20140957 Ver 2_Attachment 13_Brett Study_20170818

Attachment 13

Running head: PIPELINE INSTALLATION METHODS
Environmental Considerations of Pipeline Installation Methods
through Watercourses
by
SAMANTHA J. BRETT
A Thesis Submitted to the Faculty of Social and Applied Sciences
in Partial Fulfilment of the Requirements for the Degree of
Masters of Science
Environment and Management
Royal Roads University
Victoria, British Columbia, Canada
Supervisor: Dr. Ty Faechner
September, 2016
CC SAMANTHA BRETT, 2016

PIPELINE INSTALLATION METHODS
COMMITTEE APPROVAL
The members of Samantha Brett's Thesis Committee certify that they have read the thesis titled
Environmental Considerations of Pipeline Installation Methods through Watercourses and
recommended that it be accepted as fulfilling the thesis requirements for the Degree of Masters
of Science in Environment and Management.
Dr. Ty Faechner [signature on file]
Dr. Matt Dodd [signature on file]
Final approval and acceptance of this thesis is contingent upon submission of the final copy of
the thesis to Royal Roads University. The thesis supervisor confirms to have read this thesis and
recommends that it be accepted as fulfilling the thesis requirements:
Dr. Ty Faechner [signature on file]
2

PIPELINE INSTALLATION METHODS
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3

PIPELINE INSTALLATION METHODS
Abstract
Horizontal Directional Drilling (HDD) is a trenchless method used during pipeline
installation that is effective at minimizing disturbance on the surrounding environment. The
4
traditional method of pipeline installation under watercourses is termed isolated open -cut, where
surface and subsurface disturbance is created during pipeline construction. This thesis aims to
understand the decision-making tools utilized during pipeline construction projects in the oil and
gas industry where new pipeline construction is traversing watercourses along a pipeline route.
Case studies were developed to analyze pre -construction planning and construction
considerations made in relation to the physical properties of the studied site locations to
determine which crossing method is most suitable for each site. Geographical challenges, terrain,
regulatory requirements, economic costs and time constraints influence pipeline construction
when determining if HDD technology or isolated open -cut is the most suitable installation
method for a specific site.

PIPELINE INSTALLATION METHODS
Acknowledgements
I would like to thank my thesis supervisor, Dr. Ty Faechner at the University of Alberta
for agreeing to be my thesis supervisor just over a year ago. He provided continuous support and
motivation, making himself available upon request and was dedicated to improving the academic
rigor of my work.
Thank you to my committee member Dr. Matt Dodd at Royal Roads University for
agreeing to be part of my academic support network for the final thesis process of my Masters of
Science degree.
Thank you to Mr. Bill McLaren, a previous supervisor in my field of work for
introducing me to the world of pipeline construction. Bill invested in me by giving me the
opportunity of a lifetime; to work under his supervision as a project environmentalist.
Lastly, thank you to my friends, family and academic peers for providing limitless love
and encouragement throughout the journey of my thesis development.

PIPELINE INSTALLATION METHODS
Table of Contents
I. Problem and Its Background
Introduction.................................................................................................... 9
6
Objectives....................................................................................................... 12
Scope and Limitations........................................................................................13
Significance of the study.....................................................................................14
II. Literature Review
LiteratureReview..............................................................................................14
Relevance of Literature Review..............................................................................26
III. Research Methodology
ResearchMethod.............................................................................................27
IV: Presentation of Analysis and Results
SITE A Crossing Procedure.................................................................................30
SITE B Crossing Procedure.................................................................................49
Discussion..................................................................................................... 64
Environmental Considerations...............................................................................66
Implementation of Crossing Methods......................................................................68
V: Conclusion and Recommendations
Conclusion.................................................................................................... 71
Recommendations............................................................................................ 72
GLOSSARY..................................................................................................73
REFERENCES............................................................................................... 76

PIPELINE INSTALLATION METHODS 7
List of Figures
Figure 1: Construction Technique -Horizontal Directional Drill.......................................16
Figure 2: Site `A' and `B', map of Alberta................................................................30
Figure 3: Site `A' field -site location sketch...............................................................3 l
Figure 4: Construction Technique -Typical Dam and Pump..............................................37
Figure 5: Site `B' site -field location sketch...............................................................50
List of Photos
Photo 1: East slope (Site A) stripped of topsoil...........................................................33
Photo 2: East slope (Site A) graded out, showing clay seam.............................................36
Photo 3: Clay seam present on both slopes with constant seepage......................................36
Photo 4: East slope (Site A) facing downstream isolation plate.........................................39
Photo 5: Site A downstream isolation plate................................................................39
Photo 6: East slope (Site A), lowering -in pipe section....................................................41
Photo 7: Site A, upstream soil wraps, bed and bank restoration complete .............................42
Photo 8: Deleterious matter in watercourse following a series of rainfall events......................44
Photo 9: Looking at the west slope (Site A) final restoration............................................45
Photo 10: Watercourse channel and banks, 1st winter post -final clean up ............................46
Photo 11: Fall rye grass seed successfully growing on slopes of the watercourse ................... 47
Photo 12: West slope (Site A) surface erosion prior to final clean up................................48
Photo 13: East slope (Site B) clearing activity............................................................51
Photo 14: Typical HDD pad and drill rig set up example..............................................52
Photo 15: HDD pilot hole and stem example.............................................................53
Photo 16: Pilot -hole punch out example, showing drill head...........................................53

PIPELINE INSTALLATION METHODS 8
Photo 17: Complete HDD product line installation example...........................................54
Photo 18: Site B downstream isolation plate and ditch preparation....................................55
Photo 19: Site B pipeline installation facing east slope................................................55
Photo 20: HDD Frac-out example#1.....................................................................57
Photo 21: HDD Frac-out example#2......................................................................57
Photo 22: Site B final restoration of watercourse facing downstream................................58
Photo 23: One year post construction facing west slope................................................59

PIPELINE INSTALLATION METHODS
Chapter I: Problem and its Background
Introduction
Pipeline installation methods through watercourses during pipeline construction has
raised a number of important questions involving localized environmental disturbance and
9
impact, technological diversity, economic benefits, and managing those dynamics in the pipeline
construction industry. Open -cut pipeline installation techniques through watercourses have been
the traditional installation method of oil and gas pipelines, water lines, communication cables,
and other modern utilities for decades.
There have been a number of studies and reports developed to outline the economic and
social impacts of open -cut practices, for example in the book Horizontal Directional Drilling:
Utility and Pipeline Application (Willoughby, 2005), the website article How we cross rivers and
streams (Spectra Energy, 2013) and the online guide Horizontal Directional Drilling Guide; a
Comprehensive look at the North American HDD Industry (Trenchless Technology, 2011), to
name a few. These studies have occurred in populated regions where utilities and roadways are
abundant, close together and otherwise congested environments where the open -cut method
would be time-consuming, socially inconvenient, costly and often destructive to the existing
infrastructure in the long term. This has resulted in considerable interest in understanding and
implementing trenchless technology, specifically Horizontal Directional Drilling (HDD).
HDD technology has been used for approximately 30 to 40 years (Skonberg, 2011) in
situations where above and underground infrastructure is congested. The HDD method is useful
where there is a limited impact on the surface at the worksite, where only a small area is required
to set up the drilling rig and the pipeline is "piloted" into the ground under the existing obstacles,
and an exit point developed on the opposite side. The rest of the work takes place underground,

PIPELINE INSTALLATION METHODS
commonly completed in three separate phases which will be explained later (pilot, ream and
pullback), without disrupting daily public activities and the surface environment. With this
method often comes a higher up -front cost during project construction. HDD is typically less
costly when considering long-term environmental effects in comparison to other installation
methods such as isolated open -cut. Trenchless technology is very common in cities and places
that are heavily populated and developed.
Watercourses are extremely important and highly protected physical and ecological
features found on many landscapes across Canada. The isolated open-cut/dam and pump
installation method is used on a watercourse that is of manageable size, allowing a relatively
quick trench -line excavation to take place, pipe installation to occur, and backfilling of the
trench -line to begin immediately after installation. Creek or river bank restoration must take
10
place immediately, be done accurately, quickly, and with the appropriate design and materials to
restore the physical and ecological integrity of the site. Even the most experienced practitioners
have stability failures in their restoration work over time. Over time, river bank restorations lose
their initial structure, typically due to natural processes such as unpredictable weather, freezing
and thawing soils, flooding, seasonal watercourse fluctuations, or if slope instability is prone to
that area. Sedimentation of the watercourse may also occur due to the exposed virgin soil on the
approaching slopes that are stripped of natural vegetation and topsoil during the initial
construction inhibiting revegetation in the riparian zone post -construction.
HDD contrasts with the traditional, open -cut isolation method for watercourse crossings
and pipeline installation because very little impact is made during the pipeline installation
process. The drilling rig must be set up in suitable areas on either side of the watercourse,
typically on level topography with stable ground that allows sufficient room for the pipeline

PIPELINE INSTALLATION METHODS 11
section to be welded and fabricated (or "strung" together into a drag -section) and eventually
pulled into the earth hole called the "entry point". The drill pad and drill -rig is typically setback
at a distance of 100 m from the top -of -bank of a large permanent watercourse and 45 m from
intermittent and small permanent watercourses, according to regulatory requirements outlined in
the Integrated Standards and Guidelines, Enhanced Approval Process (Alberta Government,
2013). Topography is a factor when determining the length that the drill will travel, taking into
consideration the quality of the subsurface material, which is determined by geotechnical
investigations, as well as the width of the watercourse valley. These variables are site dependent.
Typically, the drill rig will be set up on the side of the crossing with the highest elevation to
allow the drilling operation to drill in the favour of gravity. Where the drill rig is set up is called
the entry side and where the HDD bore comes out of the ground is the exit side. The area of
disturbance is far less than that of the open -cut method because the entry and exit points are set
back from the watercourse which eliminates trenching through the riparian zone. The setback
allows the appropriate trajectory to be achieved underground, since the pipeline will be installed
at a much greater length and depth than that of the open -cut method to minimize the possibility
of frac-outs caused by the fluid pressures necessary during a HDD. This results in less impact to
the immediate watercourse bed and banks, allowing the watercourse to maintain its natural flow
pattern without the risk of construction -related bank erosion and instability. Although HDD
installations do not create a large volume of sedimentation in watercourses and generally avoid
bank disturbances in the riparian vegetation, the potential for environmental damage due to
unexpected releases of drilling mud still exists (Reid, Ade, Metikosh, 2004).
With HDD, there are other environmental risks to consider such as frac-outs, which are
surface releases of drilling -mud caused by underground drilling activity. Frac-outs can be pushed

PIPELINE INSTALLATION METHODS 12
to the surface through underground seams, causing potential damage to surface environments
and the associated ecological behaviour of the flora and fauna in the region. Frac-outs may or
may not happen during the HDD process and are typically difficult to predict given extensive
sub -surface geotechnical exploration prior to the project initiation. A frac-out can also occur in
the watercourse itself, causing high turbidity and sedimentation of the watercourse. Executing a
sufficient amount of geophysical research prior to HDD pipeline installation, along with
appropriate drill depths, will mitigate this risk.
The awareness of the environmental regulatory framework surrounding the oil and gas
industry within Canada has become critical when developing pipeline project proposals and
providing supporting documentation to the National Energy Board (NEB) or provincial
regulators, for example Alberta Energy Regulator (AER). The business responsible for the
completed pipeline project must ensure in the planning phase that all environmental regulations
are considered, and make these commitments known to the contractor who will be building the
pipeline in the field.
Objective
The objective of this research is to explore and document the benefits and constraints of
pipeline installation methods through watercourses in mitigating environmental disturbances
caused by those installation methods. To achieve this objective a review of a case study of two
methodologies for pipeline installation through naturally occurring watercourses on pipeline
projects will be undertaken. The review focuses on best management practices (BMP's) for each
particular methodology. The study objective was developed in close consultation with horizontal
directional drilling companies, oil and gas pipeline companies, and pipeline construction
companies.

PIPELINE INSTALLATION METHODS 13
Scope and Limitations
The high level of risk and cost associated with HDD along with a lag in knowledge and
experience are contributing factors as to why industry and companies are not rapidly adopting
the HDD installation method at large watercourse crossings. Another limitation is the assessment
of horizontal directional drilling and isolated open -cut site restoration and visible indicators of
restoration success. Woolsey et al., (2007) recommends that at least 1 to 3 years should be
allowed for a sufficient project assessment to take place before the effects of restoration may be
measureable, which extends the restoration process assessment. Reid, Stoklosar, Metikosh and
Evans (2002) states that sediment loads within watercourses caused by construction are usually
temporary with full recovery to pre -disturbance conditions within 1 to 2 years. Project evaluation
may be carried out at these sites for a number of years. For the purpose of this thesis, the project
was concluded 1 to 2 years post -construction, and evaluated on an immediate basis. A limitation
of long-term restoration monitoring is economic feasibility and 1 to 2 years was the extent of
funding for this project. Accessibility to information regarding the HDD project at Site B is
limited due to the project period. Environmental Impact Assessments (EIAs) performed at each
site prior to construction were not obtainable by the author. EIAs would have been performed at
these crossings under regulation of the Fisheries Act and The Canadian Environmental
Assessment Act (CEAA) Department of Justice Canada 1992), requiring an assessment of
environmental effects associated with "physical activities carried out in the water body",
determination of the significance of the effects, and mitigation of effects (Levesque and Dube
2007).
In addition, the environmental monitoring done at SITE A by the author was also limited
to two seasons and SITE B to one season, and therefore the current state of the site is unknown.

PIPELINE INSTALLATION METHODS
14
Funding and resources were limited to continue field research and the author has not documented
any long-term local environmental changes. The monitoring at each site has followed through by
the owner of the pipeline after construction commenced.
Significance of the Study
The study's significance is to provide insight for the two described methods of pipeline
installation under watercourses and ecosystems. This thesis is intended to describe industry
knowledge to a wider audience beyond the pipeline construction and oil and gas industry. By
linking ecological impacts to installation methods, a comparison can be made between two
methods of installation and provide transparency about the sustainability of watercourse
resources. A significant component of this study is to understand the decision-making tools
utilized during pipeline construction projects in the oil and gas industry where new pipeline
construction is traversing watercourses along a pipeline route. To inform the development and
consideration of the best management practices (BMPs), this work will provide comparisons of
horizontal directional drilling and isolated open -cut methodologies for pipeline construction
management plans.
Chapter II: Literature Review
In the Horizontal Directional Drilling Guide, Comprehensive Look at the North American
HDD Industry (2011), Skonberg included a chapter that discusses the benefits and risks of a
multitude of environmental factors when utilizing HDD and other trenchless technologies.
Skonberg (2011) describes the factors to consider when trying to determine which method of
pipeline installation to use (HDD or open -cut), including ground conditions, hydrology, river bed
movement, site-specific soil boring, construction impacts at the rig -sites, permit authorities and

PIPELINE INSTALLATION METHODS
regulatory requirements, drilling mud properties, frac-out cause and cleanup, and pipeline wall
thickness (thickness of the steel used to fabricate the pipe). In this Guide, Skonberg (2011)
primarily describes the benefits of HDD pipeline installation, with little discussion of the open -
cut installation method, but he acknowledges the environmental risks involved with HDD
technology during pipeline installation under watercourses. This information was helpful to the
15
development of this thesis because he asks questions that are directly pertinent to the study -sites
in this thesis, specifically providing well-rounded experiential knowledge regarding HDD
fieldwork and considerations.
Bennett and Ariaratnam (2008) wrote another widely utilized guide in the pipeline and
direction drilling industry. This book is descriptive and practical in explaining elements of HDD
and trenchless pipeline installation methods, including the economic, social and environmental
footprint caused by HDD plus the past and future of this technology. The literature in this book is
heavily based on the engineering of the HDD method. This was helpful to define and explain the
sequence of the HDD work using the appropriate terminology and identifying the steps where
unfavourable malfunctions may occur. Unfavourable malfunctions meaning a delay in the work
due to unforeseen events, or adverse effects on the surrounding environment. Trenchless
methods carry a certain level of risk since there is a dependence on technology and a reliance on
the subsurface materials and geotechnical assessment. According to Benett and Ariaratnam
(2008) the information is collected during the planning phase when determining if HDD is an
appropriate method for the crossing. Isolated open -cut is sometimes preferred for that very
reason; there is a greater sense of control at the site while working on the surface and watching
the material change as equipment cuts through the channel to prepare the ditch for pipeline
installation. In addition, open -cut requires less individual training in order to perform the work

PIPELINE INSTALLATION METHODS
required to successfully install the product line, compared to HDD technology which requires
specific technical training and ample field experience.
Horizontal
Drillin Rig Drilling Fluid
9 g Retums Prefabricated
Pull Section
Watercourse
Swivel
General Direction of
Pulling Back
Profile
(Not to Scale)
16
Figure 1. Construction Technique -Typical Horizontal Directional Drill (Canadian Association of
Petroleum Producers (CAPP), Canadian Energy Pipeline Association (CEPA) and Canada Gas
Association (CGA), 2005).
A pilot bore or pilot hole is essentially the first step in the HDD process. After the entry
site is selected, the entry pit is established and the drilling fluids are mixed and ready to be
pumped into the pilot hole in the ground, as shown in Figure 1. A pilot hole is defined as a
"small diameter hole directionally drilled along the path in advance of reaming operations and
pipe installation" (Willoughby, 2005). The pilot hole is drilled along the planned drill route from
entry to exit, with numerous technical factors to consider for the planned HDD route such as
having minimal bends, which can cause delays during installation and pullback. "Bends" are
usually part of the engineered design that allow the pipe to curve and meet the trajectory of the
planned arc of the drill. Straight -pipe, also called the tangent section, is crucial to the entry of the
drill and is necessary to gain depth, which provides better steering for the duration of the planned
Note. From Canadian Association of Petroleum Producers (CAPP), Canadian Energy Pipeline Association (CEPA)
and Canada Gas Association (CGA). (2005). Pipeline associated watercourse crossings, 3rd edition. Copyright 2005
by CAPP, CEPA, CGA & TERA Environmental Consultants. Reprinted with permission.

PIPELINE INSTALLATION METHODS
17
drill path (Bennett and Ariaratnam, 2008). The drill head steers the pipe along the planned route.
It will steer in a downward sweeping direction before following a straight tangent under the
watercourse/feature, then turn upward allowing the final curve of the drill to exit in a straight
tangent to the ground surface, also termed the `exit point' (Bennett and Ariaratnam, 2008). Once
the pilot bore is complete, the ream will begin, which is usually a section of pipe larger in
diameter than the product line that is pulled back through the pilot hole opening. This creates a
larger tunnel for the product line to be pulled through (pullback), which is the third and final set
in a successful HDD operation.
Drilling the pilot -bore and pulling the reamer during HDD is important when considering
environmental disturbance. The risk is highest for frac-outs during this phase because subsurface
conditions are unknown, other than supporting information and recommendations from a
geotechnical investigation that occurred prior to the start of work. Geological maps and models
of the area are utilized to verify the extent, behavior and variations of the soil and rock deposits
that may be encountered during the drill. Regional geology reports and maps will typically
provide descriptions of the glacial deposits, cobbles or gravel beds, boulder fields or clay -matrix
and glacial outwash deposits (Bennett and Ariaratnam, 2008).
Geotechnical investigations do not always provide an accurate representation of the
subsurface ground conditions even with previous geologic and geomorphological investigations.
More specifically, if underground artesian wells are present, these features can be easily missed.
Often geotechnical boreholes do not reach the same depth as the bottom of the no -drill zone,
which is explained in most engineered HDD drawings as the area that incorporates the
preliminary entry and exit path along a 2H:1 V (H=horizontal, V=vertical, 26.6 degree) angle.
The no -drill zone typically provides a minimum of six meters vertical cover beneath the

PIPELINE INSTALLATION METHODS 18
surveyed thaw leg of the watercourse on an engineered/designed HDD. In addition, the no -drill
zone maintains the bore within the assumed drillable strata between the entry and exit points,
with consideration given to the cover required to reduce the risk of fluid loss for a successful
HDD. It is highly problematic to have a frac-out during an HDD especially within a watercourse
while attempting the drill. The environmental disturbance and impact of a frac-out, either aquatic
or terrestrial, will be explained later in this thesis.
Bennett and Ariaratnam (2008) also explain demobilization, site clean up and restoration
once the drill is complete. They discuss frac-out prevention, response, appropriate permits, and
regulations that dictate the appropriate response plan to a surface -mud release or frac-out.
In comparison, the Environmental Handbook for Pipeline Construction prepared by
Alberta Environment (1988) details the requirements and potential impacts of open -cut isolation
through watercourses during pipeline construction. Many factors that impede successful pipeline
installation are explained in the handbook. These include poor construction schedules,
inadequate protection measures that damage fish habitat and interfere with recreation activities
downstream, alternation of stream substrates and physical or chemical changes in the water
quality such as sediment loading and interruption of stream flow or blockage of fish movements.
The handbook describes only selected methods of watercourse crossings in detail such as
traditional open -cut pipeline installation (Alberta Environment, 1988). Limited reference is made
to HDD technology and the handbook does not explore decision-making factors when
considering these options. The handbook indicates it is acceptable to set up the drill -rig and drill
pad at a minimum of 10 m away from the watercourse, which is a much shorter distance in
today's standards (minimum 100 m setback). Additionally, a watercourse is typically greater
than 20m in width or has substantial flow to be considered for an HDD, whereas today,

PIPELINE INSTALLATION METHODS 19
trenchless methods are being implemented on watercourses much smaller in width, specifically
those that are or have the potential to be fish -bearing (Alberta Environment, 1988). Since the late
1980's, HDD technology, regulations and awareness has evolved in pipeline watercourse
installations, indicating the industry is aiming to reduce the environmental footprint on linear
projects in and around sensitive ecosystems.
Prairie Area Fisheries and Oceans Canada completed a review for the Government of
Canada in 2011 of trenchless methods near watercourses (Nugent, 2011). The author monitored
aquatic species at risk at 30 Alberta sites where trenchless methods were being implemented near
watercourses with natural habitat. Operational Statements (OS) were developed by the Canadian
government for industry to streamline the approval process for construction purposes in areas
adjacent or close to natural watercourses (Nugent, 2011). OS for trenchless technology and
installation are helpful for industry, however strict regulations surrounding species at risk,
watercourses and construction methods must be carefully monitored to achieve a balance
between the natural environment and industrial development. Results from the site monitoring
indicated that there were compliance issues with the conditions and measures of the OS, such as
protecting fish and fish habitat, inadequate emergency preparedness, and evidence of frac-outs
and open -cut installation methods (Nugent, 2011). These compliance issues create a barrier for
the application of trenchless technology due to environmental commitments and regulations.
However, this supports the importance of pre -construction planning including a geotechnical site
investigation prior to implementing a trenchless method.
The Pipeline Associated Watercourse Crossings 3rd Edition (2005) published by the
Canadian Association of Petroleum Producers (CAPP) is a regulatory manual intended for
industry. This edition was developed in collaboration with the Natural Resource Industry

PIPELINE INSTALLATION METHODS 20
Associations (NRIA), Department of Fisheries and Oceans (DFO), Canadian Association of
Petroleum Producers (CAPP), the Canadian Energy Pipeline Association (CEPA) and the
Canadian Gas Association (CGA). This manual describes best management practices for low -
impact methods of crossing a watercourse with a vehicle or construction equipment without
disturbing the aquatic and riparian habitat for the duration of a pipeline construction project. The
manual provides a limited description of trenchless or HDD for watercourse crossings.
A key supporting document that can be utilized during planning and construction of a
pipeline project is the Code of Practice for Watercourse Crossings (Alberta Government, 2013)
within the Water Act and Water (Ministerial) Regulation. Schedule 2 and 3 are specific to the
conditions for instream work, which applies to all watercourses. The requirements surrounding
isolated open -cut work originate from the regulations in the Code of Practice. This document
outlines stream order classification, which dictates how a watercourse will be approached during
construction on a pipeline project.
A US study (Castro, MacDonald, Lynch and Thorne, 2015), discussed the environmental
disturbance on aquatic habitat during pipeline stream crossings where the open -cut method of
pipeline installation was performed. The study is a risk-based approach to designing and
reviewing various pipeline stream -crossing impacts with examples from the United States,
Canada and other international pipeline projects that have been refurbished or upgraded.
Research specific to pipeline crossings and other linear disturbances that intersect the
natural landscape have measured environmental disturbances over time. The documentation and
effectiveness of isolated crossing methods is important to ensure the desired level of
environmental protection (Reid et. al. 2002). These include short-term and long-term
construction -related impacts to stream hydrogeology, ecology and the response of each aquatic

PIPELINE INSTALLATION METHODS 21
ecosystem. Short-term impacts are increased turbidity, direct modification of the riparian
zone/aquatic habitat and the potential for hydrocarbons to enter the watercourse (Castro et al.
2015). Long-term impacts of open -cut pipeline installation methods on an aquatic ecosystem are
specific to the stream response potential, such as the ability to reclaim the channel incision or
mitigate lateral migration (Castro et al. 2015). Lateral movement of a watercourse into a pipeline
incision may cause the bank restoration to collapse or "slump" as backfill materials settle over
time in the previously excavated ditch. "Slumping" is either due to material settlement or
watercourse flooding and bankfull discharge into the riparian zone during periods of high flow,
resulting in the river slowly gouging itself in a lateral pattern. Then the watercourse overflows
into these low -laying incisions altering the performance of the watercourse and habitat within the
riparian zone and compromising the integrity of the pipeline installation.
Castro et al. (2015) included examples of locations where significant oil spills occurred
due to pipeline failures, causing catastrophic environmental disturbances to the surrounding
ecosystem. Reference is made to Exxon Mobil's Silvertip Oil Pipeline in Montana. The pipeline
ruptured and caused a 50,000 -gallon oil spill directly into the Yellowstone River. Another
notable spill occurred in the San Jacinto River in Texas, releasing 1.47 million gallons of
hydrocarbon into the river. This was due to multiple new channels forming (lateral migration)
during a large flood event, which resulted in eight pipeline ruptures at that watercourse. A study
of pipeline failures in Alberta during the late 1990's to early 2000 has showed that 762 pipeline
failures occurred per year, for 12,191 failures during the 15 -year period (Castro et al. 2015).
Castro et. al (2015) did not identify how many of the failures were isolated open -cut rather than
installed by HDD, however isolated open -cut installations are at greater risk of being exposed
due to erosion since they are not installed at the depths required to install using the HDD method.

PIPELINE INSTALLATION METHODS 22
Risk assessment tools are of extreme importance in the planning and maintenance phases of
pipeline development projects. This is especially true when assessing high-risk stream crossings
and the appropriate crossing method (isolated open -cut or trenchless).
Lateral movement of a watercourse may pose a significant risk to the existing pipeline,
especially if the watercourse has a turbulent flow. This leaves the pipeline exposed to debris and
rocks traveling in the watercourse, and torrents of water applying pressure to the welds, which
will ultimately shorten the lifespan of the pipe causing rupture. Pipelines are strong in
compression (pressure from each end of the product line), but weak in tension (lateral pressure
from any side exposed to a force) (Castro et al. 2015), resulting in high risks of rupture when a
pipeline becomes exposed or unsupported in a flowing watercourse.
In the United States, the Federal Energy Regulatory Commission (FERC) is the lead
federal agency managing environmental impact minimization, similar to the NEB in Canada.
When an applicant applies for a pipeline to cross an aquatic environment, FERC does not require
detailed information regarding individual site conditions, construction implementation, Best
Management Practices (BMP), site restoration, and monitoring and maintenance post -
construction (Castro et al. 2015). To address this need, the Fish and Wildlife Service (FWS)
along with Ruby Pipeline, LLC, developed the Waterbody Crossing Framework (the
Framework) and the Pipeline Risk Screening Matrix (Risk Matrix). The Framework is composed
of four linked phases:
a.) Basic Stream Data
b.) Risk Matrix
c.) Site Restoration
d.) Implementation Monitoring

PIPELINE INSTALLATION METHODS 23
Basic stream data from the risk matrix supports the idea that acquiring more physical
stream data will decrease the relative risk of the watercourse crossing, provided the appropriate
design and BMP's are allocated to that crossing. The basic stream data along with the risk matrix
identify the restoration design, quality and post -construction monitoring program. The principle
underlying the Pipeline Risk Screening Matrix is that pipeline crossings do no long-term harm to
aquatic habitat on-site, upstream, or downstream and that short and long-term negative impacts
are avoided where possible and minimized to the greatest extent possible and mitigated where
necessary. These are the same goals that the NEB regulatory system aims to achieve with
documents and regulations under the Department of Fisheries and Oceans. There is an x and y
axis associated with the Risk Screen Matrix to explain risk to the resource as a result of stream
response potential and as a result pipeline crossing impact potential, respectively.
Woolsey et al. (2007) define river restoration as `the process of returning a river section
to a near -natural state'. This article outlines various approaches taken to successfully restore a
riverbank and riparian ecosystem, along with the methods and challenges. Successful river
restoration requires consideration of a number of key elements, including evaluating the degree
to which a river deviates from natural conditions and data from the river prior to impairment.
Adaptive management is practiced extensively in watercourse restoration, since most current
restoration projects are often based on trial and error, and viewed as an experiment rather than a
tested methodology with clear and predictable outcomes. A riverbank disturbance, using an
isolated open -cut pipeline installation, may be restored with artificial materials. If this restoration
is followed by a large rainfall or flooding event, that could cause the riverbanks and riparian
zone to be impacted, allowing environmental damage to occur over a long period of time. This is
unpredictable in spite of the best risk assessment and most appropriate engineered restoration

PIPELINE INSTALLATION METHODS 24
designs, materials and experience, which is why it is important to understand the geophysical
history of the area prior to construction. The purpose of river restoration is to re-establish natural
processes that typically function within a river and riparian ecosystem.
Woolsey et al. (2007) published a document that outlines a strategy to assess river
restoration in Europe. The forces of nature can affect the physical landscapes and function of the
associated ecosystems without warning, and often at unpredictable levels of duration and
intensity. These forces of nature tend to have an impact on many other aspects of life, not
specific to the aquatic environment. There are social impacts (flooding, supply of resources such
as drinking water), environmental impacts (ecosystem resilience, maintenance of natural
biodiversity), and economic impacts (job market, industry reputation, fines, etc.). These factors
support the notion of why riverbank restoration is important after a disturbance has taken place
in the natural environment. Woolsey et al. (2007) describe larger river restoration projects, with a
focus on the social impact of appropriate restoration methods compared to smaller restoration
projects and sites that are described in this thesis.
Woolsey et al. (2007) proposes 49 indicators in 17 categories regarding 13 objectives to
assess restoration success. An indicator is `a characteristic of the environment which, when
measured, quantifies the magnitude of stress, habitat characteristics, degree of exposure to the
stressor, or degree of ecological response to the exposure' and `provides information on the
systems condition'. They developed method sheets for each indicator. Indicators allow for a
qualitative assessment in an environment that is not easily measured or predicted, such as the
condition of a river. The method sheets for actually measuring the indicators described by
Woolsey et al. (2007) include ecological and social relevance, ease of measurement,
interpretation, and cost-effectiveness. These indicators are applicable when assessing river

PIPELINE INSTALLATION METHODS 25
restorations in close proximity to urban or populated regions and remote locations. The sites
assessed in this thesis are considered isolated with a lower social impact on the surrounding
communities; however, the environmental and economic effects are important.
Levesque and Dube (2007) discuss key aspects of isolated open -cut pipeline installation
through watercourses, specifically Canadian EIA methodologies for environmental impact
assessments and the effects of in -stream pipeline crossing construction on aquatic ecosystems.
Pipeline crossings through watercourses are examined and compared with short-term
sedimentation effects during construction. Suspended sediment concentrations and
sedimentations due to construction are comparable to episodic short-term disturbances caused by
nature, where concentrated suspended sediments are released into the watercourse and dissipate
over time (Levesque and Dube, 2007). It was identified in the EIA that three potential impacts
may be made to watercourses during the crossing construction: 1.) channel morphology, 2.)
water quality deterioration, and 3.) potential impacts to fish and fish habitat. Levesque and Dube
(2007) determined that EIAs have identified that "alteration, disturbance or destruction of fish
habitat as the primary potential effect of pipeline crossing construction on aquatic ecosystems".
Researchers studying aquatic habitat and species, specifically documenting the effects on fish
and fish habitat (Levesque and Dube, 2007), developed severity -of -ill-effects (SEV) ratings, a
monitoring program for sediment effects on fish. The study design of the monitoring program,
site-specific vulnerability to, and potential for recovery from, the effects of crossing
construction, assessment of the significance of the impacts and consideration of the potential for
cumulative effects (Levesque and Dube, 2007).
Onsarigo, 2011, completed a study, Environmental Value Engineering Assessment of
Horizontal Directional Drilling and Open Cut. Although the study is not specific to the

PIPELINE INSTALLATION METHODS
26
ecological environmental impacts at watercourse crossings caused by either trenchless or open -
cut methodology, it is a supporting document for industry and provides a view on the importance
of environment in relation to the economics of construction activities. Environmental value
engineering (EVE) methodology was utilized to compare the contribution and impact to the
environment of horizontal directional drilling and open -cut construction methods. EVE is an
environmental life cycle analysis methodology that evaluates the environmental impact and
contribution of built alternatives in terms of solar energy joules (SEJ) over the life cycle of the
project.
Relevance of Literature Review
The literature review provides background on HDD and isolated open cut methods in the
pipeline construction industry. This includes environmental expectations surrounding pipeline
installation through watercourses dictated by the provincial or federal governing bodies,
technical introduction regarding HDD and isolated open -cut methods, and the potential for short-
term and long-term environmental impacts surrounding pipeline installation through
watercourses.
A goal of trenchless technologies is to prevent cumulative loss of natural habitat in
sensitive ecosystems, particularly where extensive human development and an industrial
footprint have created habitat fragmentation. Habitat fragmentation affects area -sensitive species,
which depend on larger parcels of land to provide a greater range in territory, protection from
predators, and food availability. These animals are often apex -predators such as grizzly or black
bears, wolves and cougar. Additionally, trenchless technology mitigates unnecessary destruction
of riparian environments, which typically express alpha richness, where there are many of one

PIPELINE INSTALLATION METHODS
27
species, or many different species but few individuals in a relatively small, uniform habitat such
as the riparian zone.
CAPP et al. (2005) provides a case history of open -cut and pump and dam sites, where 59
open cut sites and 30 pump and dam examples are summarized. One hundred forty six horizontal
directional drilling cases were reviewed and conclusions were made regarding the requirements
to perform a successful trenchless crossing. An in-depth comparison of the two methods in this
thesis applied under specific conditions where crossing recommendations were made and
resulted in significant environmental disturbances or failures adds to the summary created by
CAPP et al. (2005). These sites are deemed significant due to the overall length of time spent at
each site, the difficult level of the geophysical terrain at each site, the classification of the
watercourses, the size in diameter of the product pipeline (therefore large physical footprint on
the landscape compared to smaller pipeline diameters), the regulatory approval process for
Federally run projects, the extent of the environmental mitigations that were implemented during
construction and the known longevity of the post -construction monitoring. This thesis expands
the understanding of the two methodologies by explaining step-by-step in technical detail the
procedures at each Site, which CAPP does not provide in its study.
Chapter III: Research Methodology
Research Method
The scope of methodologies discussed in this study does not address different regulatory
requirements that are in place internationally. Canadian BMP's and regulations are utilized when
comparing sites on an environmental basis describing where installation methods were
successful with environmental consequences and impacts to the ecosystem.

PIPELINE INSTALLATION METHODS
This methodology describes the outcome of the two pipeline construction methods, HDD
and open -cut installation, during pipeline construction at site-specific watercourse crossing
locations. The comparisons are intended to utilize a case -study approach to describe the
environmental considerations of each installation method. In the comparison, the planning phase,
construction phase and restoration efforts are assessed to determine whether HDD or open -cut
installation is the most appropriate option for any given site. Identifying the boundaries or scope
and keeping within it helped to focus the research, including understanding the behavior patterns
of the bound system (Stake, 1995). A researcher may look at specific cases and the details of
each, and then perform a cross comparison to identify similarities and differences.
The comparisons are intended to utilize a case -study approach to describe environmental
considerations for each installation method. In the case study, the planning, construction and
restoration efforts are assessed to examine success and whether HDD or open -cut installation is
the most appropriate option for a given site. A case study is defined by individual cases, not by
the method of inquiry. Identify the boundaries or scope of the research and keep within it to
focus on the bound system (Stake, 1995): Isolated -open cut at SITE A and HDD at SITE B.
Stakian viewpoint, constructivism and existentialism should be epistemologies that orient and
inform the qualitative case study research since "most contemporary qualitative researchers hold
that knowledge is constructed rather than discovered" (Stake 1995). The thesis was constructed
from personal experience in the field. Qualitative case study research such as this thesis gathers
interpretations and a report was created based on the constructed knowledge gathered during the
investigation (Yazan, 2015).
Multiple methods of data collection are utilized during this study including personal and
colleague observations and experience, technical clarity from industry professionals, and

PIPELINE INSTALLATION METHODS 29
collection of artifacts for review (technical plans, reports and site photographs) making the
nature of the methodology qualitative rather than quantitative. The author performed visual site
assessments and daily site monitoring during construction; however, no water quality testing
took place due to funding of resources and equipment. The case study is aimed at providing
insight into an issue or problem to understand the complexities of the case and other theories that
may develop by comparison (Stake, 1995). There is also a cumulative nature to the case study
methodology, as a number of cases have been reviewed from the research to develop and
understand two broadly based, hypothetical scenarios.
As described in the Literature Review, a number of risk matrices and indicator
assessment strategies have been previously developed, to measure river restoration that may be
applied across a broad spectrum of projects. These tools were helpful when choosing the case
study sites for this thesis. This may expand the application of HDD based on the preferred site
conditions for selecting an HDD crossing installation method. One of the sites in this study
outlines where an HDD failure occurred after multiple attempts, and was followed by an isolated
open -cut crossing. The second site describes an isolated open -cut crossing with a significant
environmental disturbance on the surrounding environment. An HDD at this site would have
been favourable; however, considering the instability of the subsurface material an open -cut was
performed.
A Before -After -Control -Impact experimental design (BALI) is recommended for the
assessment of pipeline construction impacts on rivers and streams (Levesque and Dube, 2007).
BACI considers site-specific conditions, rather than just a simple before and after impact
assessment. BACI assessment design was utilized in this thesis by assessing site conditions pre
and post -construction both upstream and downstream of each proposed crossing location. Long-

PIPELINE INSTALLATION METHODS
30
term habitat and biological surveys would have taken place after construction until the recovery
of the system was back to pre -construction conditions; however, the author did not perform these
surveys.
Site Description
Two separate natural watercourse sites are presented in this thesis and compared for their
potential as suitable sites on which to perform a traditional crossing or HDD method. The sites
are described to characterize why two different crossing methods may be selected during the
planning phase of pipeline construction.
Figure 2: Map of Alberta, including study "Site A" and "Site B". Google Earth. (2016).
SITE A
The traditional crossing site, SITE A, exemplifies open -cutting into virgin ground across
a watercourse, including the planning and implementation of BMP's, restoration design and
maintenance, costs, and geo-physical aspects through a watercourse for successful pipeline
installation. SITE A illustrates where an HDD may have been a superior installation method,

PIPELINE INSTALLATION METHODS
however the subsurface materials and topography are unsuitable for the trenchless crossing
method. The installation was successful, however the initial disturbance was extensive and the
long-term impact was significant. Even though the crossing was completed, the site may have
been an appropriate candidate for HDD to prevent disturbance to sensitive materials and the
approaching slopes to the watercourse.
-SITE A-
�iL Stii I S /
�4tiS't 51.c
•
;rein � C�x`s�1��lUh
i i
Figure 3: Site A field -site sketch.
Site Properties.
Q3 S.a, 4 S ,R
S� SL_Opc
or
w i
s
r
i
Y.r1uJ
i
� 5ni4S
The site is located in a valley oriented in a north -south direction, where the watercourse
31
flows north through the channel, with the approaching slopes facing east and west. For the
purpose of this thesis, the approaching watercourse slopes will be referred to as "west slope" and
"east slope". The soil was classified as a Dark (orthic) Gray Chernozem, soil name Kehiwin

PIPELINE INSTALLATION METHODS 32
(KHW), with approximately 12-30 cm in the A and B horizon on the west slope a kilometer
south-west of the crossing (TERA Environmental Consulting (TERA), 2013a). The subsoil is till
with a loam to clay loam texture 12-30 cm deep, and well to moderate drainage. This soil
transitions into a Dark Gray Luvisol (Gabriel -GBL) at the bottom of the slope, prior to entering
the immediate watercourse valley, where the soil changes to the KHW soil classification. The
west slope is long and gradual prior to the steepening approach in the watercourse valley,
approximately 1000 m in length and subject to surface erosion from wind and water. The Dark
Gray Luvisol within the watercourse valley is a glaciofluvial till deposit, composed of sandy
loam to loamy sand/loam to clay loam textures. This soil is moderate to well drained and its
texture supports this drainage. The depth of the A and B soil horizon through this area is
approximately 15 cm. The topography is considered to be strong to very strongly sloped, ranging
between 15-45% in some areas (TERA, 2013a). The slope is part of a large catchment where
upland flow eventually collects in a large, low-lying basin surrounded by agricultural land.
Soil material found in the immediate approach to the watercourse on the west slope is
Nicot (NIT), Eluviated Eutric Brunisol at depths of 0-15 cm. This is a glaciofluvial deposit, with
a loamy sand to sand texture, and well to rapid drainage. The topography has a 5-10% slope,
which is gently sloping terrain (TERA, 2013a).
The east slope had the same soil classification, Eluviated Eutric Brunisol (EET), for
approximately 400m upslope from the watercourse to where the topography became less steep.
The east slope had a slope of 2-5% or 5-10% (very gentle to gentle slopes) (TERA, 2013a).
The soil classification of the watercourse through the channel, bed and banks is a Raised
Beach (RB). The watercourse is classified as a `Class C' watercourse in Alberta. This class of
waterbody is based on the sensitivity of fish habitats and their distribution (Government of

PIPELINE INSTALLATION METHODS 33
Alberta, 2009). A Class C watercourse is described in the Fish Habitat Manual Guidelines and
Procedures for Watercourse Crossings in Alberta (Government of Alberta, Transportation, 2009)
as a watercourse that has "moderate sensitivity; habitat areas are sensitive enough to be
potentially damaged by unconfined or unrestricted activities within the waterbody; broadly
distributed habitats supporting local fish species populations ".
The mean channel morphology of this watercourse shows that the bankfull width was
approximately 4 m with a depth of about 1.0 m. The width at the high-water mark was roughly
15 m with a depth of 1.0 m when the measurements were taken in June 2013 during pipeline
construction (TERA, 2013a) indicating there had been flooding activity due to an upstream
beaver dam complex.
Description of installation method.
The site was prepared in June 2013 by stripping topsoil to the riparian zone, 15-20 m
from the top -of -bank of the watercourse, upslope on the right-of-way, shown in Figure 2.
Photo 1. East slope (Site A) stripped of topsoil and graded out.

PIPELINE INSTALLATION METHODS
34
The west slope had a riparian zone of approximately 35 in in width from the watercourse
to the crest of the slope, and approximately 32 in of riparian buffer on the approaching slope to
the east (TERA, 2013a). This practice is a pipeline industry standard, or BMP, to allow a "buffer
zone" to be maintained for as long as possible in order to protect the riparian corridor along the
watercourse, and act as a safeguard during heavy rainfall events that may cause heavy erosion
and sediment runoff from the stripped approaching slopes. It can be detrimental to the local
ecology and reputation of the contractor and client on a pipeline project to incur sedimentation of
a watercourse, particularly a fish -bearing watercourse. A "release" of sediment, mud or any other
deleterious matter into a watercourse is treated the same as a hydrocarbon spill; it must be
reported and cleanup must commence immediately with documentation of each occurrence.
Stripping the topsoil on the rest of the slope creates vulnerability at the Site, which can result in
harmful alteration, disruption and destruction of fish habitat (HADD) (Government of Alberta,
Transportation, 2009).
The following description and explanation is articulated by field experience from the
author. Once stripping was complete, grade activity took place by removing the approaching
slopes, referred to as "cuts" in the material, to create workable access for the duration of the
construction project. A 30 in pre -fabricated clear span bridge was installed across the
watercourse for temporary vehicle and equipment access since the watercourse could be
considered navigable according to the Navigable Water's Protection Act, and was fish bearing.
The bridge spanned each side of the watercourse on carefully constructed abutments, ensuring
the bridge was not affecting the creek banks causing further disturbance to the integrity of the
watercourse and the riparian buffer zone. The cut material was transferred back upslope to the
upland area, set back from the crest of the slope, while material was piled on the side of the cuts

PIPELINE INSTALLATION METHODS
35
on top of the stripped ground. Due to the volume of subsurface material, the pressure on the cuts
caused by the weight of the subsurface material may have contributed to the site's erosion and
seepage issues during the project, prior to restoration. The cuts were monitored for ground water
seepage for 40 days. No significant rain events occurred during this time. With a perched water
table and clay shale outcrops in the bottom quarter of the slopes (Photo 2 and Photo 3), water
migrated through the ground and exiting the side cuts to the toe of the slope where the
watercourse was located.

PIPELINE INSTALLATION METHODS
Photo 2. East slope (Site A) graded out, showing clay seam.
Photo 3. Clay seam present on both slopes with constant seepage.
36
Once the grade cuts were removed, the site needed to be stabilized and temporary erosion
mitigation measures (BMP's) were installed to prevent sediments from migrating down the slope
,_� 4 -�
.� �+'i ...E ._:
�1► s .-:
. � ,-
Nkl-
.. '�"
>
t
r 11! •.. _. 4 F J HT1
a•�1� T _• `
y -
Photo 3. Clay seam present on both slopes with constant seepage.
36
Once the grade cuts were removed, the site needed to be stabilized and temporary erosion
mitigation measures (BMP's) were installed to prevent sediments from migrating down the slope

PIPELINE INSTALLATION METHODS 37
during a heavy rainfall event. Weather is an important factor on the exposed, stripped right-of-
way during a pipeline project due to its unpredictability. Without any precipitation interception
from an overhead canopy of trees, shrubs and grasses, the exposed subsoil on the slope made the
watercourse extremely vulnerable to surface runoff or erosion events. The site was exposed for
approximately two months before trenching or ditching was initiated to create a trench for the
pipeline. The watercourse crossing was an isolated open -cut crossing using the pump and dam
method, an example is shown in Figure 4.
Temo✓arr W rk- If Re ujmd
—
1 1
I 1
I I
1 I
1M I
I �nw
1 Iy �nJ y.vm
1 Tvml&W
1 � R:yrl LFt'NI I
1 3� _q pltll FtM I L'x-.nn�]e 4M
I F
� 7'—I cva[ I
I J I I
Lv�p�c ll'aru4 I-joraaa�+
� 1
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I Infl'en— �Ncrx - .� R�h
" I w.e� � Fterr FIw6�
I -
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1 f�
aavGua
I
I � I L G.s_nxpo U=
S:zy:gr � TOsc•
r9rl I
Emrabc.�
I I N
3 I
q
-----—----
el-
------_1elan waw
At 1n 5-10
Figure 4. Construction Technique- Typical Dam and Pump (CAPP et al. 2005).
Note. From Canadian Association of Petroleum Producers (CAPP), Canadian Energy Pipeline Association (CEPA)
and Canada Gas Association (CGA). (2005). Pipeline associated watercourse crossings, 3rd edition. Copyright 2005
by CAPP, CEPA, CGA & TERA Environmental Consultants. Reprinted with permission.

PIPELINE INSTALLATION METHODS
This installation and crossing method utilized six high volume water pumps (three pumps
working and three back up pumps), two 14 m steel plates, wooden access mats, four excavators,
and two heavy -haul rock trucks. An excavator on each side of the watercourse prepared the site.
The buffer zone was stripped of topsoil and the organic upper surface material was stored
adjacent to the ditch line in the extra workspace at the top of the approaching banks on each side
of the watercourse, set back from the crest of the slope. The material was set back from the crest
of the slope to ensure it did not migrate down the slope during heavy rainfall events. The
excavators began at the ditch line near the watercourse buffer zone area. Instream activity began
at this time, when the first steel plate was installed upstream from the crossing using an
excavator bucket to press the plate into the watercourse perpendicular to the direction of flow on
the edge of the right-of-way boundary. Two water pumps were equipped with fish screens (2.54
mm holes) on the intake hose, and were placed next to the watercourse upstream from the first
steel plate (upstream plate). The pump outlet hoses ran through the worksite to the downstream
portion of the crossing, where clean water was redirected back into the watercourse. Once the
flow of the watercourse was successfully maintained, the downstream plate was installed
following the same process as the upstream plate as shown in Photos 4 and 5.

PIPELINE INSTALLATION METHODS
Photo 4. East slope (Site A) facing downstream isolation plate.
Photo S. Downstream isolation plate, showing ditch side (left) and clear water (right).
39
Once the downstream plate was in place and isolation had been achieved, dewatering of
the watercourse in the isolated area began. Isolation was accomplished ensuring the steel plate

PIPELINE INSTALLATION METHODS
had pushed through and blocked off the hyporheic zone underneath the watercourse, and water
did not seep under the steel plate, resulting in loss of the isolation and ditch stability. It is best
practice to minimize the intensity and duration of instream work during pipeline installation
through watercourses and essential to have experienced individuals performing the work. The
greywater was extracted using a backup pump, and discharged from the right-of-way into a
sediment containment structure. The structure was built using filter fabric/cloth, lengths of
untreated wood, and filter bags in the structure where the hose outlets were inserted. These
structures are commonly made when large volumes of ditch water must be discharged from a
40
trench for pipe installation. Heavily vegetated areas are chosen as discharge points and set back
from the watercourse to prevent any deleterious substances from entering the watercourse. The
ditch water filtration system is cleaned up after backfill of the ditch and pipe installation.
After the ditch line was dewatered and maintained, excavators travelled into the stripped
riparian zone on "swamp mats" which are wooden mats (-2.5 x 4 m) to allow construction
equipment movement over soft or sensitive ground. Excavators were placed on mats, which
spanned across the isolated watercourse while they were digging the ditch line through the
isolated creek channel. The bed and bank material was removed from the creek and stored
separately for restoration purposes. Excavation of the ditch took place with two excavators on
each side of the crossing scooping ditch spoil back and loading it into rock trucks. The trucks
hauled it to the top of the slopes on each side of the crossing.
Once the ditch was prepared, the pre -welded 1066 mm diameter x 130 in long pipe
section was brought in using side booms. The pipe was lowered in on the access, or "work side"
of the right-of-way and laid in the bottom of the ditch and shown in Photo 6.

PIPELINE INSTALLATION METHODS
Photo 6. Lowering -in pipe section; facing east slope (Site A).
41
Survey and engineering experts are required to ensure the pipe section is sitting where it
will remain stable, and to create the as -built information for that specific crossing. When this
work is completed, shading of backfill material and complete backfill of the ditch begins in the
reverse order that the material was initially removed. At this point, the clay subsoil material is
used to re-establish the banks and backfill the approaching slopes to allow equipment on each
side of the watercourse to complete the restoration process.
Woven jute coconut fabric is used to contain subsoil in the lifts, or soil wraps. Non-
treated wooden posts typically 2 in in length by 152 mm in diameter are utilized to re-establish
the shape of the channel. Plywood sheets are placed on the upslope side, behind the wooden
posts and temporarily tied in place. The subsoil is pulled back from the end of the bank and the
jute fabric is laid down against the plywood sheets. The fabric is filled with subsoil and
compacted in the lifts. Then the remainder of the fabric is pulled back on itself over the subsoil,
using the excavator bucket to gently tighten and key -in the pullback portion of the fabric. This

PIPELINE INSTALLATION METHODS 42
bank restoration method is built in lifts, sometimes reaching three or four lifts high, depending
on the height of the natural watercourse banks. The edges of the fabric and subsoil wrap must be
slightly higher than the neighbouring virgin ground to compensate for subsurface ditch
settlement. Settlement is extremely likely during winter work due to larger pieces of frozen
backfill material and care has to be taken to use fines. The site required one lift of soil wrap.
With the soil wrap in place, more subsoil is applied to the surface of the newly installed wrap
and capped with topsoil. Now the plywood sheets are pulled from between the jute fabric and
wooden posts. The posts remain intact for the duration of the restoration, and are not removed
from the crossing unless by a natural occurrence (beavers, rotting in high water over time, etc.).
Cuttings are utilized in the soil wrap to re-establish riparian vegetation along the disturbed banks
as shown in Photo 7.
Photo 7. Facing upstream (Site A), soil wraps and bed and bank restoration complete.

PIPELINE INSTALLATION METHODS 43
Revegetation using willow cuttings and an appropriate forb seed mix is helpful to re-
establish the riparian area by allowing successional species (willow, alder) to root and
vegetatively sucker for rapid bank material stabilization. These species begin to provide shade
along the watercourse bank, which benefits aquatic species and regulates the temperature of the
water in the crossing. Restablishing an ecosystem after it has been disturbed may take a number
of seasons before the ecological engineering effectively stabilizes the site and reduces the
environmental impact. The site experienced a number of sedimentation events due to heavy
rainfall. Slope erosion occurred resulting in disruption of the natural depth and flow of the
watercourse. This resulted in more standing water and lower oxygen levels at the crossing where
material had to be removed to increase channel depth for flow improvement. These events
occurred before and after pipeline installation and restoration.
The isolation plates were pulled once the immediate bank restoration had taken place.
Typically the downstream plate is pulled first, allowing water to gently flow back into the
crossing prior to pulling the upstream plate. Once the upstream plate is pulled, the water gently
migrates through the watercourse, without an increase in velocity or sediments, which washes
away newly, restored soil material. The pumps are shut off and removed from the watercourse.
There is clean up of the ditch water discharge area where water and ditch sediments may have
accumulated in the vegetative area.
The duration of the instream work during the isolated open -cut was approximately 5
days, beginning with initial plate installation, dewatering, ditching, installation of pipe, backfill,
creek bank restoration and final plate pull at the crossing. The restoration method was done using
natural restoration materials including installing two soil wraps to re-establish the watercourse
relies on each side of the channel.

PIPELINE INSTALLATION METHODS 44
One-year post -construction, the restoration efforts were intact on the immediate banks.
The approaching slopes were not restored immediately upon completion of the restoration at this
watercourse and the subsoil on the right-of-way and cut material was piled at the top of the slope.
This material was left exposed to winter and spring runoff. This caused significant surface
erosion and moderate sedimentation of the watercourse, which is shown in Photo 8.
Photo 8. Deleterious matter in the watercourse following a series of rainfall events.
Cleanup of the watercourse took place early spring of 2014; prior to final cleanup of the
slopes and watercourse. The slope material washed into the watercourse, causing a minor
sediment release resulting in a quick cleanup of the watercourse at the crossing. The soil wraps
stayed in place without slumping; however, more coconut erosion blankets had to be installed on
the surface of the restoration. The area was seeded and additional successional plant species were
planted in the area.

PIPELINE INSTALLATION METHODS
During final clean up and restoration of the slopes, including the riparian zone, an
engineered slope restoration design was provided to the Contractor for the west slope, where
instability was consistently a problem in protecting the watercourse. The engineered design
included a subsurface drainage system of multiflow perforated tubing, bentonite ditch plugs on
the ditch line and pea gravel. The final slope restoration was designed to control the subsurface
45
flow along the interface between the virgin ground and where the grade cuts had been replaced.
The subsurface drainage system was intended to control and mitigate subsurface flow that could
saturate the soil along the edges of the right-of-way where the material cuts were exposed for a
full year. The surface erosion controls were installed on the slope once final grade was achieved.
A series of surface diversion berms and swales lined with river rock and rock check dams were
installed to manage surface runoff. The entire slope was covered in coconut matting to stabilize
seed movement and reduce risk of wind and water erosion as shown in Photo 9.
Photo 9. Looking at the west slope (Site A) final restoration.

PIPELINE INSTALLATION METHODS 46
One year post -restoration of the site, it appears to be stable and vegetation has
been restablished at the crossing (see Photo 10 and Photo 11). A third parry monitors the
site, and photographs and site visits confirm immediate, short-term restoration success.
However, the long term effect of the restoration process in unknown.
Photo 10. Watercourse channel and banks, 1St winter post -final cleanup.

PIPELINE INSTALLATION METHODS
Photo 11. Fall rye grass seed successfully growing on the slopes of the watercourse.
Challenges of the Work.
47
One of the most significant challenges at this site is that slopes had subsoil exposed to the
weather for over a year. The heavy and consistent material composed of fine silty sand and silty
clay in the surface and subsurface led to erosion on the ditch line and approaching slopes. There
were a number of major rainstorm events during this time. The through cuts were deep
(approximately 5-10 in grade cuts) and cut through a perched water table, exposing a clay seam
that allowed stored ground water from the upland terrain to seep out of the cuts onto the right-of-
way, downslope towards the watercourse. This resulted in constant monitoring of the site at all
times.
The approaching slopes had very steep gradients and short slope lengths, allowing loose,
unstable material to travel rapidly towards the watercourse, which is demonstrated in Photo 12.
Extensive use of erosion control measures including cedar -chip erosion waddles or `noodles',

PIPELINE INSTALLATION METHODS
M
wire -back silt fencing, filter fabric, straw bales, river rock, pea gravel and surface erosion berms
was required.
Photo 12. West slope surface erosion prior to final cleanup.
Environmental Disturbances at the site.
The environmental disturbance at the site was short-term, since the natural environment
was disrupted for a year from pre -construction disturbance to post -construction. After final
restoration of the slopes, the site appeared stable with no further loss of topsoil or subsurface
material due to erosion. The watercourse hydrology appeared clear and the channel remained
intact at the initial restoration site where the pipeline has been installed. The location of the
pipeline incision had not slumped and vegetation had rooted in the bank of the watercourse.
Environmental disturbances on the site included uprooting of original vegetation that was well
established and loss of topsoil in the riparian zone and approaching slopes. Some topsoil was lost

PIPELINE INSTALLATION METHODS 49
due to its movement for construction purposes, and wind and water erosion while material was
stockpiled for a year prior to restoration.
The approaching slopes were exposed to five significant rainfall and sedimentation events
prior to the watercourse being fully restored. The subsoil on the exposed right-of-way had moved
on multiple occasions to the toe slope and breached the silt-fence/straw bale erosion control
measures at the bottom of the slope. This breaching caused sediments to enter the watercourse,
impeding the flow. This was discovered and material was removed from the watercourse while
erosion control measures were repaired and reinstalled.
SITE B
SITE B illustrates the requirements for HDD at a watercourse crossing. The site has
steep approaching slopes, old growth forest, sensitive aquatic species and a turbulent
watercourse. The costs of implementation and subsequent restoration and maintenance are
briefly mentioned as cost and economics are not part of this thesis. This site illustrates an
unsuccessful HDD installation under a watercourse crossing and the reasons for its failure. Site B
was chosen to show where both methods were utilized, first an HDD, which failed followed by
traditional, isolated open -cut, which required time-consuming bank restoration and slope
stabilization. Both methods caused environmental disturbances in the watercourse.

PIPELINE INSTALLATION METHODS
Figure S. Site B site -field location sketch.
Physical Properties of the site.
50
Site B has subsoil material that is fine silty -sand with gravel seams to the surface (-20 in
depths), with clay till deposits encountered at greater depths (-30 m) in the geotechnical
investigation. The origin of the material that is typical of this location varies from glacial till, bog
and outwash materials, with sandy outwash of inconsistent thickness occurring more frequently
than till (Wynnyk, 1963). The dominant texture in the bed and banks and approaching slopes of
the watercourse is classified as fine textured (<2 mm). The soil is classified as Podzol and
minimal Podzol according to the environmental protection plan for the project (TERA, 2013b).
The mapped Class C watercourse is flowing from south to north, with east and west
banks and approaching slopes (TERA, 2013b). The east slope has a steep incised approach that

PIPELINE INSTALLATION METHODS
51
falls sharply to create the east bank of the watercourse. This outer bank dissipates the velocity of
the laminar flow of the watercourse in the channel beds at the pipeline crossing. The west slope
is long and gradual, extending back approximately one kilometer from the crossing to the highest
crest of the slope. The flow of the watercourse at the time of pre -construction was approximately
0.32 m3/S. The mean bankfull width was 9 m, wetted width of 8 in, bankfull depth of 0.68 in,
water depth of 0.37 in and a mean bank height of 2.2 in (TERA, 2013b). The recommended
pipeline crossing in the EPP is "trenchless".
At the watercourse crossing, old growth coniferous forest encroached the crossing and
riparian zone. Photo 13 shows the clearing activity taking place next to the watercourse. The
watercourse is a Class C according to the environmental pre -assessment using criteria outlined in
the Fish Habitat Manual, (Government of Alberta, Transportation, 2009).
Photo 13. East slope showing clearing activity, standing on west slope.

PIPELINE INSTALLATION METHODS 52
Description of installation method.
The initial installation using a trenchless Horizontal Directional Drill (HDD) method was
designed to include the watercourse, approaching slopes and a set of railroad tracks located at the
top of the eastern slope. The HDD was attempted twice in the winter of 2012/2013, and failed
due to the subsurface ground conditions and topography. This watercourse is located in a caribou
herd protection area, and the HDD would have minimized unfavourable impacts on wildlife in
and around the watercourse. Examples of HDD winter -season drill pad set up and HDD
execution are shown in Photo 14 — Photo 16 and are not representative of Site B.
Photo 14. Typical HDD pad and drill rig set up example.

PIPELINE INSTALLATION METHODS
Photo 17. Complete HDD product line installation example.
After the HDD was abandoned, an isolated open -cut method was implemented the
following winter using the same process described for Site A. A pump and dam method was
utilized, including steel plates installed up and down stream (see Photo 18), fishing of the
54
watercourse within the isolated area, and pumping of ditch water prior to excavation of the ditch
line. Following excavation, the pipeline section was installed, backfilled and restored (see Photo
22). The west bank received a three-tier soil wrap while the east slope was restored using a third -
party engineered design that involved Class 1 rock rip -rap to stabilize the bottom of the steep
slope. This required the pump to be effective for a longer period, and a more intense post -
construction monitoring period after the project was complete.

PIPELINE INSTALLATION METHODS 55
Photo 18. Downstream isolation plate and ditch preparation.
Photo 19. Pipeline installation through watercourse, facing east.

PIPELINE INSTALLATION METHODS
Duration of the work.
The duration of all instream activity was completed in 10 days from site preparation to
isolation, ditch digging, pipeline installation and creek restoration.
Trenchless Crossing Method.
The HDD section was about 1080 in in length and was attempted during the winter
season. The drill was set up on the east side of the watercourse crossing. The drill casing was
56
installed on the first day after mobilization into the drill pad. The pilot hole was successful under
the watercourse, with only one small frac-out observed on the right-of-way. See Photo 20 and
Photo 21 for examples of HDD surface mud releases (frac-outs). For the duration of the HDD,
there were numerous frac-outs and lost circulation was frequent throughout the reaming phase of
the drill. It was approximately 36 days from the beginning of the pilot -hole on the entry side to
final abandonment of the HDD attempt. About two-thirds of the drill was completely reamed
during this time before the frac-out frequency became too high. Approximately 240 cubic meters
of drilling fluid was contained and removed from the site to the appropriate disposal facility.
This resulted in extensive cleanup of the surrounding area where frac-out sites had been
identified and mitigated during the drill attempts. The potential for a frac-out to occur within the
watercourse was high. Monitoring took place upstream and downstream of the drill path for
changes in nephelometric turbidity units (NTU) and total suspended solids (TSS). The variation
from the background levels to the highest NTU values collected during the HDD attempt was
about 468 NTUs. The high NTU's and TSS occurred at regular intervals in the watercourse from
the frac-out events caused by the drilling operation. It is conjectured that a large gravel seam,
cobble or boulder field was encountered in the subsoil along the drill path during the first
attempt. A second attempt was made by pulling the drill out of the hole, re-entering a second

PIPELINE INSTALLATION METHODS
57
time in the same location and slightly changing the angle of the drill path to avoid the obstruction
caused by unknown debris. The second attempt was unsuccessful.
Photo 20. HDD frac-out example #1 (provided by Project Environmental Inspector)
Photo 21. HDD frac-out example #2.

PIPELINE INSTALLATION METHODS 58
Restoration method.
The clean-up effort of the frac-out took weeks to complete, using hydrovac units that
utilize warm water, to loosen and vacuum sediments that were affecting the environment,
without damaging the organic surface material. Most of the drilling mud was released on the ice
and under snow. Identifying all areas necessary for cleanup was time consuming, challenging
and labour intensive. Eventually most of the drill mud was removed and the effects of a frac-out
could not be visually observed. The sediment that entered the watercourse was washed away
naturally with the current of the creek.
The creek bank restoration after the open cut took approximately one week to complete.
It took 5 days to prepare the site and install the rock material on the east bank while the west
bank took 2 days to complete the three-tier restoration as shown in Photo 22. The isolating plates
were slowly pulled to allow the water to move back through the channel.
Photo 22. Final restoration of watercourse facing downstream.

PIPELINE INSTALLATION METHODS
Restoration 1 -year post -construction.
59
The Site was in stable condition one year post -restoration as shown in Photo 23. The east
slope had a minor release of sediment from the upland area. Erosion rilling and gullies began to
form in the steepest area of the right-of-way approximately 300 in east of the creek crossing.
Some of the sediment material was found in the rock rip rap bank that was engineered the
previous spring. The west streambank was still intact and had not experienced subsidence or
slumping. No sediments from the east slope had entered the watercourse, except one minor
release the first spring. A third parry on the east bank, which included a crib -like structure made
of wood to hold the rock in place and to protect the slope stability and watercourse, installed new
erosion control materials. The author did not perform this work.
Photo 23. One-year post -construction, facing west slope.

PIPELINE INSTALLATION METHODS 60
Challenges of the work.
Challenges of the work include the obvious failure of the initial HDD. The geotechnical
report did not recommend an HDD, however it was attempted because of approval in the
Pipeline Agreement (PLA) process (Alberta Government, 2013), which is government -
sanctioned. Therefore, the attempt to drill had to occur until deemed unsuccessful, at which time
an isolated open -cut was scheduled for the following winter. When the frac-out took place, it was
difficult to identify where the mud reached the surface due to extensive snow cover at the site
and in the forest. The frac-out was evident in the downstream watercourse, as the NTU levels
were fluctuating over a number of days when the drill was losing fluid. Monitoring mud frac-
outs or sinkholes requires competent and experienced personnel walking the drill path at regular
time intervals.
The biggest challenge with open -cut installation is site restoration and risk of loss of
isolation. The site preparation involved clearing a large number of trees and hauling them away
from the site. Access to the watercourse where the initial drill pad was located was difficult due
to steep topography and soil conditions, which can be very sensitive during freeze and thaw
periods. The watercourse had a consistent flow rate (0.19 m3/s) at the time of isolation when the
appropriate equipment such as water pumps, hoses, and back up supplies were ordered. The
weather was very cold resulting in frozen hoses and ice buildup around pumps. The water
pumping system had to be monitored continuously to prevent the loss of the crossing. The west
bank of the creek was moderate in design complexity, however the east slope required a third
party engineering design to ensure the slope seated correctly to prevent loss of the slope into the
creek during spring thaw or a large rain event. The appropriate rock rip rap material was secured
from a source 800 km from the site. The distance meant it took 1 '/z weeks to deliver the rock

PIPELINE INSTALLATION METHODS 61
material. A significant lead-time was needed to have the rock on site for installation after
backfilling of the channel.
Environmental Disturbances to the site.
The environmental disturbance at the site was not extensive in the watercourse, even
though the HDD frac-out caused increased NTU's in the watercourse for a number of days. The
environmental impact affected the vegetation and topsoil off site where the frac-out occurred and
on the area cleared to create the right-of-way. A large area of riparian and old growth forest was
disturbed and cleared to develop the right-of-way. Removal of riparian and old growth
vegetation affects the long-term success of the ecosystem. There were two construction methods
performed at this site, both resulting in an environmental disturbance. The highest risk at this site
is to the watercourse and fish habitat.
Data
The HDD drilling and water monitoring data was provided for the purpose of this thesis
by a third -party sub -contractor (B. McLaren, pers. comm.). The HDD drill took three to four
days to set up initially at the site. The pilot hole took nine days to drill and complete from entry
to exit side under the watercourse. Turbidity measurements were taken throughout the day with
water quality sondes each collecting data at 10 -minute intervals, one sonde was positioned in the
watercourse upstream of the bore line and three sondes were positioned downstream. Baseline
data indicated that the water quality in the watercourse was at 10 NTUs. Once the pilot hole
reached the exit side, a small surface mud release was discovered close to the exit site consisting
of approximately 5-10 m3 of drilling mud, which was cleaned up immediately. Reaming and
pumping was initiated once the pilot hole was completed. The first two days of reaming the drill
achieved a distance of 565 in. The water quality monitor at approximately 200 in downstream

PIPELINE INSTALLATION METHODS
62
picked up a change in NTUs from 10 to 78 NTUs and the sonde located at approximately 450 m
downstream read 75 NTUs. The drill rig was instructed to stop drilling immediately while the
turbidity in the watercourse continued to be monitored. Within three hours, the NTU turbidity
values increased to 251 NTUs at 200 m downstream and up to 213 NTUs at 450 m downstream
within 4 hours. Water quality samples were taken to test for pH, which was 8.36, which is within
the recommended Canadian Council of Ministers of the Environment (CCME) (1987) guideline
of 6.5 to 9.0 for water quality for the protection of aquatic life (freshwater). The toxicity analysis
indicated that the sample was not toxic. The turbidity value decreased back to the baseline value
of 10 NTUs within eight hours of the peak turbidity value at 450 m downstream. The value at
200 m downstream from the bore line took 18 hours to decrease to the baseline value. Reaming
activities commenced on the following day, reaming from 565 m- 633 m. Eight hours after
reaming had commenced for the second time, turbidity values spiked again from baseline to 478
NTUs at 200 m downstream, and at 433 NTUs at 450 m an hour later. There was an hour of lag -
time between measurements taken at 200 m and 450 m downstream from the bore line. The rig
was shut down again until further notice.
The following day, the drilling rig began tripping -out. Tripping -out refers to the removal
of the drill stem and cutting head to clean the hole, using a cleaning tool, of excess material in
order to continue drilling (Federal Energy Regulatory Commission (FERC), 2007). Torque -
reducing additives can be used in the drilling mud to remedy high torque on the drill pipe, which
can result in twisted -off or lodged sections of pipe in the drill hole. The rig completed tripping -
out on Day 23, and then began grouting the drill hole. Grouting thickens the drill mud, while
maintaining circulation, in order to seal off any cracks within the drill path in order to prevent
further frac-outs and allow the drill to continue drilling in a stabilized hole (FERC, 2007).

PIPELINE INSTALLATION METHODS 63
Drilling mud consistency and circulation can be critical to the success of an HDD. Increased
turbidity values were reported in the morning on Day 24, and the drill rig was shut down. A
terrestrial frac-out was identified, contained and cleaned up immediately. The rig resumed
drilling, however increased turbidity values were observed again and the rig was shut down until
the morning of Day 25. Grouting of the hole was complete on Day 25 and the rig began tripping -
out. Day 26, 762 mm reamer began tripping -in. Between Day 26 and Day 31 the rig was put on
stand-by in order to accommodate spill containment set-up, mechanical repairs and frac-out
clean up. Between Day 32 -Day 35, the rig continued tripping -in, alternating shut -down and
reaming activities depending on turbidity values. The rig tripped -in to 633m before abandoning
the HDD attempt on Day 36 due to continuous surface mud -release and drill failure. Abandoning
the HDD attempt was critical to prevent negative environmental disturbance and impacts to the
surrounding ecosystem. Approximately 240 m3 of drilling fluid was contained and removed. The
long-term impact on the local environment would be considered `minimal' due to the
watercourse having enough velocity to transport and deposit the suspended solids, which
migrated into the watercourse during the drilling activity. NTU's typically dropped within a
matter of hours once discovered and drilling activities were halted. However, as the drilling
continued, the frac-out's became more frequent and more severe which could negatively affect
the aquatic ecosystem, leading to the eventual termination of the project. Isolated open -cut
method was schedule to be implemented the following winter. Lack of total suspended solids
(TSS) monitoring data during each of the open -cut installations has prevented defensible
statements to be made about the environmental disturbance to the watercourse at each site (Reid
and Anderson, 1999).

PIPELINE INSTALLATION METHODS 64
Discussion
Industry is compliant with the legislation and direction provided by government and
regulating bodies on managing stream crossings/streambank restoration. Considerations include
cost and alternatives when HDD or isolated open -cut methods fail and there is need to intervene
during the pre -planning and planning phases of pipeline installation at watercourses. Finally, is
there evidence the process has been adjusted based on the lessons learned and how does this
change regulations and guidelines to improve industry practices, which protect the public and
society?
In the Environmental Protection Plan developed for Site A, a trenchless crossing (HDD,
bore) was recommended by a qualified aquatic environment specialist for the watercourse due to
the steep approaches at the crossing that are susceptible to erosion. At this time, it is unknown
whether a geotechnical investigation was completed at the site; however, two soil inspection sites
were located approximately 500 in east of the watercourse crossing. This is where an entry or
exit point of an HDD drill could have been set up. It was decided that an open -cut installation
would take place due to the sedimentation potential of the soils. The sedimentation could have
been mitigated during the implementation of a site-specific reclamation plan according to the
assessment. The watercourse and approaching slopes were left exposed over a year, allowing the
watercourse to be vulnerable to sediment and environmental disturbance during that time, which
would not have occurred had the installation method been an HDD.
A riparian zone, streambed and bank reclamation plan is typically prepared using field
data and surveys outlined in the aquatics assessment report, which is completed by an
environmental consulting/client company prior to project initiation. The purpose of a reclamation
plan is to describe the measures that are acceptable in conjunction with a conceptual design to

PIPELINE INSTALLATION METHODS
65
ensure that the productive capacity of the aquatic environment is maintained. Both Site A and B
had site-specific and detailed Reclamation Plans associated with the crossing methods prepared
as open -cut installations.
The surface and subsurface material found at the sample locations for Site A was a fine
sand and clay, with a higher bulk density for compacting when performing a successful HDD.
The most suitable material to encounter during a geotechnical investigation that supports an
HDD activity would be a uniform and stable material without large gravel seams, boulders,
unconsolidated materials or other features that maximize porosity. It is essential that the HDD
contractor perform a thorough review of the local geological and geotechnical reports, maps,
aerial photographs and review of depositional history (Bennett and Ariaratnam, 2008). A general
understanding of geology and depositional history is beneficial since the contractor may
encounter these subsurface conditions on the project. For example, if the parent material is
influenced by glaciation, then cobbles, boulders and gravel till may be expected. If the area is
subjected to centuries of meandering, low-energy watercourses, the resulting parent material may
represent fine-grained deposits (Bennett and Ariaratnam, 2008) similar to the Site A location.
The failure of both HDD attempts at Site B may have been influenced by the diameter of the
pipeline (762 mm) which created a large borehole making it more likely to encounter boulders,
large debris, fluid and subsurface material displacement.
The soil and parent material at Site A was considered unstable due to low compaction and
potential for sloughing and trench instability. When this is the case, it is appropriate to avoid the
loss of circulation, frac-outs and borehole collapses that may be encountered in performing a
HDD at a crossing. Assessing soil stability is a good predictor of what to expect when attempting
to open -cut the ditch line. Frac-outs occur when there is a loss of circulation and the drill head

PIPELINE INSTALLATION METHODS 66
keeps rotating underground while pushing fluid out of the reamer head when cutting through
material in the drill path. This material can become either very hard (rock, boulders) or
surrounded by void space (logs, gravel seam, boulders), causing the drilling fluid to fill the
empty spaces away from the drill path and eventually surface (fracing-out). This causes the drill
head to spin but not move forward, resulting in zero progress while drill fluid escapes from the
drill hole, as was the case at Site B. There are ways to mitigate these issues, such as installing a
pipe casing or altering the mud mixture additives to maintain consistent lubrication through the
virgin ground. Another cause of a loss of circulation occurs when fluids and surrounding
material (seams of fine sand, silt or water) are drawn into the drill path due to not drilling or
reaming at an appropriate speed for the ground conditions, causing the drill head to suck fluid
and material into the drill fluid recirculation hoses. If circulation has been lost, then sinkholes
may result and these need to be identified and filled. By choosing the isolated open -cut method
rather than a trenchless method, risks involved with the installation are generally manageable and
may be controlled during the construction process.
Environmental Considerations of each Crossing Method
Environmental risks and impacts associated with isolated open -cut pipeline installation
observed by the author include:
• Loss of isolation- this occurs when water levels rise and increase in velocity and carve
around the isolation plates. Pump failure may cause loss of isolation, and it is prudent to
always have backup pumps on-site.
• Rain events that result in large amounts of surface runoff and erosion prior to final
restoration.

PIPELINE INSTALLATION METHODS
67
• Upstream dams (beaver dams or fabricated) releasing high volumes of water resulting in
a flash flood at the watercourse crossing.
• Loose compaction in the ditch line, causing parent material to become exposed and
dislodged in periods of high or turbulent flow, resulting in higher levels of sedimentation
and turbidity in the watercourse (sediment loading).
• .Impacts to fish and fish habitat due to changes in watercourse flow, turbidity, and bed
and bank channel formation where fish spawning may have occurred.
0 Subsidence of the ditch line over time causing unnecessary pressure on the welds of
exposed pipe (which can result in pipe rupture).
• Surface water management to temporarily manage erosion on the initial disturbance,
which can alter the riparian ecosystem over the long-term, causing habitat fragmentation.
• Disturbance of the entire right-of-way due to timber clearing activities.
• Creek bank restoration failure due to poor material, design or an inexperienced
practitioner performing the work.
Environmental considerations associated with HDD/trenchless installation methods
observed by the author include:
• Surface mud releases or frac-outs/lost circulation due to buildup of drilling mud and fluid
within the drill path (or not enough drilling mud and fluid). These releases may occur on
land and migrate to a watercourse, or occur in a watercourse.
• Frac-outs are typically unpredictable in terms of where they may surface. Geotechnical
reports can assist in predicting the likelihood of a frac-out.
• Drilling additives (primarily sodium bentonite products) that are mixed with drilling mud
and water to lubricate the pipe installation may be considered harmful to the surrounding

PIPELINE INSTALLATION METHODS
environment. These additives must be approved by the project environmental
representative and meet the requirements in Section 8 of the Directive 50 Drilling
Guidelines.
• When the wall thickness of the installed pipeline begins to diminish, a new line may be
installed along a new parallel right-of-way to replace the existing line. The faulty HDD
pipe section will be abandoned while a new pipe section is installed by one of the
methods described in this paper, without removing the old line due to depth of
installation.
• Not all rivers and watercourses can be practically crossed using the HDD method because
ground conditions are not always conducive to this method. The geological and
geotechnical history for Site B indicated that the crossing was unsuitable for an HDD
type crossing due to the geomorphology of the area that is prone to glacial outwash till,
gravel seams and cobble, leading to frac-outs.
• Classification of a watercourse by regulatory agencies may offer a contractor few options
in crossing a watercourse. Significant costs may be incurred to implement the solution
before it is abandoned for a more effective and practical alternative. This can create an
expensive and environmentally disturbed site. A number of years may need to be
dedicated to post -construction monitoring to ensure the site is reclaimed.
Implementation of Crossing Methods
Iterative attempts at installation where one method fails and another is tried can result in
significant costs. Isolated open -cut is initially cheaper due to the level of control at a site.
Another option for pipeline installation through watercourses is aerial installation, where the pipe
is welded and laid in place on a supporting bridge -like structure over the watercourse. In this

PIPELINE INSTALLATION METHODS 69
case, the stream is cut into gorges of rock making HDD and open -cut impractical. If the
watercourse is very wide or turbulent, then it is difficult to drill or open -cut, so aerial installation
is an option.
The most productive ecological area at watercourse crossings is the functional riparian
zone, which has a direct influence on the aquatic habitat in transitioning between aquatic and
upland environments. Riparian zones are essential for healthy fish habitat by providing shade,
shelter, food, moderate flows and moderate temperatures in a watercourse (Government of
Alberta, 2009). Regulators, government agencies, recommend reducing the disturbance within
the riparian zone and environmental scientists to reduce the movement of sediments caused by
upland erosion and avoid contaminating the watercourse with sediments. It is a challenge to
maintain the riparian zone at pipeline crossings where the right-of-way has been stripped of
vegetation and steep approaches may affect the long-term environmental impact at the
watercourse.
Because Site A was installed using the isolated open -cut method, the immediate
environmental disturbance at the site was significant, resulting in comprehensive post -
construction monitoring to assess slope stability and ensure sedimentation of the watercourse did
not take place. An HDD would have been a good crossing method at this location and likely
would have been successful based on the subsurface material encountered when digging the
pipeline ditch. If HDD was attempted, the main risk was the perched water table and artesian
flow on the west slope that may have resulted in either a frac-out or loss of circulation. The site
was ecologically restored, which is the process of assisting the recovery of an ecosystem that is
damaged, degraded or destroyed (Society for Ecological Restoration, 2004). The primary
resource that requires protection at Site A is the fish -bearing watercourse. Fish habitat require a

PIPELINE INSTALLATION METHODS 70
series of corridors that link basic requirements for survival, which are food, reproduction and
cover or protection within a watercourse. The restoration of the pipeline crossing was stable and
effective after the first two years post -construction, once the slopes were stabilized. Further
monitoring and maintenance of the site by the pipeline owner is required to assure long-term
stability.
The environmental disturbance at Site B was extensive due to the two failed HDD
attempts. Lost circulation resulted in frac-outs in and around the watercourse, causing the NTU's
to spike while the drill was being attempted. The isolated open -cut crossing took place in the
winter following the HDD attempt; there was no visual evidence of the frac-outs from the
previous winter. The cleanup was done without causing further environmental damage; however,
a short-term disturbance occurred during the drill operation.
Because of the failed drill, the disturbance to the environment increased as the right-of-
way was cleared and the open -cut installation was implemented through the watercourse
according to the contingency pipeline crossing method recommendations in the project EPP. The
in -stream work, including isolation, installation and restoration in the watercourse at Site B was
10 days in duration compared to the 38 -day HDD operation through the same watercourse.
Both of the watercourse crossings evaluated in this study are considered high-risk
crossings due to the flashy flow regime of the watercourse, extensive riparian damage, steep
approaching slopes and erosion resistance of bed and bank material is low at Site A and
moderate at Site B. The banks at each crossing experienced channel and floodplain disturbance,
and both required the use of artificial restoration materials to reconstruct the banks of the
watercourse. The six criteria identified in the Pipeline Risk Screening Matrix (Castro et al.,
2014) that should have been applied when assessing the pipeline right-of-way for watercourse

PIPELINE INSTALLATION METHODS
crossing methods are 1. scale of problem, 2. landscape sensitivity/stream type, 3. riparian
corridor, 4. bank characteristics, 5. bed characterization, and 6. dominant hydrological regime.
Chapter V: Conclusion and Recommendations
The outcome of this study concludes that it can be very challenging under certain field
conditions to determine whether a chosen crossing method will be the most successful option
once the work begins. There are environmental, social, economic and engineering variables to
consider when assessing a site for superior crossing conditions, and often the major challenges
are faced once the work is in progress and the planning phase is over. More knowledge,
71
experience and resources are becoming available to professionals in the field during the planning
phase, however more time should be spent in the field assessing the geophysical conditions of a
site prior to the application of a watercourse installation method in order to avoid unnecessary
risk and environmental disturbance when construction commences. It is uncommon to find
`perfect' site conditions for either type of crossing method. HDD typically produces a small
environmental disturbance on the landscape; however is not always the most reliable method.
Therefore, open -cut method still has a place and purpose in pipeline construction as a back-up
option when stable subsurface site conditions for an HDD do not exist. Ideally, an environmental
and geotechnical investigation process have taken place prior to the planned construction, and an
HDD installation will take place should the preliminary geophysical findings support the
trenchless method.
The sites that are described in this thesis are smaller in scale and are not close to any
communities that could be impacted by a flood of the watercourse or the impacts of an
emergency wash out of a bank restoration. The sites are 40 in wide and 20 in deep on the right-
of-way, which could potentially affect more adventurous recreational users. These disturbances

PIPELINE INSTALLATION METHODS 72
create habitat fragmentation. For example, a 10 km riparian habitat is disturbed by 15 isolated
open -cut watercourse installations, essentially incisions through the forest and watercourse. If 10
of these installations fail, the impacts to the watercourse including high sedimentation and
suspended solids could cause localized stress to the ecosystem in the immediate disturbance
areas and anything immediately downstream. In addition, the habitat is then fragmented across
the 10 km area. These are cumulative effects associated with pipeline construction.
The importance of riparian habitat is widely understood by ecologists, biologists, and
environmental scientists (Meffe, et al. 2002). Within the pipeline construction industry,
construction personnel may not link the importance of the riparian habitat to the surrounding
environment, along with how the work can be planned and executed to mitigate environmental
disturbances at a site. Pipelines, powerlines, seismic lines and other linear developments,
particularly those that cross watercourses with functional riparian zones, result in internal
fragmentation to wildlife habitat.
Frequency and duration of TSS values at a specific site can result in conditions within a
watercourse that are unfavourable for fish survival (CCME, 1987). Exposure to increased TSS
are extremely important to understand especially as it relates to the physiological stress on fish
such as reduced growth, decreased feeding rates and adverse survival rates. The goal is to have
restoration with minimal or no changes to channel morphology, fish habitat or other productive
ecological functions within the riparian zone.
Recommendations.
If an open -cut installation is performed, it is recommended to have a post -construction
monitoring and inspection component in the EPP where follow-up of the site occurs immediately
following the first and second freshets post -construction. This is the optimum time to identify

PIPELINE INSTALLATION METHODS 73
opportunities where cost and risk can be minimized with no additional adverse biophysical
effects. However, it is essential to have qualified professionals (QP) evaluating and monitoring
the site from pre -construction to post -construction in order to mitigate environmental disturbance
at the watercourse crossing and to allow for appropriate planning of installation methods at
watercourse crossings in the future. This is not to say individuals who are not QP's have a higher
rate of failure than QP's; however, the risk of professional sanction, reputational damage, and
monetary penalties are incentives that a QP would consider prior to decision-making at a
restoration site. An individual with no professional qualification is not held accountable to the
public interest in the case of a failure and may expose the public to significant liability. Not
every watercourse is suitable for an HDD installation, and conversely, many sites are over-
looked as potential HDD sites due to the cost of the work in comparison to open -cut, regardless
of the environmental disturbance.
By investing in HDD technology, the footprint of linear development across the natural
landscape can be reduced with less environmental disruption on the surface provided the site
conditions will facilitate the success of the drill. However, knowing when to utilize the isolated -
open cut method will save time, money and ultimately the environment by lowering the risk of a
relatively safe and traditional method of pipeline installation.
Glossary
Adaptive Management Natural process of managing natural resources as an
experiment, making observations and recording them, so
a manager can learn from experience. (Meffe, 2002).
Alpha Richness Number of species within small areas of fairly uniform
habitat. (Meffe, 2002).

PIPELINE INSTALLATION METHODS
74
Area -sensitive Species
Species that require a large area to persist, because of
body size, movement, or specialized needs. (Meffe,
2002).
Artesian Well
A well that taps into a confined aquifer. (Wetlands,
2007).
Bankfull Discharge
Streamflow at which a river begins to overflow onto its
flood plain. (Wetlands, 2007).
Best Management Practices
A practice or combination of practices that are
(BMPs)
determined to be the most technologically and
economically feasible in preventing or managing
potential impacts. (CAPP, 2005).
Biodiversity
Variety of life and its processes; as in, the composition,
structure and function of life concerned with genetic to
landscape levels of organization. (Meffe, 2002).
Bankfull Width
Width of a watercourse when it completely fills its
channel and elevation of the water reaches the upper
margins of the bank. (Wetlands, 2007).
Bed and Banks
Streambed and the rising slope or face of ground
bordering a watercourse, up to the level of rooted
terrestrial vegetation. (Wetlands, 2007).
Crossing Techniques
Open Trench/Open Cut: Excavation of a trench in
flowing water. The crossing site is isolated from the
main watercourse to prevent construction materials and
sediment from entering the watercourse outside of the
isolated area.
Dam/Pump: A dam is placed in the stream channel to
prevent water from flowing through the area that will be
subject to disturbance within the stream channel. A
pump is used to move water from the upstream side of
the excavation to the downstream side to bypass the
instream construction area.
Trenchless: A crossing method in which there is no
disturbance to the bed and banks of a waterbody.
Trenchless crossing methods include horizontal bores,
horizontal punches and direction drills. (CAPP, 2005).
Cumulative loss
Ecosystems such as wetlands are lost, usually because
of human development, one small piece at a time, with
the cumulative loss being substantial. (Meffe, 2002).
Deleterious Substance
(a) Any substance that, if added to any water, would
degrade or alter or form part of a process of degradation
or alteration of the quality of that water so that it is

PIPELINE INSTALLATION METHODS
75
rendered or is likely to be rendered deleterious to fish or
fish habitat or to the use by man of fish that frequent
that water, or
(b) Any water the contains a substance in such quantity
or concentration, or that has been so treated, processed
or changed, by heat or other means, from a natural state
that it would, if added to any other water, degrade or
alter or form part of a process of degradation or
alteration of the quality of that water so that it is
rendered or is likely to be rendered deleterious to fish or
fish habitat or to the use by man of fish that frequent
that water. (CAPP, 2005).
Ecosystem engineers
Plants, animals and microbes that carry out essential
biological feedbacks in ecosystems, such as beavers and
muskrats in wetlands. (Wetlands, 2007).
Fish Habitat
Spawning ground and nursery, rearing, food supply and
migration areas in which fish depend directly or
indirectly to carry out their life processes. (CAPP,
2005).
Frac-Out
Inadvertent seepage of drilling mud onto the ground or
into surface waters through fractures in the subsurface.
Frac-outs can occur when using pressurized crossing
construction methods such as horizontal directional
drilling. (CAPP, 2005).
Freshet
Rapid temporary rise in stream discharge and water
level, caused by heavy rains or rapid melting of snow
and ice. (CAPP, 2005).
Habitat Fragmentation
Process by which a natural landscape is broken up into
small parcels of natural ecosystems, isolated from one
another in a matrix of lands dominated by human
activities. (Meffe, 2002).
Instream Activity
Usually interpreted as any activity conducted in a
waterbody (e.g., stream, river, lake, pond, isolated pool).
(CAPP, 2005).
Interception
Precipitation that is retained in the overlying vegetation
canopy. (Wetlands, 2007).
Internal Fragmentation
A process that occurs when linear or curvilinear
corridors (e.g., roads, power lines, trails) dissect an area.
(Meffe, 2002).
Mitigation
Actions taken during the planning, design, construction
and operation of equipment to alleviate potential

PIPELINE INSTALLATION METHODS
76
References
Alberta Energy Regulator. (2015). Directive 50: Drilling Waste Management.
Alberta Environment Land Reclamation Division, Edmonton, Alberta. (1988). Environmental
Handbook for Pipeline Construction. p. 66-71.
Alberta Government. (2013). Code of Practice for Watercourse Crossings.
Alberta Government. (2013). Integrated Standards and Guidelines, Enhanced Approval Process.
Bennett, D. and Ariaratnam, S.T. (2008). Horizontal directional drilling good practices
guidelines, 3Yd edition.
adverse effects on the productive capacity of fish
habitats. (CAPP, 2005).
Productive Capacity
Maximum natural capability of habitats to produce
healthy fish, safe for human consumption or to support
or produce aquatic organisms upon which fish depend.
(CAPP, 2005).
Rehabilitation
Less than full restoration of an ecosystem to its
predisturbance condition. (Wetlands, 2007).
Riparian
Area pertaining to anything connected with, or
immediately adjacent to, the banks of a watercourse or
waterbody. (CAPP, 2005).
Riparian ecosystem
Ecosystem with a high water table because of its
proximity to an aquatic ecosystem, usually a stream or
river (also called hardwood forest, floodplain forest, or
riparian buffer). (Wetlands, 2007).
Runoff
Nonchannelized surface water flow. (Wetlands, 2007).
Streamflow
Channelized surface water flow. (Wetlands, 2007).
Stream order
Numerical system that classifies stream and river
segments by size according to the order of its tributaries.
(Wetlands, 2007).
Total suspended solids (TSS)
A measure of the sediments in a unit volume of water.
(COME, 1987).
References
Alberta Energy Regulator. (2015). Directive 50: Drilling Waste Management.
Alberta Environment Land Reclamation Division, Edmonton, Alberta. (1988). Environmental
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Alberta Government. (2013). Code of Practice for Watercourse Crossings.
Alberta Government. (2013). Integrated Standards and Guidelines, Enhanced Approval Process.
Bennett, D. and Ariaratnam, S.T. (2008). Horizontal directional drilling good practices
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PIPELINE INSTALLATION METHODS
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