Safe Digging Manual Final SAMPLE - Locate Management

DISCLAIMER

This manual is aimed at developing advanced safe digging skills and attitudes for all stakeholders (individuals and companies) in the ground disturbance and excavation communities. This manual provides the PROPPER processes to plan and safely perform a ground disturbance (excavation) as per applicable regulatory requirements and industry best practices and standards.

This manual is not a definitive guide to government regulations nor is it a comprehensive guide to the practices and procedures wholly applicable to every ground disturbance or excavation.

Appropriate regulations, company-specific work practices and manufacturers’ equipment instructions must be consulted and applied with due diligence.

Despite a worker’s qualifications, training and experience, there are no guarantees that work will be performed safely.

Understanding of the content in this manual does not indicate or prove competency to safely conduct or supervise a ground disturbance.

Locate Management has made every attempt to ensure the accuracy of the content. However due to the extent of the subject matter, Locate Management and its Owners, Directors, Employees, Partners, affiliates or contributors accept no responsibility or liability with respect to this content or its application that may lead to any injury, loss or damage arising from the use of this manual.

LOCATE MANAGEMENT

Locate Management is an education, training, and assessment service provider for the ground disturbance (excavation) and line locating communities. We are your source for locator education, training and assessment, and supervisory ground disturbance and digging awareness education.

For more information about Locate Management, visit us at www.locatemanagement.com.

Version 1.0

Plan Review Organize Prepare Perform Excavate Restore

SAFE DIGGING

A Guide to PROPPER Ground Disturbance

© 2018 Locate Management All Rights reserved

Safe Digging: A Guide to PROPPER Ground Disturbance

2 © 2018 Locate Management All Rights Reserved. Version 1.0

PREFACE

The content and organization of this manual closely follows Locate Management’s online Safe Digging course and can be used as a reference for the course.

This manual is an important guide during the phases of an excavation or ground disturbance project.

DISCLAIMER

This manual is aimed at developing advanced safe digging skills and attitudes for all stakeholders (individuals and companies) in the ground disturbance and excavation communities. This manual provides the PROPPER processes to plan and safely perform a ground disturbance (excavation) as per applicable regulatory requirements and industry best practices and standards.

This manual is not a definitive guide to government regulations nor is it a comprehensive guide to the practices and procedures wholly applicable to every ground disturbance or excavation.

Appropriate regulations, company-specific work practices and manufacturers’ equipment instructions must be consulted and applied with due diligence.

Despite a worker’s qualifications, training and experience, there are no guarantees that work will be performed safely.

Understanding of the content in this manual does not indicate or prove competency to safely conduct or supervise a ground disturbance.

Locate Management has made every attempt to ensure the accuracy of the content. However due to the extent of the subject matter, Locate Management and its Owners, Directors, Employees, Partners, affiliates or contributors accept no responsibility or liability with respect to this content or its application that may lead to any injury, loss or damage arising from the use of this manual.

ACKNOWLEDGEMENTS

The PROPPER Phases of Safe Digging was developed by Locate Management for the ground disturbance/excavation and damage prevention communities with the assistance of various stakeholders, associations and members, industry facility owner/operators, and ground disturbers.

The collective input and dedication to the development of the PROPPER Phases of Safe Digging from these partners and the Locate Management employees is greatly appreciated.

TERMINOLOGY

Terms used in this manual may vary between facility owners/operators and jurisdictions. Legislation referenced in this manual are merely used to provide examples. Employers and workers must understand terms, legislation and regulations applicable to their jurisdiction.

COPYRIGHT

All rights reserved. No part of this publication may be stored in a retrieval system, reproduced, or transmitted, in any form or by any means: photocopying, electronic, mechanical, recording, or otherwise, without prior written permission from Locate Management.

© 2018 Locate Management All Rights Reserved


Version 1.0 © 2018 Locate Management All Rights Reserved. 3

TABLE OF CONTENTS INTRODUCTION TO SAFE DIGGING ................................................................................................................................................. 11

Introduction to Safe Digging ............................................................................................................................................................. 11 National Energy Board (NEB) – Ground Disturbance ...................................................................................................................... 11 National Energy Board (NEB) .......................................................................................................................................................... 12 The Alberta Pipeline Act – Ground Disturbance .............................................................................................................................. 12 Alberta Occupational Health and Safety Code (2009) – Ground Disturbance ................................................................................. 12 Alberta Electrical Utility Code (2013) – Excavation Activities .......................................................................................................... 13 Primary Ground Disturbance Stakeholders ...................................................................................................................................... 13 The Pipeline and Hazardous Materials Safety Administration – Excavation Activities .................................................................... 13 The Texas Utility Code – Excavate .................................................................................................................................................. 13 The Occupational Safety and Health Administration (OSHA) – Excavation and Trench ................................................................. 14 Buried Facility Operator ................................................................................................................................................................... 14 Ground Disturber and Best Practices............................................................................................................................................... 14 Excavator vs Ground Disturber ........................................................................................................................................................ 14 Project Owner .................................................................................................................................................................................. 15 Ground Disturber .............................................................................................................................................................................. 15 Qualified Ground Disturber .............................................................................................................................................................. 15 Competent Person ........................................................................................................................................................................... 16 Training and Experience .................................................................................................................................................................. 16 OSHA – Competent Person ............................................................................................................................................................. 16 Safe Digging ..................................................................................................................................................................................... 17 Corporate Policies, Practices, And Procedures ............................................................................................................................... 18 INTRODUCTION TO THE PROPPER PHASES OF SAFE DIGGING ............................................................................................ 19 PROPPER ........................................................................................................................................................................................ 19 Planning to Dig ................................................................................................................................................................................. 19 1. Plan .............................................................................................................................................................................................. 20 2. Review and Prepare Documentation ........................................................................................................................................... 20 3. Organize and Prepare the Worksite ............................................................................................................................................. 20 4. Perform Locates ........................................................................................................................................................................... 20 5. Pre-excavate ................................................................................................................................................................................ 20 6. Excavate ...................................................................................................................................................................................... 20 7. Restore ......................................................................................................................................................................................... 20

LEGISLATION AND DAMAGE PREVENTION ..................................................................................................................................... 21 Legislation ........................................................................................................................................................................................ 21 Ground Disturbance Preparation ..................................................................................................................................................... 21 Protecting Facilities .......................................................................................................................................................................... 21 National Energy Board ..................................................................................................................................................................... 21 Pipeline and Hazardous Materials Safety Administration ................................................................................................................ 22 Other U.S. Federal Agencies ........................................................................................................................................................... 22 Transportation and Utility Corridors ................................................................................................................................................. 22 Utility Rights-Of-Way ........................................................................................................................................................................ 22 State of Land Tenure Systems ......................................................................................................................................................... 23 Caveats ............................................................................................................................................................................................ 23 Encumbrances/Liens ........................................................................................................................................................................ 23 Studies and Approvals ..................................................................................................................................................................... 24 DAMAGE PREVENTION ................................................................................................................................................................. 24 Why is a Damage Prevention Program Important?.......................................................................................................................... 25 Damage to Buried Facilities ............................................................................................................................................................. 26 Maintenance of Buried Facilities ...................................................................................................................................................... 26 The Damage Prevention Process .................................................................................................................................................... 26 Buried Facilities ................................................................................................................................................................................ 27 Buried Facility Operators .................................................................................................................................................................. 27 Privately Owned Buried Facilities ..................................................................................................................................................... 27 The Digging Community ................................................................................................................................................................... 28 Mechanical Equipment ..................................................................................................................................................................... 28 Ground Disturbance ......................................................................................................................................................................... 28 Vehicles and Equipment Crossing Pipelines.................................................................................................................................... 29 If You Intend to Disturb the Ground ................................................................................................................................................. 30

STAKEHOLDERS AND DAMAGE PREVENTION ............................................................................................................................... 33 Damage Prevention Organizations .................................................................................................................................................. 33 COMMON GROUND ALLIANCE (CGA) .......................................................................................................................................... 33 Canadian Common Ground Alliance ................................................................................................................................................ 33 811 System ...................................................................................................................................................................................... 34



ONE-CALL CENTRES ..................................................................................................................................................................... 34 Absence of One-Call Centres .......................................................................................................................................................... 35 One-Call Centre Members’ Data ...................................................................................................................................................... 35 Processing Locate Requests ........................................................................................................................................................... 35 Response to a Notification ............................................................................................................................................................... 36 Lifespan of Locates .......................................................................................................................................................................... 37 Limitations of One-Call Centres ....................................................................................................................................................... 39 THE LOCATOR ................................................................................................................................................................................ 40 Locate Marks .................................................................................................................................................................................... 40 Locate Documentation ..................................................................................................................................................................... 40 RESPONSIBILITIES OF GROUND DISTURBERS AFTER LOCATES .......................................................................................... 41 HAND EXPOSURE .......................................................................................................................................................................... 42 Hand Expose Zone .......................................................................................................................................................................... 44 Tolerance Zone ................................................................................................................................................................................ 45 SPECIAL SITUATIONS ................................................................................................................................................................... 46 Charges for Locates ......................................................................................................................................................................... 46 Emergency Locate Requests ........................................................................................................................................................... 46 Priority Locate Requests .................................................................................................................................................................. 46 Ground Disturbance Parallel to a Buried Facility ............................................................................................................................. 47 Frozen Ground ................................................................................................................................................................................. 47 Hazardous Situations ....................................................................................................................................................................... 47 Pipelines ........................................................................................................................................................................................... 48 Pipelines – National Energy Board Act ............................................................................................................................................ 48 Pipelines – CFR 49 .......................................................................................................................................................................... 48 Prescribed Area ............................................................................................................................................................................... 49 Prohibition Area ................................................................................................................................................................................ 49 Controlled Area ................................................................................................................................................................................ 50 Search Area ..................................................................................................................................................................................... 50 Ground Disturbance Near Pipelines ................................................................................................................................................. 50 NEB Approval ................................................................................................................................................................................... 51 Mechanical Excavation Near Pipelines ............................................................................................................................................ 51 Approval of Ground Disturbance ...................................................................................................................................................... 51 Suspension of Approvals ................................................................................................................................................................. 51 Earlier Advance Notification ............................................................................................................................................................. 52 Alternative Responses to Notification .............................................................................................................................................. 52 Exceptions to Pipeline Identification ................................................................................................................................................. 53 Exemption from Hand Exposure ...................................................................................................................................................... 53 Permits ............................................................................................................................................................................................. 54 Inspections ....................................................................................................................................................................................... 55 Energized Power Cables .................................................................................................................................................................. 56 Homeowners .................................................................................................................................................................................... 56 Large-Scale Projects ........................................................................................................................................................................ 56 Private Property ............................................................................................................................................................................... 56 Modifying Locate Requests .............................................................................................................................................................. 56 Marking the Limits of a Ground Disturbance Area ........................................................................................................................... 57 Failure to Respond to Locate Requests ........................................................................................................................................... 57 STAKEHOLDER RESPONSIBILITIES ............................................................................................................................................ 58 Regulatory Agencies ........................................................................................................................................................................ 59 Municipalities .................................................................................................................................................................................... 59 Operators of Buried Facilities ........................................................................................................................................................... 59 Ground Disturbance Supervisor ....................................................................................................................................................... 60 Equipment Operator (Excavator) ..................................................................................................................................................... 61 Signaller (Spotter) ............................................................................................................................................................................ 62 Locators ........................................................................................................................................................................................... 63 One-Call Centre ............................................................................................................................................................................... 63 Educators/Training Providers ........................................................................................................................................................... 63 CAPULC ........................................................................................................................................................................................... 64 CSA .................................................................................................................................................................................................. 64

INFORMATION SOURCES AND VISUAL INSPECTION ..................................................................................................................... 65 INFORMATION SOURCES ............................................................................................................................................................. 65 Land Services .................................................................................................................................................................................. 66 Buried Facility Records .................................................................................................................................................................... 66 Buried Facility Operator-Supplied Records ...................................................................................................................................... 67 Understanding Schematic Detail ...................................................................................................................................................... 67 Mechanical, Electrical, and Instrumentation Drawings .................................................................................................................... 68



Engineering Plan .............................................................................................................................................................................. 69 Electrical Engineered Plans ............................................................................................................................................................. 70 Mechanical Engineered Plans .......................................................................................................................................................... 71 As-built Drawings ............................................................................................................................................................................. 72 Aerial Imagery .................................................................................................................................................................................. 73 Plot Plan ........................................................................................................................................................................................... 73 Survey Plan ...................................................................................................................................................................................... 74 Construction Plans ........................................................................................................................................................................... 75 Photographs ..................................................................................................................................................................................... 75 Ancillary Facilities ............................................................................................................................................................................. 76 OTHER FACILITY INFORMATION SOURCES ............................................................................................................................... 77 Land Titles ........................................................................................................................................................................................ 77 Regulatory Boards, Agencies, or Commissions ............................................................................................................................... 77 Third-Party Database Record .......................................................................................................................................................... 78 Landowners ...................................................................................................................................................................................... 78 Locator Drawings ............................................................................................................................................................................. 79 INACCURATE RECORDS ............................................................................................................................................................... 79 Importance of Comprehensive Locates ........................................................................................................................................... 80 WARNING SIGNS ............................................................................................................................................................................ 80 VISUAL INSPECTION ..................................................................................................................................................................... 81 CABLE IDENTIFICATION LABELS AND TAGS .............................................................................................................................. 82

HAZARDS, OBSTACLES, AND SAFETY ............................................................................................................................................. 83 MANAGING GROUND DISTURBANCE SAFETY ........................................................................................................................... 83 Pre-Work Safety ............................................................................................................................................................................... 84 Pre-Job Safety Meetings .................................................................................................................................................................. 84

Site Background Data ................................................................................................................................................................. 85 Site Familiarization ...................................................................................................................................................................... 85

Emergency Response Plan .............................................................................................................................................................. 86 Emergency Response Plan – Training and Equipment .............................................................................................................. 86 The ERP Cycle ........................................................................................................................................................................... 86

Work Safety ...................................................................................................................................................................................... 87 Tailgate Safety Meetings ............................................................................................................................................................ 87 Work Plan ................................................................................................................................................................................... 87 Job Briefing ................................................................................................................................................................................. 88

Post-Work Safety ............................................................................................................................................................................. 88 Termination of Work Activities .................................................................................................................................................... 88 Debriefing .................................................................................................................................................................................... 88

Personal Protection Equipment (PPE) ............................................................................................................................................. 89 Safety Equipment ............................................................................................................................................................................. 89 Tools, Machinery and Excavation Equipment .................................................................................................................................. 89 Pinch Points ..................................................................................................................................................................................... 90 Lockout and Tagout Systems ........................................................................................................................................................... 90 H2S Gas ........................................................................................................................................................................................... 91 Benzene Gas ................................................................................................................................................................................... 92 Combustible Gas Monitors ............................................................................................................................................................... 92

Function or Bump Testing ........................................................................................................................................................... 92 Confined Space Entry ...................................................................................................................................................................... 93 Exposure to Extreme Weather Conditions ....................................................................................................................................... 94 Exposure to Cold Temperatures ...................................................................................................................................................... 95

Cool/Cold Working Conditions .................................................................................................................................................... 95 Prevention of Cold Injuries .......................................................................................................................................................... 95

Exposure to Hot Temperatures ........................................................................................................................................................ 95 Hot/Humid Working Conditions ................................................................................................................................................... 95

Electric Power Hazards .................................................................................................................................................................... 96 Workplace Electrical Safety ............................................................................................................................................................. 96 Maintain a Safe Distance ................................................................................................................................................................. 97 Transformer Grounding .................................................................................................................................................................... 97 Overhead Power Lines ..................................................................................................................................................................... 97

LOCATING AND MARKING ................................................................................................................................................................. 99 SUBSURFACE UTILITY ENGINEERING ........................................................................................................................................ 99 LOCATING ..................................................................................................................................................................................... 100 LOCATE MARKS ........................................................................................................................................................................... 100 Safe and Suitable Locations .......................................................................................................................................................... 101 GUIDELINES FOR OPERATOR’S FACILITY FIELD DELINEATION ........................................................................................... 102

Length, Width, and Distance ..................................................................................................................................................... 102



Single Facility ............................................................................................................................................................................ 103 Multiple Facilities ....................................................................................................................................................................... 103 Conduit Marking ........................................................................................................................................................................ 103 Corridor Marking ....................................................................................................................................................................... 104 Joint Trench .............................................................................................................................................................................. 104 Changes in Direction ................................................................................................................................................................. 104 Offset Markings ......................................................................................................................................................................... 105 Identifier, Size, and Composition .............................................................................................................................................. 105 Casings and Structures ............................................................................................................................................................. 105 Termination Points .................................................................................................................................................................... 107 No Conflict ................................................................................................................................................................................ 107

LOCATING METHODS .................................................................................................................................................................. 109 Direct Hook-Up Method ............................................................................................................................................................ 110 Inductive Clamp Method ........................................................................................................................................................... 110 Inductive Method ....................................................................................................................................................................... 110

LOCATING OBSTACLES / TRACING PROBLEMS (AOCs) ......................................................................................................... 112 The Locating Process .................................................................................................................................................................... 113

HYDROVACING AND FACILITY VERIFICATION .............................................................................................................................. 115 HYDROVAC EXCAVATION ........................................................................................................................................................... 115 Hydrovac Procedures ..................................................................................................................................................................... 116 Hydrovacing Slots for Facility Crossings ........................................................................................................................................ 118 Hydrovac Procedures for Trenchless Crossings ............................................................................................................................ 120 Hydrovac as the Primary Means of Excavation ............................................................................................................................. 123 Pilot Holes ...................................................................................................................................................................................... 123 Slot Trenches ................................................................................................................................................................................. 124 Perimeter Slot Trench .................................................................................................................................................................... 124 Sloped Trenches ............................................................................................................................................................................ 125 Hydrovac Procedures for Managing Hazardous Spills/Leaks ........................................................................................................ 126 Identification and Verification ......................................................................................................................................................... 127

SAFE DIGGING – SAFE EXCAVATION ............................................................................................................................................ 129 SOIL FACTORS ............................................................................................................................................................................. 129 Understanding Soil Terminology .................................................................................................................................................... 130 Soil Mechanics: How Trenches Fail ............................................................................................................................................... 131 Soil Classification: Types of Soil .................................................................................................................................................... 133 Testing and Evaluating Soil Types ................................................................................................................................................. 134 SAFE EXCAVATION ...................................................................................................................................................................... 135 Sloping ........................................................................................................................................................................................... 135 Benching ........................................................................................................................................................................................ 139 Scaling and Trimming .................................................................................................................................................................... 142 Temporary Spoil ............................................................................................................................................................................. 142 TEMPORARY PROTECTIVE STRUCTURES ............................................................................................................................... 143 Shoring and Shielding .................................................................................................................................................................... 143 Temporary Protective Structures ................................................................................................................................................... 144 Alternatives to Temporary Protective Structures............................................................................................................................ 144 Underpinning .................................................................................................................................................................................. 145 Installation of Shoring, Stringers, or Bracing .................................................................................................................................. 145 Timber Shoring ............................................................................................................................................................................... 146 Hydraulic Shoring ........................................................................................................................................................................... 146 Pneumatic Shoring ......................................................................................................................................................................... 147 Screw Jacks ................................................................................................................................................................................... 147 Single-Cylinder Hydraulic Shores .................................................................................................................................................. 148 Hydraulic Shoring Hazards ............................................................................................................................................................ 148 Procedures for Installing and Removing Hydraulic Shoring ........................................................................................................... 149 Waler Rail Systems ........................................................................................................................................................................ 150 Trench Boxes (Shielding) ............................................................................................................................................................... 151 Aluminum Shields (Build-a-Box) .................................................................................................................................................... 152 Slide Rail Shoring Systems ............................................................................................................................................................ 153 Combined Use ............................................................................................................................................................................... 153 Supports for Buried Facilities ......................................................................................................................................................... 154 WORKER ACCESS ....................................................................................................................................................................... 155 Ladders .......................................................................................................................................................................................... 156 Ramps ............................................................................................................................................................................................ 156 Earth Steps and Stairways ............................................................................................................................................................. 157 Guardrails and Covers ................................................................................................................................................................... 157 Walkways ....................................................................................................................................................................................... 157



TEMPORARY CROSSING RAMPS .............................................................................................................................................. 158 Temporary Dirt Crossing Ramps .................................................................................................................................................... 159 Engineered Crossing Mats ............................................................................................................................................................. 160

The PROPPER Phases of Safe Digging ............................................................................................................................................. 161 1. Plan ............................................................................................................................................................................................ 161 Utilize a Ground Disturbance Checklist .......................................................................................................................................... 162 Adhere to Legislation ..................................................................................................................................................................... 164 Define the Ground Disturbance ...................................................................................................................................................... 164 Complete Environmental Work Site Assessments ......................................................................................................................... 165 Obtain Facility Information ............................................................................................................................................................. 165 Obtain All Authorizations, Permits, Agreements, and Approvals ................................................................................................... 166 Obtain Landowner(s) Consent ....................................................................................................................................................... 166 Identify Necessary Policies and Codes of Practice ........................................................................................................................ 166 Create an Emergency Response Plan (ERP) ................................................................................................................................ 167 Ensure All Contractors/Workers Are Qualified ............................................................................................................................... 167 2. Review and Prepare Documentation ...................................................................................................................................... 168 Utilize Ground Disturbance Checklist and Review Ground Disturbance Package ........................................................................ 168 Review Information Sources and Records ..................................................................................................................................... 168 Review Crossing, Encroachment, and Access and Other Agreements ......................................................................................... 169 Review Relevant Permits ............................................................................................................................................................... 169 3. Organize and Prepare the Worksite ....................................................................................................................................... 170 Review Ground Disturbance Package ........................................................................................................................................... 170 Adhere to Agreements, Approvals, and Permits ............................................................................................................................ 170 Build and Maintain a Work Plan ..................................................................................................................................................... 170 Maintain Documentation at the Work Site ...................................................................................................................................... 170 Place One-Call ............................................................................................................................................................................... 171 Identify and Document Hazards, Hazard Controls, and Update ERP ............................................................................................ 171 Implement Safety Monitoring and Controls .................................................................................................................................... 171 Assess Environmental Requirements and Implement Controls ..................................................................................................... 172 Assess Special Construction Procedures ...................................................................................................................................... 173 Communicate with Landowners and/or Land Agents .................................................................................................................... 173 Communicate with Field Personnel/Office ..................................................................................................................................... 174 Establish Field Office ..................................................................................................................................................................... 174 Prepare Staging Area(s) ................................................................................................................................................................ 174 Verify That the Work Site Is Marked, Surveyed, and Staked ......................................................................................................... 175 Perform a Visual Inspection ........................................................................................................................................................... 175 Clear Surface Obstructions from the Work Site ............................................................................................................................. 176 Communicate with One-Call Members .......................................................................................................................................... 176 Notify One-Call Non-Members ....................................................................................................................................................... 176 Meet with Ground Disturbers to Discuss the Scope of Work ......................................................................................................... 177 Take Photographs of the Work Site ............................................................................................................................................... 177 4.Perform Locates ........................................................................................................................................................................ 178 Manage Locate Requests .............................................................................................................................................................. 178 Discuss the Scope of Work with the Locator.................................................................................................................................. 178 Perform a Visual Inspection with the Locator ................................................................................................................................. 179 Ensure Locates are Performed Safely ........................................................................................................................................... 179 Ensure All Facilities Are Located and Sufficiently Marked ............................................................................................................. 180 Review Information and Obtain Locate Documentation ................................................................................................................. 181 Take and Retain Photographs of Locates Performed .................................................................................................................... 181 Utilize Independent Locating Crews to Verify the Locates ............................................................................................................. 181 5.Pre-excavate .............................................................................................................................................................................. 182 Meet with Facility Crossing Operators ........................................................................................................................................... 182 Determine Isolation Points, Lockout Requirements, Review Safety Procedures ........................................................................... 182 Meet with Ground Disturbers to Discuss Scope of Work ............................................................................................................... 183 Inspect Tools, Machinery, and Equipment ..................................................................................................................................... 183 Ensure Safety Markers for Overhead Power Lines Are in Place ................................................................................................... 183 Ensure Ramps, Gates, and/or Access Are Suitable ...................................................................................................................... 183 Supervise Hand Exposure of Facilities .......................................................................................................................................... 184 Identify, Inspect, and Support Facilities ......................................................................................................................................... 184 Erect Safety Fences and Barricades at Crossings......................................................................................................................... 185 Resolve Locate Discrepancies with the Locator and Buried Facility Operator .............................................................................. 185 6.Excavate ..................................................................................................................................................................................... 186 Meet with Ground Disturbers to Discuss Scope of Work ............................................................................................................... 186 Inspect Tools, Machinery, and Equipment ..................................................................................................................................... 186 Adhere to Environmental Requirements ........................................................................................................................................ 187



Protect and Maintain Facility Services and Infrastructure .............................................................................................................. 188 Adhere to Tolerance Zones ............................................................................................................................................................ 188 Observe Ground Disturbance Near Facilities................................................................................................................................. 189 Clear and Grade the Work Site ...................................................................................................................................................... 189 Maintain Markings .......................................................................................................................................................................... 189 Excavate Safely ............................................................................................................................................................................. 190 Conduct Soil Classifications and Determine Soil Stabilization Requirements ............................................................................... 190 Excavate Bore Pits ......................................................................................................................................................................... 190 Resolve Incorrectly Marked Facilities ............................................................................................................................................. 191 Report Facility Damages ................................................................................................................................................................ 191 Adhere to Safe Blasting and Boring Procedures............................................................................................................................ 192 Work Safely in Rugged Terrain ...................................................................................................................................................... 192 Work Safely at Roads, Railways, and Crossings ........................................................................................................................... 192 Work Safely at Wetland Crossings ................................................................................................................................................. 193 Protect Workers in and around Excavations .................................................................................................................................. 193 Notify Facility Operators of Deviations to the Construction Plan ................................................................................................... 193 Lower Pipe Safely .......................................................................................................................................................................... 194 Manage Emergencies .................................................................................................................................................................... 194 7.Restore ....................................................................................................................................................................................... 195 Inspect Pipelines Prior to Backfilling .............................................................................................................................................. 195 Protect Facilities When Backfilling ................................................................................................................................................. 196 Complete Backfill Inspection Report .............................................................................................................................................. 197 Cleanup and Restore the Work Site ............................................................................................................................................... 197 Install Warning Signs ..................................................................................................................................................................... 198 Update Records ............................................................................................................................................................................. 198 File All Documentation ................................................................................................................................................................... 198 Due Diligence ................................................................................................................................................................................. 199

INCIDENTS AND UNSAFE DIGGING PRACTICES .......................................................................................................................... 201 Investigations of Incidents, Accidents, and Damages .................................................................................................................... 201 Incident-Producing Conditions and Preventative Procedures ........................................................................................................ 201 Insufficient Practices Causing Line Strikes .................................................................................................................................... 202 Failure to Confirm the Work Area ................................................................................................................................................... 203 Proper Confirmation Procedures .................................................................................................................................................... 203 Failure to Provide Locate Documentation ...................................................................................................................................... 203 Proper Information Sharing ............................................................................................................................................................ 203 Failure to Identify and Mark a Line in Its Entirety ........................................................................................................................... 204 Proper Line Locating Procedures ................................................................................................................................................... 204 Failure to Identify Ancillary Facilities .............................................................................................................................................. 204 Proper Ancillary Facility Identification Procedures ......................................................................................................................... 204 Failure to Verify Locates Match Records ....................................................................................................................................... 205 Proper Line Verification Procedures .............................................................................................................................................. 205 Failure to Prove Warning Signs or Locate Marks........................................................................................................................... 205 Proper Confirmation Procedures .................................................................................................................................................... 205 Failure to Locate a Live Line .......................................................................................................................................................... 206 Proper Line Locating Procedures ................................................................................................................................................... 206 Failure to Identify All Facilities Prior to Ground Disturbance .......................................................................................................... 206 Proper Line Identification Procedures ............................................................................................................................................ 206 UNSAFE DIGGING PRACTICES AND PROPER CORRECTIVE ACTIONS ................................................................................ 207 Failure to Provide Safe Worker Access ......................................................................................................................................... 207 Proper Worker Access ................................................................................................................................................................... 207 Failure to Adequately Install Temporary Protective Structures ...................................................................................................... 208 Proper Temporary Structure Installation ........................................................................................................................................ 208 Failure to Maintain a Safe Distance within the Danger Zone of an Overhead Power Line ............................................................ 209 Proper Procedures When Working Near Overhead Power Lines .................................................................................................. 209 Failure to Maintain a Safe Distance from the Edge of Open Excavations and Slopes .................................................................. 209 Proper Procedures When Excavating Near Open Excavations ..................................................................................................... 209 Failure to Use Adequate Hydrovac Procedures ............................................................................................................................. 210 Proper Hydrovac Procedures ......................................................................................................................................................... 210 Failure to Safely Cut Back Walls .................................................................................................................................................... 210 Proper Procedures for Cutting Back Walls ..................................................................................................................................... 210 Failure to Keep a Safe Distance from the Swing Area of Heavy Equipment ................................................................................. 211 Proper Procedures When Working Near Heavy Equipment .......................................................................................................... 211 Failure to Scale and Trim Loose Materials ..................................................................................................................................... 211 Proper Scaling and Trimming of Loose Materials .......................................................................................................................... 211 Failure to Protect a Worker in an Excavation ................................................................................................................................. 212



INTRODUCTION TO SAFE DIGGING 1. Explain safe digging and why it is important to workers, companies, and the public. 2. Describe how corporate policies, codes of practices, and procedures relate to safe digging. 3. Identify the PROPPER phases and best practices of safe digging.

Introduction to Safe Digging Infrastructure is constantly being upgraded, modified, and expanded through various excavation, construction, and ground disturbance projects.

Each jurisdiction may define ground disturbance differently; however, these all have similar intent.

Simply put, any man-made disturbance of the soil is a ground disturbance.

Many activities, including excavation, can result in a ground disturbance; thus, the preferred term ground disturbance is considered more inclusive than the word excavation.

National Energy Board (NEB) – Ground Disturbance The National Energy Board Act (NEB Act) states:

“Ground disturbance does not include a ground disturbance caused by (a) any activity that is specified in the orders or regulations made under subsection 112(5), (b) cultivation to a depth of less than 45 cm below the surface of the ground, or (c) any other activity to a depth of less than 30 cm and that does not result in a reduction of the earth cover over the pipeline to a depth that is less than the cover provided when the pipeline was constructed.” (National Energy Board Act (2))

Regulation means an Act, Regulation, Rules, code or Bylaw enacted by a level of government.

Under the NEB Act, anyone planning to dig near a pipeline and the pipeline company share the responsibility of preventing pipeline damage. Pipeline companies must ensure that people understand how to perform activities near a pipeline, or on a pipeline right-of-way (ROW), safely. People planning activities near pipelines must verify the location of pipelines and meet all authorization conditions prior to the commencement of activities.

With respect to ground disturbance, a project includes the construction, demolition, repair, alteration or removal of a structure, building, complex, street, road or highway, pipeline, sewage system or electric, telecommunication or transmission line; or the digging of, working in or filling of a trench, excavation, shaft or tunnel.

It is imperative that we implement safe digging practices throughout the entire ground disturbance process (i.e., from planning through restoration phases).

While there are many regulations regarding ground disturbance there is no single document which fully encompasses the various types of ground disturbance tasks, buried facilities, and safety concerns. Industry often develops acceptable practices to fulfill the requirements of various ground disturbance regulations.

Excavate or Excavation - means an operation using equipment or explosives to move earth, rock or other material below existing grade. (Note: Excavation can include augering, blasting, boring, coring, digging, ditching, dredging, drilling, driving-in, grading, plowing-in, pulling-in, ripping, scraping, trenching and vacuuming) [CCGA Best Practices]

Right-of-way – An agreement, usually registered on the certificate of title of a property, that confers on an individual, company or municipality the right to use a landowner’s property in some way. While these agreements grant rights, they also have the effect of partially restricting an owner’s use of the affected portions of land. They remain with the land and are automatically transferred from one owner to another as the land is sold. They remain on the title until the holder of the easement discharges their rights from the certificate of title. (Alberta Land Surveyors’ Association) Note: The plural form of right-of-way is rights-of-way.

Authorization – means the written consent given by a pipeline company to construct a facility across, along or under a pipeline, other than the construction of an overhead line or to undertake any activity that would cause a ground disturbance (National Energy Board Act (112), National Energy Board Damage Prevention Regulations – Authorizations (6), (7), (10) (11))



Alberta Electrical Utility Code (2013) – Excavation Activities The Alberta Electrical Utility Code (2013) in section 2-020 Excavation Activities in the Vicinity of Underground Power Lines states:

(1) Before an excavation is started the person responsible for the excavation shall contact the operator of the utility system in the area to determine if underground cables are present at the excavation site.

(2) Before an excavation is commenced the operator of underground utility cables located at the proposed excavation site shall identify and mark any underground cables that could be interfered with when the excavation is undertaken.

(3) The person responsible for an excavation shall ensure that no excavations are undertaken within 1 m of any underground utility cable unless:

(a) the excavation is done under the control of the operator of the utility system; and

(b) the excavation method is acceptable.

Primary Ground Disturbance Stakeholders Primary stakeholders in a ground disturbance near (in the vicinity of) buried facilities are:

Buried facility operators Ground disturbers Project owners Locators Regulatory agencies One-call centre

The Pipeline and Hazardous Materials Safety Administration – Excavation Activities The Pipeline and Hazardous Materials Safety Administration (PHMSA), an agency within the United States Department of Transportation (DOT), is the federal pipeline safety authority.

PHMSA regulations 192.614 and 195.442 defines excavation activities as

excavation, blasting, boring, tunneling, backfilling, the removal of aboveground structures by either explosive or mechanical means, and other earthmoving operations.

The Texas Utility Code – Excavate According to the Texas Utility Code (251.002)

excavate means to use explosives or a motor, engine, hydraulic or pneumatically powered tool, or other mechanized equipment of any kind and includes auguring, backfilling, boring, compressing, digging, ditching, drilling, dragging, dredging, grading, mechanical probing, plowing-in, pulling-in, ripping, scraping, trenching, and tunneling to remove or otherwise disturb soil to a depth of 16 or more inches.

Buried Facility Operator Responsibilities APPENDIX B – NOTES ON RULES of the AEUC is an informational (non-mandatory) part of the code. Section 2-020 of this non-mandatory appendix places the responsibility, to assure that excavation and exposure of cables is done safely, on the operator of the underground cable. The operator must determine if direct supervision is required or if the excavation activity will be conducted in a safe manner without direct supervision based on the competence of the excavator and the type of installation involved.

NOTE: There are no exemptions regarding ground disturbance practices in the vicinity of electrical cables.

AEUC APPENDIX B: 2-020 The operator of the underground cable is responsible for assuring that excavation and exposure of cables is done safely. The operator must determine if direct supervision is required or if the activity will be done in a safe manner without direct supervision. This will depend on the reliability of the excavator and the type of installation involved.

(1) defines notification

(2) defines requirement to locate

(3) defines excavation responsibilities

AEUC definition of ground disturbance activities

PHMSA definition of excavation activities

Texas Utility Code definition of excavation



LEGISLATION AND DAMAGE PREVENTION 1. Explain legislation as it pertains to ground disturbance. 2. Describe damage prevention and the damage prevention process.

Legislation A ground disturber must be aware of federal, provincial, state, and municipal regulations, as well as industry guidelines that pertain to ground disturbance within their area of responsibility.

Modern and useful regulations are necessary for ensuring the integrity of pipelines and other buried facilities; safety of employees, contractors, and the public; protection of property; and safeguarding the environment.

Ground Disturbance Preparation Three key components pertaining to preparation for ground disturbance are:

taking all precautions reasonably necessary are taken to determine whether an underground facility exists in or near the proposed work area prior to any work, operation

providing notification to buried facility operators, prior to commencing the ground disturbance (excavation), of the intent to disturb the ground and request that the buried facility operator identify and mark the location of the underground facility

not proceeding with a ground disturbance (excavation) until the locating, marking and positive identification of underground facilities has been completed

Protecting Facilities A person who obstructs or causes any obstruction to the construction, repair, or operation of an underground facility or wilfully does any damage to an underground facility may be guilty of an offence.

National Energy Board Acts and regulations, under the umbrella of the NEB, that impose obligations on any party, including pipeline operators, with respect to ground disturbances and other activities near pipelines include (but are not limited to) the National Energy Board Act, the National Energy Board Pipeline Damage Prevention Regulations – Authorizations and the National Energy Board Pipeline Damage Prevention Regulations – Obligations of Pipeline Companies.

It is imperative that we implement safe digging practices throughout the entire ground disturbance This manual will provide examples of the legislative requirements and industry best practices that are similar in purpose and meaning within Canada and the United States.

Note that legislative or regulatory requirements may not apply to all buried facility operators or ground disturbers, or in all ground disturbance situations.

The NEB Act and its regulations are accessible online at www.neb-one.gc.ca or laws.justice.gc.ca.

Any ground disturbance, activity, operation or construction of a facility near an NEB regulated pipeline (other than in an “offshore area”) must receive authorization (approval) from the pipeline company.

NEB regulations describe the conditions under which a party (e.g., buried facility operator, ground disturber) is authorized to perform these functions.

NEB requirement for authorization



STAKEHOLDERS AND DAMAGE PREVENTION 1. Define damage prevention organizations. 2. Identify the importance and limitations of one-call centres. 3. Describe a locator’s role and locate requirements. 4. Explain responsibilities of ground disturbers after locates. 5. Define hand exposure and hand expose zones. 6. Recognize and differentiate special situations. 7. Summarize stakeholder responsibilities.

Damage Prevention Organizations A damage prevention organization is a committee or other legal entity that promotes, supports, endorses, or fosters buried facility damage prevention by adopting best practices as one of its core objectives.

COMMON GROUND ALLIANCE (CGA) The Common Ground Alliance endeavors to ensure that best practices remain current; and to identify, validate, publish, and promote the adoption of new best practices. There are several regional partners of the CGA.

The motto for the CGA is:

“Damage Prevention Is a Shared Responsibility”

The Common Ground Study and the efforts of the CGA established a blueprint for the evolution of the damage prevention process. Any member of the stakeholder groups can use the current list of best practices to benchmark and monitor their adoption of best practices.

Canadian Common Ground Alliance The mission of the CCGA is “To enhance public safety, and increase the integrity and reliability of Canada’s underground utility infrastructure, through the development and implementation of effective and efficient damage prevention practices across Canada.” (Canadian Common Ground Alliance, 2014).

These local, regional, provincial/state, national or international organizations may consist of one or multiple damage prevention stakeholder groups.

The CGA fulfills its mandate by

preventing damage to the underground infrastructure and increasing safety by encouraging a sense of shared responsibility for the protection of underground facilities

supporting research development conducting public awareness and education programs identifying and disseminating stakeholder best practices serving as a clearinghouse for damage data collection, analysis, and dissemination

CGA Regional Partners and CCGA - Benefits to the Digging Community

ongoing contact and information exchange among underground stakeholders participation in developing damage prevention best practices more effective standards with improved consistency throughout regions and industries improved worker and community safety fewer working days lost to incidents or work stoppage input into regulatory development third-party investigation to provide demonstration of due diligence in the event of an incident recognition of stakeholders as responsible partners in safety and damage prevention

Regional Canadian CGA

Alberta Common Ground Alliance (ABCGA) Atlantic Canada Common Ground Alliance (ATLCGA) British Columbia Common Ground Alliance (BCCGA) Manitoba Common Ground Alliance (MCGA) Ontario Regional Common Ground Alliance (ORCGA) Québec Common Ground Alliance (APISQ) – L’Alliance pour la protection des infrastructures souterraines du

Québec Saskatchewan Common Ground Alliance (SCGA)

The CCGA publishes and periodically updates an Underground Infrastructure Damage Prevention Best Practices document.



INFORMATION SOURCES AND VISUAL INSPECTION 1. Identify various information sources and understand their importance. 2. Read, comprehend, and utilize buried facility operator-supplied records and other facility information. 3. Read, comprehend, and utilize other information sources. 4. Recognize inaccurate records. 5. Recognize warning signs. 6. Use visual inspection skills to recognize facilities. 7. Utilize cable identification labels and tags.

INFORMATION SOURCES There are many sources of information pertaining to (the presence or absence of) buried facilities.

All available sources of information should be used throughout every phase of a ground disturbance.

Information sources (companies or individuals) include, but are not limited to:

one-call centres buried facility operators (e.g., field personnel) – oil and gas, electric power utilities, gas distribution, telecommunications,

water and sewer, etc. engineering and surveying companies (e.g., land surveyors) regulatory boards (e.g., inspectors) third-party databases line locating companies (e.g., individual buried facility locators) municipal or county offices irrigation district offices landowners or occupants excavation equipment operators (e.g., backhoe operators with prior experience at the work site)

Proficiency in map reading is a critical skill and a key component in interpreting which buried facilities should be expected at a given location, leading to a safer ground disturbance.

It is important to understand general plant infrastructure and is critically important to understand the fine details pertaining to each of the facility components contained within the infrastructure.

Buried facility operators have area operations (field) personnel to operate or maintain their facilities in both urban and rural environments. Area operations personnel can assist in identifying their infrastructure, such as labels and tags on electrical and telecommunication housings, manholes and hand holes, and pipe infrastructure.

Retain a copy of any information obtained from area operations personnel. Document verbal communication(s) including name(s), date, and pertinent information.

Never rely on an information source without confirming it.

Unfortunately, there is no single repository of information that provides the details of these facilities.

Using any information source in conjunction with other information will assist in determining what facilities may be present in the ground disturbance and search areas.

There is always a risk associated with relying solely on any one source of information – each record must be proven through additional research methods.

A detailed visual inspection includes recognizing the various types, materials, sizes, and purposes of the facilities to verify that the facilities shown on the records match those found on site.

Some records may be difficult to read for non-experts and may require specific expertise or training to read or understand the information portrayed in them.

Field personnel or occupants may have additional information relating to abandoned, discontinued, deactivated, suspended, re-routed, or newly installed facilities (cables, pipes, etc.), or knowledge of facilities that are not on records.

A buried facility information source (written or verbal) may be incomplete or not accurate.



HAZARDS, OBSTACLES, AND SAFETY 1. Manage ground disturbance safety.

2. Explain electric power hazards and safety.

MANAGING GROUND DISTURBANCE SAFETY It is the responsibility of the stakeholders involved in a ground disturbance to reduce hazards and protect people, infrastructure, and the environment. This is accomplished in part through effective management of safety information gathering and communication. All ground disturbance activities are conducted with safety as the priority. Employees are thoroughly trained and briefed regarding safety measures (safe work practices), such as minimizing exposures to potentially hazardous conditions, avoiding unnecessary risks, and ensuring personal safety.

Safety management Courtesy Enbridge

To properly determine and control hazards and to mitigate risks, ground disturbance activities must include:

pre-work safety work safety post-work safety

A hazard is any thing, condition or situation that may be dangerous to the health and safety of workers.

Manage Hazards


LOCATING AND MARKING 1. Describe the quality levels of subsurface utility engineering and how they pertain to locating and ground disturbance.

2. List the questions to ask during the locating and marking phases of a ground disturbance and identify locate marks.

3. Explain field delineation guidelines for operator’s facilities.

4. Summarize various locating methods.

5. Recognize locating obstacles and tracing problems that can affect the accuracy of locates.

SUBSURFACE UTILITY ENGINEERING The American Society of Civil Engineers (ASCE) has created four levels of quality for subsurface utility engineering (SUE) that are based on risks of conflict with other buried pipelines and utilities. The higher the risk of conflict, the higher the level of information required.

The levels ranging from low to high are as follows:

Quality Level D – this basic level is based on researching existing pipeline and utility records and oral recollection.

Quality Level C – this is the most common level and is based on surveying and mapping visible above ground pipeline and utility infrastructure, and comparing it with the information obtain at Quality Level D.

Quality Level B – this level uses surface geophysical equipment that employs electromagnetic, magnetic, or elastic wave methods to locate the existence and to mark the approximate alignment of underground pipelines and utilities.

Quality Level A – this is the highest level and uses non-destructive techniques to identify the precise horizontal and vertical position of the underground pipelines and utilities.

The components of SUE should be used in sequence to manage the risk of working near buried facilities —

Quality Level D to search information. Quality Level C to perform visual inspections. Quality Level B to locate and mark the approximate alignment of buried facilities. Quality Level A is used to visually confirm the identity of the facilities after levels D, C, and B are completed.

Steps of Subsurface Utility Engineering

Locating, which is generally achieved using electromagnetic locating equipment, is performed at Quality Level B.


HYDROVACING AND FACILITY VERIFICATION 1. Describe hydrovac procedures.

2. Use hydrovac slots at facility crossings.

3. Apply hydrovac procedures for trenchless crossings.

4. Explain hydrovacing as the primary means of excavation.

5. Identify hydrovac procedures for spills and leaks.

6. List facility identification and verification procedures.

HYDROVAC EXCAVATION Hydrovac excavation is a water pressure and vacuum system used to expose buried facilities.

Hydrovac equipment uses high-pressure water to cut the soil and a vacuum to remove the excavated materials.

If the soil has not been analyzed and classified by a competent person prior to excavating with a hydrovac, then proceed as though the soil requires the most protection from cave in or trench collapse. A hydrovac system can operate at temperatures greater than 65.5ºC (~150ºF) and pressures above 3000 psi (20,684 kPa).

A hydrovac can be used to expose electrical cables. However, there are safety limitations based on specific voltages and types of cables that can be exposed while still energized.

Direct contact from the high-pressure water stream can cause damage to cables.

Buried facility operators may have high-risk cables that can only be exposed using a hydrovac after they have been de-energized and grounded.

Although a hydrovac is intended as a safe and convenient form of exposing buried facilities, the equipment has the potential of damaging facilities if proper operating procedures are not followed.

These, alone or in combination, have the potential of causing damage to the underground infrastructure.

If an electrical cable must be exposed using hydrovac while it is still energized, then non-conductive safety ground mats with the appropriate resistance rating must be used to protect workers from accidental electrical shock.

Some cables are prone to damage due to moisture migration even from low-pressure water that may enter through gaps in the cable coating/jacket.

Perform a thorough inspection of high-risk cables for possible damage prior to the cables being re-energized and backfilled.

Non-conductive safety ground mat in place

Hydrovac in use


Hydrovacing Slots for Facility Crossings The I-Slot and the Tabled I-Slot are two types of hydrovac slots commonly used at facility crossings. These slots are constructed to confirm adequate distance between exposed facilities and excavation equipment.

The ends of the slots must be wide and deep enough to allow for excavation equipment to dig without causing the inside walls to collapse onto the exposed facility.

An aerial view of an I-Slot looks like an uppercase letter “I”.

Unless otherwise specified by the buried facility operator, a safe I-Slot length is 1.5 m (~5 ft.) on either side of the exposed facility.

The depth of the I-Slot below the exposed facility is determined by the diameter of the new facility.

Unless otherwise specified, maintain a minimum separation of 600 mm (~24 in.) between the top of the new facility and the bottom of the exposed facility.

A Tabled I-Slot allows for new facilities to cross safely above existing facilities.

New facilities should not be installed above existing facilities without written permission from the existing buried facility operator.

The width of the I-Slot should be able to accommodate the equipment that is used to excavate away from the I-Slot.

Unless otherwise specified, maintain a minimum separation of 600 mm (~24 in.) between the bottom of the new facility and the top of the exposed facility.

Hydrovac I-Slot

Hydrovac I-Slot specifications

Tabled I-Slot specifications


Regardless of the slope configuration, the excavation must remain safe for workers.

It is imperative to know that the sloping regulations or standards vary between Canada and the United States.

In Canada, sloping requirements vary from province to province. However, the intent is the same across the country: to protect workers in an open excavation or trench.

In Alberta, Part 451 of the OH&S Code, defines that an employer must slope the walls of an excavation based on soil classification. The code states:

If the walls of an excavation are cut back, an employer must ensure that

(a) if the soil is classified as “hard and compact soil”, the walls are sloped to within 1.5 metres of the bottom of the excavation at an angle of not less than 30 degrees measured from the vertical,

(b) if the soil is classified as “likely to crack or crumble soil” the walls are sloped to within 1.5 metres of the bottom of the excavation at an angle of not less than 45 degrees measured from the vertical, and

(c) if the soil is classified as “soft, sandy or loose soil” the walls are sloped from the bottom of the excavation at an angle of not less than 45 degrees measured from the vertical.

The image below illustrates the Alberta requirements for cutting back walls.

Requirements for cutting back walls in Alberta

In the United States, sloping or other methods of protecting workers is required whenever an excavation is 1.2 m (4 ft.) or greater in depth or whenever an excavation shows signs of potential trench failure. Excavations exceeding 6 m (20 ft.) in depth require approval by a professional engineer.

The OSHA horizontal (width) to vertical (depth) ratio for trenches or excavations less than 6 m (20 ft.) deep are defined in the table below.

SOIL TYPE HORIZONTAL TO VERTICAL RATIO FOR

EXCAVATIONS LESS THAN 20 FEET DEEP SLOPE ANGLE

SOLID ROCK VERTICAL 90˚

TYPE A ¾ TO 1 53˚

TYPE B 1 TO 1 45˚

TYPE C 1 ½ to 1 34˚

OSHA soil classification sloping requirements chart

The image to the right illustrates a simple slope configuration based on soil type, using OSHA guidelines. Note that the slope angle is measured from the horizontal.

OSHA requirements for a simple slope configuration


Scaling and Trimming Inspections must be conducted throughout the course of a work project to ensure that the stability of the excavation walls has not been compromised.

Factors such as precipitation, vibration of equipment, and the movement of equipment, may cause cracking of the face of the excavation or otherwise loosen the materials at the edge of the excavation. The cracked face or loose materials must be scaled and trimmed from the sides of an excavation, if workers may be on or near the sides. If loose materials cannot be scaled or trimmed to safeguard the workers, then a temporary protective structure must be installed.

Temporary Spoil Topsoil or subsoils that are removed and temporarily stored (piled) during excavation activities are called spoil piles. Temporary spoil must be carefully managed to maintain safety on the work site while providing space for equipment to work and move. In some situations, the various strata of soil must be excavated and stored separately to avoid mixing. Additional temporary work space may be required for the storage of these materials. This may also include snow or surface structures that must be moved to conduct the work.

Temporary spoil must be placed no closer than 0.6 m (~2 ft.) from the surface edge of the excavation, measured from the nearest base of the spoil to the cut. A spoil pile should be placed so that it channels water away from the excavation and placed so that it cannot fall back into the excavation.

Temporary spoil piles at a pipeline ROW

Scaling and trimming loose materials Pipe protected with rubber rock-guard mat


Temporary Dirt Crossing Ramps A temporary dirt ramp may be constructed of various types of soil.

To prevent ramp materials from mixing with top soil, a geo-membrane liner may need to be laid on the ground prior to placing the ramp materials.

A liner will also prevent mixing during ramp deconstruction.

The image below illustrates the typical dimensions of a compacted-fill temporary pipeline crossing ramp.

Typical dimensions of a compacted-fill temporary pipeline crossing ramp

Temporary pipeline crossing ramps with geo-cloth


The PROPPER Phases of Safe Digging Describe and apply the PROPPER phases of safe digging

1. Plan.

2. Review and prepare documentation.

3. Organize and prepare the work site.

4. Perform locates.

5. Pre-excavate.

6. Excavate.

7. Restore.

1. Plan This is the first phase of the PROPPER process for safe digging.

No matter what the scale of the ground disturbance – always use the PROPPER approach to ensure the safety of the workers and to prevent damage to the facilities.

Depending on the scope of the ground disturbance, some of the steps listed in each phase may not be required. Larger projects may require additional steps or further definition not identified in these phases, including a Company Code of Practice (COP).

Planning for a ground disturbance


Complete Environmental Work Site Assessments A COP may include an Environmental Work Site Assessment that must be conducted by a qualified person.

For Environmental Site Assessments (ESA), Phase l includes reviewing records, interviewing personnel, and completing a site visit and evaluation; Phase 2 is intrusive investigation that usually includes ground disturbance and may follow Phase l depending on the findings.

Obtain Facility Information Prior to commencing ground disturbance activities, a COP should include obtaining all buried facility operator–supplied records including as-builts, route sheets, alignment sheets, plant drawings, instrumentation and cathodic protection drawings, electrical and mechanical drawings, survey plans, construction plans, and photographs.

Gather information from other information sources such as land titles, local authorities, and oral recollections.

The assessment will determine if contaminants are present and if some are found, a cleanup plan must be implemented to remedy the hazard prior to the ground disturbance activities.

Samples of soil, surface water, and ground water are taken and analyzed to determine the remedial actions needed to restore the site to its original condition.

Performing this task during the planning phase

minimizes or eliminates hazards reduces cost and work to produce the final project enhances safety eliminates or lessens unexpected facility conflicts decreases the number of construction changes reduces delays in gathering approvals minimizes facility relocations

This information is used to determine route selection and to conduct preliminary impact studies. Gathering information on large-scale projects should include an onsite visual inspection and preliminary locates.

Drilling and testing soil samples Courtesy Earthmaster

Obtain information


INCIDENTS AND UNSAFE DIGGING PRACTICES 1. Describe incident-producing conditions or situations and explain proper preventative procedures. 2. Recognize unsafe digging practices and explain proper corrective actions.

Investigations of Incidents, Accidents, and Damages The entire ground disturbance community should work closely together to avoid incidents, accidents, and damages. There are regulatory requirements to report and investigate these, especially in the event of serious injury or accident.

Personnel (e.g., project owner, ground disturber, facility owner/operator, or regulator) conducting incident investigations should be trained for this specific responsibility. Corporate policy may require that a ground disturbance supervisor participate (or lead) in an investigation.

An investigation may result in recommendations for appropriate corrective actions and, if agreed upon, must be carried out both corporately and by the affected individuals.

Should the existing facility owner or regulator determine (or suspect) that unsafe work practices were (or are being) used and lead to incidents (or without incident), either may suspend the ground disturber’s approval to work.

Incident-Producing Conditions and Preventative Procedures The Common Ground Alliance Damage Information Reporting Tool (DIRT) Annual (2012) Report states

The number of events submitted to DIRT for 2011 totals 207,779 (for Canada and the U.S.). It is not known exactly how many underground excavation damages actually occur in a given year.

Employers (e.g., corporations) are responsible for damage investigation and identification of corrective action.

Under some regulations, the facility owner must notify the regulator and provide reasoning for suspension.

This image illustrates the known events by root cause.

DIRT provides a mechanism for those concerned with damage prevention to submit reports of incidents to CGA regional partners (i.e., ABCGA) to determine the number of incidents (each year) and to classify the types of facilities damage and root causes with the goal of reducing damages through education and public awareness programs. Reporting of incidents by ground disturbers and facility owners to DIRT is strictly voluntary and can be made anonymously.


Failure to Verify Locates Match Records Facility owner/operator-supplied records indicated four pipelines, a 32″, 24″, 36″ and 36″. A section of the 32″ pipeline had been rerouted “B” and the abandoned section “A” was deleted from records.

Four pipelines “A”, “B”, “D”, and “E” were located, marked, and hand exposed for new pipeline construction.

Hand exposure identified two 32″ pipelines and 36″ pipelines.

The 24″ pipeline “C” went undetected during the locate phase as it was installed deeper and therefore was not identified during hand exposure.

The facility owner/operator and ground disturber confirmed the number of pipelines however they did not confirm the size of the pipelines as they appeared on record.

During boring operations, the unidentified live 24″ pipeline “C” was struck.

Proper Line Verification Procedures

The ground disturber must verify that hand exposed facilities match those on records.

Whenever there is any discrepancy found between the locates, hand exposed facilities and records, further investigations must take place prior to any ground disturbance.

Failure to Prove Warning Signs or Locate Marks City maintenance workers responding to an emergency water main break ruptured a transmission pipeline when they attempted to repair the water main.

A transmission pipeline warning sign for line “A” had been incorrectly placed over the electric power cable “F,” and was used as a starting point to locate and mark the presumed transmission line.

There was no warning sign for the electric power cable; consequently, the deeper transmission pipeline was not located.

The marked cable “F”— presumed to be one of the five transmission pipelines — was outside the hand-exposed zone and therefore not positively confirmed.

The facility owner/operator was present to witness the encroachment and repair to the water main when the transmission pipeline “A” was hit.

Proper Confirmation Procedures

Never assume that warning signs or other locate marks are placed correctly.

Always perform proper locating procedures and positive confirmation.


LOCATE MANAGEMENT

Locate Management, A Division of Hot Line Inc. is an education, training, and assessment service provider for the ground disturbance (excavation) and line locating communities. We are your source for locator education, training and assessment, and supervisory ground disturbance and digging awareness education.

For more information about Locate Management, visit us at www.locatemanagement.com.

Version 1.0

SAFE DIGGING

© 2018 Locate Management All Rights Reserved.

Locate Management is an international education, training, and assessment service provider for damage prevention stakeholders. This manual is a general guide to plan and safely perform a ground disturbance (excavation) as per applicable federal and provincial/state legislation, and industry best practices. It is a must-have for any person involved in ground disturbance and excavation activities. Designers and planners, engineers, project owners, facility owners and operators, excavators, contractors, locators, surveyors, and regulators will benefit from this manual.

For more industry-related education and training visit us at www.locatemanagement.com.

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Safe Digging Manual Final SAMPLE - Locate Management