsa.ca

© Copyright 2011. All Rights Reserved Rev. Sep 2013

Infrastructure Health & Safety Association SPG4