Contractor 2018-03-29 Trans Mountain Expansion Project Revision Geotechnical HDD Feasibility Contractor A Whitemud Creek at SSEID 005 KP 28.2 Revision

Page 1 of 158 TMEP18-025

Trans Mountain Expansion Project

Geotechnical HDD Feasibility Whitemud Creek at SSEID 005 KP 28.2

KMC Document #01-13283-S1-0000-PL-RPT-0035 RA

Reviewed by Pages Rev No. Prepared by / Date Reviewed by / Date Approved by / Date Issued Type TMEP Revised Shannon Ashe Pete Quinn Alex Baumgard A Leo Moreno Issued for Review 2018-03-29 2018-03-29 2018-03-29

TRANS MOUNTAIN PIPELINE ULC

TRANS MOUNTAIN EXPANSION PROJECT

GEOTECHNICAL HDD FEASIBILITY ASSESSMENT WHITEMUD CREEK AT SSEID 005.5 KP 28.2

PROJECT NO.: 0095150-14 DATE: March 29, 2017 DOCUMENT NO.: TMEP18-025

Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

EXECUTIVE SUMMARY

As part of the engineering design and assessment for the Trans Mountain Expansion Project (TMEP), BGC Engineering Inc. (BGC) has been retained to complete geotechnical feasibility assessments for trenchless crossings at select watercourse and overland crossings along the proposed pipeline corridor. This report provides a feasibility-level geotechnical assessment for a Horizontal Directional Drill (HDD) crossing of Whitemud Creek located at approximately Kilometer Post (KP) 28.2, in south Edmonton, Alberta. In June of 2013, Advisian Geophysics Group (a consulting division of WorleyParsons Group), under subcontract to BGC, completed geophysical surveys at the crossing along the proposed TMEP alignment. In June and July of 2014, BGC monitored the drilling of two geotechnical boreholes adjacent to the proposed TMEP alignment as part of an investigative program for four stream crossings identified by Universal Pegasus International (UPI). Initially, the proposed primary crossing method was planned as a conventional trench, with HDD identified as a contingency crossing method. A letter report (BGC 2015) provided geotechnical drilling data collected during the 2014 site investigation. HDD has recently been selected as the primary crossing method. The scope of work for this assessment included a desktop review of the relevant local and regional geological settings, existing available third-party data, examination of records of historic underground coal mining, 2013 and 2014 geophysical surveys and drilling, and compilation and interpretation of this data to provide, from a geotechnical perspective, an indication of the feasibility of the proposed 726 m long HDD crossing. The conclusions presented herein are based solely on the limited scope of the investigation undertaken at this time for the purpose of obtaining information for the feasibility study. Results of geotechnical drilling and the electrical resistivity tomography (ERT) survey indicate the subsurface soils at the proposed crossing consist of silty clays and silty sands/sandy silts that were very soft to firm at shallow depths, becoming very stiff below 10 m depth (on the west side of the crossing). The ERT survey results suggest the possible presence of buried channel fill, potentially including coarse gravel, cobbles and boulders, below the existing creek to a depth near the proposed borepath invert. A review of the location of the proposed HDD at the Whitemud Creek crossing relative to the inferred location of the mapped thalwegs of known nearby pre- glacial valleys (New Sarepta Ellerslie Valleys) suggests that they do not intersect. It may be possible that the ERT survey results indicate the presence of historic coal mines, rather than buried valley channel fill. Horseshoe Canyon Formation (HCF) Bedrock consisting of interbedded sandstone, claystone and siltstone was encountered at approximate depths of 3.4 mbgs and 15.4 mbgs in BH-BGC14-WM-01 and -02, respectively. While advancing through claystone and siltstone, thin layers of very stiff, light green, very high plasticity bentonite clay seams (plasticity index greater than 300%) were encountered at different depths, as noted in both boreholes. Coal

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page i BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 seams containing black, shiny, heavily fractured coal were also encountered at different depths in the claystone and siltstone in both boreholes; a 1.5 m thick coal seam was observed at an elevation of 653.4 metres above sea level (masl) at BH-BGC14-WM-01, while a 1.1 m thick coal seam was observed at 651.4 masl at BH-BGC14-WM-02. Data from the online atlas of historic coal mines developed by Alberta Energy Regulator (AER 2017) indicates the approximate footprints of known mines, their years of operation, the target coal seam thickness, and the approximate depth of mining below ground surface. The proposed HDD alignment will pass through or along coal seams that have been targeted by known mines. Reported coal seam thicknesses, and therefore room heights, are 1.1 to 1.5 m. The maximum depth to the base of the known mine workings varies from 22.9 to 43.9 m below ground surface. In 2016, Southwest Edmonton Connector Project of ATCO Pipelines (ATCO) installed a 51 cm (20 inch) pipeline beneath Whitemud Creek using an HDD crossing method. Due to the likelihood of the proposed HDD borepath intersecting the former underground coal mines, a jet grouting program was implemented to fill voids with low-strength cement grout. The grout was injected into more than a hundred drilled holes and was completed in early 2017. No investigative geotechnical report, including grouting technical information, geophysical testing, coring of the area, nor HDD construction records were available to BGC at the time of writing. The proposed TMEP HDD alignment across Whitemud Creek is designed to be constructed within the Edmonton transportation and utility corridor (TUC), parallel to the ATCO pipeline. The current TMEP HDD alignment is proposed to be approximately 10 m south of, and with a maximum depth of approximately 16 m above, the ATCO HDD. Given the above, and based on the desktop study, available public information and results of the geotechnical and geophysical site investigation, an HDD at this location may be considered feasible from a geotechnical perspective provided the following concerns are addressed during detailed design and construction:  Possible hazards related to historical coal mines: ○ TMEP HDD may encounter voids, timbers, steel rails or loose/destressed rock in or near the boundaries of old mine workings. The portion of the pipeline installed above old coal mines may be exposed to future subsidence (i.e., vertical displacement of the ground over the footprint of the mine, and horizontal ground displacement). The rocks above the mine workings may be disturbed, loosened, or partially destressed due to previous displacements following mining. Discontinuous (i.e., non-uniform) displacement may also be expected due to future failure of the mine roof and localized subsidence of the overlying strata. ○ Although no geotechnical data was available regarding the ATCO HDD construction, it is known that several mitigation measures were taken, including a jet grouting program to improve conditions at the depth of the old coal mines prior to the installation of the pipeline, and it is also understood that considerable subsurface investigation was completed to support the design of mitigation.

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page ii BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

○ Additional subsurface investigations (i.e., geotechnical drilling targeting the area where the proposed HDD will intersect the coal seams in the footprint of the old coal mines) will allow the project to assess the intersection zone and determine whether a grouting program or other mitigation measures would be necessary. ○ A review and evaluation of any available geotechnical or construction reports for the ATCO HDD, including borehole logs, borehole photos, geophysics, grouting design, and HDD construction records, may reduce the needed efforts of further geotechnical investigation.  Coarse clasts in buried channel fill: There is some chance the bore may encounter coarse channel fill below the existing creek, as suggested by the ERT survey. If encountered, the coarse clasts could cause challenges for borepath stability, deflect the HDD borepath and/or damage the carrier pipe when it is pulled into the borepath. Deepening the borepath by up to about 20 m to avoid the area where channel fill deposits are inferred may be considered as a means of reducing uncertainty and associated risk; alternatively, additional geotechnical investigation may be considered to determine whether buried channel fills are present.  Steering difficulties and borepath stability: The rocks above old mine workings may be disturbed, loosened, or partially destressed due to prior displacements associated with collapse and subsidence of old mine workings. The permeability of this disturbed rock mass may be higher than rock outside the mine footprints, and there may also be increased steering issues compared to surrounding undisturbed rock. Bedrock in the 2014 site investigation was observed to be poorly lithified (soil-like) with extremely weak to very weak strength, which may also contribute to steering issues (i.e., bit skipping on the harder materials encountered at flat angles).  Loss of drilling fluids: Drilling conditions in the vicinity of old mine workings may be poor and lost circulation zones may be more common, compared to areas outside the mine footprints. Loss of fluid in these formations was observed during the geotechnical drilling. 100% fluid loss was noted from 13.4 to 16.5 mbgs (653.6 to 650.5 masl) at BH-BGC14- WM-01, beginning just above the point where a 1.5 m thick coal seam was intersected (from 653.4 to 651.9 masl). These observations suggest that loss of circulation and drill fluids is possible along the HDD bore. In the event that grout injection is used to reduce the potential of the bore encountering the workings themselves, the process would also reduce the possibility of fluid loss in dilated, fractured rock near old workings.  Highly plastic material: High plasticity zones were identified within the bedrock deposits (32.85 – 33.0 mbgs at BH-BGC14-WM-01). This has the potential to thicken the drill mud and to impact cuttings management (causing mud rings). Such conditions may be mitigated with careful management of drill fluids and cuttings.  Swelling material: During the geotechnical drilling at BH-BGC14-WM-01, the drill bit got stuck while advancing through the HCF bedrock and was inferred to be caused by the swelling of a bentonite seam observed in the claystone bedrock at BH-BGC14-WM-01, and the swelling of the siltstone at BH-BGC14-WM-02. The potential for the rock to swell after reaming the HDD borepath should be addressed in detailed design.

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page iii BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

TABLE OF CONTENTS

EXECUTIVE SUMMARY ...... i TABLE OF CONTENTS ...... iv LIST OF TABLES ...... v LIST OF FIGURES ...... v LIST OF DRAWINGS ...... vi LIST OF APPENDICES ...... vi LIMITATIONS ...... vii 1.0 PROJECT DESCRIPTION ...... 1 2.0 SCOPE OF WORK ...... 2 3.0 SITE DESCRIPTION, GEOLOGY, AND HYDROTECHNICAL ASSESSMENT ...... 3 3.1. Overview ...... 3 3.2. Surficial Geology ...... 4 3.2.1. Regional ...... 4 3.2.2. Local ...... 4 3.3. Historic Coal Mining in Edmonton Area ...... 7 3.4. Bedrock Geology...... 9 3.5. Terrain Mapping ...... 10 3.5.1. Terrain Types ...... 10 3.6. Existing Water Well Logs ...... 10 3.7. Historical Borehole Data ...... 11 3.8. Adjacent ATCO HDD Crossing ...... 11 3.9. Hydrotechnical Assessment ...... 12 3.9.1. Flood Frequency Analysis ...... 12 3.9.2. Scour ...... 13 3.9.3. Bank Erosion ...... 13 3.9.4. Encroachment ...... 14 3.9.5. Avulsion ...... 14 4.0 SITE INVESTIGATION ...... 16 4.1. Geotechnical Drilling and Laboratory Testing ...... 16 4.2. Groundwater Observations ...... 18 4.3. Borehole Stability ...... 18 4.4. Drill Fluid Circulation ...... 18 4.5. Geophysical Survey Data ...... 18 5.0 INFERRED GEOTECHNICAL CONDITIONS ALONG THE HDD BOREPATH ...... 20 5.1. Geotechnical Conditions Along the Borepath ...... 22 6.0 GEOTECHNICAL FEASIBILITY ASSESSMENT ...... 25 6.1. General Considerations ...... 25 6.2. Historical Coal Mines ...... 26 6.3. Steering Difficulties...... 26 6.4. Borepath Stability...... 26

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page iv BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

6.5. Circulation and Potential for Loss of Fluids ...... 26 6.6. Geotechnical Feasibility ...... 26 7.0 CLOSURE ...... 29 REFERENCES ...... 30 LIST OF TABLES

Table 3-1. Peak instantaneous flow estimates (QIMAX) for the Whitemud Creek [KP 28.2] crossing...... 13 Table 3-2. Whitemud Creek historical imagery database...... 14 Table 4-1. Borehole locations, elevations and depths...... 17 Table 4-2. Groundwater observations in BH-BGC14-WM-01 and BH-BGC14-WM- 02...... 18 Table 5-1. Summary of geological units identified during BGC’s geotechnical investigation...... 24

LIST OF FIGURES

Figure 3-1. Location of the proposed Whitemud crossing...... 3 Figure 3-2. Surficial geology of the Edmonton area (modified after Kathol and McPherson 1975)...... 5 Figure 3-3. Index map illustrating the location of the Whitemud Creek HDD crossing relative to geological cross-sections (modified after Kathol and McPherson 1975)...... 6 Figure 3-4. Select portion of geological cross-section #1 – east to west (modified, from Kathol and McPherson 1975)...... 7 Figure 3-6. Approximate locations of historic coal mine footprints from AER coal mine atlas (red hatch), the proposed TMEP pipeline alignment (red line with KP markers), and area of the proposed HDD crossing (black rectangle)...... 8 Figure 3-7. Loading a coal car at the Humberstone Mine (northeast Edmonton) in 1917. Photograph by City of Edmonton archives...... 9

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LIST OF DRAWINGS

DRAWING 01A TERRAIN MAP DRAWING 01B TERRAIN MAP LEGEND DRAWING 02 INTERPRETED GEOLOGIC CROSS-SECTION DRAWING 03 BANK EROSION AND AVULSION REVIEW DRAWING 04 GEOPHYSICS RESULTS DRAWING 05 FIELD PHOTOS DRAWING 06A PHOTOGRAPHIC LOG OF BH-BGC14-WM-01 (1 OF 3) DRAWING 06B PHOTOGRAPHIC LOG OF BH-BGC14-WM-01 (2 OF 3) DRAWING 06C PHOTOGRAPHIC LOG OF BH-BGC14-WM-01 (3 OF 3) DRAWING 07A PHOTOGRAPHIC LOG OF BH-BGC14-WM-02 (1 OF 3) DRAWING 07B PHOTOGRAPHIC LOG OF BH-BGC14-WM-02 (2 OF 3) DRAWING 07C PHOTOGRAPHIC LOG OF BH-BGC14-WM-02 (3 OF 3)

LIST OF APPENDICES

APPENDIX A HYDROTECHNICAL ASSESSMENT METHODOLOGY APPENDIX B BGC BOREHOLE LOGS APPENDIX C LABORATORY TEST RESULTS APPENDIX D PRELIMINARY ASSESSMENT OF COAL MINE RELATED HAZARDS KP 26 TO KP 29 (SOUTH EDMONTON)

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page vi BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

LIMITATIONS

BGC Engineering Inc. (BGC) prepared this document for Trans Mountain Pipeline ULC (Trans Mountain). The material in this report reflects the judgment of BGC staff based upon the information made available to BGC at the time of preparation of the report, including that information provided to it by Trans Mountain. Any use which a third-party makes of this report or any reliance on decisions to be based on it is the responsibility of such third parties. BGC accepts no responsibility whatsoever for damages, loss, expenses, loss of profit or revenues, if any, suffered by any third-party as a result of decisions made or actions based on this report. As a mutual protection to our client, the public and BGC, the report, and its drawings are submitted to Trans Mountain as confidential information for a specific project. Authorization for any use and/or publication of the report or any data, statements, conclusions or abstracts from or regarding the report and its drawings, through any form of print or electronic media, including without limitation, posting or reproductions of same on any website, is reserved by BGC, and is subject to BGC's prior written approval. Provided however, if the report is prepared for the purposes of inclusion in an application for a specific permit or other government process, as specifically set forth in the report, then the applicable regulatory, municipal, or other governmental authority may use the report only for the specific and identified purpose of the specific permit application or other government process as identified in the report. If the report or any portion or extracts thereof is/are issued in electronic format, the original copy of the report retained by BGC will be regarded as the only copy to be relied on for any purpose and will take precedence over any electronic copy of the report, or any portion or extracts thereof which may be used or published by others in accordance with the terms of this disclaimer.

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page vii BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

1.0 PROJECT DESCRIPTION Trans Mountain Pipeline ULC (Trans Mountain) is a Canadian corporation with its head office located in Calgary, Alberta. Trans Mountain is a general partner of Trans Mountain Pipeline L.P., which is operated by Kinder Morgan Canada Inc. (KMC), and is fully owned by Kinder Morgan Energy Partners, L.P. Trans Mountain is the holder of the National Energy Board (NEB) certificates for the Trans Mountain pipeline system (TMPL system). The TMPL system commenced operations in 1953 and now transports a range of crude oil and petroleum products from Western Canada to locations in central and southwestern British Columbia (BC), Washington State, and offshore. The TMPL system currently supplies much of the crude oil and refined products used in BC. In December 2016, the NEB granted approval for the Trans Mountain Expansion Project (referred to as “TMEP” or “the Project”) under Section 52 of the National Energy Board Act (NEB Act). The proposed expansion will comprise the following:  Pipeline segments that complete a twinning (or “looping”) of the pipeline in Alberta (AB) and BC with about 987 km of new buried pipeline  New and modified facilities, including pump stations and tanks  Three new berths at the Westridge Marine Terminal in Burnaby, BC, each capable of handling Aframax class vessels. As part of the design process for the twinning of the pipeline, geotechnical and hydrotechnical investigations are being undertaken at select watercourse crossings and where the pipeline will be installed by trenchless methods to avoid existing infrastructure. These investigations support the feasibility assessments for establishing the preferred crossing methodology, and where appropriate, contingency options. Known reference points along the existing TMPL system are commonly referred to as Kilometer Post or “KP.” KP 0.0 is located at the Edmonton Terminal in Edmonton, AB, where the existing Trans Mountain system originates. KPs are approximately 1 km apart and are primarily used to describe features along the pipeline for operations and maintenance purposes. All references to KPs along the TMEP corridor are for the Route SSEID 005.5 alignment provided by Universal Pegasus International (UPI) in March 2018.

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 1 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

2.0 SCOPE OF WORK As part of the engineering design and assessment for installing new sections of pipeline, Trans Mountain has retained BGC Engineering Inc. (BGC) to complete geotechnical feasibility assessments for trenchless crossings at select locations along the proposed pipeline corridor. A trenchless crossing by horizontal directional drilling (HDD) is proposed for the Whitemud Creek crossing, located at SSEID 005.5 KP 28.2, in Edmonton, Alberta. A 726 m long (2D length in plan view) HDD crossing is proposed for this site, as illustrated in the preliminary design drawing for the proposed HDD crossing (UPI 2018). BGC’s scope of work for the feasibility assessment of the Whitemud Creek crossing consisted of the following:  Desktop study including: ○ A review of the published literature on the local and regional geological setting at the HDD crossing ○ A review of historic underground coal mining via an online atlas developed by Alberta Energy Regulator (AER 2017), and a preliminary assessment of coal mine related hazards (BGC 2016) ○ A review of the 1:20,000 scale terrain mapping assessment (Trans Mountain 2014) along the pipeline corridor ○ A review of available information of an existing nearby HDD crossing by ATCO Pipelines, parallel to the proposed TMEP HDD ○ A hydrotechnical assessment of the site, which consisted of a flood frequency analysis and assessment of hydrotechnical hazards including scour and lateral migration of the creek.  Drilling of two geotechnical boreholes adjacent to the proposed HDD crossing (supervised and logged by BGC)  Geophysical surveys completed by Advisian along the proposed TMEP alignment  Compilation and interpretation of this data, and assessment of geotechnical feasibility for the proposed HDD crossing. Planning for contingency construction methods is outside the scope of this study and will be addressed by the pipeline design engineer for the portion of the route under consideration, in this case, UPI. As such, no comments on the applicability of the current route to alternate crossing methods are provided herein. The purpose of this report is to summarize the anticipated geotechnical and hydrotechnical conditions at the proposed Whitemud crossing, and to provide an indication, from a geotechnical perspective, of the feasibility of an HDD crossing at this location.

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 2 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

3.0 SITE DESCRIPTION, GEOLOGY, AND HYDROTECHNICAL ASSESSMENT

3.1. Overview The proposed HDD crossing is located in south Edmonton, Alberta, approximately 200 m north of the Anthony Henday South Highway (HWY 216) and crosses Whitemud Creek and 142 Street SW. The location of the proposed TMEP alignment is shown in Figure 3-1.

Whitemud Creek

Approximate location of the 142 Street SW two Alberta Water Wells HDD Exit Point

HDD Entry Point

Figure 3-1. Location of the proposed Whitemud crossing.

The TMEP alignment at the proposed crossing (UPI 2018) is oriented approximately east to west and crosses Whitemud Creek at approximately a 75° angle to the creek. The proposed HDD entry and exit points are located approximately 290 m west and 435 m east of the Whitemud Creek

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 3 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 thalweg, respectively. From entry to exit point, the proposed HDD borepath is approximately 726 m long (2D horizontal length in plan view), and crosses approximately 33 m beneath Whitemud Creek.

3.2. Surficial Geology

3.2.1. Regional The proposed HDD crossing is within the Central Parkland natural subregion, which lies within the Eastern Alberta Plains physiographic region of Alberta. This area is primarily characterized by undulating till plains. Additionally, approximately 30 percent of the region consists of hummocky uplands with more pronounced topographic relief. The vegetation of the region consists of either a patchwork of aspens and native prairie vegetation or cultivated agricultural fields and urban areas (Downing and Pettapiece 2006). The dominant surficial materials in this region are thick glaciolacustrine sediments and glacial till with lesser glaciofluvial, fluvial, colluvial and eolian soils, and bedrock outcrops (Shetsen 1990). Glaciolacustrine and till deposits overlie discontinuous pre-glacial Saskatchewan Sands and Gravels, and sedimentary bedrock (Edwards et al. 2006). Overburden depth is variable, and generally thins to the west. Surficial material in this physiographic region is controlled by the glacial history of the Laurentide Ice Sheet during the Wisconsin Glaciation (Young et al. 1994). The Edmonton region was submerged beneath Glacial Lake Edmonton, a large lake that formed as the Laurentide Ice Sheet retreated and downwasted to the north and east, blocking the eastward drainage system. Sediment-rich post-glacial streams deposited clays, silts, and sands into the Edmonton area. Glaciolacustrine deposits are characterized as dark sands, silts, and clays (Shetsen 1990). Glaciofluvial deposits, both pre- and post-glacial, contain gravels, sands, and silts. Tills are medium to moderately fine textured, and moderately calcareous (Downing and Pettapiece 2006). The Alberta Geological Survey surficial geology maps suggest the presence of glaciolacustrine deposits in the general vicinity of the proposed HDD crossing at Whitemud Creek (Fenton et al. 2013).

3.2.2. Local Kathol and McPherson (1975) present a summary of basic geologic data available for the Edmonton area, including cross-sections of the local geology. The approximate location of the study area is shown in plan view overlying the surficial geology of Edmonton mapped by Kathol and McPherson 1975 in Figure 3-2. The location of the proposed HDD crossing at Whitemud Creek relative to the nearest geological cross-section (#1) is illustrated in Figure 3-3. Cross- section #1 is presented in Figure 3-4. Based on the surficial geology map shown in Figure 3-2, Kathol and McPherson observed gullies, creek valleys, and scarp features consisting of thin colluvial cover on the valley slopes, a thin cover of alluvial materials along the streams, and mixed glacial and bedrock material.

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Approximate location of proposed HDD drill path

Figure 3-2. Surficial geology of the Edmonton area (modified after Kathol and McPherson 1975).

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Approximate location of proposed HDD drill path

Cross Section #1 1 1

Figure 3-3. Index map illustrating the location of the Whitemud Creek HDD crossing relative to geological cross-sections (modified after Kathol and McPherson 1975).

Based on the cross-section, the following deposit types may be encountered by the drill path, in descending order from the ground surface: a. Glaciolacustrine deposits (unit 8, light blue, in Figure 3-4): bedded sands, silts, and clays deposited in a large pre-glacial lake called Glacial Lake Edmonton. b. Glacial till (unit 5, brown, in Figure 3-4): unstratified sediment deposited by a glacier; lenses of outwash sand or gravel or disturbed bedrock are common. c. Bedrock (unit 1, orange, in Figure 3-4): Edmonton Formation, also known as Horseshoe Canyon Formation (HCF), composed of interbedded bentonitic shales, siltstones, and sandstones with numerous coal seams.

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Approximate location of proposed HDD drill path

Figure 3-4. Select portion of geological cross-section #1 – east to west (modified, from Kathol and McPherson 1975).

McPherson and Kathol (1972) and Kathol and McPherson (1975) have also mapped the presence of buried valley gravels in the area. These are pre-glacial valleys that have been partially or fully infilled with glacial or other materials during the Wisconsin glaciation. These materials pre-date the glacial deposits and are referred to in the literature as Tertiary-Quaternary gravels. A review of the location of the proposed HDD entry point at the Whitemud Creek crossing relative to the inferred location of the mapped thalwegs of known nearby pre-glacial valleys (New Sarepta Valley and Ellerslie Valley) suggests that they do not intersect.

3.3. Historic Coal Mining in Edmonton Area Underground coal mining has been undertaken in Alberta, and specifically the Edmonton region, since the late 1800s (City of Edmonton Archives). The Alberta Energy Regulator (AER 2017) has developed an online atlas of known historical coal mines. Data provided by the atlas includes the approximate footprints of the mines, the years of operation, the target seam thickness, and the estimated depth of mining below ground surface. Mines in the area of Whitemud Creek crossing (Figure 3-6) were active from the 1920s to the late 1940s (AER 2017). The coal was recovered with limited mechanization by room and pillar mining methods, whereby the seam is exploited by excavating certain areas (i.e., rooms) and leaving intact rock in place (i.e., pillars) to support the roof. The roofs of mines were also supported by timber. Over time, room and pillar mine workings often collapse due to progressive weakening and deterioration of the pillars. Pillar weakening can be accelerated by informal or illegal removal of additional coal (i.e., pillar robbing). Therefore, where the coal seam has been mined, it is possible to find intact coal in unmined areas or at pillars, or to encounter voids or mine infrastructure, including timbers and steel rails. It is also possible to find that the roof has collapsed and is in contact with the floor, with the surrounding rock potentially highly fractured and / or dilated. City of Edmonton Archives’ anecdotal reports indicate that pillar retreat mining may have been undertaken in some areas; the removal or thinning of pillars would result in a less stable

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 7 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 mine roof. The proposed HDD borepath crossing Whitemud Creek will traverse coal seams targeted by recorded mines. These coal seams are interbedded in the extremely weak to weak shales and sandstones of the Cretaceous aged HCF. The bore could therefore encounter potential pillars, steel rails, timbers and voids (rooms) left by mine development. Reported coal seam thicknesses, and therefore room heights, are 1.1 to 1.5 m. The maximum reported depths to the base of the mine workings vary from 22.9 to 43.9 m below ground surface.

UNDERGROUND

SURFACE

Figure 3-5. Approximate locations of historic coal mine footprints from AER coal mine atlas (red hatch), the proposed TMEP pipeline alignment (red line with KP markers), and area of the proposed HDD crossing (black rectangle).

BGC completed a desktop assessment (BGC 2016) of potential coal mine hazards affecting the proposed pipeline from KP 26 to KP 29 (South Edmonton). That report compiled available information in the public domain for historical coal mining in the southern parts of the City of Edmonton, including geology and mining methods, as well as a review of potential hazards that may affect the pipeline during construction or operations due to the presence of the old coal mines below the pipeline alignment. Figure 3-7 illustrates typical mine development along a flat-lying coal seam less than 2 m thick; here the roof is supported by timbers extending up from the floor, and coal is hauled away in rail cars on steel rails. Both timbers and rails were likely left in place following coal extraction.

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Figure 3-6. Loading a coal car at the Humberstone Mine (northeast Edmonton) in 1917. Photograph by City of Edmonton archives.

Possible hazards to the TMEP trenched pipeline related to the historic coal mines were then provided by BGC (2016), and are discussed in Section 6.0.

3.4. Bedrock Geology The proposed HDD crossing is underlain by HCF bedrock of the Upper Cretaceous to Tertiary Edmonton Group. These rock units are generally very gently dipping to the west and have not been tectonically deformed although minor folds and faults are known (Dawson et al. 1994). Bedrock generally is of decreasing age to the west within this physiographic region. The HCF is characterized as interbedded non-marine sandstone, siltstone, and shale, with numerous coal and bentonite beds (Hamblin 1998). Sandstones are soft, light-grey to greenish grey, poorly sorted, very fine to medium grained, feldspathic, and argillaceous (Hamblin 1998). Mudstones are grey-green or brown, argillaceous and bentonitic, and also carbonaceous. Units usually contain wood fragments, thin coal streaks, ironstone concretions, and beds with plant and dinosaur fossils (Hamblin 1998). As described above, coal beds in this unit were historically mined

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 9 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 in the Edmonton area using underground room and pillar techniques. Subsidence within the mined seams has historically caused damage to the surface and buildings in the Edmonton area (Edwards et al. 2006). Ice-shoved bedrock is also common in the Edmonton area and may be present within this subregion. This consists of blocks of bedrock that have been displaced laterally and deposited by glacial action atop of other glacial deposits (typically tills or sands and gravels; Kathol and McPherson 1975).

3.5. Terrain Mapping As part of an overall terrain assessment for TMEP, BGC has produced terrain mapping along the proposed pipeline corridor at a nominal scale of 1: 20,000 from the analysis of air photos, satellite imagery, and LiDAR topography. Terrain mapping was spot-checked by site visits and field observations (Trans Mountain 2014). Local variations in terrain over areas of about 2 to 3 hectares, or over distances of less than approximately 150 m, may not be captured in the scale of terrain mapping. Terrain mapping for the Whitemud Creek crossing is shown in Drawing 01A, and a terrain code legend for this is shown in Drawing 01B.

3.5.1. Terrain Types The dominant surficial materials along the Whitemud Creek crossing are mapped as glaciolacustrine sediments and fluvial deposits, as illustrated in Drawing 01A. Glaciolacustrine soils typically consist of silts, clays, and fine sands deposited in glacial lakes. Higher energy deposition that occurred at the margins of glacial lakes could also result in coarse deposits. Deposits are often layered due to seasonal variations in stream flow and sediment grain size. Fluvial deposits are typically thin and consist of silt, sand and gravel. Glacial till and bedrock have not been mapped but may underlie the mapped surficial deposits. BGC completed a terrain stability analysis in conjunction with terrain mapping of the TMEP route (Drawing 01A). This analysis classified a range of stability classes for the regions along the proposed HDD crossing. The regions surrounding the HDD entry and exit points are classified as a Stability Class I, suggesting that no significant stability problems exist at those locations. Whitemud Creek valley walls adjacent to the creek have been mapped as terrain stability class IV, suggesting the potential for construction-related instability if they need to be graded to support the project (the current HDD design avoids these slopes).

3.6. Existing Water Well Logs Several drilled wells are located nearby. These records provide limited geotechnical information and are not considered a reliable source of information. Water well drilling reports from the Alberta Government (Alberta Government 2018) include the following information:  Well ID 1065489, approximately 220 m northeast of BH-BGC14-WM-02 (Figure 1): ○ Brown Clay (0.0 to 6.4 mbgs) ○ Gray Clay (6.4 to 9.1 mbgs) ○ Gray Sand (9.1 to 9.8 mbgs) ○ Gray Shale Shale (9.8 to 17.4 mbgs)

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○ Light Gray Shale (17.4 to 18.0 mbgs) ○ Gray Hard Shale (18.0 to 23.2 mbgs) ○ Gray Soft Shale (23.2 to 26.5 mbgs) ○ Coal (26.5 to 28.3 mbgs) ○ Gray Shale (28.3 to 30.5 mbgs).  Well ID1065490, located nearby Well ID 1065489, approximately 220 m northeast of BH- BGC14-WM-02 (Figure 1): ○ Brown Clay (0.0 to 9.8 mbgs) ○ Gray Clay and Sand (9.8 to 10.1 mbgs) ○ Gray Shale (10.1 to 13.1 mbgs) ○ Light Gray Shale (13.1 to 14.9 mbgs) ○ Gray Shale (14.9 to 21.0 mbgs) ○ Gray Sticky Sandstone (21.0 to 22.6 mbgs) ○ Light Gray Shale (22.6 to 25.3 mbgs) ○ Coal (25.3 to 27.1 mbgs) ○ Gray Shale (27.1 to 29.6 mbgs) ○ Gray Sticky Sandstone (29.6 to 29.9 mbgs) ○ Gray Shale (29.9 to 30.5 mbgs). These two wells show bedrock covered by 9.8 m of overburden consisting of clay and sand, with bedrock being predominantly shale and sandstone. A 1.8 m thick coal seam was observed at 26.5 mbgs at Well ID 1065489 and at 25.3 mbgs at Well ID 1065490.

3.7. Historical Borehole Data McPherson and Kathol (1972) summarize the results of a drill program carried out in 1972 by the Geology Division of the Research Council of Alberta. Their borehole BH-31 is offset from the proposed borepath by approximately 810 m to the north. The general stratigraphy of BH-31 from the ground surface down includes lacustrine silty clay, lacustrine sandy silt, glacial sand and gravel, till, and shale and sandstone bedrock. No other third-party subsurface data were available at the time of writing.

3.8. Adjacent ATCO HDD Crossing The proposed TMEP HDD alignment across Whitemud Creek is to be installed within the Edmonton transportation and utility corridor (TUC), parallel to an existing ATCO HDD crossing. The following discussion of that installation is based on third-party sources as indicated, and is not known with confidence by BGC to be factually correct or complete. In 2016, as part of their Urban Pipeline Replacement Program, Southwest Edmonton Connector Project of ATCO Pipelines (ATCO) designed the installation of a 501 mm (20-in) pipeline below Whitemud Creek using an HDD crossing method. Thurber Engineering (Thurber) conducted a geotechnical investigation that included the drilling of 24 geotechnical boreholes (up to 80 m in depth), and the collection of seismic tomography data to determine the potential for voids and the

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 11 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 presence of existing mine works (North American Society for Trenchless Technology (NASTT 2018). Based on the information collected by Thurber, a ground improvement plan was reportedly implemented, consisting of jet grouting at a target depth to fill voids. A low-strength cement grout was reportedly injected in over one hundred drilled holes. The grouting was reportedly completed in early 2017, followed by geophysical testing and a geotechnical drilling program to check that the area was safe for the HDD installation (CEPA 2018). NASTT (2018) also indicates that the ground improvement plan was broken into two parts: a pilot grouting (proof of concept) section followed by a full grouting section. Associated Engineering (AE) completed the design of the ATCO HDD, including borepath design, fluid pressure, and pipe stress analysis. AE and Thurber carried out a parametric study using the finite element method (FEM) to optimize the pipe wall thickness within the limits of the ground improvement zone and to optimize the borepath design. No formal reports on the geotechnical investigation, drilling program grouting technical information, geophysical testing, coring of the area, nor HDD construction records were available to BGC at the time of preparing this assessment.

3.9. Hydrotechnical Assessment LiDAR imagery, historical air photographs, 2014 survey data, and site observations were used to assess the potential for hydrotechnical hazards to impact the proposed pipeline. Hazards evaluated by BGC included scour, bank erosion, encroachment and avulsion. The methodologies used to complete this hazard assessment are presented in Appendix A.

3.9.1. Flood Frequency Analysis Flood quantiles for the Whitemud Creek crossing were estimated using a flood frequency analysis (FFA). The drainage area at the crossing was estimated to be 333 km2 and a prorated FFA was used to estimate peak instantaneous streamflow (QIMAX) for various return periods. This FFA is based on Water Survey of Canada (WSC) hydrometric station Whitemud Creek near Ellersie (05DF006). This station is located approximately 2.7 km upstream (southwest) of the proposed crossing. This station has a record length of 39 years between 1970 and 2018 and has a published watershed area of 330 km2. The flood quantiles from the gauging station were prorated to the proposed crossing along with a climate change allowance of +10% based on guidance by APEGBC1 (2012). Peak instantaneous streamflow estimates at the Whitemud Creek crossing for various return periods are as listed in Table 3-1.

1 The Association of Professional Engineers and Geoscientists of BC (APEGBC) recently changed its name to Engineers & Geoscientists British Columbia (EGBC).

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Table 3-1. Peak instantaneous flow estimates (QIMAX) for the Whitemud Creek [KP 28.2] crossing.

Basin 3 Pipeline QIMAX for Given Return Periods (m /s) Area Crossing (km2) 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 200-yr

Whitemud Creek 333 15 32 48 76 105 144 196

Average cross-sectional flow hydraulics for the crossing were estimated using Manning’s equation, a surveyed cross-section, a channel gradient of 0.03% and the peak flows listed in Table 3-1. The channel gradient was calculated using the Canadian Digital Elevation Data (CDED). The cross-section used for the evaluation is based on a surveyed cross-section by Opus Stewart Weir from June 2014. The corresponding water elevation for the 200-year return period flood is 663.2 masl as shown on Drawing 02. The proposed HDD entry point is located at an elevation of 684.3 masl and the proposed exit point is located at an elevation of 683.7 masl. The proposed HDD entry point and exit point are approximately 21 m above the estimated 200-year return period flood level. Given this result, submergence of the entry point and exit point is not considered a hazard for the proposed HDD borepath.

3.9.2. Scour BGC completed a scour analysis for the site to evaluate general scour conditions over the point at which the proposed HDD alignment crosses below Whitemud Creek. The scour analysis was conducted using the estimated peak flows presented in Table 3-1, and the channel cross-section from the survey completed by Opus Stewart Weir in June 2014. Results from the analysis estimate a maximum scour depth of approximately 0.8 m below the channel thalweg (deepest elevation of the channel) elevation of 656.8 masl during a 200-year flood event, corresponding to a maximum scour elevation of 656.0 masl. The elevation of maximum scour is shown on Drawing 02 and the depth of cover above the proposed HDD borepath remains greater than 30 m at the current creek channel should this amount of scour occur. Given this result, scour is not considered a hazard for the proposed HDD borepath.

3.9.3. Bank Erosion BGC completed an evaluation of the historical lateral erosion of Whitemud Creek at the crossing by comparing aerial imagery from 1949 and 2011 (Table 3-2). The 1949 aerial photograph was georeferenced to make the comparison with the 2011 orthoimage, and Drawing 03 demonstrates how the channel planform has changed over the 62-year period.

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Table 3-2. Whitemud Creek historical imagery database. Date Ref No. Photo No. Scale Source 1949 A0137 97 1:40,000 Alberta Environment and Parks (AEP)1

2011 - - City of Edmonton

Notes: 1. AEP was previously known as Alberta Environment and Sustainable Resource Development (AESRD).

A comparison of the channel thalweg location between 1949 and 2011 illustrates that Whitemud Creek migrated approximately 25 m to the west over a 62-year period (Drawing 03). BGC considers 25 m of lateral migration conservative given the estimated error associated with the air photo analysis. Some of this adjustment may be related to underground coal mining in the area that was active to the late 1940s (AER 2017), and to construction of an upstream highway, Anthony Henday Drive. Whitemud Creek is confined within a large meandering valley, which formed during deglaciation as a result of much larger flows. Although the channel migrated historically, presently the channel is confined by valley slopes on the left (west) bank and the stream has limited capacity to erode into the valley walls.

A June 10, 2013 site visit by Terra Environmental observed evidence of erosion on the left bank, with slumping and exposure of bare earth observed over a length of 1.5 m near the crest. However, this erosion is minor and is not expected to impact the proposed HDD alignment within its operational life span. Both banks of the Whitemud Creek crossing are well vegetated with grasses and some mature trees, which also contributes to bank stability. Given that the proposed HDD entry and exit points are located outside of the valley, and are both set back approximately 200 m from the crests of the east and west valley walls, bank erosion in the vicinity of the proposed HDD crossing is not considered a hazard for the proposed HDD borepath.

3.9.4. Encroachment A severe meander bend is located approximately 30 m downstream of the proposed crossing, and the river flows parallel to the pipeline for approximately 70 m. Historically, between 1949 and 2010, the meander bend has migrated downstream away from the proposed HDD borepath (Drawing 03), and is not expected to progress upstream in the future. Furthermore, there is sufficient perpendicular distance to the pipeline (>30 m) and sufficient cover (i.e., the borepath is at >25 m depth), that encroachment is not considered a hazard for the proposed HDD borepath.

3.9.5. Avulsion Whitemud Creek is incised approximately 3 m within a 50 m floodplain at the proposed crossing. No active side channels are obvious within the floodplain at the proposed crossing. A severe meander bend is located approximately 30 m downstream of the proposed crossing, and a cutoff channel may eventually develop. The cutoff channel would decrease the length of the channel downstream of the crossing and gradient downstream of the crossing would increase. However,

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 14 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 as the depth of cover of the proposed HDD remains greater than 25 m, avulsion is not considered a hazard for the proposed HDD borepath.

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4.0 SITE INVESTIGATION In June 2013, Advisian, under subcontract to BGC, completed geophysical surveys along a preliminary TMEP alignment (SSEID 1.003 Edmonton to Hinton, dated April 15, 2013), using both electrical resistivity tomography (ERT) and seismic refraction survey methodologies (Drawing 04). Terrestrial ERT was conducted along the preliminary alignment in an approximately 800 m long section across the east and west banks and the bottom of Whitemud Creek, between approximately KP 27.9 and KP 28.6. A seismic refraction survey was also carried out parallel to the ERT survey. The seismic survey was completed from the west bank of Whitemud Creek and extended approximately 350 m west, from KP 28.2 to just beyond KP 28.5. In June and July of 2014, BGC monitored the drilling of two geotechnical boreholes adjacent to the preliminary version of the TMEP alignment at Whitemud Creek. Initially, the primary crossing method was planned to be conventional trenching, with HDD as a contingency crossing method. A letter report (BGC 2015) provided the geotechnical drilling data collected during the 2014 site investigation. The primary crossing method has since been changed to HDD. A preliminary HDD crossing design was provided to BGC in February 7, 2018 (UPI 2018).

4.1. Geotechnical Drilling and Laboratory Testing

Boreholes BH-BGC14-WM-14-01 and -02 were planned and drilled as a contingency in the event the original trenched crossing needed to be revised to trenchless. The boreholes were drilled to the east and west of the Whitemud Creek and approximately 25 m north of the proposed HDD crossing. As the preliminary HDD borepath was not designed at the time, the boreholes were not optimized or located in consideration of the design. Details including the locations, elevations and final depths of the boreholes are summarized in Table 4-1.

To support the drilling investigation, UPI obtained approval on behalf of Trans Mountain for temporary workspace within the Transportation Utility Corridor. BGC was responsible for:  Executing the terms of the granted permits in coordination with the utility owners’ representatives in the field  Performing and coordinating all ground disturbance checks and utility locates prior to drilling, supervising the drilling, logging the recovered soil and rock, collecting and submitting samples for laboratory analysis, and managing sub-contractors involved in the drilling, and restoring the sites of the borehole locations. Foundex Exploration Ltd. conducted the drilling during this site investigation.

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Table 4-1. Borehole locations, elevations and depths. Borehole Coordinates Location Relative Ground Final UTM NAD 83 Zone 12U to HDD Borepath Surface Elevation/Depth Alignment and Elevation1 Entry/Exit Points Easting (m) Northing (m) Masl masl mbgs 25 m north of BH-BGC14- alignment, 285 m 329,839 5,923,252 667.0 617.0 50.0 WM-01 west of the exit point 25 m north of BH-BGC14- 329,591 5,923,219 alignment, 180 m 682.3 621.3 61.0 WM-02 east of entry point Note: 1. Borehole elevation from LiDAR provided by UPI, dated September 2014. Mud rotary drilling was used to advance each borehole with Standard Penetration Tests (SPTs) completed every 1.5 m (5 feet) until bedrock was encountered. A tri-cone bit was used between the SPTs in the overburden and no recovery was obtained. Continuous triple-tube diamond coring was used from the top of the bedrock to the end of borehole. Both boreholes were advanced to their planned target depths. Data collected during the geotechnical investigation included the following:  Pocket penetrometer tests on recovered soil and bedrock core at various depths  SPTs (ASTM D1586) at 1.5 m intervals. The SPT casing was 60 cm (24-in) long with a 5 cm (2-in) outside diameter, driven by a 63-kg automatic trip hammer that was dropped 76 cm above the anvil  Description of soil units in terms of lithology, colour, grain size, bedding, and structural features based on visual examination of material retrieved in the SPT and core samples (ASTM D2487, ASTM D2488, and the Unified Soil Classification System)  Moisture content (ASTM D2216)  Grain size distribution (ASTM D422 with CFEM modification for a silt/clay threshold of 2 µm), including hydrometer (ASTM D7928)  Atterberg limits (ASTM D4318)  Unconfined compressive strength (UCS) laboratory testing results for representative bedrock samples  Core recovery (%)  Depth to groundwater as observed upon completion of drilling and during drilling (typically at the beginning of shift), when applicable. The geotechnical borehole logs and results from laboratory analyses are provided in Appendix B and Appendix C, respectively. Drawing 05 presents site photographs of drilling activities during the 2014 site investigation. Drawings 06A through 06C and 07A through 07C present photographic logs showing visual profiles of the material as observed in the sampler’s split tubes immediately after core retrieval in BH-BGC14-WM-01, and -02, respectively.

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4.2. Groundwater Observations Water levels were measured in the BGC boreholes after the boreholes had been left open overnight for approximately 12 hours after drilling activities had been completed the previous day. The groundwater elevations measured in BH-BGC14-WM-01 and -02 are described below in Table 4-2 and included on Drawing 02.

Table 4-2. Groundwater observations in BH-BGC14-WM-01 and BH-BGC14-WM-02. Inferred Water Casing Depth Borehole Level Comments mbgs masl mbgs masl Measured on July 1, 2014, when BH-BGC14-WM-01 7.7 659.3 7.3 659.7 borehole was advanced to final depth of 50.0 mbgs Measured on July 5, 2014, when BH-BGC14-WM-02 11.6 670.7 16.9 665.4 borehole was advanced to final depth of 61.0 mbgs

4.3. Borehole Stability

In general, both borehole walls remained stable, although some squeezing was experienced while advancing in the HCF formation and inferred to be caused by swelling. Swelling in a bentonite seam was observed at 7.6 mbgs (659.4 masl) in the claystone unit (BH-BGC14-WM-01), and at 25.7 mbgs (656.6 masl) in the siltstone unit (BH-BGC14-WM-02).

4.4. Drill Fluid Circulation Drill fluid circulation at BH-BGC14-WM-02 and in the overburden soils at BH-BGC14-WM-01 was generally high (ranging from approximately 90 to 100% circulation); however, several zones of fractured zones in the HCF bedrock at BH-BGC14-WM-01 were associated with poor circulation as noted below:  From 13.4 to 16.5 mbgs (653.6 to 650.5 masl): Circulation 0%  From 16.5 to 18.0 mbgs (650.5 to 649.0 masl): Circulation 0 to 10%  From 18.0 to 19.1 mbgs (649.0 to 647.9 masl): Circulation 25%  From 27.1 to 50.0 mbgs (639.9 to 617.0 masl): Circulation 40 to 50 %

4.5. Geophysical Survey Data The geophysical survey scope for the Whitemud Creek crossing included provision of the following from Advisian:  Terrestrial ERT surveys completed along an earlier TMEP alignment version, with a total length of approximately 800 m, and with imaging to a variable depth of approximately 70 mbgs (590 masl)  A seismic refraction survey completed along a length of 350 m

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 Interpretations of the anticipated subsurface geology based on both aforementioned survey methods. The resistivity scale shown on each ERT survey is unique. The electrical resistivity range observed at this crossing, and shown in Drawing 04, is indicated in Figure 4-1 below.

WHITEMUD CREEK RESISTIVITY RANGE

Figure 4-1. The Electrical Resistivity Range for the Whitemud Creek ERT Survey (after Palacky 1987).

Electrical resistivity values at the Whitemud Creek site range from 7 to 45 ohm-m. This is indicative of sedimentary bedrock and clay rich glacial soils commonly found in Alberta and described in Section 3.0 above. The resistivity survey values are interpreted to indicate the presence of the following materials (Dahlin 1996):  ~4 to 100 ohm m: Clay  ~7 to 40 ohm m: Shale  ~10 to 500 ohm m: Lignite, Coal.

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5.0 INFERRED GEOTECHNICAL CONDITIONS ALONG THE HDD BOREPATH Based on the results of the geotechnical drilling and geophysical surveys completed as part of this investigation, a summary of the geological units identified during BGC’s geotechnical investigation is provided below, along with a description of the drilling conditions encountered within those units. Geotechnical borehole logs and results from laboratory analyses are provided in Appendices A and B, respectively. An interpreted geological cross-section along the proposed HDD crossing has been developed (Drawing 02), along with a summary of field photos of select, representative core samples (Drawing 05), and photographic logs of the materials encountered in each borehole (Drawings 06A to 06C and 07A to 07C). Similar geologic units were identified at boreholes BH-BGC14-WM-01 and -02. The following units were observed:

ANTHROPOGENIC FILL (Silty Clay)

Fill material was observed at BH-BGC14-WM-01 (located within the creek valley) from the ground surface to 3.4 mbgs. The material consisted of a low plasticity, silty clay with trace sand. The consistency of the fill deposit was very soft with a single SPT value of 1. Atterberg limits performed on one representative sample (WM-01-SPT-01) indicate this unit has low plasticity with a liquid limit (LL) of 44.7%, a plastic limit (PL) of 25.4%, and a wetter than plastic limit moisture content (36.4%). The material on the east side of the creek is inferred to be fill associated with old mining activities. The 1949 air photo (Drawing 03) suggests that fill is located in the area.

GLACIOLACUSTRINE (Silty Clay/Silty Sand/Sandy Silt) A glaciolacustrine deposit was observed from ground surface to 15 mbgs at BH-BGC17-WM-02 (located on the west bank). This interpretation is consistent with the relevant surface geology literature for the area, and BGC terrain mapping, which both suggest the presence of glaciolacustrine sediments at ground surface. At BH-BGC14-WM-02, the observed glaciolacustrine unit consisted of a low plasticity, silty clay deposit with trace sand, overlying silty sands and sandy silt layers with trace gravel and weak cementation, and can be summarized as follows:  From 0.0 to 11.0 mbgs: Clay, silty to some silt, trace sand. Atterberg limits performed on two samples retrieved from the upper silty clay unit resulted in an average LL of 41.0% (ranging from 40.8 to 41.2%), an average PL of 23.7% (ranging from 21.6% to 25.8%), and an average moisture content of 37.7% (ranging from 36.5 to 38.8%). A grain size distribution test performed on one sample showed 0.0% gravel, 0.6% sand, 71.3% silt and 28.0% clay. The consistency of the upper glaciolacustrine deposit was soft to firm with N values ranging from 3 to 5. Photograph 2 in Drawing 05 is representative of this upper glaciolacustrine deposit.

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 From 11.0 to 13.7 mbgs: Sand, silty to some silt, some clay. A grain size distribution test performed on sample WM-02-SPT-08 (retrieved from the silty sand layer observed underlying the upper glaciolacustrine clay deposits) shows 0.0% gravel, 78.0% sand, and 22.0% fines. The consistency of this deposit was compact, with an N value of 18.  From 13.7 to 15.4 mbgs: Silt, sandy, some clay, trace gravel. Atterberg limits conducted on the lower glaciolacustrine sandy silt deposit indicated a LL of 28.2%, a PL of 24.2% and a moisture content of 25.0%. A grain size distribution test performed indicated a material consisting of 8.6% gravel, 23.0% sand, 54.4% silt, and 14.0% clay. This material was very stiff with a single N value of 20. The core recovery was generally high (90 to 100%) while drilling through the glaciolacustrine deposit. A zone of slightly lower recovery (approximately 80%) was observed in the silty sand layer from 12.2 to 12.8 mbgs (670.1 to 669.5 masl). Photograph 3 and 4 in Drawing 05 are representative of the silty sand and sandy silt observed during the 2014 site investigation, respectively.

BEDROCK (Interbedded Sandstone, Siltstone, and Mudstone) HCF bedrock was encountered at 663.6 masl (3.4 mbgs) in BH-BGC14-WM-01 and at 666.9 masl (15.4 mbgs) in BH-BGC14-WM-02, continuing in both cases to the termination of the borehole. The bedrock consisted of highly weathered to fresh, poorly lithified, interbedded sandstone, siltstone, and claystone. The sandstone was extremely weak to very weak, light grey and brown, and fine to medium grained. The siltstone consisted of extremely weak to very weak, light bluish grey and brown, fine grained, moderately fractured, with coal seams present. The claystone was extremely weak to very weak, dark greenish grey to pale green, fine grained and highly to moderately fractured. Atterberg limits test performed on one fine grained bentonite clay sample within the HCF showed a LL of 364.8%, a PL of 40.5%, and a drier than plastic limit moisture content (36.4%). In general, core recovery in BH-BGC14-WM-01 and -02 was high (greater than 90%). However, a reduced recovery (core recovery of approximately 70%) in BH-BGC14-WM-01 and a 100% loss of fluid circulation was observed when a 1.5 m thick, heavily fractured coal seam encountered between 13.6 and 15.1 mbgs (653.4 and 651.9 masl) at BH-BGC14-WM-01. A 1.1 m thick coal seam was also observed between the elevations of 651.4 and 650.3 masl at BH-BGC14-WM-02. The rock mass near the coal seams may be destressed, displaced, and disturbed as a result of ground deformation following past mining. Reduced recovery in BH-BGC14-WM-02 was observed between 16.8 to 18.0 mbgs (core recovery of approximately 85%), between 25.4 to 25.8 mbgs (core recovery of approximately 40%), and between 33.6 to 35.0 mbgs (core recovery of approximately 40%). Photographs 5 and 6 in Drawing 05 are representative of the HCF bedrock encountered in the 2014 investigation.

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 21 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

5.1. Geotechnical Conditions Along the Borepath The proposed HDD entry point is situated approximately 300 m west of Whitemud Creek thalweg, and 180 m west of 142 Street, at an elevation of approximately 684.3 masl (Drawing 02). ERT results and geotechnical observations made at BH-BGC14-WM-02 suggest that the HDD borepath will enter glaciolacustrine unit containing some or all of the following: low plasticity, soft to firm glaciolacustrine silty clay, compact silty sand, and very stiff sandy silt. The borepath is expected to advance through this unit for approximately 50 m (2D length in plan view) before encountering the bedrock contact. It is anticipated that the HDD borepath will encounter extremely weak to very weak interbedded sandstone, siltstone, and claystone bedrock starting approximately 50 m east of the HDD entry point. While drilling through the HCF bedrock, there is the potential of encountering material which could swell after reaming and affect overall borehole stability and drilling fluid circulation; extremely weak, high plasticity bentonite clay seams were observed at elevations of 659.4 masl at BH-BGC14-WM-01 and 656.6 masl at BH-BGC14-WM-02. Swelling of bentonite seams was inferred after a drill bit became stuck in the siltstone unit at BH-BGC14-WM-01, and in the claystone unit at BH-BGC14-WM-02 (656.6 masl). Highly fractured, discontinuous coal seams were observed at BH-BGC14-WM-01 and -02 at elevations of 653.4 masl (1.5 m thick) and 651.4 masl (1.1 m thick), respectively. 100% fluid loss was noted beginning just above the coal seam at BH-BGC14-WM-01. It is anticipated that the HDD borepath will encounter a similar coal seam approximately 110 m from the HDD entry point. Several thinner coal seams were encountered during the 2014 site investigation, and the maximum reported depth to the base of historic mine workings varies from 22.9 to 43.9 mbgs (AER 2017). The uncertainty associated with the depth and thicknesses of potential coal seams is depicted in Drawing 02. This range of depths is interpreted to roughly constrain the coal seams known to host historical coal mines, and the borepath is expected to travel through this zone for approximately 530 m (approximately 80 m from HDD entry point to approximately 115 m before the HDD exit point). Geotechnical conditions may differ considerably through this zone due to the potential existence of rooms, pillars, steel rails, timbers, disturbed coal, and/or disturbed bedrock due to mining development. It is anticipated that the borepath will pass below the Whitemud Creek thalweg with a vertical offset of approximately 32.8 m from the creek invert to the borepath. The ERT survey results suggest the possible presence of buried channel fill, potentially including coarse gravel, cobbles and boulders, below the existing creek to a depth near the proposed borepath invert (Drawing 02). When ascending to the exit point, the HDD borepath may intercept the observed large (1.1 m to 1.5 m thick) coal seam approximately 150 m before the HDD exit point. Geotechnical conditions within this zone may differ from those on the entry side of the borepath. Upon exiting the bedrock unit, the borepath is expected to re-enter a glaciolacustrine deposit, expected to contain some mix of silt, sand and clay. The soil consistency is uncertain; the nearest borehole, BH-BGC14-WM-01, is located approximately 285 m west of the proposed

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 22 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment, Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

HDD exit point and the ERT survey line ends approximately 115 m west of the exit point. The uncertainty surrounding the surficial material in the vicinity of the HDD exit point is shown on Drawing 02. The proposed HDD exit point is situated at an elevation of approximately 683.7 masl and located approximately 535 m east of 142 Street SW. The estimated lengths along the borepath for the soil and bedrock transitions indicated above should be taken as a general guide, as the transition to materials encountered within each zone could vary significantly from what is interpreted. This is due to the relatively low angle of the intersection of the borepath with the geological unit boundaries and the extrapolation of unit boundaries between the widely spaced boreholes. A summary of the geological units identified and the drilling conditions encountered during BGC’s geotechnical investigation is provided in Table 5-1.

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Table 5-1. Summary of geological units identified during BGC’s geotechnical investigation. Depth (mbgs) Elevation (masl) Water Level 1 (mbgs) SPT Relative BH- BH- BH- BH- Blow Geological Unit Typical Soil Description Density/ Typical Recovery Circulation BH-BGC17- BH-BGC17- Additional Comments BGC14- BGC14- BGC14- BGC14- Counts Consistency WM-01 WM-02 WM-01 WM-02 WM-01 WM-02 (N)

667.0 The material on the east side of 0.0 to CLAY (CL), silty, trace sand, Fill – to – 1 Very Soft SPTs only 100% Unsaturated Unsaturated the creek is thought to be fill from 3.4 grey, orange-brown 663.6 old mining activities. From 0.0 to 11.0 mbgs: Soft to firm CLAY (CL), silty to some silt, 3 – 5

trace sand

A zone of lower recovery Water level 682.3 From 11.0 to 13.7 mbgs: (approximately 80%) was 0.0 to 90 to 100 % measured at Glaciolacustrine – – to SAND (SM), fine to medium, SPTs only Unsaturated observed in the silty sand layer 15.4 18 Compact 11.6 mbgs 666.9 silty to some silt, some clay from 12.2 to 12.8 mbgs (670.1 to (670.7 masl) 669.5 masl).

From 13.7 to 15.4 mbgs:

SILT (ML), Sandy, some clay, 20 Very Stiff trace gravel Coal seams were observed at the following depths:

BH-BGC14-WM-01: BH-BGC14-WM-01: From 653.6 to 650.5 > 90 % masl: 0% From 13.6 to 15.1 mbgs (653.4 to 651.9 masl) From 150.5 to 649.0 From 33.2 to 33.4 mbgs BH-BGC14-WM-01: masl: 0 to 10% Water level 663.6 666.9 Poorly lithified, interbedded Extremely From 653.4 to 652.1 masl: 70% (633.8 to 633.6 masl) 3.4 to 15.4 to 24 - From 649.0 to 647.9 measured at HCF Bedrock to to Silstone, Sandstone, and weak to very Saturated 50.0 61.0 123 masl: 25% 7.7 mbgs From 34.8 to 34.9 mbgs 617.0 621.3 Mudstone weak BH-BGC14-WM-02: (632.2 to 632.1 masl) From 639.9 to 617.0 (660.0 masl)

From 657.0 to 656.5 masl: 40% masl: 40 to 50% From 648.8 to 647.2 masl: 50% BH-BGC14-WM-02: BH-BGC14-WM-02: From 30. 9 to 32.0 mbgs 90 to 100 % (651.4 to 650.3 masl) From 49.2 to 49.6 mbgs (633.1 to 632.7 masl) Note: 1. The water levels were observed shortly after drilling activities were completed and likely do not represent stabilized groundwater levels.

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 24 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

6.0 GEOTECHNICAL FEASIBILITY ASSESSMENT The following conclusions can be drawn from the regional surficial and bedrock geology, terrain mapping, available third-party borehole data, geophysical surveys and the results of the subsurface investigations completed along the proposed HDD crossing, and are based solely on the limited scope of the investigation undertaken at this time.

6.1. General Considerations

 The stratigraphy observed at both geotechnical boreholes drilled as part of this investigation was relatively similar.  Core recovery was generally good during drilling in the 2014 site investigation (average of > 90%) with some zones of low recovery in the HCF bedrock as noted below: ○ From 13.6 to 14.9 mbgs (653.4 to 652.1 masl): 70% ○ From 25.3 to 25.8 mbgs (657.0 to 656.5 masl): 40% ○ From 33.5 to 35.1 mbgs (648.8 to 647.2 masl): 50% These zones could potentially indicate voids or loose/destressed rock near the boundaries of old mine workings. Sloughing, hole collapse, and potential surface subsidence may occur in mapped historic coal mines areas, and may affect the HDD borepath area.  High plasticity zones were identified in the HCF bedrock deposits. Beds of high plasticity bentonite were observed in BH-BGC14-WM-01 and -02. Atterberg Limits testing in the bedrock deposits yielded high liquid limits (one LL of 364%); this has the potential to thicken the drill mud and to impact drill cutting return (causing mud rings). Squeezing of the HDD bore may also occur between reaming passes.  The HDD borepath will encounter extremely weak to very weak bedrock, and encounters with occasional more lithified, stronger intervals of weak interbedded sandstone and siltstone are possible. This could affect steering if hard beds are encountered at flat angles.  Several utilities (buried and on surface) are present in the TUC corridor. It’s known that ATCO had successfully installed a 20-in pipeline at this crossing using a HDD method, with significant advance effort for ground improvement required to reduce the uncertainty associated with old coal mines.  The banks of the Whitemud Creek appear stable and the proposed HDD alignment is not expected to be compromised by bank erosion or avulsion. The HDD entry and exit points are located at a significant elevation above the 200-year flood level and submergence of the entry and exit point is not considered a hazard for the proposed HDD borepath.  Results from the scour analysis estimate a maximum scour depth of approximately 0.8 m below the channel thalweg elevation of 656.8 masl during a 200-year flood event, corresponding to a maximum scour elevation of 656.0 masl. The depth of cover above the proposed HDD borepath remains adequate in the channel should this amount of scour occur.

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 25 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

6.2. Historical Coal Mines The Whitemud Creek crossing is located within an area identified to contain historic coal mine workings, although the potential mine layout beneath the crossing is currently unknown. There is the potential that the portion of the pipelines installed above old cola mines or at shallow depths may be exposed to subsidence in the event of ongoing future collapse of old mine workings. During HDD construction, loss of drilling fluids could occur in the vicinity of the coal mines where bedrock may have been disturbed/weakened, and in potential voids left by mining development.

6.3. Steering Difficulties The rocks above the mine workings are likely disturbed, loosened, or partially destressed due to prior or ongoing displacement due to collapse of old mine workings. The permeability of this disturbed rock mass may be higher than the rock outside the mine footprints. If rock impacted by historic mining is encountered, there could be steering issues related to the strength contrasts between the disturbed and undisturbed rock mass. Bedrock encountered during the drilling investigation was observed to be poorly lithified (soil-like) with extremely weak to very weak strength, that may also suggest steering issues are a possibility (i.e., bit skipping on the lower harder material).

6.4. Borepath Stability It is possible that the ground above the mined area has subsided in response to the extraction of coal and is relaxed, displaced, and disturbed. Challenging or unsuccessful drilling conditions due to poor rock mass quality and losses of circulation caused by dilated joints and bedding planes or the presence of mine voids may be expected to depths between about 22 to 45 mbgs.

Some squeezing was experienced during the 2014 geotechnical drilling investigation while advancing through the claystone and siltstone bedrock; swelling was recorded in a bentonite seam (found at 659.4 masl) at BH-BGC14-WM-01, as well as in the siltstone unit (found at 656.6 masl) at BH-BGC14-WM-02. The potential for the rock to swell after reaming the HDD borepath should be addressed in detailed design.

6.5. Circulation and Potential for Loss of Fluids Drill fluid circulation was good (approximately > 90%) while drilling in the overburden soils. However, loss of fluid was observed in the HCF bedrock. 100 % fluid loss was recorded beginning just above a coal seam at an elevation of 653.6 masl. Drilling conditions in the footprint of the old mines in the area may be poor and lost circulation zones may be more common compared to that in the surrounding rock.

6.6. Geotechnical Feasibility Given the above, and based on the desktop study, available public information and results of the geotechnical and geophysical site investigation, an HDD at this location may be considered

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 26 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 feasible from a geotechnical perspective provided the following concerns are addressed during detailed design and construction:  Possible hazards related to historical coal mines: ○ TMEP HDD may encounter voids, timbers, steel rails or loose/destressed rock in or near the boundaries of old mine workings. The portion of the pipeline installed above old coal mines may be exposed to future subsidence (i.e., vertical displacement of the ground over the footprint of the mine, and horizontal ground displacement). The rocks above the mine workings may be disturbed, loosened, or partially destressed due to previous displacements following mining. The permeability of this disturbed rock mass may be higher than that outside the mine footprints. Drilling conditions in the area of the mines may be poor and lost circulation zones are possible. Discontinuous (i.e., non-uniform) displacement may also be expected due to future failure of the mine roof and localized subsidence of the overlying strata. ○ Although no geotechnical data was available regarding the adjacent ATCO HDD construction, it is known that several mitigation measures were taken, including a grouting program to improve conditions at the depth of the old coal mines prior to the installation of the pipeline, and it is also understood that considerable subsurface investigation was completed to support the design of mitigation. ○ Additional subsurface investigations (i.e., including geotechnical drilling targeting the area where the proposed HDD will intersect the coal seams in the footprint of the old coal mines) will allow the project to assess the intersection zone and determine whether a grouting program or other mitigation measures would be necessary. ○ A review and evaluation of any available geotechnical report for the ATCO HDD, including borehole logs, borehole photos, geophysics, grouting design, and HDD construction records, may reduce the needed efforts of further geotechnical investigation.  Coarse clasts in buried channel fill: There is some chance the bore may encounter coarse channel fill below the existing creek, as suggested by the ERT survey. If encountered, coarse clasts could deflect the HDD borepath and/or damage the carrier pipe when it is pulled into the borepath. Lowering the borepath by up to approximately 20 m to avoid the area where channel fill deposits have been inferred may be an alternative for the designers to consider. However, it may be preferable to carry out a geotechnical investigation to check the findings of the geophysics survey in this area to better assess the need to lower the borepath. The optimum approach may need to balance the risk of encountering coarse clasts for a borepath at shallower depth with the risk of interaction with the nearby (i.e., approximately 10 m offset laterally) ATCO pipeline for a deeper borepath.  Steering difficulties and borepath stability: The rocks above old mine workings may be disturbed, loosened, or partially destressed due to prior displacements associated with collapse and subsidence of old mine workings. The permeability of this disturbed rock mass may be higher than the rock outside the mine footprints. Steering issues in the area of the mines may increase compared to surrounding rock. Bedrock in the 2014 site investigation was observed to be poorly lithified (soil-like) with extremely weak to very

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 27 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

weak strength, which may also contribute to steering issues (i.e., bit skipping on the harder materials encountered at flat angles).  Loss of drilling fluids: Drilling conditions in the area of old mines may be poor and lost circulation zones may be more common, compared to areas outside the mine footprints. Loss of fluid in these formations was observed during the geotechnical drilling. 100% fluid loss was noted from 13.4 to 16.5 mbgs (653.6 to 650.5 masl) at BH-BGC14-WM-01, beginning just above the point where a 1.5 m thick coal seam was intersected (from 653.4 to 651.9 masl). These observations suggest that loss of circulation and drill fluids is possible along the HDD bore. As described above, a geotechnical drilling program targeting the area where the proposed HDD will intersect the coal seams will benefit the design and execution of HDD drilling. In the event that grout injection is used to reduce the potential of the bore encountering the workings themselves, the process would also reduce the possibility of fluid loss in dilated, fractured rock near old workings.  Highly plastic material: High plasticity zones were identified within the bedrock deposits. This has the potential to thicken the drill mud and to impact cuttings management (causing mud rings). Such conditions may be mitigated with careful management of drill fluids and the rate of cutting return.  Swelling material: During the geotechnical drilling at BH-BGC14-WM-01, the drill bit got stuck while advancing through the HCF bedrock, inferred to be caused by the swelling of a bentonite seam observed in the claystone bedrock at BH-BGC14-WM-01, and the swelling of the siltstone at BH-BGC14-WM-02. The potential for the rock to swell after reaming the HDD borepath should be addressed in detailed design.

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 28 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

7.0 CLOSURE We trust the above satisfies your requirements at this time. Should you have any questions or comments, please do not hesitate to contact us.

Yours sincerely,

BGC ENGINEERING INC. per:

Shannon Ashe, B.A. Sc., EIT (AB) Leonardo Moreno, P.Eng (BC, AB), Ing. Civil Junior Geological Engineer (Argentina, Bolivia) Senior Civil/Geotechnical Engineer

Reviewed by:

Pete Quinn, Ph.D., ing., P.Eng. (BC, YT, ON, NL) Principal Geotechnical Engineer

SAA/LM/pq/kj/sk

APEGA Permit to Practice: 5366

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 29 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

REFERENCES

Alberta Government. 2018 Alberta Water Well Information Database Map. Available from: http://groundwater.alberta.ca/waterwells/d/. [accessed 23 March 2018]. Alberta Energy Regulators. 2017. AER Coal Mine Web Map. Online database (http://mapviewer.aer.ca/Html5/Index.html?viewer=aercoalmine) consulted in July 2017. American Society for Testing and Materials. Standard D2487-11: Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System). Developed by Sub-Committee D18.07. West Conshocken, PA. American Society for Testing and Materials. Standard D2488-09a: Standard Practice for Description and Identification of Soils (Visual-Manual Procedure). Developed by Sub-Committee D18.07. West Conshocken, PA. City of Edmonton, 2012. American Society for Testing and Materials. Standard D422-63(2007) e2: Standard Test Method for Particle-Size Analysis of Soils (Withdrawn 2016). Developed by Sub-Committee D18.03. West Conshocken, PA. American Society for Testing and Materials. Standard D7928-17: Standard Test Method for Particle-Size Distribution (Gradation) of Fine-Grained Soils Using the Sedimentation (Hydrometer) Analysis. Developed by Sub-Committee D18.03. West Conshocken, PA. American Society for Testing and Materials. Standard D1586-11: Standard Test Method for Standard Penetration Test (SPT) and Split Barrel Sampling of Soils. Developed by Sub- Committee D18.02. West Conshocken, PA. American Society for Testing and Materials. Standard D2216-10: Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass. Developed by Sub-Committee D18.03. West Conshocken, PA. American Society for Testing and Materials. Standard D4318-17: Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils. Developed by Sub-Committee D18.03. West Conshocken, PA. Association of Professional Engineers and Geoscientists of BC (APEGBC). 2012. Professional Practice Guidelines – Legislated Flood Assessments in a Changing Climate in BC. Version 1.1. June 2012. Dawson, F.M., Evans, C.G., Marsh, R., and Richardson, R. 1994. Uppermost Cretaceous and Tertiary strata of the Western Canadian Sedimentary Basin. In Geological atlas of the Western Canada Sedimentary Basin Edited by G.D. Mossop and I. Shetsen. Canadian Society of Petroleum Geologists and Alberta Research Council, pp. 387-406. Downing, D.J. and Pettapiece, W.W. 2006. Natural regions committee 2006. Natural regions and subregions of Alberta. T/852, Government of Alberta, Edmonton.

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Edwards, W.A.D., Magee, D., Langenberg, C.W., Grobe, M., and Mussieux, R. 2006. Geoscape Edmonton information series 126. Alberta Geological Survey. Fenton, M.M., Waters, E.J., Pawley, S.M., Atkinson, N., Utting, D.J., Mckay, K. 2013. Surficial Geology of Alberta, Generalized Digital Mosaic (DIG 2013-0002). http://geology-ags- aer.opendata.arcgis.com/datasets/745bb49973194f46b19d5ad2f84afd61_0 Hamblin, A.P. 1998. Edmonton Group/St. Mary river formation: Summary of literature and concepts open file. GSC Open File 3578, Geological Survey of Canada. Kathol, C.P., and McPherson, R.A. 1975. Urban Geology of Edmonton, Alberta Research Council, Bulletin 32. pp. 92. McPherson, R.A., and Kathol, C.P. 1972. Stratigraphic Sections and Drill Hole Logs, Edmonton Area, Alberta. Alberta Research Council Report 72-6. Palacky, G.J, 1987, Resistivity Characteristics of Geologic Targets, Society of Exploration Geophysics, v. 1. Pettapiece, W.W. 1986. Physiographic subdivisions of Alberta. Agriculture Canada, Ottawa. Shetsen, I. 1990. Quaternary geology, Central Alberta. Alberta Research Council. Trans Mountain Pipeline ULC. 2014. Trans Mountain Expansion Project Application to the National Energy Board. Terrain Mapping and Geohazard Inventory - Revision 1, filed as part of NEB Technical Update #1, August 1, 2014. Universal Pegasus International (UPI). 2018, Trans Mountain Expansion Project, Plans and Profiles, City of Edmonton, Anthony Henday Drive Northwest, NE-28-51-24-W4M, Preliminary HDD Drill Path Drawing No 01-13283-M002-XD00026-01 Rev A, issued February 7, 2018. Young, R.R., Burns, J.A., Smith, D.G., Arnold, L.D., and Rains, R.B. 1994. A single, late Wisconsin, Laurentide glaciation, Edmonton area and Southwestern Alberta. Geology, 22: 683- 686. BGC Engineering Inc., 2016. Preliminary Assessment of Coal Mine Related Hazards KP26 to KP 29 (South Edmonton). April 6, 2016. Canadian Energy Pipeline Association (CEPA) 2018. Member initiative: ATCO Pipelines uses latest technology to stabilize a historic coalmine, July 7, 2017 [online]. Available from https://pr17.cepa.com/safety/member-initiative-atco-pipelines-uses-latest-technology-to- stabilize-a-historic-coalmine/ [accessed March 12, 2018]. North American Society for Trenchless Technology (NASTT) 2018. NASTT Northwest Chapter 2018. Edmonton Technical Lunch – Thursday, January 25, 2018 [online]. Available from http://www.nastt-nw.com/?p=379 [accessed March 12, 2018].

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek Page 31 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

DRAWINGS

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek BGC ENGINEERING INC. 329,500 330,000

MULLEN PLACE NORTH-WEST Edmonton ^_! SITE ! zcLGk-Vm WHITEMUD ³ LOCATION ³ IVL CREEK

Fptm Calgary! IL

Vancouver! zcLGa/Ca-Fum 5,923,250 IVM SCALE 1:10,000,000

!KP 0028.6

zcLGpm BH-BGC14-WM-02 BH-BGC14-WM-01 IL A@ A@ zcLGbm HDD EXIT POINT IL KP 0028.4 KP 0028.2 KP 0028.0 KP 0027.8 HDD ENTRY POINT ! ! ! ! ! ! ! LEGEND A@ BGC BOREHOLE 5,923,250 ! KILOMETRE POSTS (KPS)

! PROPOSED HDD ENTRY/EXIT POINTS PROPOSED TMEP SCALE 1:2,500 ALIGNMENT VERSION 50 0 50 100 SSEID 005 ! KP 0027.6 PRIMARY SURFICIAL METRES MATERIAL TYPE LABEL LEGEND THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. 10Cb-Rs TERRAIN LABEL FLUVIAL ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE III M TERRAIN STABILITY CLASS AND BASED ON ORIGINAL FORMAT DRAWINGS. 329,500 330,000 NATURAL HAZARD CLASS GLACIOLACUSTRINE

BH-BGC14-WM-02 ELEVATION PROFILE - NO VERTICAL EXAGGERATION (m) BH-BGC14-WM-01

! A@ ! A@

ENTRY EXIT

!

ELEVATION (masl) ELEVATION SCALE 1:2,500 50 25 0 50 100

! METRES

KP DISTANCE (m) NOTES: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. SCALE: 1:2,500 PROJECT: 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED "GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT SSEID 005.5 KP 28.2", AND DATED MARCH 2018. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT 3. PROPOSED TMEP SSEID 005.5 PIPELINE ALIGNMENT PROVIDED BY KMC, DATED MARCH, 2018. DATE: WHITEMUD CREEK AT SSEID 005.5 KP 28.2 4. WATERBODY AND STREAM DATA FROM NRCAN CANVEC. MAR 2018 BGC ENGINEERING INC. AN APPLIED EARTH SCIENCES COMPANY TITLE: 5. PROPOSED HDD ALIGNMENT PROVIDED BY UPI, DRAWING NO. M002-XD0002601-01 RA, ISSUED FEBRUARY 7, 2018. DRAWN: LL B GC TERRAIN MAP 6. FOR A FULL EXPLANATION OF THE TERRAIN MAPPING TERMS AND SYMBOLS SEE THE COMPLETE LEGEND IN DRAWING 01B. TERRAIN POLYGONS BASED ON TERRAIN MAPPING COMPLETED UP TO JULY 2015 BY BGC. DRAFT CLIENT: 7. THIS MAP IS A SNAPSHOT IN TIME. CHANGES IN LAND USE (E.G. DEVELOPMENT, RIVER MIGRATION) MAY WARRANT RE-DRAWING OF CERTAIN AREAS. CHECKED: 8. PROJECTION IS NAD 1983 UTM ZONE 12N. SAA PROJECT No.: DWG No.: 9. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH BGC GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS APPROVED: 0095-150-14 01A ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT NOT AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. X:\Projects\0095\150\GIS\Production\Reports\20180313_Geotechnical_HDD_Feasibility_Assessment_Whitemud_Creek_at_SSEID_005_KP_28pt1\01A_Terrain_Mapping_Whitemud_Creek.mxd Date: March 27, Time: 2018 2:23 PM Terrain Mapping Legend Geomorph olog icProcesses SoilDrainag eClasses R R apidlandslide (runout zone) V Gullyerosion SimpleTerrain Symbols U sedwh enone surficial material ispresent within apolyg on R “ R apidlandslide (initiation zone) F“ Slowlandslide (initiation zone) r R apidlydrained: W aterisremov edfrom the soilrapidly inrelation tosupply. H Kettled L Seepag e Example: zCb –Rb U Flooding E Meltwater ch annels w W ell-drained: W aterisremov edfrom the soilreadily but not rapidly. Material Texture A SnowAvalanch es B BraidedChannel m Moderatelywell-drained: W aterisremov edfrom the soilsomew h atslow inrelation ly tosupply. SurficialMaterial Geomorph olog icalprocess sub-type M MeanderingChannel I Irreg ularChannel Surface expression Geomorph Surface expression olog ical process (up mayto 3 be assigned) Imperfectlydrained: W aterisremov edfrom the soilsufficiently slow inrelation ly tosupply J AnastamosingChannel K Karst i N Nivation P P iping tokeep the soilwet for asignificant part ofthe grow ingseason. CompositeTerrain Symbols U sedwh enorterrain2 3 types are present within apolyg on S Solifluction W W ash ing P oorlydrained: W aterisremov edso slow inrelation ly tosupply that the soilremains X P ermafrost Z P eriglacialProcesses p Cv.Mv indicatesthat and‘C’ ‘M’are roug hequal ly inextent G Anthropog enicmodification w etfor acomparatively large part ofthe time the soilis not frozen. Cv/Mv indicatesthat isgreater‘C’ inextent than ‘M’(about 60:40) v V erypoorly drained: W aterisremov edfrom the soilso slow that ly the water tab remains le Cv//Mv indicatesthat ismuch‘C’ greater inextent than ‘M’(about 80:20) Cv.Rs/Mv indicatesthat and‘C’ are‘R’ roug hequal ly inextent and both are gre aterinextent than Mv (about 40:40:20) Geomorph olog icalProcess Subtypes atoron the surface for the greater part ofthe time the soilis not frozen.

b R ockfall r R ockslides e Earthflow Stratigraph icTerrain Symbols d Debrisflow s m Bedrockslump k Tensioncracks/sackung s Debrisav alanch es u Surficialmaterial slump Ud Debrisfloods Cv|Mj indicatesthat ‘Cv’ov erlies‘Mj’ a Channelav ulsion c Soilcreep g R ockcreep

SurficialMaterial Types Examples

C Colluvium R Bedrock LG Glaciolacustrine R s//Cv–VR ”bd Steepbedrock slope with <20% cov erofa colluvial veneer; L Lacustrine M Glacial Till W G Glaciomarine g ulliedwith initiation zones for rockfall and debris flow s. F Fluvial O O rganic U Glaciolacustrine, Till, Glaciofluvial (interbedded) FAp–U Activefloodplain potentially subject toflooding E Eolian FG Glaciofluvial D W eatheredbedrock –F”g Cj Thick,gentle colluvium forming arock glacier A Anthropog enic Cf–Rd Colluvialfan subject todebris flow s Ck–Rb Colluvialslope subject torockfall (talus slope)

SurfaceExpressions TerrainStability Class p P lain(0-3°) v V eneermthick (0-2 deposit) j j GentleSlope (4-14°) b Blanketmthick (>2 deposit) I Nosignificant stability problems exist. a ModerateSlope (15-26°) w V ariableThickness Deposit) II Thereis avery low likelihood of landslides follow ingtimber harvesting orroad construction. Minor slumping isexpected k ModeratelySteep Slope (27-35°) m R olling alongroad cuts, especially foror years1 2 follow ingconstruction s SteepSlope (>35°) h H ummocky c Cone(>15°) f Fan(<15°) III Thereisa low (<30%) likelihood of landslide initiation follow ingtimber harvesting orroad construction. Minor slumping is r R idg e u U ndulating expectedalong road cuts, especially foror years1 2 follow ingconstruction. t Terrace d Depression IV Expectedto contain areas with amoderate (30-70%)likelihood of landslide initiation follow ingtimber harvesting orroad construction.Wet season construction significantly will increase the potential for road-related landslides.

TexturalTerms and Symbols V Expectedto contain areas with a high (>70%) likelihood of landslide initiation follow ingtimber harvesting orroad construction.Wet season construction significantly will increase the potential for road-related landslides. a blocks b boulders k cobbles p pebbles s sand z silt c clay d mixedfrag ments x ang ularfrag ments NaturalHazard Class g g rav el m mud r rubble L Noexisting hazard, or hazard is dormant, hazard i.e. has not been active inthe lastyearsto100 1,000 orit has dev elopedunder different climatic conditions. ActivityLev el M H azardisinactive. Veg etatedtracks can be observed inairph otos.Smaller more frequent ev ents,such as rockmay fall, affectasmallarea of the polyg on.No ev idencethat the hazard has been active within the years20 but trigg erispresent. FAp ‘AIndicates’ active floodplain (subject toch annelch ang es) H azardisunlikely tooccur within the lifeof the project. CIf ‘I’ Indicatesinactive fan H H azardiscurrently active orsh ow sev idenceofactivity inthe lastyears.20 Hazard likelyto occur within lifeof project.

SCALE: P R O J ECT: NO TES: NTS GEO TECH NICALHDD FEASIBILITY ASSESSMENT 1. THISDR 1. AW INGMU STBEREAD COIN NJU NCTIONWITH BGC'S REPO RTITLED T "GEO TECH NICALHDD FEASIBILITY ASSESSMENT WH - ITEMUCR D EEKAND ATSSEIDKPDATED 005.5 28.2", MAR CH2018. DATE: W H ITEMU DCR EEKATSSEIDKP 005.5 28.2 2. UNLESS 2. BGC AGR EESOTH ERWWRIN ISE THISDR ITING, AW INGSH ALLNO BEMO T DIFIEDOR USED FO RANY PU R P O SEOTHER THAN THE PU R P O SEFO RWH ICHBGC GENER BGC ATED SHIT. ALL MAR2018 BGCENGINEERING INC. HAVE NO LIABILITYFO RANY DAMAGES OR LO SSARISING ANYIN WAY FRO MANY USE OR MO DIFICATIONOF THISDO CU MENTNO AU T THO R IZEDBY BGC. ANY USE OF OR RELIANCE UP OTHIS N ANAPP LIEDEARTH SCIENCES CO MP ANY TITLE: DR AW N: DO CU MENTOR COITS NTENTBY THIRD PAR SH TIES ALLBESUAT CHTHIRD PAR SO TIES' LERISK. JVC B GC TER RMAP AIN LEGEND CLIENT: CH ECKED: SAA P R O J ECTNo.: DW GNo.: APP R O V ED: 0095-150-14 01B X :\P rojects\0095\150\GIS\P roduction\R eports\20180313_Geotech nical_H DD_Feasibility_Assessment_W h itemud_Creek_at_SSEID_005_KP_28pt1\01B_Terrain_Leg end.mxd Date: March 28, 2018 Time: 1:13 PM 1:13 Time: 2018 28, March Date: end.mxd h itemud_Creek_at_SSEID_005_KP_28pt1\01B_Terrain_Leg DD_Feasibility_Assessment_W nical_H eports\20180313_Geotech roduction\R rojects\0095\150\GIS\P X :\P T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\WHITEMUD_CREEK_KP_28.2\02.dwg Layout: RM-B-SIZE Plot Date Mar 28 18 Time: 3:47 PM .ALL DIMENSIONSAREINMETRESUNLESSOTHERWISENOTED. 1. NOTES: .SPECIFIC OBSERVATIONSPERTAINING TOTHEWATERLEVELMEASUREMENTS AREAVAILABLEINTHEREPORT. 7. .UNLESS BGCAGREESOTHERWISE INWRITING, THISDRAWINGSHALL NOTBEMODIFIED ORUSEDFOR ANY PURPOSE OTHERTHANTHEPURPOSE FORWHICH BGC 8. PROJECTIONISUTMNAD83ZONE12. 6. PROPOSED TMEPSSEID005.5PIPELINE ALIGNMENTPROVIDEDBYKMC,DATED MARCH2018.PROPOSEDHDD ALIGNMENTPROVIDEDBYUPI,DRAWING NO.01-13283-M002-XD00026-01REV A, 5. BASETOPOGRAPHIC DATABASEDONLIDARPROVIDEDBYUPI,DATEDSEPTEMBER2014.CONTOUR INTERVALIS1.0m. 3. 2. .IMAGESOURCE:ESRIWORLDIMAGERY SERVERRETRIEVEDFROMBINGIMAGERY. 4. AUTHORIZED BYBGC.ANY USEOFORRELIANCE UPONTHISDOCUMENT ORITS CONTENTBYTHIRD PARTIESSHALLBE ATSUCHTHIRD PARTIES'SOLERISK. GENERATED IT.BGCSHALL HAVENOLIABILITY FORANYDAMAGES ORLOSSARISING INANYWAYFROM ANYUSEOR MODIFICATIONOF THISDOCUMENTNOT BH-BGC14-WM-02 BH-BGC14-WM-01

LEGEND -PLAN N ISSUED FEBRUARY 07,2018.ATCOGAS20"HDDPROFILE PROVIDEDBYUPI,DATEDFEBRUARY 23,2018.

THIS DRAWINGMUSTBEREADINCONJUNCTION WITHBGC'SREPORTTITLED“GEOTECHNICALHDDFEASIBILITY ASSESSMENT-WHITEMUDCREEKATSSEID005.5KP28.2”,ANDDATEDMARCH 2018. BOREHOLE N 5,923,250 N

ERT SURVEYALIGNMENT PROPOSED HDDENTRY/0+00EXITPOINT BGC BOREHOLE KILOMETRE POINT(KP) PROPOSED HDDBOREPATH

SSEID 005.5TRANSMOUNTAINPIPELINEALIGNMENT

WHITEMUD CREEKFLOWDIRECTION ATCO GAS20"PIPELINECENTRELINE(APPROX.) 680

28+600

680 685 ELEVATION (masl)

685 KP 28+525 BH COLLAR ELEVATION (m) 682.3 667.0 605 620 640 660 680 700 036-0+300 -0+326 HORIZONTAL SCALE:1:2,500 VERTICAL SCALE:1:1,250(2xEXAGGERATION) (E: 329,381;N:5,923,190)

KP 28+500

POTENTIAL TO INTERSECT 28+500 -

COAL SEAMS (AER 2017) A INFERRED WATER

685 LEVEL (mbgs) HDD ENTRY HDD ENTRY 11.6 ? 7.7 OF COALSEAMUNKNOWN ? DEPTH ANDTHICKNESS BH-BGC14-WM-02 (OFFSET=23mN) ELEVATION (masl) NORTHWEST WATER LEVEL

KP 28+400 28+400 -0+200 670.7 659.3

25 E 329,500

GROUNDWATER OBSERVATIONS E 329,500 BH-BGC14-WM-02 (400 mmTHICK) 0 SCALE 1:2,500 MEASURED ONJULY5,2014,WHEN BOREHOLEWASADVANCEDTOFINALDEPTHOF61.0 m bgs MEASURED ONJULY1,2014,WHENBOREHOLEWASADVANCED TOFINALDEPTHOF50.0mbgs COAL SEAM METRES (1.1 mTHICK) COAL SEAM ? ? 25

KP 28+300 680 28+300 -0+100 755025

0 675

SCALE 1:2,500 680 EXISTING GROUND (SEPT 2014) METRES HDD 0+00POINT

670 675

665 ? 670 665 660 (656.0 masl) 200-YEAR SCOURELEVATION 755025 COMMENTS

KP 28+200 ?

660 28+200 660 (663.2 masl) 200-YEAR RETURNPERIODFLOOD 0+000

HDD 0+00POINT 665 660 PROPOSED HDDCHAINAGE(m) POSSIBLE COARSEGRAINED CHANNEL MATERIAL

COAL SEAM(100mmTHICK) COAL SEAM(200mmTHICK) E 329,750 CROSS-SECTION THIS DRAWINGMAY HAVEBEENREDUCEDORENLARGED. ALL FRACTIONALSCALE NOTATIONSINDICATEDARE 665 E 329,750 BH-BGC14-WM-01 BASED ON ORIGINALFORMAT DRAWINGS. 670

KP 28+100 28+100 0+100 WHITEMUD CREEK A - ? 670 ?

BH-BGC14-WM-01 (OFFSET=22mN) 670 670 COAL SEAM(1.5mTHICK) DRAFT

KP 28+000 28+000 0+200 675 ?

APPROVED: CHECKED: DRAWN: DATE: SCALE: 675

LEGEND -CROSS-SECTION 680 ? 680 ? ? MAR 2018 INFERRED BEDROCKCONTACT INFERRED GEOLOGICALINTERFACE INFERRED WATERLEVEL PROPOSED HDDENTRY/0+00 /EXITPOINT BGC BOREHOLE PROPOSED HDDPROFILE (ADVISIAN) (APPROXIMATELOCATION) ATCO GAS20"HDDPROFILE(APPROX.) 1:2,500 SAA

CR KP 27+900 E 330,000 27+900 - DEPTH ANDTHICKNESS OF COALSEAMUNKNOWN 0+300 CLIENT: B G

C E 330,000 BGC ENGINEERINGINC. AN APPLIEDEARTHSCIENCES COMPANY EAST

KP 27+800 27+800 0+400 (E: 330,168;N:5,923,276) HDD EXIT HDD EXIT

675 BOREHOLE PROJECT No.: TITLE: PROJECT: GEOTECHNICAL HDDFEASIBILITYASSESSMENT - WHITEMUDCREEKATSSEID005.5KP28.2 INTERPRETED GEOLOGIC CROSS-SECTION 0095-150 POTENTIAL TO INTERSECT KP 27+725 0+474 INTERPRETED GEOLOGY

COAL SEAMS (AER 2017) 27+600 27+700 A - 605 620 640 660 680 700 FORMATION BEDROCK HORSESHOE CANYON LOW RECOVERY COAL SEAM GLACIOLACUSTRINE SAND BED- ANTHROPOGENIC (FILL) ELEVATION (m) ? DWG No.:

685 675

680

E 330,250

02 N 5,923,250 N

E 330,250 1949IMAGERY 2010IMAGERY ³ 329,500 E 329,750 E 330,000 E 329,500 E 329,750 E 330,000 E N5,923,750

N5,923,500 N5,923,500 670

670

680

670 660

680

! ! 670

KP0027.8 ! KP0027.8 ! N5,923,250 ! ! N5,923,250 KP0028.6 KP0028.0 KP0028.6 KP0028.0 ! ! ! ! KP0028.2 KP0028.2 ! ! KP0028.4 KP0028.4 ! ! KP0027.6 KP0027.6 ! ! ! !

W EST NO R TH- DAY DR IVE ANTHO NY HEN N5,923,000 680 N5,923,000 H-W EST E NO R T NDAY DR IV ! ANTHO NY HE !

680 660

W HITEMUD CRW EEK HITEMUD CRW EEK HITEMUD

N5,922,750 N5,922,750 SCALE1:5,000 200 100 0 200 LEGEND FLOWDIRECTION METRES PRO PO SEDHDD BO R EPATH THISDR AW INGMAY HAVE BEEN REDUCED OR ENLARGED. ALLFRACTIONAL SCALE NO TATIONSINDICATED ARE PRO PO SEDTMEP ALIGNMENT BASEDON OR IGINALFO R MATDR AW INGS. VERSIONSSEID 005.5 E 329,750 E 330,000 E 329,500 E 329,750 E 330,000 E

SCALE: PR O JECT: NO TES: 1:5,000 GEO TECHNICALHDD FEASIBILITYASSESSMENT – 1. ALLDIMENSIONS 1. AR METRESIN E UNLESS OTHERW NO ISE TED. PR O 7. PO SEDTMEP SSEIDPIPELINE 005.5 ALIGNMENT PRO VIDEDBYKMC DATE: W HITEMUDCR EEKATSSEIDKP28.2 005.5 2. THISDR AW2. INGMUST BEREAD COIN NJUNCTIONW BGC'S ITH REPO RTITLED T "GEO TECHNICALHDD FEASIBILITY ASSESSMENT –WHITEMUD DATED MAR CH2018. MAR2018 CR EEK AND AT SSEIDDATED KP 28.2," 005.5 MARCH 2018. PR O 8. PO SEDHDD ALIGNMENT PR O VIDEDDRBY UPI, AW INGNO . BGCENGINEERING INC. ANAPPLIED EARTH SCIENCES CO MPANY TITLE: DR AW N: 3. BASE TO 3. PO GR APHICDATA BASED ON LiDAR PR O VIDEDBYVAR IOUSCO MPANIESBETW EENAND2005CO 2014. NTO URINTERVAL m.5 IS 01-13283-M002-XD00026-01 Rev ISSUED 2018. A, FEB.7, MIB B GC 4. PR O 4. JECTIONUTM IS NAD ZO83 NE12. DR AFT CLIENT: BANKERO SIONAND AVUSION REVIEW 5. OR THO5. IMAGEON RIGHT MAP, PR O VIDEDBYKINDER MO R GANCANADA, FRO MCITYOF EDMO NTODATED N, 2011. CHECKED: 6. UNLESS 6. BGC AGR EESOTHER WWIN ISE RTHISDR ITING, AW INGSHALL NO BE TMO DIFIEDOR USED FO RANY PUR PO SEOTHER THAN THE PUR PO SEFO RWHICH BGC SAA PR O JECTNo.: DW GNo: GENERATED BGC SHALLIT. HAVE NO FOLIABILITY RANY DAMAGES OR LO SSAR ANY ISINGIN WAY FRO MANY USE OR MO DIFICATIONOF THISDO CUMENTNO T APPR O VED: 0095-150 03 AUTHO R IZEDBYBGC. ANY USE OF OR RELIANCE UPO THIS NDO CUMENTOR COITS NTENTBYTHIRD PARTIES SHALL BEATSUCH THIRD PARTIES' SO LERISK. X:\Projects\0095\150\GIS\Production\Rep orts\20180313_Geotechnical_HDD_ Fea sibility_ Assessment_W hitem ud_ Creek_ a t_SSEID_005_KP_28pt1\03_Bank_ Erosion_ Avulsion_ R eview_W hitem ud.mxd Date: Ma rch 28, 2018 Time: 1:10 PM 1:10 Time: 2018 28, Ma rch Date: ud.mxd R hitem eview_W Avulsion_ Erosion_ a t_SSEID_005_KP_28pt1\03_Bank_ Creek_ ud_ hitem Assessment_W sibility_ Fea orts\20180313_Geotechnical_HDD_ X:\Projects\0095\150\GIS\Production\Rep T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\WHITEMUD_CREEK_KP_28.2\04.dwg Layout: RM-B-SIZE Plot Date Mar 28 18 Time: 3:52 PM .ALLDIMENSIONSAREINMETRESUNLESSOTHERWISENOTED. 1. NOTES: .PROJECTION ISUTMNAD83ZONE 12. 7. .UNLESS BGCAGREESOTHERWISE INWRITING, THISDRAWINGSHALL NOTBEMODIFIED ORUSEDFOR ANY PURPOSE OTHERTHANTHEPURPOSE FORWHICH BGC SPECIFICOBSERVATIONSPERTAININGTO THEWATERLEVELMEASUREMENTS AREAVAILABLEINTHEREPORT. 9. 8. GEOPHYSICS SURVEYINTERPRETATION ANDGROUNDSURFACEPROFILEPROVIDED BYWORLEYPARSONS, RECEIVEDONAPRIL23,2014. 6. PROPOSEDTMEP SSEID005.5PIPELINEALIGNMENTPROVIDEDBYKMC,DATEDMARCH2018.PROPOSED HDDALIGNMENTPROVIDEDBYUPI,DRAWINGNO.01-13283-M002-XD00026-01 REVA, 5. BASETOPOGRAPHIC DATABASEDONLIDARPROVIDEDBYUPI,DATEDSEPTEMBER2014.CONTOUR INTERVALIS1.0m. 3. 2. .IMAGESOURCE:ESRIWORLDIMAGERY SERVERRETRIEVEDFROMBINGIMAGERY. 4. AUTHORIZED BYBGC.ANY USEOFORRELIANCE UPONTHISDOCUMENT ORITS CONTENTBYTHIRD PARTIESSHALLBE ATSUCHTHIRD PARTIES'SOLERISK. GENERATED IT.BGCSHALL HAVENOLIABILITY FORANYDAMAGES ORLOSSARISING INANYWAYFROM ANYUSEOR MODIFICATIONOF THISDOCUMENTNOT

LEGEND -PLAN N

ISSUED FEBRUARY07,2018.ATCOGAS 20"HDDPROFILEPROVIDEDBYUPI,DATEDFEBRUARY23,2018.

THIS DRAWINGMUSTBEREADINCONJUNCTION WITHBGC'SREPORTTITLED“GEOTECHNICALHDDFEASIBILITY ASSESSMENT-WHITEMUDCREEKATSSEID005.5KP28.2”,ANDDATEDMARCH 2018. N 5,923,250 N ELEVATION (m) ERT SURVEYALIGNMENT PROPOSED HDDENTRY/0+00EXITPOINT BGC BOREHOLE KILOMETRE POINT(KP) PROPOSED HDDBOREPATH SEISMIC SURVEYALIGNMENT SSEID 005.5TRANSMOUNTAINPIPELINEALIGNMENT ATCO GAS20"PIPELINECENTRELINE(APPROX.)

580 600 625 650 675 700 28+700 25

0

B - (E: 329,251;N:5,923,144)

E 329,250 0 SCALE 1:2,500 METRES

28+600

680 685

685 100 755025 WEST 25

0 ELEVATION (m) SCALE 1:2,500 675 650 700 METRES 0

(E: 329,251;N:5,923,144) 28+500 685 25 HDD ENTRY 0 200 SCALE 1:2,500 METRES 755025

E 329,500

100 28+400 WEST E 329,500 755025 BH-BGC14-WM-02 300

ELECTRICAL RESISTIVITY(ohm-m) 680

200 28+300 675 680 CROSS-SECTION P-WAVE VELOCITY(m/s) HDD 0+00POINT CROSS-SECTION DISTANCE (m)

DISTANCE (m) 670 675

400 665 670 665 THIS DRAWINGMAY HAVEBEENREDUCEDORENLARGED. 660 ALL FRACTIONALSCALE NOTATIONSINDICATEDARE B

- 660 660 BASED ON ORIGINALFORMAT DRAWINGS. B -

300 28+200 665 660

E 329,750 500

665E 329,750 BH-BGC14-WM-01 670 EAST DRAFT WHITEMUD CREEK

400 28+100

670 (E: 329,734;N:5,923,187) APPROVED: CHECKED: DRAWN: DATE: SCALE: 600 670 670 FIELD PARAMETERS: SOURCE: SLEDGEHAMMER SHOT SPACING:20m GEOPHONE SPACING:5m ELECTRODE CONFIGURATION:GRADIENTPLUS DATE COLLECTED:JUNE19,2013 FIELD PARAMETERS: MINIMUM ELECTRODESPACING:5m MAR 2018 1:2,500

SAA 675 CR

500 28+000 - 700 650 675 CLIENT:

B 675 G EAST

C ELEVATION (m) 700 680 BGC ENGINEERINGINC. AN APPLIEDEARTHSCIENCES COMPANY 680 (E: 330,023;N:5,923,249)

E 330,000

27+900

E 330,000

B - 800 PROJECT No.: TITLE: PROJECT: 580 600 625 650 675 700 GEOTECHNICAL HDDFEASIBILITYASSESSMENT - WHITEMUDCREEKATSSEID005.5KP28.2

0095-150 ELEVATION (m) GEOPHYSICS RESULTS HDD EXIT

675

LEGEND -CROSS-SECTION 27+800 DWG No.: EXISTING GROUND 27+700

04 N 5,923,250 N PHOTO 1: LOOKING WEST TOWARD WHITEMUD CREEK AND BOREHOLE LOCATION PHOTO 2: BH-BGC14-WM-01 SPT SAMPLE FROM 1.5 m TO 2.1 m. TYPICAL FILL DEPOSIT PHOTO 3: BH-BGC14-WM-02 SPT SAMPLE FROM 12.2 m TO 12.8 m. TYPICAL BH-BGC14-WM-01 CONSISTING OF SILTY CLAY WITH TRACE SAND. GRAIN SIZE DISTRIBUTION: 0.0 % GRAVEL, GLACIOLACUSTRINE DEPOSIT CONSISTING OF FINE TO MEDIUM SAND WITH SOME FINES. 7.8 % SAND, 57.8 % SILT AND 34.4 % CLAY. GRAIN SIZE DISTRIBUTION: 0.0 % GRAVEL, 78.0 % SAND, 22.0 % FINES 05.dwg Layout: RM-B-SIZE Plot Date 05.dwgRM-B-SIZE Mar 28 182:18 PM Time: Layout:

PHOTO 4: BH-BGC14-WM-02 SPT SAMPLE FROM 13.7 m TO 14.3 m. TYPICAL PHOTO 5: BH-BGC14-WM-01 RUN FROM 13.4 m TO 14.9 m. TYPICAL EXTREMELY WEAK PHOTO 6: BH-BGC14-WM-02 - BOX 1 TO 4 - FROM 16.7 m TO 35.1 m. TYPICAL EXTREMELY GLACIOLACUSTRINE DEPOSIT CONSISTING OF SANDY SILT WITH SOME CLAY. GRAIN SIZE SANDSTONE WITH 1.5 m THICK COAL SEAM. WEAK SILTSTONE, SANDSTONE AND CLAYSTONE. 1.1 m THICK COAL SEAM FROM 31 m TO DISTRIBUTION: 8.6% GRAVEL, 23.0% SAND, 54.4% SILT, 14.0% CLAY. ATTERBERG LIMITS: 32.0 m. LIQUID LIMIT = 28.2%, PLASTIC LIMIT = 24.2%

SCALE: N.T.S PROJECT: GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT SSEID 005.5 KP 28.2 DATE: MAR 2018 BGC ENGINEERING INC. NOTES: DRAFT BGC AN APPLIED EARTH SCIENCES COMPANY TITLE: 1. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT DRAWN: CR FIELD PHOTOS SSEID 005.5 KP 28.2”, AND DATED MARCH 2018. CLIENT: THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. CHECKED: 2. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH BGC ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE SAA PROJECT No.: DWG No.: GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT NOT BASED ON ORIGINAL FORMAT DRAWINGS. APPROVED: 0095-150 05 AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. - T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\WHITEMUD_CREEK_KP_28.2\ 06.dwg6AMar 28 182:22 PM Time: Layout: Plot Date

NOTES: SCALE: N.T.S PROJECT: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT - WHITEMUD CREEK AT SSEID 005.5 KP 28.2 DATE: MAR 2018 SSEID 005.5 KP 28.2”, AND DATED MARCH 2018. DRAFT BGC ENGINEERING INC. BGC AN APPLIED EARTH SCIENCES COMPANY TITLE: 3. THIS PHOTOGRAPHIC LOG DOES NOT REPRESENT A COMPLETE CONTINUOUS PROFILE OF THE MATERIAL ENCOUNTERED. THE INDICATED DEPTHS ARE DRAWN: CR PHOTOGRAPHIC LOG BH-BGC14-WM-01 - 1 OF 3 APPROXIMATE AND SHOULD BE TREATED AS A GENERAL GUIDELINE CLIENT: THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. 4. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH CHECKED: ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE SAA PROJECT No.: DWG No.: BGC GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT BASED ON ORIGINAL FORMAT DRAWINGS. 0095-150 06A NOT AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. APPROVED: - T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\WHITEMUD_CREEK_KP_28.2\ 06.dwg6BMar 28 182:22 PM Time: Layout: Plot Date

NOTES: SCALE: N.T.S PROJECT: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT - WHITEMUD CREEK AT SSEID 005.5 KP 28.2 DATE: MAR 2018 SSEID 005.5 KP 28.2”, AND DATED MARCH 2018. DRAFT BGC ENGINEERING INC. BGC AN APPLIED EARTH SCIENCES COMPANY TITLE: 3. THIS PHOTOGRAPHIC LOG DOES NOT REPRESENT A COMPLETE CONTINUOUS PROFILE OF THE MATERIAL ENCOUNTERED. THE INDICATED DEPTHS ARE DRAWN: CR PHOTOGRAPHIC LOG BH-BGC14-WM-01 - 2 OF 3 APPROXIMATE AND SHOULD BE TREATED AS A GENERAL GUIDELINE CLIENT: THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. 4. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH CHECKED: ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE SAA PROJECT No.: DWG No.: BGC GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT BASED ON ORIGINAL FORMAT DRAWINGS. 0095-150 06B NOT AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. APPROVED: - T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\WHITEMUD_CREEK_KP_28.2\ 06.dwg6C2:21 PM Time: Plot Date Layout: Mar 28 18

NOTES: SCALE: N.T.S PROJECT: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT - WHITEMUD CREEK AT SSEID 005.5 KP 28.2 DATE: MAR 2018 SSEID 005.5 KP 28.2”, AND DATED MARCH 2018. DRAFT BGC ENGINEERING INC. BGC AN APPLIED EARTH SCIENCES COMPANY TITLE: 3. THIS PHOTOGRAPHIC LOG DOES NOT REPRESENT A COMPLETE CONTINUOUS PROFILE OF THE MATERIAL ENCOUNTERED. THE INDICATED DEPTHS ARE DRAWN: CR PHOTOGRAPHIC LOG BH-BGC14-WM-01 - 3 OF 3 APPROXIMATE AND SHOULD BE TREATED AS A GENERAL GUIDELINE CLIENT: THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. 4. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH CHECKED: ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE SAA PROJECT No.: DWG No.: BGC GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT BASED ON ORIGINAL FORMAT DRAWINGS. 0095-150 06C NOT AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. APPROVED: - T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\WHITEMUD_CREEK_KP_28.2\ 07.dwg7AMar 28 182:25 PM Time: Layout: Plot Date

NOTES: SCALE: N.T.S PROJECT: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT - WHITEMUD CREEK AT SSEID 005.5 KP 28.2 DATE: MAR 2018 SSEID 005.5 KP 28.2”, AND DATED MARCH 2018. DRAFT BGC ENGINEERING INC. BGC AN APPLIED EARTH SCIENCES COMPANY TITLE: 3. THIS PHOTOGRAPHIC LOG DOES NOT REPRESENT A COMPLETE CONTINUOUS PROFILE OF THE MATERIAL ENCOUNTERED. THE INDICATED DEPTHS ARE DRAWN: CR PHOTOGRAPHIC LOG BH-BGC14-WM-02 - 1 OF 3 APPROXIMATE AND SHOULD BE TREATED AS A GENERAL GUIDELINE CLIENT: THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. 4. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH CHECKED: ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE SAA PROJECT No.: DWG No.: BGC GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT BASED ON ORIGINAL FORMAT DRAWINGS. 0095-150 07A NOT AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. APPROVED: - T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\WHITEMUD_CREEK_KP_28.2\ 07.dwg7BMar 28 182:24 PM Time: Layout: Plot Date

NOTES: SCALE: N.T.S PROJECT: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT - WHITEMUD CREEK AT SSEID 005.5 KP 28.2 DATE: MAR 2018 SSEID 005.5 KP 28.2”, AND DATED MARCH 2018. DRAFT BGC ENGINEERING INC. BGC AN APPLIED EARTH SCIENCES COMPANY TITLE: 3. THIS PHOTOGRAPHIC LOG DOES NOT REPRESENT A COMPLETE CONTINUOUS PROFILE OF THE MATERIAL ENCOUNTERED. THE INDICATED DEPTHS ARE DRAWN: CR PHOTOGRAPHIC LOG BH-BGC14-WM-02 - 2 OF 3 APPROXIMATE AND SHOULD BE TREATED AS A GENERAL GUIDELINE CLIENT: THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. 4. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH CHECKED: ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE SAA PROJECT No.: DWG No.: BGC GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT BASED ON ORIGINAL FORMAT DRAWINGS. 0095-150 07B NOT AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. APPROVED: - T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\WHITEMUD_CREEK_KP_28.2\ 07.dwg7C2:23 PM Time: Plot Date Layout: Mar 28 18

NOTES: SCALE: N.T.S PROJECT: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT - WHITEMUD CREEK AT SSEID 005.5 KP 28.2 DATE: MAR 2018 SSEID 005.5 KP 28.2”, AND DATED MARCH 2018. DRAFT BGC ENGINEERING INC. BGC AN APPLIED EARTH SCIENCES COMPANY TITLE: 3. THIS PHOTOGRAPHIC LOG DOES NOT REPRESENT A COMPLETE CONTINUOUS PROFILE OF THE MATERIAL ENCOUNTERED. THE INDICATED DEPTHS ARE DRAWN: CR PHOTOGRAPHIC LOG BH-BGC14-WM-02 - 3 OF 3 APPROXIMATE AND SHOULD BE TREATED AS A GENERAL GUIDELINE CLIENT: THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. 4. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH CHECKED: ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE SAA PROJECT No.: DWG No.: BGC GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT BASED ON ORIGINAL FORMAT DRAWINGS. 0095-150 07C NOT AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. APPROVED: - T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\WHITEMUD_CREEK_KP_28.2\ Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

APPENDIX A HYDROTECHNICAL ASSESSMENT METHODOLOGY

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment – Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

A.1. INTRODUCTION

This appendix documents the methodology followed by BGC Engineering Inc. (BGC) to complete hydrotechnical assessments at pipeline watercourse crossings. A description of hydrotechnical hazards is provided in Section A.2, followed by the flood frequency analysis (FFA) methodology in Section A.3. The hydrotechnical assessment methods specific to each hydrotechnical hazard are presented in Sections A.4 (scour), A.5 (bank erosion and encroachment), and A.6 (avulsion). Several industry terminology conventions are used in this methodology report, and in supporting hydrotechnical reports. Definitions of the terminology are as follows: Downstream Direction of water flow. Upstream Direction opposite to water flow. Right & left banks Reference convention for banks when facing downstream. DoC Depth of cover (burial depth) over the pipeline. RoW Pipeline right of way. Thalweg Line defining the lowest points along the length of a river bed or valley. Hazards Characterisation of hydrotechnical processes such as scour, channel bed degradation, and bank erosion that could result in a loss of DoC. Likelihood Qualitative assessment of how often an event may occur (e.g., the likelihood of scour hazard occurring is high). Probability Quantitative assessment of how often an event may occur (e.g., the probability of scour hazard occurring is 0.05 yr -1). Return Period The inverse of probability, it gives the estimated average time interval between events of a similar intensity (e.g., 1/[0.05 yr -1] = 20 yr return period). A.2. HYDROTECHNICAL HAZARDS

The following hydrotechnical hazards are included as part of the hydrotechnical assessment: • Scour of the channel bed; • Bank erosion caused by lateral channel migration or channel widening; • Encroachment of the channel towards the pipeline due to bank erosion; and • Avulsion of the channel within the floodplain.

A.2.1. Scour

Scour is the localized removal of granular bed material from the channel substrate by hydrodynamic forces during a flood event. Scour can happen at any location where local flow velocities increase within an otherwise uniform flow situation. Scour also occurs when the

Appendix A_Hydrotechnical Assessment Methodology_1 A-2 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment – Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 direction of flow changes at channel bends, confluences, constrictions, obstructions, and impingements. There are two types of scour: general scour and local scour. General scour occurs due to the complex interaction between flow rates and volumes, sediment transport rates, and channel morphology. Intermittent general scour occurs when a mobile-bed watercourse floods and the channel bed degrades (lowers) to accommodate the increased flow. Pipelines can become exposed or undermined during an intermittent flood event, becoming vulnerable to damage. The channel bed can experience significant scour during a flood event but this is often not detected because of compensating deposition that can occur as the flood flows decline (Leopold et al. 1964). Local scour results from acceleration of flow due to an obstruction or constriction to flow near piers, abutments, riprap revetments, large woody debris or other structures obstructing or constricting the flow. These obstructions cause vortices with accelerated flow that erode the surrounding bed and bank sediments. Contraction scour is a form of local scour where acceleration of flow is caused by a local narrowing of the channel. Local and general scour depths are shown in the schematic in Figure A-1. General scour depth is measured relative to the design flood water level and local scour depth is measured from the bottom of the general scour elevation. Both general and local scour contribute to the total scour depth below the design flood water level.

Figure A-1. Schematic of general and local scour (reproduced from Veldman 2008).

A.2.2. Bank Erosion and Encroachment

Patterns of sediment transport and deposition naturally cause the channel banks to migrate laterally, resulting in bank erosion. Erosion can take place slowly over a period of years or suddenly during a single flood event. Gradual bank erosion most often occurs on outer bends of low gradient, meandering river channels. Large flood events may cause sudden widening, particularly in braided or wandering rivers, as the channel geometry adjusts to convey the

Appendix A_Hydrotechnical Assessment Methodology_1 A-3 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment – Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 additional flow. Bank migration (erosion) at a pipeline crossing, either through lateral migration or episodic widening, can result in exposure of the sagbends and overbends of the pipeline. Encroachment may be a hazard to the pipeline where bank erosion is occurring along a section of the channel that flows parallel and adjacent to the pipeline RoW. Bank erosion can lead to lateral movement of the watercourse toward the pipeline, potentially leading to exposure and freespan of a section of the pipeline outside of a designed watercourse crossing.

A.2.3. Avulsion

Avulsion, also referred to as outflanking or abandonment, occurs when streams leave their present channel and establish a new channel. This process can lead to pipe exposure if the new channel intersects the pipeline outside of the designed watercourse crossing where the top of pipe elevation may be higher. Avulsion frequently takes place on alluvial fans that carry high loads of bed material. It may also occur where rivers meander on a wide floodplain, although in this case the avulsion is typically into an existing side channel or abandoned channel. For the latter scenario, avulsion typically occurs progressively over a period of years rather than suddenly during a large flood event (although the large flood event may be the final tipping point for the avulsion to occur). In braided channels, the term avulsion is sometimes used to describe a shift in the main thread of current to the other side of a mid-channel bar, but in general, is intended to denote a complete shift of the main channel. Avulsions commonly result when an event (usually a flood) of sufficient magnitude occurs along a reach of river that is at or near an avulsion threshold (Schumm 2005). Avulsion channels can be characterized as active, transitional, or inactive based on the hydrological regime. Active avulsions are characterized by the presence of standing or flowing water. Transitional avulsions are dry without established vegetation. Inactive avulsions are dry and vegetated in the channel suggesting conditions have remained constant for several years. A.3. FLOOD FREQUENCY ANALYSIS

Flood discharge magnitudes and frequencies are estimated using a flood frequency analysis (FFA). Flood discharge quantiles are estimated for one or several representative hydrometric gauge stations, which are then related to the pipeline crossing using a site-specific relationship to estimate flood discharge quantiles at the crossing. This relationship could be a proration using a station on the same watercourse or a regression using several representative stations near the crossing. The flood discharge quantiles estimated using an FFA form the basis for the hydrotechnical hazard assessment for scour, bank erosion, encroachment, and avulsion. The methods used to conduct an FFA are described herein. The FFA is based on an approach known as Annual Maximum Series (AMS), which uses the maximum discharge value over a period of time. The selected AMS is the maximum peak instantaneous streamflow for each year on record, which is assumed to be a random sample from the underlying population of hydrological events and can thus be estimated by the selection of an appropriate statistical distribution.

Appendix A_Hydrotechnical Assessment Methodology_1 A-4 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment – Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

Extreme value statistics are used to estimate flood discharge quantiles from the AMS. A distribution known as the Generalized Extreme Value (GEV) distribution, which is described by location, scale, and shape parameters, is fitted to the AMS to estimate the flood discharges associated with selected event probabilities (Gilleland and Katz 2006). This statistical analysis is conducted using the Extremes package in R, a non-proprietary software environment for statistical computing and graphics (Gilleland 2016).

A.3.1. Historical Peak Flow Records

The FFA requires the input of streamflow data. In Canada, the Water Survey of Canada (WSC) monitors and manages hydrometric stations and publishes their data. The hydrometric stations for FFA are selected based on proximity to the crossing, available streamflow data (i.e., record length), drainage basin area, station elevation, hydro-climatic zone, and regulation type.

The preferred input to the FFA is peak instantaneous streamflow (QIMAX) for each available year on record. However, peak streamflow records at hydrometric stations are often limited to maximum average daily streamflow (QMAX) which are lower in magnitude than QIMAX. The difference between peak instantaneous and average daily flows are typically greater for small basins than for very large drainage areas. In some cases, QIMAX values may be estimated from available QMAX records using regression analyses techniques.

A.3.2. Prediction Limit of Dataset

The maximum return period for which a peak streamflow can be estimated reliably (i.e., the prediction limit) at a given hydrometric station is limited by the record length of the dataset defined by the number of years with a complete peak streamflow record. Generally, in cases where the record length of the station of interest is too short, the dataset can sometimes be extended using a correlation analysis with another nearby hydrometric station to estimate flood frequencies of higher return periods.

A.3.3. Climate Change

Flood frequency analyses use extreme value statistics that rely on assumptions of stationarity and homogeneity in the hydrologic data; however, climate change may invalidate the assumption of stationarity by producing a temporal trend in flood magnitude over time. Flood magnitude may be directly influenced by changes in annual precipitation or intensity, but is also indirectly affected by changes in precipitation phase related to temperature fluctuations (e.g., greater frequency of rain-on-snow events). The assumption of homogeneity in flow records will also be invalidated in many regions, as hydrologic regimes may shift from snowmelt-dominated or hybrid to rainfall- dominated, creating mixed populations of data. The impacts of climate change on hydrology are expected to vary regionally based on differences in temperature and precipitation changes across Canada. Potential impacts are described in the following sub-sections for select regions according to Canadian Ecozones (i.e., broad ecological

Appendix A_Hydrotechnical Assessment Methodology_1 A-5 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment – Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 units) (Li and Hélie 2014), as shown in Figure A-2. These regions were selected to capture the geographic range of hydrotechnical assessments for the Trans Mountain Expansion Project. The magnitude and timing of climate change impacts on hydrology in these different regions are uncertain. It is expected that some areas will experience more frequent, high-intensity flood events while others will experience less frequent flood events of the same intensity. These descriptions are intended to serve as general information only. Statistical analyses have not been incorporated in the FFAs to account for regional climate change impacts on hydrology at this time. Instead, flood quantiles for sites in all ecozones are conservatively increased by 10% to account for this uncertainty.

BRITISH COLUMBIA ALBERTA N

Edmonton

Vancouver

300 km

Figure A-2. Geographic map of Canadian ecozones across the geographic range of the Trans Mountain Expansion Project.

A.3.3.1. Pacific Maritime The dominant form of precipitation dictates runoff patterns throughout much of Canada (Whitfield 2001). Thus, although changes in the annual volume of precipitation due to climate change are uncertain (e.g., Zwiers et al. 2011), much of the Pacific Maritime region will experience changes in runoff timing as a result of increased winter temperature, as the contribution of snowmelt to annual runoff decreases. As a result, many streams in the Pacific Maritime region will shift from nival (i.e., snowmelt-dominated) to hybrid regimes, which are characterized by earlier snowmelt and more frequent rain-on-snow events (Loukas and Quick 1999; Whitfield 2001). Meanwhile hybrid streams are anticipated to transition to a fully pluvial regime, as the

Appendix A_Hydrotechnical Assessment Methodology_1 A-6 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment – Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 importance of the spring freshet decreases due to a loss of winter snowpack, especially in coastal areas (Zwiers et al. 2011; Schnorbus et al. 2014). As nival watersheds trap precipitation from winter storms in the snowpack, releasing it gradually during the spring freshet, this transition may be accompanied by an increase in the size and variability of floods (Pitlick 1994). To date, the impacts appear to be greatest in headwater streams; the Columbia River, for example, has shown little change in runoff magnitude or timing (Hatcher and Jones 2013), though this resilience is in part due to an increase in snowpack at high elevations (Schnorbus et al. 2014).

A.3.3.2. Semi-Arid Plateaux A decrease in the number and magnitude of flood events is predicted for many snowfall- dominated watersheds, particularly in the semi-arid interior regions of British Columbia (Loukas et al. 2002). In drier climates, evaporation from water surfaces and from the land as well as transpiration from vegetation make up a large component of the regional water balance suggesting that temperature changes have the potential to affect runoff. Trends suggest that the Okanagan Basin is getting warmer and wetter with minimum temperatures and the number of frost-free days increasing (Cohen and Kulkarni 2001). Climate change scenarios predict an increase in winter temperature of 1.5 to 4.0 ⁰C and an increase in summer temperatures by approximately 2 to 4 ⁰C by the 2050s compared to the 1961 to 1990 baseline (Merritt et al. 2006). Taylor and Barton (2004) analyzed precipitation records from six sites in the Okanagan Basin and identified statistically significant positive trends in spring-time and summer precipitation for most stations. In contrast, climate change scenarios show precipitation increases on the order of 5 to 20% during the winter season and more variable predictions in the summer with changes ranging from no change to a 35% decrease by the 2050s compared to the 1961to1990 baseline, depending on the Global Climate Model and emission scenario (Merritt et al. 2006). Despite the warmer and wetter climate, little impact on the total water supply has been observed to date, which likely reflects a cancellation of the increase in precipitation inputs versus evapotranspiraton losses (Fleming and Barton 2015). Most studies seem to agree that climate change is resulting in an earlier onset of the spring freshet, a more rainfall-dominated hydrograph, and reduction in the annual and spring flow volumes with large variation in the flow volume and magnitude of the timing shift (Cohen and Kulkarni 2001; Merritt et al. 2006; Fleming and Barton 2015).

A.3.3.3. Montane Cordillera Extreme flooding in the Montane Cordillera is often associated with rain-on-snow events during the spring freshet (Harder et al. 2015). Although the effects of climate change on precipitation are not clear in this region, projected increases in temperature are expected to have the largest impact on annual minimum temperatures occurring in the winter months (Harder et al. 2015). As a result, the temperature rise will dramatically impact the ratio of rainfall to snowfall throughout the winter and spring, leading to a decrease in snowpack accumulation and changes in melt timing (Farjan et al. 2016). Researchers anticipate that streamflow will increase in the winter and spring in this region due to earlier snowmelt and more frequent rain-on-snow events (Schnorbus et al. 2014; Farjan et al. 2016).

Appendix A_Hydrotechnical Assessment Methodology_1 A-7 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment – Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

The effects of temperature change differ throughout the region, however, based on watershed elevation; high elevation regions throughout parts of the Montane Cordillera are projected to experience increases in snowpack, which would limit changes to peak flow in high elevation basins (Loukas and Quick 1999). To date, the sustained snowpack accumulation in some watersheds has limited changes in peak flows from climate change (Schnorbus et al. 2014, Harder et al. 2015). For example, Whitfield and Pomeroy (2016) recently studied the historical flow record for the upper Bow River, which contains over 100 years of records, and found that when flood events generated by different processes (snowmelt versus rain-on-snow) are analyzed separately, there are no clear trends in flood magnitude associated with climate index. The continued resilience of high elevation watersheds to future change is uncertain, though, as climate change is anticipated to affect snowpack accumulation at increasingly higher elevation regions throughout the century (Schnorbus et al. 2014, Harder et al. 2015).

A.3.3.4. Boreal Plains Global Circulation Model predictions are in general agreement that the climate in the southern boreal forest will likely become warmer and drier in the future, especially in the summer due to greater water loss by evapotranspiration (Cubasch et al. 2001; Gregory et al. 1997). Regional climate models indicate that the predicted warming could increase evaporation by up to 55% in certain areas of Alberta, Saskatchewan, and Manitoba (Schindler and Donahue 2006). Paleolimnological studies have shown a drying trend with reduced flood frequency and intensity in the northern Boreal Plains since 1850 (Wolfe et al. 2006). In contrast to temperature, precipitation trends are weaker and less certain. None of the data from reference climate stations within the Boreal Plains show significant trends in total precipitation over the time period 1950 to 2010 (Ireson et al. 2015). Data from some stations show a decline in annual snowfall and consequently a reduction in the fraction of precipitation that falls as snow due to the shortening cold season (Mekis and Vincent 2011). The response of hydrological processes to winter warming is highly uncertain. Earlier spring snowmelt and delayed autumn snowfall are predicted to be very likely but the impacts are not clear due to the complex runoff generation mechanisms in the Boreal Plains. For example, earlier melt could mean a shift to an earlier peak in streamflow and less water available in the late summer or it could mean more soil infiltration due to the increased proportion of rainfall over snowmelt which could increase soil moisture, stream baseflow, and hydraulic connectivity between wetland and streams (Barnett et al. 2005). Nevertheless, the net effect will be warmer and drier over time due to an increase in air temperature (Ireson et al. 2015).

A.3.3.5. Prairies Peak runoff in the Canadian Prairies is primarily a result of spring snowmelt over frozen soils but can also be caused by intense rainfall from summer storms (Shook and Pomeroy 2012). The fraction of spring snowmelt forming runoff is strongly influenced by the rate of melt and the presence of ice layers near the surface in frozen soils or at the base of the snowpack, all of which can be influenced by rainfall in the spring and late fall. In 2008, earlier occurrence of spring runoff

Appendix A_Hydrotechnical Assessment Methodology_1 A-8 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment – Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 and decreasing trends in the spring snowmelt runoff volume, magnitude of peak flow, and summer baseflows were attributed to a combination of a reduction in snowfall and increases in temperatures during the winter months (Burn et al. 2008). More recently, the fraction of monthly precipitation falling as rain was found to increase at many locations in the Canadian Prairies over the periods 1901 to 2000 and 1951 to 2000 (Shook and Pomeroy 2012). Short-duration summer convective rainfall events show significant decreases in frequency while multiple-day rainfall events have significantly increased in frequency at many locations in the Canadian Prairies over these time periods. Longer rainfall events strongly suggest greater spatial extents for storms and increasing tendencies for basin-scale rainfall– runoff events (Shook and Pomeroy 2012). Warming air temperatures, increased rainfall fraction in peak flows, earlier snowmelt, and higher occurrence of multiple-day rainfall events have, along with extensive wetland drainage (and corresponding reduction in runoff storage within basins), have resulted in an increase in flows generated from snowmelt, rain-on-snow, and rainfall runoff processes, with the greatest increases for rainfall runoff and a relative decline in the proportion of streamflow derived from snowmelt from over 85% in the 20th century to less than 50% in the last 5 years (Dumanski et al. 2015).

A.3.4. Pro-rated FFA

In cases where a single representative station is located along the same watercourse as the proposed pipeline crossing, a pro-rated FFA can be conducted by transposing the flood quantiles from the station to the crossing. This type of FFA uses a pro-rated calculation to relate the QIMAX quantiles at the hydrometric station to the pipeline crossing based on basin area. The equation used for this relation is as follows (Eq. A-1):

n QU  AU     [Eq. A-1] QG  AG 

3 where QU and QG are the peak instantaneous flow estimates (m /s) at the ungauged site (pipeline crossing) and gauged site (hydrometric station) respectively, AU and AG are the drainage basin areas (km2) for the ungauged and gauged sites respectively, and n is a site-specific exponent that relates peak streamflow data at both sites (Transportation Association of Canada [TAC] 2004). The value of n is selected based on the drainage area, as shown in Table A-1. The drainage area at the pipeline crossing is typically estimated by BGC using available topographic datasets while drainage areas for the hydrometric stations are obtained from WSC records.

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Table A-1. Approximate drainage area exponents for prorating flood quantiles (from TAC 2004). Drainage Area (km2) Exponent, n

10 to 100 0.8

100 to 1000 0.65

1000 to 10,000 0.5

10,000 to 100,000 0.35

100,000 to 1,000,000 0.2

A.3.5. Regional FFA

A regional FFA approach is used to estimate design flood flows at the proposed pipeline crossing when there are several representative hydrometric stations in the area, either along the crossing watercourse or on nearby watercourses with similar catchment characteristics. A regional FFA is conducted using regression analysis, where QIMAX quantiles are estimated from a regression with the form of a power law, which is described by equation (Eq. A-2):

b Qp  aA [Eq. A-2]

where Qp is the peak flood estimate at the pipeline crossing, A is the upstream drainage area for the crossing, and a and b are regression coefficients developed from the estimated QIMAX and calculated drainage area of several regional hydrometric stations (TAC 2004). A.4. SCOUR ANALYSIS

Scour is the localized removal of granular bed material from the channel substrate by hydrodynamic forces during a flood event. The likelihood of a pipeline becoming exposed due to scour in a flood event is assessed by estimating the maximum scour depth associated with a range of return period floods. If the pipe’s crown elevation within the bankfull channel is higher than the estimated scour elevation, then the pipe is considered to be susceptible to exposure for that particular magnitude of flood event. The scour elevation is estimated by subtracting the predicted scour depth from the design flood elevation, which is generated using an estimate of channel hydraulics with Manning’s equation.

A.4.1. Channel Hydraulics

As part of the scour assessment, hydraulic parameters (i.e., water surface elevation, average flow depth etc.) are estimated at the pipeline crossing site for the design flood. The hydraulics are assessed by modeling flow through the study reach, or by applying Manning’s equation at the pipeline crossing. Manning’s equation is an empirical formula for open channel flow, and it is applicable in cases where flow is driven by gravity and is considered uniform. Manning’s equation is defined in equation A-3.

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1 푉 = 푅 2/3 ∙ 푆1/2 푛 ℎ [Eq. A-3] where V is the cross-sectional average velocity (m/s), n is Manning’s roughness coefficient (unitless), Rh is the hydraulic radius (m), and S is the slope of the water surface (m/m). The hydraulic radius, Rh, is calculated as the cross-sectional area of the flow divided by the wetted perimeter. The slope of the water surface is generally assumed to be comparable to the regional slope of the channel bed for uniform flow. Manning’s coefficient values typically range from 0.025 to 0.07 for streams with boulder to sand substrates; selection of an appropriate value is based on professional judgment.

A.4.2. General Scour Equations

Various empirical hydraulic equations have been developed to estimate general scour depth during a peak flow event (Table A-2). The selection and use of these equations requires engineering judgment, resulting in semi-quantitative results. Each method was designed by its authors based on a specific range of boundary conditions, and care must be taken to select appropriate methods for the site under study.

Table A-2. Methods for estimating the potential depth of general scour. Method Reference

Lacey’s Regime Lacey (1930)

Blench Regime Blench (1969)

Yaremko and Cooper Yaremko and Cooper (1983)

A.4.2.1. Lacey’s Regime Most of the work on general scour can be traced back to the concept of channel regime, starting with Lacey in 1930. The regime concept is generally considered synonymous with that of equilibrium or balance, and was a concept that originated with British engineers working in India from the study of the dimensions of stable alluvial, irrigation canals. The regime concept was originally formalized by Lindley (1919) who noted that “when an artificial channel is used to convey silty water, both bed and banks scour or fill, changing depth, gradient, and width, until a state of balance is attained at which the channel is said to be in regime.” Lacey (1930) expanded on the regime concept of Lindley by quantifying it. He defined a regime channel as a channel carrying a constant discharge under uniform flow in an unlimited incoherent alluvium having the same characteristics as that transported without changing the bottom slope, shape, or size of the cross-section over a period of time. Using data from irrigation canals on the Indian subcontinent, Lacey developed equations that related hydraulic parameters – namely wetted perimeter, velocity, hydraulic radius, and channel slope – to discharge and a silt factor (f), which takes into consideration the effect of sediment size on the channel dimensions. Lacey’s regime equation for mean depth is shown in Equation A-4.

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푄 1/3 푑 = 0.47 ( ) 푚 푓 [Eq. A-4] where:

• dm is the mean hydraulic depth of the main channel at the design discharge (m) • Q is the design discharge (m3/s) 1/2 -1 • f is Lacey’s silt factor = 1.76 (D50) , (s ) • And D50 is the median bed particle size (mm).

The regime method of Lacey is limited to channels with a sand1 bed, similar to conditions observed at the irrigation canals. However, Lacey also stated he was “inclined to believe that his formulas were general for all channels in the alluvium with which the engineer may be called upon to deal.” While the equation was developed from canal data, it has since been checked against data from a number of stable bridge sites on large sand-bed rivers, with remarkably good agreement (Neill 1964). The silt factor was introduced to account for differences in velocity-depth relations between different canal systems and was initially assumed to be a function of the grain size of transported sediment. For standard “silt” (actually medium sand) of 0.4 mm, the silt factor was taken as 1. The above equation only gives an estimated mean depth across the channel. To estimate the maximum general scour depth for a given flow, a multiplying factor must be applied. Lacey (1930) stated that “in a river flowing through a stable reach the maximum depth should approximate to the mean depth multiplied by 1.273 (elliptical section). For moderate, severe and right-angled bends, he recommended replacing the multiplier by 1.5, 1.75, and 2.0 m (the last based on a triangular section), respectively. However, Lacey (1930) gave no numerical guidance as to sharpness of curvature. Table A-3 gives coefficients (Zf factors) recommended by the Indian bridge code (1966), which are based mainly on consideration of the local channel morphology.

Table A-3. Empirical Lacey Z factors for maximum scour depth (after Neill 1973). Correction Factor Channel Morphology (Zf Factor)

Straight reach 1.25 Moderate bend 1.5 Severe bend 1.75 Right-angled abrupt turn 2.0 Noses of piers 2.0 Alongside cliffs and weirs 2.25 Noses of guide banks 2.75

1 The term “silt” was used at that time in India for canal sediment (Neill 1964).

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The resulting equation is then:

푑푠 = 푍푓푑푚 [Eq. A-5] where ds is the scour depth below the channel bed (m) and Zf is the correction factor (Table A-3). The average depth, dm (m), is assumed to be the hydraulic depth over the incised portion of the channel. It is further noted that the above equations are based on an unconstrained river, where the width is not constricted or imposed. As an example, if the mean channel depth for a given flow is estimated by Equation A-4 to be 2.0 m and the site is at a moderate bend, then the maximum scour depth estimated using Equation A.5 would be 1.5 times the mean depth, or 3.0 m, as measured from the water level for the given flow. Most subsequent regime equations for estimating general scour are variants of Lacey’s equations.

A.4.2.2. Blench Regime Depth Blench (1969) extended previous regime methods to include cases of different bank material. With this method, the bed factor is similar to Lacey’s silt factor. Blench defined the regime depth as follows:

2/3 1/3 푑푟 = 푞 /퐹푏 [Eq. A-6]

Where dr = regime depth (m) q = Q/b = unit discharge (m3/s/m) Q = design discharge (m3/s) b = water surface width (m)

Fb = Fbo (1 + 0.12 C) = bed factor (m/s2)

Fbo = zero bed factor (m/s2) C = bed load charge.

The value of Fbo is the larger of the values determined from Equation A-7, which has been converted by BGC to metric units, or from Figure A-3:

0.5 퐹푏표 = 14.63 (퐷50/푑푟) [Eq. A-7] where D50 = median diameter of bed material (m).

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Figure A-3. Blench’s zero bed factor, Fbo, versus particle diameter, D50, from Pemberton and Lara (1984).

Fbo is the zero bed factor, or the value to which the bed factor tends as C tends to zero. Because the value of Fbo is calculated using the regime depth, solving the equation is an iterative process. The estimated bed load charge, C, is essentially an adjustment factor to dampen estimated scour depths when significant bed load transport occurs; under these conditions a portion of the stream’s energy is committed to sediment transport rather than to scour of the channel bed. BGC’s does not generally adjust for bed load charge as this leads to less conservative results. Finally, similar to Lacey’s method, the regime depth is multiplied by a Z factor to calculate the scour depth as per Equation A-8:

푑푠 = 푍푓푑푟 [Eq. A-8] where ds is the scour depth relative to the design flood stage (m), Zf is the empirical correction factor, and dr is Blench’s regime depth (m). Northwest Hydraulic Consultants Ltd. (NHC) (1973) investigated Zf factors to be applied to the Blench regime equation using both field and model results, and recommended the values shown in Table A-4.

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Table A-4. Zf factors for scour depth applied to Blench’s regime equation (after NHC 1973). Correction Factor Channel Morphology (Zf factor) Forced, Rigid Bends 1.4 – 2.5 Free, Eroding Bends 1.4 – 1.75 Confluence 1.5 – 2.0 Tip of Spurs 2.0 – 2.75 Braided Channel1 2.5 – 3.0 Note: 1. Applicable to the bankfull mean depth of the largest existing channel in the vicinity of the crossing.

There is considerable range in Zf factors for a given channel morphology, and NHC noted that selection of appropriate Zf factors requires considerable experience in river engineering design. A conservative Zf factor at the upper end of the range is typically selected to account for uncertainty in the scour analysis inputs and empirical methods.

A.4.2.3. Yaremko and Cooper Yaremko and Cooper’s (1983) scour equation assumes that scour depth is proportional to the mean channel depth for a given flow event. Essentially, the Yaremko and Cooper equation is a simplification of other regime equations, with the assumption that the mean depth is an approximation of the regime depth (Figure A-4). The mean channel depth is assumed to be the hydraulic depth (wetted area/top width). The Yaremko and Cooper scour equation is defined by equation A-9.

푑푠 = 푍푓푑푟 [Eq. A-9] where ds is the depth of maximum scour relative to the design flood stage (m), dr is defined as the hydraulic depth over the main (incised) portion of the channel, and Zf is the correction factor. For appropriate Zf factors, the authors quote the values shown in both Table A-3 and Table A-4.

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Figure A-4. Application of estimated scour depths relative to the design flood stage (after Yaremko and Cooper 1983).

Yaremko and Cooper (1983) note that on northern pipeline projects, a great deal of attention was focused on the importance of accurately estimating an appropriate design discharge for use in determining depth of scour. However, the authors note that the design procedure for estimating scour is much more sensitive to the selection of an appropriate Z factor, than it is to the accurate determination of a design flood discharge.

A.4.2.4. BGC Z Factors As a general rule, BGC uses the Z factors specified in Table A-3 and Table A-4. An atypical example might be a braided river, where a local multiplier of 3 is used to account for increased scour at confluences, which are characteristic features of such rivers due to multiple channels and mid-channel bars. The mid-channel bars add geomorphic complexity that results in convergent flow downstream of these deposits, which can cause localized changes in bed planform, including scour holes (Ashworth 1996). Galay et al. (1987) indicate that scour multipliers for braided rivers can be as high as 5 under certain circumstances.

A.4.3. Maximum Bed Mobility

Channel bed mobility controls the adjustment of alluvial river channels and is driven by scour and entrainment. The maximum mobile particle size is estimated based on a combination of the shear velocity (u*) and channel bed shear stress (휏푏), which are calculated using Equations A-10 and A-11, respectively.

푢∗ = (푔푅푆)1/2 [Eq. A-10]

휏푏 = 푔휌푅푆 [Eq. A-11]

Appendix A_Hydrotechnical Assessment Methodology_1 A-16 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment – Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 where g is acceleration due to gravity (9.81 m/s2), R is the hydraulic radius (m), S is the regional channel slope (m/m), and 휌 is the density of water (1000 kg/m3). Shear velocity is expressed in units of m/s. Several empirical equations are available to estimate the maximum mobile particle size and each is considered a check on the others (Table A-5) (Pemberton and Lara 1984). The methods described below use channel hydraulic flow parameters, shear velocity, and channel bed shear stress. The maximum mobile particle size in a channel is estimated by taking the average of the different methods.

Table A-5. Methods for estimating bed material mobility. Method Reference

Shields’ Incipient Motion Shields (1936)

Lane’s Tractive Force Theory Pemberton and Lara (1984)

Borah Bed Armouring Borah (1989)

Meyer-Peter Muller Pemberton and Lara (1984)

The estimated maximum mobile particle size is used to assess the mobility of the bed material in the channel by comparison with an estimate of the median particle size present in the channel. Under conditions where the maximum mobile particle size is greater than the median particle size of the channel bed, the bed material is considered to be frequently mobile. Alternatively, in cases where the maximum mobile particle size is less than the median particle size of the channel bed, bed mobility is considered infrequent.

A.4.4. Wolman Sampling

Various regime and scour equations require an estimation of the median diameter of the bed material (D50). For gravel-bed rivers, the D50 of the bed material is assessed using field data collected following the standardized Wolman river bed material sampling method (Wolman 1954). This technique involves randomly picking up and measuring at least 100 pebbles from the river bed at the pipeline crossing or in a representative location in the same reach). The pebbles are measured and classified by size, then counts of pebbles in each size class are compiled to develop a grain size distribution, from which the D50 particle size is estimated.

A.4.5. Channels with Cohesive Beds

Conventional approaches to scour prediction were developed from field observations and laboratory experiments in non-cohesive soils, and are generally regarded as overly conservative when applied to cohesive soils. Accurate and accepted methods for predicting scour depths in the more scour-resistant cohesive soils are not yet available to practicing geomorphologists and engineers. The lack of an accurate predictive method often results in an overly conservative design scour depth for cohesive bed channels.

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Quantification of channel bed resistance to erosion is site specific and requires laboratory analysis on in-situ samples. Given that the cohesiveness and scour resistance of the substrate is generally not quantified, it is typically assumed by BGC that the bed materials at the pipeline crossings are non-cohesive. In cases where the channel bed material is obviously cohesive, scour depth results may be overestimates. A.5. BANK EROSION AND ENCROACHMENT ANALYSIS

Much of the methodology presented in the following section has been developed by BGC, and rely significantly on engineering judgement. Bank erosion occurs when bank locations change due to erosion at the channel margins, generally due to channel widening or progressive, gradual erosion from lateral migration of the channel. Channel widening occurs in response to flood events where the channel is forced to convey large flows. Bank erosion may also occur in the absence of large flow events and as a result of gradual erosion along one bank; in this case, the erosion typically occurs along the outer bank of a meander bend and is systematically balanced by the deposition of a point bar on the opposite bank, thus maintaining the channel width (Figure A-5) (Fuller 2007). Encroachment occurs when bank erosion results from migration of the channel bank toward a pipeline that travels parallel and adjacent to the channel flow direction.

Figure A-5. Illustration of gradual lateral channel migration in meandering rivers (Church 2006).

Figure A-6 illustrates different channel planforms as related to sediment supply and channel stability. These channel types can similarly be related to different forms of bank erosion; erosion due to channel widening is typically associated with inherently unstable channels such as braided

Appendix A_Hydrotechnical Assessment Methodology_1 A-18 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment – Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14 or wandering rivers, whereas progressive lateral channel migration is commonly observed in unconfined to semi-confined meandering rivers. The following sections describe the methods used by BGC to assess and quantify bank erosion.

Figure A-6. Illustration of channel planform and related sediment supply and stability (Church 2006).

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A.5.1. Historical Assessment of Channel Changes

A channel’s susceptibility to lateral migration can be assessed by looking at changes in channel position over time. Historical aerial photographs and satellite imagery can be used to compare and measure changes in the channel position and planform over time. The oldest available aerial photograph is compared to the most recent available imagery (satellite image or orthophoto) to observe noticeable trends in channel stability and lateral movement over a period of decades. This method will generally provide more accurate and reliable results for medium to large rivers (> 15-20 m width) due to limitations in the spatial scale of available imagery and the precision of mapping techniques. Historical aerial photographs at a scale of 1:30,000 or larger are preferred for this assessment. Aerial photographs are manually georeferenced to enable 2-dimensional (2D) comparison. Georeferencing is done using control points that are constant over time; where possible, a higher density of control points near the watercourse or in the valley is used to minimize distortion near the river banks. For some sites where adequate control data such as LiDAR are available, high- precision orthorectified models are created that are viewable in 3-dimensional (3D) space using the program Summit EvolutionTM. In both 2D and 3D cases, banks are delineated from the aerial photographs or models using geographic information system (GIS) software, and the differences in bank locations, which represent erosion or deposition, can be observed and quantified, as relevant. When multiple sets of LiDAR topographic data are available, change analysis techniques can be used to obtain higher precision estimates of recent channel change. Similar methodologies for historical imagery comparison using both aerial photographs and LiDAR imagery have resulted in spatial error of +/- 2.5 m (Fuller 2007). The spatial accuracy in the BGC method is estimated to be typically about +/-15 m because aerial photographs were not flown specifically for the proposed pipeline crossings and therefore may not be centered, resulting in potential distortion near the crossing location during the georeferencing process.

A.5.2. Encroachment

Progressive lateral movement of the channel toward the pipeline as a result of bank erosion can be evaluated using the same qualitative and quantitative methods as outlined for bank erosion described in the section above. An example of an encroachment hazard is shown in (Figure A-7).

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Encroachment Hazard

Figure A-7. Example of an encroachment hazard. The blue arrow indicates the channel centerline and flow direction and the red line shows a pipeline centerline location (imagery source: Google Earth, 2004).

A.6. AVULSION ANALYSIS

A.6.1. Background

Avulsion is the creation of a new channel on a floodplain or alluvial fan adjacent to the existing channel location. Scour within an avulsion channel could expose a pipeline, especially where the pipeline rises (and DoC decreases) outside of the boundaries of the main channel or existing channel location. Figure A-8 depicts a typical avulsion hazard in plan view and cross-section.

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Figure A-8. Example of avulsion in plan view (left) and cross-section (right).

Avulsions in floodplains tend to occur within a limited area known as the channel migration zone (Olson et al. 2014). This zone comprises the modern valley bottom as well as adjacent areas that could be incorporated into the valley bottom through erosion and it can be defined based largely on historical landforms visible in aerial photographs and satellite imagery; however, in streams subject to post-glacial incision, distinguishing between recent and historical landforms that may be abandoned (e.g., oxbow lakes on floodplain surface versus those on elevated terraces) can require considerable judgement. Within the channel migration zone, the likelihood of island-forming avulsions to occur is highest in previously abandoned secondary channels (Konrad 2012). In meandering streams, avulsion is most likely to occur between meander bends from the formation of neck and chute cutoffs (Slingerland and Smith 2004). Avulsions typically occur in response to a trigger, such as channel blockage (e.g. a log jam) or overland flooding, and the likelihood of avulsion will be greatest when at least one of these triggers is present. According to Schumm (2005), the underlying causes of avulsions can be organized into four groups as shown in Table A-6. The groupings represent different processes and events that create instability and can lead to avulsion. Generally, increases in the ratio of the potential avulsion path gradient (Sa) to the gradient of existing main channel (Se) the lead to greater instability and potentially to avulsion. Slingerland and Smith (1998) observed that avulsion tends to occur when the Sa/Se ratio is greater than 4. Therefore, Groups 1 and 2 include processes or events that affect the Sa/Se ratio in different ways, while processes and events in Group 3 and 4 are not related to the Sa/Se ratio.

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Table A-6. Causes of avulsions according to Schumm (2005). Ability of the existing main Processes and events that create instability and lead to avulsion channel to transport sediment and/or discharge Group 1 a) Sinuosity increases Decrease Avulsion due to increased ratio of b) Delta growth (lengthening of channel) Decrease Sa/Se resulting from a c) Base level fall Decrease decrease in Se d) Tectonic uplift Decrease Group 2 Avulsion due to a) Natural levee/alluvial ridge growth No change increased ratio of b) Alluvial fan and delta growth (convexity) No change Sa/Se resulting from an increase in Sa c) Tectonism (resulting in lateral tilting) No change Group 3 a) Hydrologic change in flood peak discharge Decrease Avulsion not b) Increased sediment load Decrease associated with a c) Vegetative encroachment Decrease change in ratio of Sa/Se d) Log Jams Decrease e) Ice Jams Decrease Group 4 a) Animal trails No Change Other avulsions b) Capture (diversion into adjacent drainage) No Change

Note: Se is the gradient of the existing (main) channel and Sa is the gradient of the potential avulsion course. Avulsion potential is assessed with qualitative consideration for various factors. Without a floodplain or fan, for example, the potential for avulsion is restricted spatially; channel patterns formed through avulsion (streams with multiple adjacent channels) generally occur in floodplains that are at least four times wider than the bankfull channel width (Beechie and Imaki 2014). Avulsion therefore poses little hazard in entrenched streams as it requires flooding onto elevated terraces, which would only be possible under extreme flows. In reaches bounded by floodplains, avulsion is most likely to occur within the channel migration zone, typically through the reoccupation of abandoned side channels or as cutoffs between successive meander bends. Avulsion is of greatest concern in aggrading streams, often typified by braided or anabranching channel patterns, where sediment deposition and other triggering factors such as large woody debris may force flows onto the adjacent floodplain (Slingerland and Smith 2004).

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Another factor that influences avulsion is the resistance of the valley bottom to vertical erosion. Factors that influence erosion resistance include the nature and abundance of vegetation and the composition and cohesion of floodplain sediments (Constantine et al. 2009; Dunne et al. 2010). Avulsion channels may be more likely to develop in areas with sparse vegetation, such as tilled agricultural fields, than in those with forest cover (Olson et al. 2014).

Olson et al. (2014) recommend that the following factors be considered in an assessment of avulsion potential: • Cross-valley gradients relative to main channel gradients; • Areas at lower elevations than the main channel with downstream outlets; • The presence of abandoned, side or secondary channels that have steeper slopes than the main channel; • The composition and cohesion of the floodplain and valley bottom sediments; • Abundance and type of vegetation in potential avulsion pathways; • Indications of active channel aggradation; and • Accumulations of large woody debris and channel-spanning log jams.

A.6.2. Assessment

The first step in assessing the potential avulsion hazard for proposed crossings is to delineate the floodplain or fan extents, if relevant, and to identify any contributing factors such as levees, cutoff structures, debris jams, sediment accumulation, beaver dams, debris flow potential, or extreme flooding. Next, the threshold flow depth for avulsion to occur is quantitatively defined based on the bank elevations at the crossing, which are obtained from survey and LiDAR data. The bank elevation is determined visually as the maximum elevation of the land that separates the stream channel from the floodplain, or the height of the terrace if no floodplain is present. The minimum bank elevation, which is the elevation of the lower of the two banks, defines the threshold flow depth needed to cause overbank flooding and to enable avulsion at the crossing. If this threshold is high, which is typically the case for entrenched reaches, then the design flow does not overtop the banks and avulsion cannot develop in the absence of a blockage. This is common in many Canadian streams, where they flow through valleys carved by larger glacial meltwater channels and are bounded by glaciofluvial terraces. Due to the complex nature of the combination of mechanisms that can initiate avulsion, it is difficult to predict exact avulsion flow paths through a floodplain or fan, even with detailed topographic information for the entire study area. In addition to establishing an elevation threshold for avulsion at the proposed crossing, avulsion is assessed qualitatively with consideration for additional contributing factors at the reach scale. Avulsion most often initiates at locations with triggering factors (e.g. log jams), or in existing or abandoned side channels that begin in locations where bank elevations are lower than at the crossing; therefore, if active or abandoned side channels are evident in imagery or on the crossing elevation profile, then this may indicate that the elevation threshold for avulsion is lower in a location upstream of the crossing.

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REFERENCES

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Barnett, T.P., Adam, J.C., and Lettenmaier, D.P. 2005. Potential impacts of a warming climate on water availability in snow-dominated regions. Nature 438: 303–309. Beechie, T. and Imaki, H. 2014. Predicting natural patterns based on landscape and geomorphic controls in the Columbia River basin, USA. Water Resources Research 50: 39-57. Blench, T. 1969. Mobile-bed Fluviology. University of Alberta Press, Edmonton, Alberta. Borah, D.K. 1989. Scour depth prediction under armouring conditions. Journal of Hydraulic Division, ASCE 115 (HY10):1421-1425. Burn, D. 1994. Hydrologic effects of climatic change in west-central Canada. Journal of Hydrology 160: 53-70. Burn, D., Fan, L., and Bell, G. 2008. Identification and quantification of streamflow trends on the Canadian Prairies. Hydrological Sciences 53: 538-549. Church, M. 2006. Bed material transport and the morphology of alluvial river channels. Annual Review of Earth and Planetary Sciences 34: 325-354. Cohen, S., and Kulkarni, T. (Eds.), 2001. Water management and climate change in the Okanagan Basin. Final Report, Climate Change Action Fund Project A206, 75 pp. Constantine, J.A., McLean, S.R., and Dunne, T. 2009. A mechanism of chute cutoff along large meandering rivers with uniform floodplain topography. Geological Society of America Bulletin 122: 855–869. Cooper, R., Peterson A. and Blench T. 1973. Critical review of sediment transport experiments. Proceedings of the American Society of Civil Engineers, Vol. 98, No. HY5. May 1972. Cubasch, U., Meehl, G.A., Boer, G.J., Stouffer, R.J., Dix, M., Noda, A., Senior, C.A., Raper, S., and Yap, K.S. (eds) 2001. Projections of future climate change. Cambridge University Press, Cambridge, United Kingdom. Dumanski, S., Pomeroy, J. W., and Westbrook, C. J. 2015. Hydrological regime changes in a Canadian Prairie basin. Hydrological Processes 29: 3893–3904. Dunne, T., Constantine, J.A., and Singer, M.B. 2010. The role of sediment transport and sediment supply in the evolution of river channel and floodplain complexity. Transactions, Japanese Geomorphological Union 31: 155–170. Farjan, B., Gupta, A., and Marceau, D.J. 2016. Annual and seasonal variations of hydrological processes under climate change scenarios in two sub-catchments of a complex watershed. Water Resources Management, 30(8): 2851-2865.

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Ferguson, R.I. 2003. The missing dimension: effects of lateral variation on 1-D calculations of fluvial bedload transport. Geomorphology 56: 1-14. Fleming, S.W. and Barton, M. 2015. Climate trends but little net water supply shift in one of Canada’s most water stressed regions over the last century. Journal of the American Water Resources Association 51: 833-841. Fuller, I.C. 2007. Geomorphic work during a “150-Year” storm: contrasting behaviors of river channels in a New Zealand catchment. Annals of the Association of American Geographers 97(4): 665-676. Galay, V.J., Yaremko, E.K., and Quazi, M.E. 1987. River bed scour and construction of stone rip rap protection. In: Sediment Transport Gravel Bed Rivers. Edited by: C.R. Thorne, J.C. Bathurst and R.D. Hey. John Wiley and Sons Ltd., p. 353-382. Gilleland, E. and Katz, R.W. 2006. Analyzing Seasonal to Interannual Extreme Weather and Climate Variability with the Extremes Toolkit. Research Applications Laboratory, National Center for Atmospheric Research. Gilleland, E. 2016. Package ‘extRemes’ Extreme Value Analysis [software package]. Version 2.0- 8. CRAN. Available from: https://cran.r-project.org/web/packages/extRemes/extRemes.pdf Gregory, J.M., Mitchell, J.F.B., and Brady, A.J. 1997. Summer drought in northern midlatitudes in a time-dependent CO2 climate experiment. Journal of Climate 10: 662-686. Harder, P., Pomeroy, J.W., and Westbrook, C.J. 2015. Hydrological resilience of a Canadian Rockies headwaters basin subject to changing climate, extreme weather, and forest management. Hydrological Processes 29: 3905-3924. Haschenburger, J.K. and Wilcock, P.R. 2003. Partial transport in a natural gravel bed channel. Water Resources Research 39(1): 1020. Hatcher, K.L. and Jones, J.A. 2013. Climate and streamflow trends in the Columbia River Basin: evidence for ecological and engineering resilience to climate change. Atmosphere-Ocean, 51(4): 436-455. Indian Roads Congress. 1966. Standard Specifications and Code of Practice for Bridges. India. Ireson, A. M., Barr, A. G., Johnstone, J. F., Mamet, S. D., van der Kamp, G., Whitfield, C. J., Michel, N. L., North, R. L., Westbrook, C. J., DeBeer, C., Chun, K. P., Nazemi, A., and Sagin, J. 2015. The changing water cycle: The Boreal Plains ecozone of Western Canada. WIRES Water doi: 10.1002/wat2.1098. Konrad, C.P. 2012. Reoccupation of floodplains by rivers and its relation to the age structure of floodplain vegetation. Journal of Geophysical Research 117: G00N13. Lacey, G. 1930. Stable Channels in Alluvium. In Proceedings of the Institution of Civil Engineers. Volume 229.

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Leopold, L.B., Wolman, M.G., and Miller, J.P. 1964. Fluvial Processes in Geomorphology. San Francisco: W.H. Freeman. Li, T., and Hélie, R. 2014. Ecozones of Canada. Update Version – 2014.02. 1:1,000,000. Canadian Council on Ecological Areas (CCEA). Lindley, E.S. 1919. Regime Channels. Proceedings, Punjab Engineering Congress, 7. Lindley, E.S. 1919. Regime channels. In Proceedings of the Punjab Engineering Congress, Lahore, Pakistan, Vol. 7. pp. 63-74. Loukas, A., and Quick, M.C. 1999. The effect of climate change on floods in British Columbia. Nordic Hydrology 30: 231-256. Loukas, A., Vasiliades, L., and Dalezios, N.R. 2002. Potential climate change impacts on flood producing mechanisms in southern British Columbia, Canada using the CGCMA1 simulation results. Journal of Hydrology 259: 163–188. McParland, D.J., Eaton, B. and Rosenfeld, J. 2014. At-a-station hydraulic geometry simulator. River Research and Applications, doi:10.1002/rra. Mekis, É., and Vincent, L.A. 2011. An overview of the second generation adjusted daily precipitation dataset for trend analysis in Canada. Atmos Ocean 49: 163–177. Merritt, W.S., Younes, A., Barton, M., Taylor, B., Cohen, S., and Neilsen, D. 2006. Hydrologic response to scenarios of climate change in subwatersheds of the Okanagan basin, British Columbia. Journal of Hydrology 326: 79-108. Neill, C.R. 1964. River-bed Scour: A Review for Bridge Engineers. Research Council of Alberta. Canadian Good Roads Association. Technical Publication No. 23. pp.47. Neill, C.R. [Editor]. 1973. Guide to Bridge Hydraulics. University of Toronto Press, Toronto, Canada. Northwest Hydraulic Consultants Ltd. 1973. Hydraulic model study of scour in gravel-bed rivers. Report prepared for Alyeska Pipeline Service Company. April 1973. Olson P., Legg, N., Abbe, T., and Reinhardt, M., 2014. A methodology for delineating planning- level channel migration zones. Publication no. 14-06-025, Washington State Department of Ecology, Olympia, Washington. Pemberton, E.L. and Lara, J.M. 1984. Computing degradation and local scour. Technical Guideline for Bureau of Reclamation, Denver, Colorado, United States. Pitlick, J. 1994. Relation between peak flows, precipitation, and physiography for five mountainous regions in the western USA. Journal of Hydrology 158: 219-240. Schindler, D.W., and Donahue, W.F. 2006. An impending water crisis in Canada's western prairie provinces. Proceedings of the National Academy of Science USA 103: 7210-7216.

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Schnorbus, M., Werner, A., and Bennett, K. 2014. Impacts of climate change in three hydrologic regimes in British Columbia, Canada. Hydrological Processes 28: 1170-1189. Schumm, S. A. 2005. River Variability and Complexity. Mussetter Engineering, Inc., USA. Cambridge University Press. Chapter 3, pp 31. Shields, I.A. 1936. Application of similarity principles and turbulence research to bed-load movement. United States Department of Agriculture Soil Conservation Service, Pasadena, California. Shook, K. and Pomeroy, J. 2012. Changes in hydrological character of rainfall on the Canadian prairies. Hydrological Processes 26: 1752-1766. Slingerland, R. and Smith, N.D. 2004. River avulsions and their deposits. Annual Review of Earth and Planetary Sciences 32: 257-285. Slingerland, R., and Smith, N.D. 1998. Necessary conditions for a meandering-river avulsion: Geology 26, p. 435, doi: 10.1130/0091-7613(1998). Transportation Association of Canada. 2004. Guide to Bridge Hydraulics, 2nd ed. Thomas Telford Publishing, London, U.K. Taylor, B., and Barton, M., 2004. Chapter 4. Climate. In Cohen, S., Neilsen, D., and Welbourn, R. (Eds.) Expanding the dialogue on climate change and water management in the Okanagan Basin, British Columbia, Final Report, 24–45. Veldman, W. 2008. Pipeline Geo-Environmental Design and Geohazard Management. Chapter 3, Open Cut and Elevated River Crossings. Edited by Moness Rizkalla. ASME. Whitfield, P.H. 2001. Linked hydrologic and climate variations in British Columbia and Yukon. Environmental Monitoring and Assessment 67: 217-238. Whitfield, P.H., and Pomeroy, J.W. 2016. Changes to flood peaks of a mountain river: implications for analysis of the 2013 flood in the Upper Bow River, Canada. Hydrological Processes, 30(25): 4657–4673. doi:10.1002/hyp.10957. Wilcock, P.R. and Crowe, J.C. 2003. Surface-based transport model for mixed-size sediment. Journal of Hydraulic Engineering 129: 120-128. Wolfe, B.B., Hall, R.I., Last, W.M., Edwards, T.W.D., English, M.C., Karst-Riddoch, T.L., Paterson, A., and Palmini, R. 2006. Reconstruction of multi-century flood histories from oxbow lake sediments, Peace-Athabasca Delta, Canada. Hydrological Processes 20: 4131–4153. Wolman, M. 1954. A method of sampling coarse river-bed material. Transactions of the American Geophysical Union 35(6): 951-956. Yaremko, E.K., and Cooper, R.H. 1983. Influence of Northern Pipelines on River Crossing Design. In: Pickell, M.B. (Ed.). Proceedings of the Conference on Pipelines in Adverse Environments II, American Society of Civil Engineers. San Diego, California, November 14-16, 1983. pp. 49-63.

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Zwiers, F.W., Schnorbus, M.A., and Maruszeczka, G.D. 2011. Hydrologic impacts of climate change on BC water resources. Summary Report for the Campbell, Columbia and Peace River Watersheds. Pacific Climate Impacts Consortium.

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APPENDIX B BGC BOREHOLE LOGS

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek BGC ENGINEERING INC. SYMBOLS AND TERMS FOR SOIL DESCRIPTIONS ON BOREHOLE LOGS

Project Name: Trans Mountain Expansion Project Project Number: 0095-150-14 USCS CLASSIFICATION (1) PROPORTION OF MINOR COMPONENTS (4) GROUP GROUP NAME BY WEIGHT MAJOR DIVISIONS SYMBOL “and” > 35% Coarse Clean gravel Well graded gravel, fine Gravel GW “y/ey” 20% to 35% grained <5% smaller to coarse gravel > 50% of “Some” 10% to 20% soils — than No. 200 coarse fraction Poorly graded gravel more sieve GP “Trace” > 0% to 10% retained on No. than 50% 4 (4.75 mm) Gravel with GM Silty gravel (2) retained PARTICLE SHAPE sieve >12% fines GC Clayey gravel on No. Flat Particles with width/thickness > 3 200 Clean sand SW Well graded sand, fine Particles with length/width > 3 (0.075 Sand to coarse sand Elongated >= 50% of < 5% passes Flat and Particles that meet both criteria mm) No. 200 sieve SP Poorly graded sand sieve coarse fraction Elongated passes No. 4 Silty sand Sand with SM (2) sieve >12% fines SC Clayey sand ANGULARITY Fine ML Silt Angular Particles have sharp edges and rela- Inorganic tively planar sides with unpolished grained Silt and clay CL Clay soils — surfaces. Liquid limit < 50 OL Organic silt, organic more Organic Particles are similar to angular de- than 50% clay Subangular passes MH High plasticity silt scription but have some rounded Silt and clay Inorganic edges. No. 200 CH High plasticity clay sieve Liquid limit Organic clay, organic Subrounded Particles have nearly planar sides but >= 50 Organic OH silt have well rounded corners and edg- Highly organic soils PT Peat es. (1) Rounded Particles have smoothly curved sides CLASSIFICATION BY PARTICLE SIZE and no edges. SIZE RANGE DENSITY OF GRANULAR SOILS(4) US STANDARD SIEVE SIZE DESCRIPTION SPT N FIELD (6, 9) IDENTIFICATION NAME (mm) (3) Retained Passing None Boulders >300 12 inch - “Very Loose” 0-4 Cobbles 75 - 300 3 inch 12 inch “Loose” 4-10 Easily penetrated by 13 mm Gravel: Coarse 19 - 75 0.75 inch 3 inch rod pushed by hand Fine 4.75 - 19 No. 4 0.75 inch “Compact” 10-30 Easily penetrated by 13 mm rod driven by hammer Sand: Coarse 2 - 4.75 No. 10 No. 4 Medium 0.43 - 2 No. 40 No. 10 “Dense” 30-50 Penetrated 0.3 m by 13 mm Fine 0.075 - 0.43 No. 200 No. 40 rod driven by hammer

Fines (Silt or Clay)(4) <0.075 - No. 200 “Very dense” >50 Penetrated few cm by 13 mm rod driven by hammer CONSISTENCY OF COHESIVE SOILS GRADE DESCRIPTION SPT UNDRAINED SHEAR FIELD IDENTIFICATION (8, 9) (7) “N” STRENGTH - “Su” kPa S1 “Very soft” <2 <12 Easily penetrated several cm by the fist. S2 “Soft” 2-4 12-25 Easily penetrated several cm by the thumb. S3 “Firm” 4-8 25-50 Can be penetrated several cm by the thumb with moder- ate effort. S4 “Stiff” 8-15 50-100 Readily indented by the thumb but penetrated only with great effort. S5 “Very Stiff” 15-30 100-200 Readily indented by the thumb nail. S6 “Hard” >30 >200 Indented with difficulty by the thumbnail. SYMBOLS AND TERMS FOR SOIL DESCRIPTIONS ON BOREHOLE LOGS

Project Name: Trans Mountain Expansion Project Project Number: 0095-150-14 PLASTICITY OF COHESIVE SOILS (10) DESCRIPTION SILT CLAY CRITERIA (10) High WL >50% WL >50% It takes considerable time rolling and kneading to reach the plastic limit. The thread can be rerolled several times after reaching the plastic limit. The lump can be formed without crumbling when drier than the plastic limit. (4) Intermediate - 30%< WL<50% The thread is easy to roll and not much time is required to reach the plastic limit. The lump crumbles when drier than the plastic limit.

Low WL<50% WL<30% The thread can barely be rolled and the lump cannot be formed when drier than the plastic limit. Non-Plastic NP - A 1/8 inch (3 mm) thread cannot be rolled at any water content. PLASTICITY OF COHESIVE SOILS(10) MOISTURE CONDITION (2) Description Criteria Dry Absence of moisture

Moist Damp but no visible water Wet Visible free water, usually soil is below water table

CEMENTATION (2) Description Criteria Weak Crumbles or breaks with handling or little pressure (12) DILATANCY Moderate Crumbles or breaks Description Criteria with considerable None No visible change in the spec-men during shaking or squeezing finger pressure Slow Water appears slowly on the surface of the specimen during shaking and disappears slowly upon squeezing Strong Will not crumble or break with finger Rapid Water appears quickly on the surface of the specimen during shaking pressure and disappears quickly upon squeezing

Notes: (1) ASTM D2487-11, Unified Soil Classification System (USCS). (2) ASTM D2488-09a. (3) Approximate metric conversion. (4) Canadian Foundation Engineering Manual (CFEM), 2006. (5) Fines are classified as silt or clay on the basis of Atterberg limits (refer to Plasticity Chart). (6) Standard Penetration Test (SPT) blow count uncorrected, after Terzaghi and Peck, 1948. (7) Undrained shear strength can be estimated by shear vane (gives Su), pocket penetrometer (gives unconfined compressive strength, qu = 2 * Su), or unconfined compression test (gives qu = 2 * Su). (8) Approximate correlation with Standard Penetration Test blow counts, after Terzaghi and Peck, 1948. (9) “R” represents sampler refusal during Standard Penetration Test. (10) This plasticity classification conforms to the Unified Soil Classification System (USCS) and to ASTM D-2487 (11) WL = Liquid Limit (%) (12) Test for dilatancy conducted by shaking and squeezing a moulded ball of soil that is 12 mm in diameter. (13) Test for dry strength conducted on natural soil pieces or moulded balls about 25 mm in diameter that have been dried at less than 60°C. SYMBOLS AND TERMS FOR SOIL DESCRIPTIONS ON BOREHOLE LOGS

Project Name: Trans Mountain Expansion Project Project Number: 0095-150-14 STRUCTURE (2) Soil Symbols Legend Description Criteria High Plastic Clay Low Plastic Clay Stratified Alternating layers of varying material or colour with layers at least 6 mm thick; note thickness Silt/Clay High Plastic Silt Laminated Alternating layers of varying material or colour with the layers less than 6 mm thick; note thickness Low Plastic Silt Clay/Sand Fissured Breaks along definite planes or fracture with little re- sistance to fracturing Slickensided Fracture planes appear polished or glossy, some- Silt/Sand Poorly-graded Sand times striated

Blocky Cohesive soil that can be broken down into small Well-graded Sand Clay/Gravel angular lumps which resist further breakdown

Lensed Inclusion of small pockets of different soils, such as Silt/Gravel Sand/Gravel small lenses of sand scattered through a mass of clay; note thickness Homogeneous Same colour and appearance throughout Well-graded Gravel Poorly-graded Gravel Heterogeneous Colour and appearance vary throughout High Plastic Organic Low Plastic Organic (2) SENSITIVITY Soil Soil St = Ratio of intact to remoulded strength Fill Peat/Topsoil St Sensitivity

St < 2 Low Sensitivity Boulders and Cobbles 2 < St < 4 Medium Sensitivity 4 < St < 8 Sensitive 8 < St < 16 Extra Sensitive Simplified Soil Symbols St > 16 Quick Clay Clay Sand DRY STRENGTH (2) Description Criteria(13) Silt Gravel None The dry specimen crumbles into powder upon applying pressure or handling Testing Results Legend Low The dry specimen breaks into pieces or crumbles with considerable finger pressure High The dry specimen cannot be broken with finger pres- sure. Specimen will break into pieces between thumb and a hard surface Very High The dry specimen cannot be broken between the thumb and a hard surface Sample Symbols SYMBOLS AND TERMS FOR ROCK DESCRIPTIONS ON BOREHOLE LOGS

Project Name: Trans Mountain Expansion Project Project Number: 0095-150-14

WEATHERING/ALTERATION (14) GRADE Description Field Identification A/W 1 Fresh and Unweathered No visible sign of rock material weathering A/W 2 Slightly Weathered or Discolouration indicated weathering of rock material and discontinuity surfaces. All Altered rock material may be discoloured by weathering and may be weaker than in its fresh condition. A/W 3 Moderately Weathered Less than 50% of rock material decomposed and/or disintegrated to soil. Fresh/ or Altered discoloured rock present as a continuous framework or corestones. A/W 4 Highly Weathered or More than 50% rock material is decomposed or disintegrated to soil. Fresh/ Altered Discoloured rock present as discontinuous framework or corestones. A/W 5 Completely Weathered All rock material decomposed and/or disintegrated to soil. Original mass structure or Altered still largely intact A/W 6 Residual Soil All rock material converted to soil; mass structure and material fabric destroyed. HARDNESS CLASSIFICATION FOR ROCK (15) GRADE Description Field Identification R6 Extremely Strong Specimen can only be chipped with flat end of geological hammer R5 Very Strong Specimen requires many blows of flat end of geological hammer to fracture R4 Strong Specimen requires more than one blow of flat end of geological hammer to fracture R3 Medium Strong Cannot be scraped or peeled with pocket knife; can be fractured with single firm blow of flat end of the geologic hammer R2 Weak Can be peeled with pocket knife with difficulty; shallow indentation made by firm blow with point of geological hammer R1 Very Weak Crumbles under firm blow with point of geological hammer; can be peeled by a pocket knife R0 Extremely Weak Indented by thumbnail JOINT CONDITION(16) Condition of Joints Rating Very rough surfaces. Not continuous. No 25 separation. Hard joint wall rock. Slightly rough surfaces. Separation 20 <1mm. Hard joint wall rock. Slightly rough surfaces. Separation 12 <1mm. Soft joint wall rock. Slickensided surfaces or gouge <5mm 6 thick or joints open 1-5mm. Continuous joints. Soft gouge >5mm thick or joints open 0 >5mm. Continuous joints. (14) After ISRM, 1981. (15) ISRM, 1977 (16) Joint condition is a numerical index that summarizes the typical surface properties and infilling of discontinuities within an interval (Bieniawski, 1976). SYMBOLS AND TERMS FOR ROCK DESCRIPTIONS ON BOREHOLE LOGS

Project Name: Trans Mountain Expansion Project Project Number: 0095-150-14

Lithological Graphic Log Legend Texture (14) Rock Term Particle Size Examples Very Coarse > 60 mm Porphyritic Shale Sandstone Coarse 2 - 60 mm Breccia, Gneiss (measurable grains) Medium 0.06 - 2 mm Sandstone, Gabbro, Granite, Schist Coal, Lignite Breccia (visible grains) Fine 0.002 - 0.06 mm Tuff, Siltstone, Claystone, Mudstone, Siltstone Mudstone Very Fine < 0.002 mm Basalt Fabric Conglomerate Limestone Term Description Homogeneous/ Equigranular or homogeneous grains Granite Rhyolite Uniform Bedded Deposited in layers, can be sedimentary or volcaniclastic rocks Dolomite Chalk Foliated Minerals are aligned due to shearing or metamorphism Gneissic Alternating layers of different colour or texture with mineral Chert, Flint Halite alignment and typically parts along layers Porphyritic Crystalline texture with bimodal grain size distribution, fine to medium grained groundmass with coarse to very coarse Gypsum Anhydrite phenocrysts Stockwork Veins (typically quartz, calcite, or gypsum/anhydrite) make up greater than 10% of the rock mass, they may be aligned Diorite, Syenite Andesite, Trachyte with foliation or irregularly oriented Microfractured Hairline fractures are the primary fabric of the rock, typically oriented in all directions and intersecting one another Gabbro Basalt Brecciated Healed or welded angular clasts with matrix, may be matrix – or clast-supported

Peridotite Granite Porphyry, (17) Felsite Rock Mass Rating

Porphyrite, Porphyry Dolerite/Diabase RMR Rock Quality 81-100 Very Good Slate, Phyllite Schist 61-80 Good

Migmatite Gneiss 41-60 Fair

21-40 Poor Quartzite Serpentinite 0-20 Very Poor

Marble Amphibolite, Eclogite

(17) The Rock Mass Rating (RMR) system, published by Bieniawski (1976) classifies Fault Zone Bedrock rock on a linear scale of 0-100 based on the sum of the ratings given to five parameters. The five parameters are: rock quality designation, facture intercept, joint condition, intact strength, and groundwater conditions. For core logging purposes, the value of the groundwater condtions parameter is assumed to be 10. The sum of the rating may then be used to assess the quality of the rock based on the classification table. SYMBOLS AND TERMS FOR ROCK DESCRIPTIONS ON BOREHOLE LOGS

Project Name: Trans Mountain Expansion Project Project Number: 0095-150-14

REFERENCES

American Society for Testing and Materials. Standard D2487-11: Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System). West Conshohocken, PA. American Society for Testing and Materials. Standard D2488-09a: Standard Practice for Description and Identification of Soils (Visual-Manual Procedure). West Conshohocken, PA.

Bieniawski, Z.T. 1976. Rock Mass Classification in Rock Enginereing. Proceedings of the Symposium on Exploration for Rock Engineering. Cape Town, Balkema, 1, 97-106. Canadian Geotechnical Society 2006. Canadian Foundation Engineering Manual 4th Edition. pp. 488. International Society of Rock Mechanics (ISRM). 1977. International Society for Rock Mechanics Com- mission of Standardization of Laboratory and Field Tests: Suggested Methods for the Quantitative Description of Discontinuities in Rock Masses. Committee on Field Tests, Document No. 4, pp. 319-368. International Society of Rock Mechanics (ISRM). 1981. International Society for Rock Mechanics: Com- mission of Classification of Rocks and Rock Masses, Basic Geotechnical Description of Rock Masses. International Journal of Rock Mechanics, Mineral Science, and Geomechanics. Vol. 18, pp. 85-110. Terzaghi, K., and Ralph B. Peck, 1948, Soil Mechanics in Engineering Practice, John Wiley and Sons, New York

Revision: June 11, 2015 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 1 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 0 CLAY (CL) Silty, trace sand, low plasticity, very soft, grey, orange-brown, moist (wetter than plastic limit), no structure, no to weak cementation, no odour, medium dry strength, slow to no dilatancy. [ANTHROPOGENIC] 0.0-3.7 m - Mud rotary drilling using a 6¼ inch tri-cone drill bit. 1

SPT 01 SPT 01 - Recovered 0.55 m. Plasticity Index = 19.4%. 0 2 0 1

3

INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE SANDSTONE, highly weathered to fresh, extremely weak to very weak, >> light "salt and pepper" grey, fine to medium grained, bedded to massive, 8 4 SPT 02 dark mudstone bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis. 10 CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, 14 dark greenish grey to dark pale green, fine grained, bedded to massive, black speckles, coal seams present, highly to moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. 5 SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, >> moderately fractured, close to moderate joint spacing, one joint set at SPT 03 approximately 90° to the core axis, some silt infill, mild reaction to HCl. 14 3.4 m - Top of bedrock unit inferred from drilling action and increase in 19 drilling pressure. 27 3.4-6.9 m - Sandstone, extremely weak. 6 R1 SPT 02 - Recovered 0.56 m. 3.7 m - Switched to a 5½ inch tri-cone drill bit. SPT 03 - Recovered 0.61 m. W 5.8 m - Switched drilling methods to triple tube coring using a HQ3 drill 3 bit. 5.8-6.2 - UCS = 0.5 MPa. 7 6.9-7.6 m - Siltstone, extremely weak. W 2 7.6 m - Drill bit became stuck while advancing, inferred due to swelling of the siltstone bedrock. 7.6-9.8 m - Claystone, extremely weak. Water observed at a depth of 7.7 m below ground surface on July 1, 2014 W with the drill hole at the final depth of 50.0 m. 8 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 2 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 8 3 INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE SANDSTONE, highly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, W dark mudstone bands approximately 1-10 mm thick, slightly fractured, 2 moderate joint spacing, one joint set at approximately 90° to core axis. CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, 9 dark greenish grey to dark pale green, fine grained, bedded to massive, black speckles, coal seams present, highly to moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at 10 approximately 90° to the core axis, some silt infill, mild reaction to HCl. 9.1-9.2 m - Bentonite clay, very stiff, pale greenish grey. 9.8-10.8 m - Siltstone, extremely weak.

W 1.5 10.8-12.7 m - Claystone, extremely weak. 11

W 2

11.9 m - Replaced HQ3 drill bit with a PDC drill bit. 12

12.7-13.6 m - Sandstone, extremely weak.

13

13.4-16.5 m - Total (100%) loss of drilling fluid circulation. 13.6-15.1 m - Coal, black, shiny, heavily fractured. 13.6 m - Drill rods advanced very rapidly while drilling. 14

15 15.1-15.8 m - Claystone, extremely weak.

15.8-17.7 m - Siltstone, extremely weak. 16 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 3 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 16 INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE W SANDSTONE, highly weathered to fresh, extremely weak to very weak, 1.5 light "salt and pepper" grey, fine to medium grained, bedded to massive, dark mudstone bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis. CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, 17 dark greenish grey to dark pale green, fine grained, bedded to massive, W black speckles, coal seams present, highly to moderately fractured, close 2 to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at 18 W 1.5 approximately 90° to the core axis, some silt infill, mild reaction to HCl. 16.5-18.0 m - Approximately 90%-100% loss in drilling fluid circulation. 17.7-18.0 m - Claystone, extremely weak. 18.0-19.1 m - Siltstone, extremely weak. 18.0-27.1 m - Approximately 75% loss in drilling fluid circulation.

19 19.1-19.5 m - Mudstone, tan, black speckles, fresh, weak, no fractures.

W 1 19.5-23.0 m - Sandstone, extremely weak.

W 20 1.5

21 W 1

22 W 1.5

W 23 1 23.0-23.2 m - Claystone, extremely weak, mudstone clasts. 23.2-23.8 m - Sandstone, extremely weak.

23.8-24.1 m - Claystone, extremely weak. 24 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 4 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 24 INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE SANDSTONE, highly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark mudstone bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis. CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, W 25 dark greenish grey to dark pale green, fine grained, bedded to massive, 1.5 black speckles, coal seams present, highly to moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at 26 approximately 90° to the core axis, some silt infill, mild reaction to HCl. 24.1-27.1 m - Sandstone, siltstone, and claystone become stratified, extremely weak, beds are approximately 15-30 cm thick, tan mudstone clasts present, sand infill.

27 27.1-30.4 m - Sandstone, very weak. 27.1-50.0 m - Approximately 50%-60% loss in drilling fluid circulation.

W 1 28

28.4 m - Brown siltstone clasts, approximately 1 cm wide by 3 cm long.

29

30

30.4-31.7 m - Claystone and sandstone become laminated and stratified, extremely weak.

31 W 2

31.7-32.8 m - Claystone, extremely weak.

32 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 5 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 32 INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE SANDSTONE, highly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark mudstone bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis. G1 CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, >> 33 W dark greenish grey to dark pale green, fine grained, bedded to massive, 4 black speckles, coal seams present, highly to moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at 34 approximately 90° to the core axis, some silt infill, mild reaction to HCl. W 32.8-33.2 m - Bentonite clay, plastic index greater than 300%, very high 2 plasticity, very stiff, light pale green, moist (near plastic limit), no odour, no structure, moderate cementation, high dry strength, no dilatancy. 33.2-33.4 m - Coal. 33.4-34.8 m - Claystone, extremely weak. 35 34.8-34.9 m - Coal. 34.9-37.6 m - Claystone, mudstone, and sandstone become stratified, extremely weak.

36

37

37.6-37.8 m - Sandstone, extremely weak. W 37.8-39.5 m - Siltstone, extremely weak to very weak. 38 1.5

W 2 R2 38.6-38.8 m - UCS = 9.3 MPa.

39 W 1

39.5-40.8 m - Claystone, siltstone and sandstone become stratified, extremely weak, strata are approximately 1-10 cm thick, two joint sets present. 40 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 6 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 40 INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE SANDSTONE, highly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark mudstone bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis. CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, 41 dark greenish grey to dark pale green, fine grained, bedded to massive, black speckles, coal seams present, highly to moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at 42 approximately 90° to the core axis, some silt infill, mild reaction to HCl. 40.8-46.3 m - Claystone, extremely weak to very weak.

43

44

45

46

46.3-46.6 m - Mudstone with sandstone bands, light tan, very weak, fresh, convoluted fabric, fine grained, moderate joint spacing. 46.6-48.5 m - Claystone, siltstone and sandstone become laminated and stratified, extremely weak to very weak. 47

48 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 7 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 48 INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE SANDSTONE, highly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark mudstone bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis. CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, 49 dark greenish grey to dark pale green, fine grained, bedded to massive, black speckles, coal seams present, highly to moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at 50 approximately 90° to the core axis, some silt infill, mild reaction to HCl. 48.5-48.8 m - Bentonite clay, high plastic, very stiff, pale green. 48.8-49.3 m - Claystone and sandstone become stratified and laminated, very weak. 49.3-50.0 m - Sandstone, extremely weak, laminated siltstone approximately 1-5 mm thick. 51 Borehole completed at target depth of 50.0 m below ground surface. Borehole grouted to surface with bentonite grout. No instrumentation installed. Bentonite chips alone added at 13.7 m to block zone of circulation loss and prevent loss of grout.

SPT Sampler Details: 61 cm length, 5 cm diameter, driven by automatic trip hammer. All SPT sampling was carried out in accordance with ASTM 52 D1586.

BH coordinates estimated by handheld GPS.

Pocket penetrometer tests conducted on base of SPT sample when possible and on opened face of SPT sample as appropriate. 53

54

55

56 TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 1 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 0 CLAY (CL) Silty to some silt, trace sand, low plasticity, soft to firm, light brown to light greyish brown, no odour, moist (wetter than plastic limit), weak structure, medium to high dry strength, no dilatancy, trace organics present as coal. [GLACIOLACUSTRINE] 0.0-2.1 m - Slight organic odour. 1 0-17.2 m - Mud rotary drilling using a 4¾ inch tri-cone drill bit.

2 SPT 01 SPT 01 - Recovered 0.47 m. 2 1 2

3

1 SPT 02 SPT 02 - Recovered 0.55 m. Plasticity Index = 19.6%. 2 3

4

4.8-4.9 m - Soft, wet. SPT 03 1 5 SPT 03 - Trace gravel. Recovered 0.53 m. 2 2

6

1 SPT 04 SPT 04 - Recovered 0.60 m. 2 2

7

SPT 05 - Recovered 0.61 m. SPT 05 1 8 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 2 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 8 CLAY (CL) 1 Silty to some silt, trace sand, low plasticity, soft to firm, light brown, light 2 greyish brown, no odour, moist (wetter plastic limit), no structure, weak structure, medium to high dry strength, no dilatancy, trace organics present as coal. [GLACIOLACUSTRINE] 9

1 SPT 06 SPT 06 - Recovered 0.61 m. Plasticity Index = 15.0%. 1 2

10

2 11 SPT 07 SPT 07 - Recovered 0.47 m. 7 SAND (SM) 11 Fine to medium, silty to some silt, poorly graded, compact, grey, no odour, moist, homogenous, weak cementation, organics present as coal seams, approximately 3 mm thick. [GLACIOLACUSTRINE] Groundwater observed at a depth of 11.6 m below ground surface on July 12 5, 2014 with the borehole at the final depth of 61.0 m.

6 SPT 08 SPT 08 - Sand (SM), fines content 22.0%. Recovered 0.49 m. 9 9 13

SILT (ML) 14 SPT 09 Sandy, some clay, trace gravel, low plasticity, very stiff, grey, no odour, 4 moist (near plastic limit), no structure, weak cementation, slow dilatancy. 8 [GLACIOLACUSTRINE] 12 SPT 09 - Recovered 0.57 m. Plasticity Index = 9.0%.

15 15.2-15.4 m - Trace sand, moderate cementation.

SPT 10 SPT 10 - Recovered 0.45 m. 5 INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE 10 14 16 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 3 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 16 INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE SANDSTONE, slightly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis, some sand >> and silt infill, mild reaction to HCl. 33 17 SPT 11 CLAYSTONE, highly weathered to fresh, extremely weak to weak, dark >> 52 greenish grey to dark pale green, fine grained, bedded to massive, trace coal seams present, moderately fractured, close to moderate joint 71 spacing, one joint set at approximately 90° to the core axis, occasional W clay infill. 2.5 SILTSTONE, slightly weathered to fresh, extremely weak to weak, dark grey to black, fine grained, bedded to massive, trace coal seams present, 18 carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional silt infill, mild reaction to HCl. W 15.4 m - Top of bedrock unit inferred from drilling action and increase in 2 drilling pressure increase. 15.4-18.7 m - Claystone, extremely weak, slightly to highly weathered. 19 SPT 11 - Recovered 0.46 m. 17.2 m - Switched to triple tube coring with HQ3 drill bit. 18.7-22.6 m - Sandstone, extremely weak.

R1 19.8-20.1 m - UCS = 1.1 MPa. 20

21

21.3-22.6 m - Tan mudstone clasts approximately 2 cm wide by 5 cm long.

22 W 1.5

22.6-22.9 m - Siltstone, convoluted fabric, very weak.

W 22.9-24.4 m - Claystone, extremely weak. 23 1

W 2 24 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 4 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 24 INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE SANDSTONE, slightly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis, some sand and silt infill, mild reaction to HCl. 25 CLAYSTONE, highly weathered to fresh, extremely weak to weak, dark greenish grey to dark pale green, fine grained, bedded to massive, trace coal seams present, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to weak, dark grey to black, fine grained, bedded to massive, trace coal seams present, 26 carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional silt infill, mild reaction to HCl. 24.4-25.0 m - Siltstone, extremely weak. 25.0-25.9 m - Claystone with bentonite clay, high plastic, very stiff, pale greenish grey. 27 25.7 m - Drill bit became stuck while advancing, inferred due to swelling of the bentonite in the claystone unit. 25.9-27.4 m - Claystone, siltstone and sandstone become stratified, extremely weak. 27.4-28.5 m - Sandstone, extremely weak, coal and siltstone lenses present.

28 W 1

28.5-30.5 m - Sandstone and siltstone become stratified and laminated, extremely weak, seams of bentonite clay, high plastic, very stiff. W 29 2

30

30.5-30.9 m - Bentonite clay, high plastic, very stiff, pale greenish grey.

W 30.9-31.95 m - Coal, black, shiny, easily fractured. 31 2.5

31.95-32.0 m - Mudstone, tan, weak, black specks present. 32 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 5 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 32 W INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE 1 SANDSTONE, slightly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis, some sand W and silt infill, mild reaction to HCl. 33 1.5 CLAYSTONE, highly weathered to fresh, extremely weak to weak, dark greenish grey to dark pale green, fine grained, bedded to massive, trace coal seams present, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to weak, dark grey to black, fine grained, bedded to massive, trace coal seams present, 34 carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional silt infill, mild W reaction to HCl. 2 32.0-35.1 m - Claystone, very weak, zones of bentonite clay, high plastic, very stiff, brown to pale green.

35 35.1-38.9 m - Sandstone, very weak.

W 36 1

37

38

38.9-40.0 m - Mudstone, tan, very weak, convoluted fabric, specks of 39 black sediment.

40 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 6 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 40 INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE SANDSTONE, slightly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis, some sand and silt infill, mild reaction to HCl. 41 CLAYSTONE, highly weathered to fresh, extremely weak to weak, dark greenish grey to dark pale green, fine grained, bedded to massive, trace coal seams present, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to weak, dark grey to black, fine grained, bedded to massive, trace coal seams present, 42 carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional silt infill, mild reaction to HCl. 40.0-40.8 m - Sandstone, very weak. 40.8-43.7 m - Siltstone and sandstone become stratified and laminated, very weak. 43

43.7-44.6 m - Siltstone, very weak to weak.

44

44.6-48.2 m - Sandstone, weak.

45 W 2

46

W 1 47

48 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 7 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 48 R2 47.9-48.3 m - UCS = 6.2 MPa. POOR QUALITY INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE SANDSTONE, slightly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark bands approximately 1-10 mm thick, slightly fractured, moderate 49 W joint spacing, one joint set at approximately 90° to core axis, some sand 4 and silt infill, sandstone is likely quartzite, mild reaction to HCl. CLAYSTONE, highly weathered to fresh, extremely weak to weak, dark greenish grey to dark pale green, fine grained, bedded to massive, trace coal seams present, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional clay infill. 50 W SILTSTONE, slightly weathered to fresh, extremely weak to weak, dark 4 grey, black, fine grained, bedded to massive, trace coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional silt infill, mild W reaction to HCl. 2 48.2-48.8 m - Siltstone, weak. 51 48.8-49.0 m - Claystone, extremely weak, highly weathered. W 49.0-49.2 m - Bentonite clay, high plastic, hard, pale green. 1.5 49.2-49.6 m - Coal, black, shiny. 49.6-50.3 m - Claystone, extremely weak, highly weathered, likely W bentonite. 1 50.3-50.7 m - Claystone, very weak. 50.7-50.9 m - Sandstone, extremely weak. 52 50.9-51.8 m - Siltstone, extremely weak to very weak. 51.8-53.0 m - Sandstone, siltstone, and claystone become stratified and laminated, very weak.

53 53.0-54.4 m - Claystone, extremely weak to weak.

54

54.4-56.4 m - Siltstone, sandstone and claystone become stratified and laminated, very weak.

55

56 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 8 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 56 INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE SANDSTONE, slightly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis, some sand and silt infill, mild reaction to HCl. 57 CLAYSTONE, highly weathered to fresh, extremely weak to weak, dark greenish grey to dark pale green, fine grained, bedded to massive, trace coal seams present, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to weak, dark grey to black, fine grained, bedded to massive, trace coal seams present, 58 carbonaceous, moderately fractured, close to moderate joint spacing, one W joint set at approximately 90° to the core axis, occasional silt infill, mild 2 reaction to HCl. 56.4-57.9 m - Sandstone, very weak. 57.9-58.3 m - Siltstone and sandstone become stratified and laminated, W very weak. 59 1 58.3-59.1 m - Sandstone, very weak. 59.1-59.6 m - Claystone, extremely weak. W 1.5 59.6-61.0 m - Siltstone, extremely weak.

60

61 Borehole completed at target depth of 61.0 m below ground surface. Hole backfilled to surface with grout/bentonite mix. One batch of ten 20 kg bags of cement, one 20 kg bag of bentonie and 150 gallons of water added. No instrumentation installed.

0%-10% loss in drilling fluid circulation throughout the entire hole. 62 SPT Sampler Details: 61 cm length, 5 cm diameter, driven by automatic trip hammer. All SPT sampling was carried out in accordance with ASTM D1586.

BH coordinates estimated by handheld GPS.

63 Pocket penetrometer tests conducted on base of SPT sample when possible and on opened face of SPT sample as appropriate.

64 TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18 Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

APPENDIX C LABORATORY TEST RESULTS

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek BGC ENGINEERING INC. SIZE OF OPENING (in) U.S. STANDARD SIEVE SIZE 3 3 " 24" 12" 6" 4" 3" 1" /4" /8 #4 #6 #10 #20 #40 #100 #200 100

90

80

70

60

50 Creek\WM_GSA_2015.grf

40

PERCENT FINER THAN FINER PERCENT 30

20

10

0 1000 100 10 1 0.1 0.01 0.001 0.0001 GRAINSIZE (mm)

0 - TMEP Pipeline Project\04 HDD Assessment\lab data\WhiteAssessment\labMud HDD Project\04 Pipeline TMEP - 0 GRAVEL SAND BOULDER COBBLE FINES COARSE FINE COARSE MEDIUM FINE

NOTES: 1. Material classification plotted according to the Unified Soil Classification System (USCS). 2. Laboratory analysis completed by Shelby Engineering Ltd.

NTS SZ GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT SSEID 005 KP 28.2 MARCH 2018 SAA BGC ENGINEERING INC. GRAIN SIZE ANALYSIS RESULTS NW LDM AN APPLIED EARTH SCIENCES COMPANY BGC BH-BGC14-WM-01, & -02 DWG TO BE READ WITH BGC REPORT TITLED "GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT SSEID 005 KP 28.2", DATED C-01 0 MARCH 2018. \\bgcengineering.ca\Shares\N\BGC\Projects\0095 Kinder Morgan\15 Kinder \\bgcengineering.ca\Shares\N\BGC\Projects\0095 50 Note 1. >>

40

30 Creek\WM_Atterberg_2015.grf

20 PLASTICITY INDEX (%) PLASTICITY

10

0 0 102030405060708090100 LIQUID LIMIT (%) 0 - TMEP Pipeline Project\04 HDD Assessment\lab data\WhiteAssessment\labMud HDD Project\04 Pipeline TMEP - 0

Notes: 1.BH-BGC14-WM-01 sample G1 (32.85 - 33.00 mbgs) tested with a liquid limit of 364.8% and a plasticity index of 324.3%, resulting in a very high plastic bentonite clay. Details of Atterberg Limits are in lab data provided.

NTS SZ GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT SSEID 005 KP 28.2 MARCH 2018 SAA BGC ENGINEERING INC. ATTERBERG LIMIT ANALYSIS RESULTS NW LDM BGC AN APPLIED EARTH SCIENCES COMPANY BH-BGC14-WM-01, & -02 DWG TO BE READ WITH BGC REPORT TITLED "GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - WHITEMUD CREEK AT SSEID 005 KP 28.2", DATED C-02 0 MARCH 2018. \\bgcengineering.ca\Shares\N\BGC\Projects\0095 Kinder Morgan\15 Kinder \\bgcengineering.ca\Shares\N\BGC\Projects\0095

Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2017 Geotechnical HDD Feasibility Assessment Whitemud Creek at SSEID 005.5 KP 28.2 Project No.: 0095150-14

APPENDIX D PRELIMINARY ASSESSMENT OF COAL MINE RELATED HAZARDS KP 26 TO KP 29 (SOUTH EDMONTON)

0095-150-14 HDD Geotechnical Feasibility Report - Whitemud Creek BGC ENGINEERING INC.

234 St. Paul Street Kamloops, BC Canada V2C 6G4 Telephone (250) 374-8600 Fax (250) 374-8606

April 6, 2016 Project No.: 0095150-11 John MacLeod, P.Eng. Trans Mountain Pipeline ULC Suite 2700, 300 – 5th Avenue SW Calgary, AB, T2P 5J2

Dear Mr. MacLeod,

Re: Preliminary Assessment of Coal Mine Related Hazards KP 26 to KP 29 (South Edmonton)

Following a meeting on September 29, 2015, with Mr. Randy Wight of Universal Pegasus International (UPI) and Trans Mountain Pipeline ULC (TMEP), BGC Engineering Inc. (BGC) was asked to: 1. Compile available information for historic coal mining in the southern parts of the City of Edmonton, including geology and mining methods, along the pipeline alignment from KP 26 to KP 29 2. Review and discuss the potential hazards that may affect the pipeline during construction or operations due to the presence of the historic coal mines below the pipeline alignment. The current work has been undertaken via a desktop study based on resources available in the public domain. No site visits or field work have been undertaken. Trans Mountain Pipeline ULC April 6, 2016 Preliminary Assessment of Coal Mine Related Hazards KP 26 to KP 29 (South Edmonton) Project No.: 0095150-11

1.0 HISTORIC COAL MINING IN EDMONTON, ALBERTA Underground coal mining has been undertaken in Alberta, and specifically the Edmonton region, since the late 1800s (City of Edmonton Archives). The Alberta Energy Regulator (AER) has developed an online atlas of historic coal mines. Data provided by the atlas includes the approximate footprints of the mines, the years of operation, the target seam thickness, and the approximate depth of mining below ground surface. Mines in area of interest in the current work (Figure 1) were active from the 1920s to the late 1940s (AER 2015). The coal was recovered with limited mechanization by room and pillar mining methods. The roofs of mines were supported by timber. Anecdotal reports indicate that pillar retreat mining may have been undertaken in some areas; the removal or thinning of pillars would result in a less stable mine roof. Similar mines were active over similar periods in Drumheller and Canmore. The proposed pipeline crosses at least three mines from the AER database (Table 1): Black Point, Rabbit Hill, and Blue Point. The coal seams targeted by mines are found interbedded in the extremely weak to weak shales and sandstones of the Cretaceous aged Horseshoe Canyon. The extraction ratios, pillar dimensions, or typical room sizes for these mines are not included in the AER data. Reported seam thicknesses, and therefore room heights, are 1.1 to 1.5 m. The maximum depth to the base of the mine workings varies from 22.9 to 43.9 m below ground surface. BGC was unable to locate any plans showing details of the mine layouts. Images of the layout of the Humberstone Mine in northeast Edmonton were available from the City of Edmonton archives. The plan shows a series of long tunnels with a series of mined out areas and pillars at approximately right angles to the main drives (Figure 2). Historic mines in the area of interest in the current work may have similar general layouts. The scale of mine workings estimated from archival photographs of mines in the northeast area of Edmonton (Figure 3) suggest that room widths may have been 3 m to 5 m. These dimensions are similar to underground workings at Smokey River Coal in western Alberta (Cain 1999); though the underground development at Smokey River Coal is approximately 25 years younger than the mines in the area of the pipeline. Similar dimensions have been assumed for coal mines in Edmonton by others (Wu et al. 2015).

TMEP_CoalMineSubsidence_FINAL_20160406 Page 2 BGC ENGINEERING INC. Trans Mountain Pipeline ULC April 6, 2016 Preliminary Assessment of Coal Mine Related Hazards KP 26 to KP 29 (South Edmonton) Project No.: 0095150-11

Figure 1. Approximate locations of historic coal mine footprints from the AER coal mine atlas (red hatch) and the proposed pipeline (red line with kp markers).

TMEP_CoalMineSubsidence_FINAL_20160406 Page 3 BGC ENGINEERING INC. Trans Mountain Pipeline ULC April 6, 2016 Preliminary Assessment of Coal Mine Related Hazards KP 26 to KP 29 (South Edmonton) Project No.: 0095150-11

Table 1. Historic coal mines in the area of interest from the AER coal mine atlas. Maximum depth Cover Average Seam Mine Years to base of mine Name thickness seam elevation Number operational workings (m) thickness (m) (masl) (m) Black 1034 1922-1949 43.9 27 1.1 646 Point Rabbit 1091 1923-1940 32.2 15-34 1.5 639 Hill Blue 1233 1926-1946 22.9 0-21 1.4 639 Point

Figure 2. Plan of the Humberstone Mine (1917), northeast Edmonton.

TMEP_CoalMineSubsidence_FINAL_20160406 Page 4 BGC ENGINEERING INC. Trans Mountain Pipeline ULC April 6, 2016 Preliminary Assessment of Coal Mine Related Hazards KP 26 to KP 29 (South Edmonton) Project No.: 0095150-11

Figure 3. Loading a coal car at the Humberstone Mine (northeast Edmonton) in 1917. Photograph from the City of Edmonton archives.

TMEP_CoalMineSubsidence_FINAL_20160406 Page 5 BGC ENGINEERING INC. Trans Mountain Pipeline ULC April 6, 2016 Preliminary Assessment of Coal Mine Related Hazards KP 26 to KP 29 (South Edmonton) Project No.: 0095150-11

2.0 COAL MINE RELATED HAZARD RELEVANT TO THE PIPELINE Possible hazards to the pipeline may exist related to the historic coal mines. Pipelines at surface or at shallow depths may be exposed to subsidence; while pipelines installed at greater depths may encounter voids or loose/destressed rock near the boundaries of the old mine workings (Figure 4). Traditionally, subsidence is divided into two categories: continuous and discontinuous. Continuous subsidence includes (Brauner 1973): 1. Vertical displacement of the ground over the footprint of the mine 2. Horizontal ground displacements. A trough-like ground profile may be formed over the mine footprint. The ground displacements will extend beyond the limits of the mine, as determined by the angle of draw of the rocks and soil overlying the mine. The magnitude of the vertical ground displacements may be 40 to 90% of the seam thickness mined (Mager 1993; Lee and Abel 1983). The majority of this subsidence is expected soon after mining is completed. An analysis of InSAR data by Dehls et al. (2010) did not identify any locations of ongoing subsidence related to mining from 1992 to 2009 in Edmonton. It is likely that continuous subsidence related to historic mining was complete by the time of the study. The rocks above the mine workings are likely disturbed, loosened, or partially destressed due to these displacements. The permeability of this disturbed rock mass is likely increased compared to the rock outside the mine footprints. Drilling conditions in the area of the mines may be poor and lost circulation zones may be more common, again compared to areas outside of the mine footprints. Discontinuous subsidence occurs due to failure of the mine roof and localized subsidence of the overlying strata. Typical discontinuous subsidence features are (Brauner 1973): 1. Open cracks at the ground surface 2. A stepped ground surface profiled due to the down-dropping of discrete blocks of the rock overlying the mine 3. Sinkholes or breccia filled chimneys that have propagated up from the working level or old access tunnels toward the ground surface. The maximum diameter of these features is controlled by the mine room widths and distance between pillars. At least one sinkhole feature and one void were identified during the investigation for bridge foundations for the Northeast section of Anthony Henday Drive in Edmonton (Wu et al. 2015). These features were attributed to historic coal mining in that part of the city. Sinkholes related to room and pillar coal mine workings have be identified in Canmore, Alberta (Rocky Mountain Outlook 2014). The issues with the historic mines in Canmore appears to be common enough that specific regulations have been developed to address municipal development over historic coal mines because of possible discontinuous subsidence (Province of Alberta 2012). BGC is not aware of any similar regulations for the City of Edmonton. At this time, BGC does not have maps that show the workings for any of the mines cross by the pipeline. Therefore, the locations of these possible discontinuous subsidence hazards cannot be

TMEP_CoalMineSubsidence_FINAL_20160406 Page 6 BGC ENGINEERING INC. Trans Mountain Pipeline ULC April 6, 2016 Preliminary Assessment of Coal Mine Related Hazards KP 26 to KP 29 (South Edmonton) Project No.: 0095150-11 predicted. While no published reports of discontinuous subsidence features in the area of interest were found by BGC during this work, it is expected that these feature do exist within the mine footprints. They may exist along the proposed pipeline alignment. One suspect subsidence feature was identified during BGC’s review of LiDAR data in the area of interest (Figure 5); no ground truthing has been conducted to prove the nature of this landform.

Figure 4. Schematic distribution of ground disturbance above mined areas.

Figure 5. An apparent localized depression in the LiDAR data coincides with the footprint of an historic coal mine.

TMEP_CoalMineSubsidence_FINAL_20160406 Page 7 BGC ENGINEERING INC. Trans Mountain Pipeline ULC April 6, 2016 Preliminary Assessment of Coal Mine Related Hazards KP 26 to KP 29 (South Edmonton) Project No.: 0095150-11

3.0 SUMMARY The completed work confirms that the proposed TMEP pipeline crosses an area of at least three historic room and pillar coal mines. It is likely that the ground above the mined area has subsided in response to extraction of the coal. It is likely that the rock mass above the mines is relaxed, displaced, and disturbed. Challenging drilling conditions due to poor rock mass quality and losses of circulation to dilated joints and bedding planes or mine voids should be expected to depths up to 44 m below ground surface. Alternatives to horizontal directional drilling and deep pipeline installations in this rock mass should be considered. Conventional open cut methods for pipeline installation, with designs appropriate for the soils along the alignment, may be more suitable in the areas of historic coal mining. Some residual subsidence hazards, such as discrete cracks, voids, or chimneys of brecciated rock, may exist and cannot be discounted by the current work. Sinkholes or breccia chimneys as large as 3 to 5 m in diameter may be possible; but the frequency of these features is unknown at this time. If the pipeline crosses both the mined areas and pillars, discrete subsidence features would be limited to the size of rooms or the distance between pillars. If the pipeline were aligned with a main tunnel or drift that subsided, longer zones of subsidence could develop and affect the pipe. The impacts of these hazards on the pipeline will be dependent on the stress and strain capacity of the pipe, the depth of burial at the location of subsidence, and the method of pipeline construction/installation. Heavy wall pipe or pipe stress relief installations may be required through this corridor of historic mining.

TMEP_CoalMineSubsidence_FINAL_20160406 Page 8 BGC ENGINEERING INC. Trans Mountain Pipeline ULC April 6, 2016 Preliminary Assessment of Coal Mine Related Hazards KP 26 to KP 29 (South Edmonton) Project No.: 0095150-11

4.0 CLOSURE BGC Engineering Inc. (BGC) prepared this document for the account of Trans Mountain Pipeline ULC. The material in it reflects the judgment of BGC staff in light of the information available to BGC at the time of document preparation. Any use which a third party makes of this document or any reliance on decisions to be based on it is the responsibility of such third parties. BGC accepts no responsibility for damages, if any, suffered by any third party as a result of decisions made or actions based on this document. As a mutual protection to our client, the public, and ourselves, all documents and drawings are submitted for the confidential information of our client for a specific project. Authorization for any use and/or publication of this document or any data, statements, conclusions or abstracts from or regarding our documents and drawings, through any form of print or electronic media, including without limitation, posting or reproduction of same on any website, is reserved pending BGC’s written approval. A record copy of this document is on file at BGC. That copy takes precedence over any other copy or reproduction of this document.

Yours sincerely,

BGC ENGINEERING INC. per:

Derek Kinakin, M.Sc., P.Geo., P.G. Senior Engineering Geologist

Reviewed by:

Dr. Alex Baumgard, P.Eng., P.Geo. Senior Geotechnical Engineer

DK/AB/PB/cs

TMEP_CoalMineSubsidence_FINAL_20160406 Page 9 BGC ENGINEERING INC. Trans Mountain Pipeline ULC April 6, 2016 Preliminary Assessment of Coal Mine Related Hazards KP 26 to KP 29 (South Edmonton) Project No.: 0095150-11

REFERENCES

Alberta Energy Regulator. 2015. Coal mine atlas operating and abandoned coal mines in Alberta. Serial publication ST45, May 15, 2015 [online]. Available from https://www.aer.ca/data-and- publications/statistical-reports/st45 [accessed October 26, 2015]. Cain, P.1999. Developments in coal pillar design at Smoky River Coal Limited, Alberta, Canada. Proceedings, 2nd International Workshop on Coal Pillar Mechanics and Design, National Institute for Occupational Safety and Health, Information Circular 9448, Pittsburgh, Pa. pp. 15-22. Dehls, J.F., Larsen, Y., Lauknes, T.R., Froese, C., and Lewycky, D. 2010. Assessment of subsidence and riverbank stability in Edmonton using X-band and C-band InSAR. In Proceedings of GeoCanada 2010, Geological Association of Canada, Calgary, AB. May 10-14 2010. Lee, J. F., and Abel, F. T. Subsidence from underground mining: environmental analysis and planning considerations. Geological Survey Circular 876, U.S. Department of the Interior. Magers, J. 1993. Surface subsidence over a room-and-pillar mine in the Western United States. United States Department of the Interior – Bureau of Mines Information Circular 9347. Province of Alberta. 2012. Alberta Regulation 114/97 – Municipal Government Act – Canmore Undermining Review Regulation, Queen’s Printer, http://www.qp.alberta.ca/documents/Regs/1997_114.pdf. Rocky Mountain Outlook, 2014, Canmore looking for old shaft at Dyrgas Gate, Aug 28, 2014 [online]. http://www.rmoutlook.com/Canmore-looking-for-old-shaft-at-Dyrgas-Gate-20140828. Accessed November 27, 2015. Wu, Z., Hu, B., Foley, S., and Richardson, R. 2015. Build a safe bridge over worked coal mines. In Proceedings of the 2015 Conference of the Transportation Association of Canada, Charlottetown, PEI. September 27 – 30, 2015.

TMEP_CoalMineSubsidence_FINAL_20160406 Page 10 BGC ENGINEERING INC.

Trans Mountain Expansion 19731-506-RPT-00080 Project

Feasibility Report for the Rev Date Whitemud Creek Crossing 0 04/27/2018

Table of Contents 1.0 INTRODUCTION...... 1 2.0 SITE VISIT ...... 1 3.0 GEOTECHNICAL INVESTIGATIONS ...... 1 4.0 REVIEW OF AVAILABLE WATERCOURSE CROSSING METHODOLOGIES...... 1 4.1 Horizontal Directional Drill...... 1 4.2 Direct Pipe® ...... 2 4.3 Bore...... 2 4.4 Isolated Crossing Techniques ...... 2 4.5 Open Cut...... 3 5.0 GEOTECHNICAL/GEOPHYSICAL PROGRAM ...... 3 5.1 Adjacent Crossing...... 3 6.0 CROSSING DESIGN ...... 3 6.1 Primary Crossing Method - HDD Crossing Design...... 3 6.2 Contingency Crossing Method - Isolated In-stream Crossing Design...... 4 7.0 RECOMMENDATIONS...... 4

Appendices A. Appendix A – Abbreviations and Acronyms...... A-1 B. Appendix B – Mean Monthly Flows for Whitemud Creek ...... B-1 C. Appendix C – Geotechnical Borehole Logs at Whitemud Creek ...... C-1 D. Appendix D – Interpreted Geological Section at Whitemud Creek...... D-1 E. Appendix E – HDD Crossing Plan and Profile, Whitemud Creek ...... E-1 F. Appendix F – Calculated Fracture Pressure for Whitemud Creek...... F-1 G. Appendix G – Whitemud Creek - Contingency Design...... G-1

Combined PDF Pages Page 3 of 36 Trans Mountain Expansion 19731-506-RPT-00080 Project

Feasibility Report for the Rev Date Whitemud Creek Crossing 0 04/27/2018

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This report represents the work of UniversalPegasus International (UPI) performed to recognized engineering principles and practices appropriate for engineering work and the terms of reference provided by UPI’s contractual Customer. This report may not be relied upon for any other purpose not specifically identified within this report. This report is confidential and prepared solely for the use of the Customer. The contents of this report may not be used or relied upon by any party other than the Customer, and neither UPI, its sub- consultants nor their respective employees assume any liability for any reason, including, but not limited to, negligence, to any other party for any information or representation herein. The extent of any warranty or guarantee of this report or the information contained therein in favour of the Customer is limited to the warranty or guarantee, if any, contained in the contract between the Customer and UPI.

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1.0 INTRODUCTION UniversalPegasus International (UPI) has been retained by Kinder Morgan Canada Inc. (KMC) to undertake the routing and engineering design for the Trans Mountain Expansion Project (TMEP) pipeline. As part of this work, a number of watercourse crossings have been identified as potential candidates for a trenchless crossing methodology. This report evaluates the Whitemud Creek Crossing KP 28.2 SSEID 005.5 with the intent of determining the feasibility of an HDD. The applicability of several other crossing methodologies has been considered in this study. The purpose of this feasibility report is to evaluate existing information and the results of the geotechnical and geophysical investigations that have been completed at Whitemud Creek for the TMEP, in order to provide an assessment of the feasibility of the selected crossing methodology for this crossing. Appendix A lists the abbreviations and acronyms used in this report.

2.0 SITE VISIT Site visits and investigations were carried out at the Whitemud Creek Crossing by BGC Engineering Inc. (BGC) in June 2014 to ascertain an understanding of the subsurface conditions at this site.

3.0 GEOTECHNICAL INVESTIGATIONS As part of the HDD feasibility evaluation process BGC has completed geotechnical and geophysical investigations at several major water crossing locations, specifically to determine which of the trenchless technologies could be a viable crossing methodology at these locations. BGC issued a Geotechnical HDD Feasibility Assessment report for the Whitemud Creek Crossing (KMC Document #01-13283-S1-0000-PL-RPT- 0035 R0) on March 29th, 2018. In addition, ATCO Pipelines successfully constructed an HDD approximately 10 metres north of, and parallel to, the TMEP alignment. TMEP obtained the early ATCO borehole data and this information was included in the BGC report, which were considered to be somewhat shallow, relative to the depth of the TMEP HDD. As noted in the BGC report, additional borehole information was obtained by ATCO prior to their HDD construction, but this information has not been provided to TMEP. From the hydrological data attached, Appendix B, Mean Monthly Flows for Whitemud Creek Crossing, April is the month with the highest flow, with lowest flow in the winter months (October to February).

4.0 REVIEW OF AVAILABLE WATERCOURSE CROSSING METHODOLOGIES A number of watercourse crossing methodologies, including trenchless techniques (HDD, Direct Pipe®, and Bore), isolated crossing technique and open cut are typically considered for crossing watercourses such as the Whitemud Creek. These methodologies include both primary methods as well as contingency methods. These methodologies are described below

4.1 HORIZONTAL DIRECTIONAL DRILL Horizontal Directional Drilling is one of the most commonly accepted trenchless methods for a pipeline watercourse crossing. The method involves setting up an HDD drill rig and drilling a pilot hole with subsequent reaming passes to enlarge the borehole to an adequate diameter for pull-in of carrier pipe. The make-up section is typically fabricated in one piece, hydrostatically tested, and then pulled into the bore. Buoyancy water within the pipe is normally used to minimize pull forces for larger diameter pipes. The constructability of an HDD typically ranges from 400 m to 3,500 m in length for NPS 36 pipe. In some instances, the HDD methodology may also require a large diameter surface casing if sands or gravels are encountered near surface. The feasibility of utilizing an HDD method is normally compromised where large boulders or deep deposits of gravel containing cobbles and boulders are encountered. Topography, geometry, and available workspace may also impact the feasibility of using an HDD. Potential obstacles for HDD:

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 Loss of drilling fluid circulation in a sand and gravel stratum, or possibly into mine shafts and mined out zones;  Pilot hole steering problems when encountering boulders, or if voids are present along the drill profile;  Need for additional workspace for the pullback area; and  Cobbles and boulders which may be present.

® 4.2 DIRECT PIPE The Direct Pipe® method involves attaching a Micro-Tunnel Boring Machine (MTBM) in front of the product pipe (or a casing). The MTBM and product pipe are then “thrust” into the ground using the Herrenknecht ‘thruster’. This technique can be utilized to tunnel through soft or hard ground below the water table. The excavated material is mixed with water or drilling mud in the micro-tunnelling cutting head and pumped back to surface to be cleaned and reused, much like the HDD method. Gravel and cobbles which are able to enter the MTBM, are crushed and mixed with the drilling mud and then pumped back up to surface. Small to medium sized boulders that are able to enter the MTBM may also be broken down by disk cutters on the cutter head. Larger boulders that are unable to be broken down need to be pushed away from the bore alignment. Boring through large boulders or numerous boulders would not be feasible. This has been seen on a recent project North East of Hope, BC on a crossing of the Coquihalla River. This methodology has length limitations of approximately 500 m for NPS 36 and 800 m for NPS 42. The size and number of boulders encountered also limits the feasibility of using this technique. The use of the Direct Pipe® method in Europe has been growing rapidly over the last 5 years. To date a number of relatively straight forward crossings have been completed in Canada using this methodology. Potential obstacles for Direct Pipe®:  Quantity and size of boulders present along the drill path;  Complicated entry pit setup; and  Possibly requires additional geotechnical information.

4.3 BORE This is a common crossing technique that utilizes a boring machine operating within an excavation to advance a casing pipe and auger beneath a road. Length is normally limited to a maximum of approximately 100m but some contractors now state that advances in equipment capabilities can increase this maximum length limit. This technique is generally not ideal for watercourse crossing due to the difficulties with controlling water migration into the bell holes but is very well suited to road and rail crossings. Proper procedural criteria need to be maintained to minimize the formation of voids during the bore. Feasibility is generally assisted with geotechnical information. Potential obstacles for Bored methodology:  Large boulders which the boring equipment is not capable of handling; and  High water table in coarse granular soils.

4.4 ISOLATED CROSSING TECHNIQUES Isolated crossing techniques (which are in-stream bypass techniques) typically involve isolating the location of the work from the water flow by the use of temporary dams or steel plates and then diverting the water using a pump, a flume or by excavating a side channel. The dam and pump method generally works well for maximum flows up to approximately 1.2 to 1.4 m³/s for summer construction and up to approximately 1.0 m³/s for winter construction. The flume method works well for maximum flows up to approximately 8.0 m³/s (i.e. double super flume). After the crossing location is isolated the pipeline trench is excavated followed by pipe placement and backfill. The final steps include re-contouring the riverbed and restoration of the banks.

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4.5 OPEN CUT The Open Cut method involves excavating a trench through the watercourse (without isolation) to the required depth, installing the pipe and then backfilling. The final steps include re-contouring the riverbed and restoration of the banks. This method is best used when flows are at their lowest point. Potential obstacles for Open Cut:  Unexpected soil conditions within the riverbed;  Lack of available workspace;  Fisheries sensitivity; and  Unanticipated high water conditions.

5.0 GEOTECHNICAL/GEOPHYSICAL PROGRAM The Whitemud Creek site has been geotechnically investigated by BGC. BGC drilled two boreholes in June 2014. Borehole BH-BGC14-WM-01 was drilled approximately 136m from the east bank of the creek, and BH- BGC14-WM-02 approximately 100m from the west bank. ERT and Seismic investigations were carried out on June 19th, 2013. Borehole logs for these investigations are included in Appendix C, and an interpreted geological section is presented in Appendix D. Based on the information obtained, the borepath is expected to pass through varying depths of glaciolustrine materials at entry and exit. Interbedded sandstone/claystone/siltstone bedrock of the Horseshoe Canyon formation was encountered at a depth of ~3mbgs at WM-01 and ~15mbgs at WM-02. The majority of the drill profile will pass through that siltstone/sandstone bedrock. Losses in HDD drilling circulation may be encountered in the upper portion of the sandy silt and clay layer, and if encountered, would have to be addressed through the use of appropriate drilling fluids, casing, or by other techniques. As noted on both logs, traces of heavily fractured coal seams were encountered at different depths of claystone and siltstone. The conclusion from the results of the geotechnical and geophysical investigation is that, from a geotechnical perspective, an HDD at this location is considered feasible from a geotechnical perspective, but challenging due to the potential for encountering various difficulties associated with the presence of abandoned coal mining operations in the area. It is recommended that the geotechnical report be provided to the HDD contractor for planning purposes and for considering the use of appropriate loss control materials. The contractor will also be responsible for determining the necessity of grouting or any other loss control measures.

5.1 ADJACENT CROSSING In the fall of 2016, ATCO Pipelines crossed Whitemud Creek using the HDD technique for their NPS 20 pipeline. The maximum depth of their crossing of Whitemud was 45-50 metres. The successful drill performed by ATCO was supplemented by an extensive geotechnical program which mapped out the voids in the drill path, and the voids were grouted before commencement of drilling operations.

6.0 CROSSING DESIGN

6.1 PRIMARY CROSSING METHOD - HDD CROSSING DESIGN As a result of the TMEP constructability meetings with the contractor the primary crossing method has been confirmed to be HDD. The proposed NPS 36 TMEP pipeline crosses Whitemud Creek at about KP 24.2 SSEID 005.5. The pipeline alignment is from East to West and will cross the river at approximately 50°. The river flows from North to South at the location of the crossing. An HDD crossing plan and profile drawing for the Whitemud Creek has been prepared and is included in this report as Appendix E. A hydrofracture analysis diagram is also presented in Appendix F. The ground profile utilized in the design was derived from LiDAR dated November 2007, June 2009, and November 2012. As shown in the HDD crossing plan and profile, Drawing M002-XD-00026, the drill path for the

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NPS 36 pipeline will be about 740m long. The pipe will cross the creek at a depth of about 33m below the bottom elevation of the creek. This design profile has an entry angle of 18° and an exit angle of 12°. The setback from the creek centre is about 291 m on the West side and 436 m from the East side. This design has placed the drill profile 5m or more below the bedrock profile highlights for the majority of the crossing. The West side has been selected as the entry primarily because the make-up section of pipe will be located on the East side of the crossing and the entry/exit elevations are approximately the same. There is sufficient workspace available on the East side to accommodate a single section of pipe in the make-up area. This design has placed the drill profile 5m or more below the bedrock profile highlights for the majority of the crossing. Casing, if required, is anticipated to have a minimum diameter of about 1,524 mm OD (NPS 60) to accommodate the anticipated final ream size of 1,219 mm (NPS 48). No casing was employed on the ATCO crossing. (The calculated pull force for the 914 mm OD (NPS 36) pipe is estimated to be approximately 2,269 kN (510,000 lbf) without buoyancy water, and 801 kN (180,000 lbf) by utilizing 100% buoyancy control. Based on the length and overall geometry of this crossing we would recommend a drill rig size of at least 2,669 kN (600,000 lbf). NPS 36 pipe is normally installed using buoyancy control to minimize the pull force. The initial hydrofracture analysis (Appendix F) supported by the successful ATCO crossing, illustrates that this HDD crossing should be feasible at the depth shown. Construction of the Whitemud Creek Crossing may require a drilling schedule of 4-5 weeks for the 914 mm OD (NPS 36) pipe, excluding the time that may be required to install casing (if required). This duration is based on the HDD Contractor working twenty four (24) hours per day, 7 days per week, to complete the installation. As recommended by BGC, the contractor is to review the data and determine if they will need to do additional boreholes to determine if voids do exist on the borepath that may cause the drill to lose fluid. The contractors must determine the need to carry out a grouting program to ensure no loss of drilling fluid during HDD drilling.

6.2 CONTINGENCY CROSSING METHOD - ISOLATED IN-STREAM CROSSING DESIGN The contingency crossing method for Whitemud Creek was determined to be an isolated in-stream crossing method with water quality monitoring. The contingency crossing drawing appears in Appendix G. The construction window for the contingency crossing method is currently planned to occur during low flow conditions (outside RAP).

7.0 RECOMMENDATIONS Based on the geotechnical and geophysical information provided for this feasibility report as well as the successful adjacent HDD crossing, the following is recommended: The Whitemud Creek Crossing location is a feasible candidate for an HDD crossing method. Based on the results and recommendations included in the BGC Feasibility Assessment, the following difficulties may be encountered:  Possible hazards related to historical coal mines: The HDD may encounter voids, timbers, steel rails or loose/de-stressed rock in or near the boundaries of old mine workings. The rocks above the mine workings may be disturbed, loosened, or partially de-stressed due to previous displacements following mining. The permeability of this disturbed rock mass may be higher than that outside the mine footprints. Drilling conditions in the area of the mines may be poor and lost circulation zones are possible.  Coarse clasts in buried channel fill: The ERT survey suggests that the HDD may encounter coarse channel fill beneath the creek, which may deflect the borepath and/or lead to carrier pipe damage during installation.  Steering difficulties and borepath stability: Disturbed/de-stressed rock formations above the old mine workings may lead to abrupt changes in permeability on the HDD bore path, which may lead to steering issues. The weak, poorly-lithified bedrock on the borepath may also cause some steering issues.  Loss of drilling fluids: The presence of old mining operations may lead to lost circulation zones and generally poorer conditions than outside of the mining area. Complete loss of fluid was observed during geotechnical investigations at the intersection of a 1.5m thick coal seam. Losses could be minimized via a geotechnical drilling program targeting the mine area in conjunction with a grouting program to reduce fluid loss.

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 Highly plastic material: High plasticity zones were identified within the bedrock deposits. This has the potential to thicken the drill mud and to impact cuttings management. Such conditions may be mitigated with careful management of drill fluids and the rate of cutting return.  Swelling material: Swelling bentonite and siltstone were inferred to have been encountered during the geotechnical investigations.

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A. Appendix A – Abbreviations and Acronyms The following is a list of abbreviations and acronyms used in this report.

Term Meaning o degree % percent BGC BGC Engineering Inc. DWG Drawing ERT Electrical Resistivity Tomography HDD Horizontal Directional Drill KMC Kinder Morgan Canada Inc. kN kilonewton KP Kilometer Post KPa kilopascal lbf Pounds force LiDAR Light Detection and Ranging m metre m3/s cubic metres per second mm millimeter MTBM micro-tunnel boring machine NPS nominal pipe size OD outside diameter ® Registered Trademark symbol SPT Standard Penetration Test TMEP Trans Mountain Expansion Project TMPL Trans Mountain Pipeline UPI UniversalPegasus International

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B. Appendix B – Mean Monthly Flows for Whitemud Creek

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Combined PDF Pages Page 11 of 36 Crossing Name Whitemud Creek Crossing Catchment Area (km2) 352 Reference Gauge 05DF006 Catchment Area (km2) 330

Mean Monthly Flows - Whitemud Creek 2.5

2 NOV DEC

1.5 Flow (m3/s) Flow

1

0.5

0 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Mean Monthly Median Lower Upper Discharge Discharge Quartile Quartile in m3/s in m3/s in m3/s in m3/s JAN #N/A #N/A #N/A #N/A FEB 0 0 0 0 MAR 0.64 0 0 0.11 APR 2.02 0.32 0 1.7 MAY 0.21 0.11 0 0.21 JUN 0.21 0 0 0.11 JUL 0.53 0 0 0.21 AUG 0.11 0 0 0.11 SEP 0.11 0 0 0 OCT 0 0 0 0 NOV 0 0 0 0 DEC #N/A #N/A #N/A #N/A

Daily streamflow records used in the calculation of monthly flow statistics are recorded by hydrometric stations that have been established and are operated across Canada by the Water Survey Canada (WSC) to help understand and manage water resources.

N/A denotates that no records were available at the hydrometric gauges for that month.

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C. Appendix C – Geotechnical Borehole Logs at Whitemud Creek

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Combined PDF Pages Page 13 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 1 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 0 CLAY (CL) Silty, trace sand, low plasticity, very soft, grey, orange-brown, moist (wetter than plastic limit), no structure, no to weak cementation, no odour, medium dry strength, slow to no dilatancy. [ANTHROPOGENIC] 0.0-3.7 m - Mud rotary drilling using a 6¼ inch tri-cone drill bit. 1

SPT 01 SPT 01 - Recovered 0.55 m. Plasticity Index = 19.4%. 0 2 0 1

3

INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE SANDSTONE, highly weathered to fresh, extremely weak to very weak, >> light "salt and pepper" grey, fine to medium grained, bedded to massive, 8 4 SPT 02 dark mudstone bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis. 10 CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, 14 dark greenish grey to dark pale green, fine grained, bedded to massive, black speckles, coal seams present, highly to moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. 5 SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, >> moderately fractured, close to moderate joint spacing, one joint set at SPT 03 approximately 90° to the core axis, some silt infill, mild reaction to HCl. 14 3.4 m - Top of bedrock unit inferred from drilling action and increase in 19 drilling pressure. 27 3.4-6.9 m - Sandstone, extremely weak. 6 R1 SPT 02 - Recovered 0.56 m. 3.7 m - Switched to a 5½ inch tri-cone drill bit. SPT 03 - Recovered 0.61 m. W 5.8 m - Switched drilling methods to triple tube coring using a HQ3 drill 3 bit. 5.8-6.2 - UCS = 0.5 MPa. 7 6.9-7.6 m - Siltstone, extremely weak. W 2 7.6 m - Drill bit became stuck while advancing, inferred due to swelling of the siltstone bedrock. 7.6-9.8 m - Claystone, extremely weak. Water observed at a depth of 7.7 m below ground surface on July 1, 2014 W with the drill hole at the final depth of 50.0 m. 8 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 14 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 2 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 8 3 INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE SANDSTONE, highly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, W dark mudstone bands approximately 1-10 mm thick, slightly fractured, 2 moderate joint spacing, one joint set at approximately 90° to core axis. CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, 9 dark greenish grey to dark pale green, fine grained, bedded to massive, black speckles, coal seams present, highly to moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at 10 approximately 90° to the core axis, some silt infill, mild reaction to HCl. 9.1-9.2 m - Bentonite clay, very stiff, pale greenish grey. 9.8-10.8 m - Siltstone, extremely weak.

W 1.5 10.8-12.7 m - Claystone, extremely weak. 11

W 2

11.9 m - Replaced HQ3 drill bit with a PDC drill bit. 12

12.7-13.6 m - Sandstone, extremely weak.

13

13.4-16.5 m - Total (100%) loss of drilling fluid circulation. 13.6-15.1 m - Coal, black, shiny, heavily fractured. 13.6 m - Drill rods advanced very rapidly while drilling. 14

15 15.1-15.8 m - Claystone, extremely weak.

15.8-17.7 m - Siltstone, extremely weak. 16 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 15 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 3 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 16 INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE W SANDSTONE, highly weathered to fresh, extremely weak to very weak, 1.5 light "salt and pepper" grey, fine to medium grained, bedded to massive, dark mudstone bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis. CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, 17 dark greenish grey to dark pale green, fine grained, bedded to massive, W black speckles, coal seams present, highly to moderately fractured, close 2 to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at 18 W 1.5 approximately 90° to the core axis, some silt infill, mild reaction to HCl. 16.5-18.0 m - Approximately 90%-100% loss in drilling fluid circulation. 17.7-18.0 m - Claystone, extremely weak. 18.0-19.1 m - Siltstone, extremely weak. 18.0-27.1 m - Approximately 75% loss in drilling fluid circulation.

19 19.1-19.5 m - Mudstone, tan, black speckles, fresh, weak, no fractures.

W 1 19.5-23.0 m - Sandstone, extremely weak.

W 20 1.5

21 W 1

22 W 1.5

W 23 1 23.0-23.2 m - Claystone, extremely weak, mudstone clasts. 23.2-23.8 m - Sandstone, extremely weak.

23.8-24.1 m - Claystone, extremely weak. 24 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 16 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 4 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 24 INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE SANDSTONE, highly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark mudstone bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis. CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, W 25 dark greenish grey to dark pale green, fine grained, bedded to massive, 1.5 black speckles, coal seams present, highly to moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at 26 approximately 90° to the core axis, some silt infill, mild reaction to HCl. 24.1-27.1 m - Sandstone, siltstone, and claystone become stratified, extremely weak, beds are approximately 15-30 cm thick, tan mudstone clasts present, sand infill.

27 27.1-30.4 m - Sandstone, very weak. 27.1-50.0 m - Approximately 50%-60% loss in drilling fluid circulation.

W 1 28

28.4 m - Brown siltstone clasts, approximately 1 cm wide by 3 cm long.

29

30

30.4-31.7 m - Claystone and sandstone become laminated and stratified, extremely weak.

31 W 2

31.7-32.8 m - Claystone, extremely weak.

32 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 17 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 5 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 32 INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE SANDSTONE, highly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark mudstone bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis. G1 CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, >> 33 W dark greenish grey to dark pale green, fine grained, bedded to massive, 4 black speckles, coal seams present, highly to moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at 34 approximately 90° to the core axis, some silt infill, mild reaction to HCl. W 32.8-33.2 m - Bentonite clay, plastic index greater than 300%, very high 2 plasticity, very stiff, light pale green, moist (near plastic limit), no odour, no structure, moderate cementation, high dry strength, no dilatancy. 33.2-33.4 m - Coal. 33.4-34.8 m - Claystone, extremely weak. 35 34.8-34.9 m - Coal. 34.9-37.6 m - Claystone, mudstone, and sandstone become stratified, extremely weak.

36

37

37.6-37.8 m - Sandstone, extremely weak. W 37.8-39.5 m - Siltstone, extremely weak to very weak. 38 1.5

W 2 R2 38.6-38.8 m - UCS = 9.3 MPa.

39 W 1

39.5-40.8 m - Claystone, siltstone and sandstone become stratified, extremely weak, strata are approximately 1-10 cm thick, two joint sets present. 40 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 18 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 6 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 40 INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE SANDSTONE, highly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark mudstone bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis. CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, 41 dark greenish grey to dark pale green, fine grained, bedded to massive, black speckles, coal seams present, highly to moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at 42 approximately 90° to the core axis, some silt infill, mild reaction to HCl. 40.8-46.3 m - Claystone, extremely weak to very weak.

43

44

45

46

46.3-46.6 m - Mudstone with sandstone bands, light tan, very weak, fresh, convoluted fabric, fine grained, moderate joint spacing. 46.6-48.5 m - Claystone, siltstone and sandstone become laminated and stratified, extremely weak to very weak. 47

48 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 19 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-01 Page 7 of 7 Location: Whitemud Creek - East Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 28 Jun 14 Co-ordinates (m): 329,839E, 5,923,252N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 667.0 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 50.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 7.3 Reviewed by: LDM Direction: N/A Depth To Rock (m): 3.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 48 INTERBEDDED SANDSTONE, CLAYSTONE, and SILTSTONE SANDSTONE, highly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark mudstone bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis. CLAYSTONE, slightly weathered to fresh, extremely weak to very weak, 49 dark greenish grey to dark pale green, fine grained, bedded to massive, black speckles, coal seams present, highly to moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to very weak, fine grained, bedded to massive, coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at 50 approximately 90° to the core axis, some silt infill, mild reaction to HCl. 48.5-48.8 m - Bentonite clay, high plastic, very stiff, pale green. 48.8-49.3 m - Claystone and sandstone become stratified and laminated, very weak. 49.3-50.0 m - Sandstone, extremely weak, laminated siltstone approximately 1-5 mm thick. 51 Borehole completed at target depth of 50.0 m below ground surface. Borehole grouted to surface with bentonite grout. No instrumentation installed. Bentonite chips alone added at 13.7 m to block zone of circulation loss and prevent loss of grout.

SPT Sampler Details: 61 cm length, 5 cm diameter, driven by automatic trip hammer. All SPT sampling was carried out in accordance with ASTM 52 D1586.

BH coordinates estimated by handheld GPS.

Pocket penetrometer tests conducted on base of SPT sample when possible and on opened face of SPT sample as appropriate. 53

54

55

56 TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 20 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 1 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 0 CLAY (CL) Silty to some silt, trace sand, low plasticity, soft to firm, light brown to light greyish brown, no odour, moist (wetter than plastic limit), weak structure, medium to high dry strength, no dilatancy, trace organics present as coal. [GLACIOLACUSTRINE] 0.0-2.1 m - Slight organic odour. 1 0-17.2 m - Mud rotary drilling using a 4¾ inch tri-cone drill bit.

2 SPT 01 SPT 01 - Recovered 0.47 m. 2 1 2

3

1 SPT 02 SPT 02 - Recovered 0.55 m. Plasticity Index = 19.6%. 2 3

4

4.8-4.9 m - Soft, wet. SPT 03 1 5 SPT 03 - Trace gravel. Recovered 0.53 m. 2 2

6

1 SPT 04 SPT 04 - Recovered 0.60 m. 2 2

7

SPT 05 - Recovered 0.61 m. SPT 05 1 8 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 21 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 2 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 8 CLAY (CL) 1 Silty to some silt, trace sand, low plasticity, soft to firm, light brown, light 2 greyish brown, no odour, moist (wetter plastic limit), no structure, weak structure, medium to high dry strength, no dilatancy, trace organics present as coal. [GLACIOLACUSTRINE] 9

1 SPT 06 SPT 06 - Recovered 0.61 m. Plasticity Index = 15.0%. 1 2

10

2 11 SPT 07 SPT 07 - Recovered 0.47 m. 7 SAND (SM) 11 Fine to medium, silty to some silt, poorly graded, compact, grey, no odour, moist, homogenous, weak cementation, organics present as coal seams, approximately 3 mm thick. [GLACIOLACUSTRINE] Groundwater observed at a depth of 11.6 m below ground surface on July 12 5, 2014 with the borehole at the final depth of 61.0 m.

6 SPT 08 SPT 08 - Sand (SM), fines content 22.0%. Recovered 0.49 m. 9 9 13

SILT (ML) 14 SPT 09 Sandy, some clay, trace gravel, low plasticity, very stiff, grey, no odour, 4 moist (near plastic limit), no structure, weak cementation, slow dilatancy. 8 [GLACIOLACUSTRINE] 12 SPT 09 - Recovered 0.57 m. Plasticity Index = 9.0%.

15 15.2-15.4 m - Trace sand, moderate cementation.

SPT 10 SPT 10 - Recovered 0.45 m. 5 INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE 10 14 16 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 22 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 3 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 16 INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE SANDSTONE, slightly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis, some sand >> and silt infill, mild reaction to HCl. 33 17 SPT 11 CLAYSTONE, highly weathered to fresh, extremely weak to weak, dark >> 52 greenish grey to dark pale green, fine grained, bedded to massive, trace coal seams present, moderately fractured, close to moderate joint 71 spacing, one joint set at approximately 90° to the core axis, occasional W clay infill. 2.5 SILTSTONE, slightly weathered to fresh, extremely weak to weak, dark grey to black, fine grained, bedded to massive, trace coal seams present, 18 carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional silt infill, mild reaction to HCl. W 15.4 m - Top of bedrock unit inferred from drilling action and increase in 2 drilling pressure increase. 15.4-18.7 m - Claystone, extremely weak, slightly to highly weathered. 19 SPT 11 - Recovered 0.46 m. 17.2 m - Switched to triple tube coring with HQ3 drill bit. 18.7-22.6 m - Sandstone, extremely weak.

R1 19.8-20.1 m - UCS = 1.1 MPa. 20

21

21.3-22.6 m - Tan mudstone clasts approximately 2 cm wide by 5 cm long.

22 W 1.5

22.6-22.9 m - Siltstone, convoluted fabric, very weak.

W 22.9-24.4 m - Claystone, extremely weak. 23 1

W 2 24 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 23 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 4 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 24 INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE SANDSTONE, slightly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis, some sand and silt infill, mild reaction to HCl. 25 CLAYSTONE, highly weathered to fresh, extremely weak to weak, dark greenish grey to dark pale green, fine grained, bedded to massive, trace coal seams present, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to weak, dark grey to black, fine grained, bedded to massive, trace coal seams present, 26 carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional silt infill, mild reaction to HCl. 24.4-25.0 m - Siltstone, extremely weak. 25.0-25.9 m - Claystone with bentonite clay, high plastic, very stiff, pale greenish grey. 27 25.7 m - Drill bit became stuck while advancing, inferred due to swelling of the bentonite in the claystone unit. 25.9-27.4 m - Claystone, siltstone and sandstone become stratified, extremely weak. 27.4-28.5 m - Sandstone, extremely weak, coal and siltstone lenses present.

28 W 1

28.5-30.5 m - Sandstone and siltstone become stratified and laminated, extremely weak, seams of bentonite clay, high plastic, very stiff. W 29 2

30

30.5-30.9 m - Bentonite clay, high plastic, very stiff, pale greenish grey.

W 30.9-31.95 m - Coal, black, shiny, easily fractured. 31 2.5

31.95-32.0 m - Mudstone, tan, weak, black specks present. 32 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 24 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 5 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 32 W INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE 1 SANDSTONE, slightly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis, some sand W and silt infill, mild reaction to HCl. 33 1.5 CLAYSTONE, highly weathered to fresh, extremely weak to weak, dark greenish grey to dark pale green, fine grained, bedded to massive, trace coal seams present, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to weak, dark grey to black, fine grained, bedded to massive, trace coal seams present, 34 carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional silt infill, mild W reaction to HCl. 2 32.0-35.1 m - Claystone, very weak, zones of bentonite clay, high plastic, very stiff, brown to pale green.

35 35.1-38.9 m - Sandstone, very weak.

W 36 1

37

38

38.9-40.0 m - Mudstone, tan, very weak, convoluted fabric, specks of 39 black sediment.

40 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 25 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 6 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 40 INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE SANDSTONE, slightly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis, some sand and silt infill, mild reaction to HCl. 41 CLAYSTONE, highly weathered to fresh, extremely weak to weak, dark greenish grey to dark pale green, fine grained, bedded to massive, trace coal seams present, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to weak, dark grey to black, fine grained, bedded to massive, trace coal seams present, 42 carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional silt infill, mild reaction to HCl. 40.0-40.8 m - Sandstone, very weak. 40.8-43.7 m - Siltstone and sandstone become stratified and laminated, very weak. 43

43.7-44.6 m - Siltstone, very weak to weak.

44

44.6-48.2 m - Sandstone, weak.

45 W 2

46

W 1 47

48 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 26 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 7 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 48 R2 47.9-48.3 m - UCS = 6.2 MPa. POOR QUALITY INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE SANDSTONE, slightly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark bands approximately 1-10 mm thick, slightly fractured, moderate 49 W joint spacing, one joint set at approximately 90° to core axis, some sand 4 and silt infill, sandstone is likely quartzite, mild reaction to HCl. CLAYSTONE, highly weathered to fresh, extremely weak to weak, dark greenish grey to dark pale green, fine grained, bedded to massive, trace coal seams present, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional clay infill. 50 W SILTSTONE, slightly weathered to fresh, extremely weak to weak, dark 4 grey, black, fine grained, bedded to massive, trace coal seams present, carbonaceous, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional silt infill, mild W reaction to HCl. 2 48.2-48.8 m - Siltstone, weak. 51 48.8-49.0 m - Claystone, extremely weak, highly weathered. W 49.0-49.2 m - Bentonite clay, high plastic, hard, pale green. 1.5 49.2-49.6 m - Coal, black, shiny. 49.6-50.3 m - Claystone, extremely weak, highly weathered, likely W bentonite. 1 50.3-50.7 m - Claystone, very weak. 50.7-50.9 m - Sandstone, extremely weak. 52 50.9-51.8 m - Siltstone, extremely weak to very weak. 51.8-53.0 m - Sandstone, siltstone, and claystone become stratified and laminated, very weak.

53 53.0-54.4 m - Claystone, extremely weak to weak.

54

54.4-56.4 m - Siltstone, sandstone and claystone become stratified and laminated, very weak.

55

56 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 27 of 36 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-WM-02 Page 8 of 8 Location: Whitemud Creek - West Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 Start Date: 02 Jul 14 Co-ordinates (m): 329,591E, 5,923,219N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 05 Jul 14 Ground Elevation (m): 682.3 Drill Method: Mud Rotary/Triple Tube Coring Final Depth of Hole (m): 61.0 Datum: NAD 83 UTM Zone 12U Fluid: Water and Polymer Logged by: NW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 16.9 Reviewed by: LDM Direction: N/A Depth To Rock (m): 15.4 Approved by: AJB

Su - kPa

40 80 120 160

% Fines UCS/2 Lithologic Description Pocket Pen /2 RQD DCT (blows/300mm)

SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%

Depth (m) Depth Type Sample No. Sample Grade Weathering Symbol 150mm per Blows SPT 20 40 60 80 20 40 60 80 56 INTERBEDDED SANDSTONE, CLAYSTONE and SILTSTONE SANDSTONE, slightly weathered to fresh, extremely weak to very weak, light "salt and pepper" grey, fine to medium grained, bedded to massive, dark bands approximately 1-10 mm thick, slightly fractured, moderate joint spacing, one joint set at approximately 90° to core axis, some sand and silt infill, mild reaction to HCl. 57 CLAYSTONE, highly weathered to fresh, extremely weak to weak, dark greenish grey to dark pale green, fine grained, bedded to massive, trace coal seams present, moderately fractured, close to moderate joint spacing, one joint set at approximately 90° to the core axis, occasional clay infill. SILTSTONE, slightly weathered to fresh, extremely weak to weak, dark grey to black, fine grained, bedded to massive, trace coal seams present, 58 carbonaceous, moderately fractured, close to moderate joint spacing, one W joint set at approximately 90° to the core axis, occasional silt infill, mild 2 reaction to HCl. 56.4-57.9 m - Sandstone, very weak. 57.9-58.3 m - Siltstone and sandstone become stratified and laminated, W very weak. 59 1 58.3-59.1 m - Sandstone, very weak. 59.1-59.6 m - Claystone, extremely weak. W 1.5 59.6-61.0 m - Siltstone, extremely weak.

60

61 Borehole completed at target depth of 61.0 m below ground surface. Hole backfilled to surface with grout/bentonite mix. One batch of ten 20 kg bags of cement, one 20 kg bag of bentonie and 150 gallons of water added. No instrumentation installed.

0%-10% loss in drilling fluid circulation throughout the entire hole. 62 SPT Sampler Details: 61 cm length, 5 cm diameter, driven by automatic trip hammer. All SPT sampling was carried out in accordance with ASTM D1586.

BH coordinates estimated by handheld GPS.

63 Pocket penetrometer tests conducted on base of SPT sample when possible and on opened face of SPT sample as appropriate.

64 TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 3/21/18

Combined PDF Pages Page 28 of 36 Trans Mountain Expansion 19731-506-RPT-00080 Project

Feasibility Report for the Rev Date Whitemud Creek Crossing 0 04/27/2018

D. Appendix D – Interpreted Geological Section at Whitemud Creek 0A

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Combined PDF Pages Page 29 of 36 T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\WHITEMUD_CREEK_KP_28.2\02.dwg Layout: RM-B-SIZE Plot Date Apr 4 18 Time: 8:32 AM .ALL DIMENSIONSAREINMETRESUNLESSOTHERWISENOTED. 1. NOTES: .SPECIFIC OBSERVATIONSPERTAINING TOTHEWATERLEVELMEASUREMENTS AREAVAILABLEINTHEREPORT. 7. .UNLESS BGCAGREESOTHERWISE INWRITING, THISDRAWINGSHALL NOTBEMODIFIED ORUSEDFOR ANY PURPOSE OTHERTHANTHEPURPOSE FORWHICH BGC 8. PROJECTIONISUTMNAD83ZONE12. 6. PROPOSED TMEPSSEID005.5PIPELINE ALIGNMENTPROVIDEDBYKMC,DATED MARCH2018.PROPOSEDHDD ALIGNMENTPROVIDEDBYUPI,DRAWING NO.01-13283-M002-XD00026-01REV A, 5. BASETOPOGRAPHIC DATABASEDONLIDARPROVIDEDBYUPI,DATEDSEPTEMBER2014.CONTOUR INTERVALIS1.0m. 3. 2. .IMAGESOURCE:ESRIWORLDIMAGERY SERVERRETRIEVEDFROMBINGIMAGERY. 4. AUTHORIZED BYBGC.ANY USEOFORRELIANCE UPONTHISDOCUMENT ORITS CONTENTBYTHIRD PARTIESSHALLBE ATSUCHTHIRD PARTIES'SOLERISK. GENERATED IT.BGCSHALL HAVENOLIABILITY FORANYDAMAGES ORLOSSARISING INANYWAYFROM ANYUSEOR MODIFICATIONOF THISDOCUMENTNOT BH-BGC14-WM-02 BH-BGC14-WM-01

LEGEND -PLAN N ISSUED FEBRUARY 07,2018.ATCOGAS20"HDDPROFILE PROVIDEDBYUPI,DATEDFEBRUARY 23,2018.

THIS DRAWINGMUSTBEREADINCONJUNCTION WITHBGC'SREPORTTITLED“GEOTECHNICALHDDFEASIBILITY ASSESSMENT-WHITEMUDCREEKATSSEID005.5KP28.2”,ANDDATEDMARCH 2018. BOREHOLE N 5,923,250 N

ERT SURVEYALIGNMENT PROPOSED HDDENTRY/0+00EXITPOINT BGC BOREHOLE KILOMETRE POINT(KP) PROPOSED HDDBOREPATH

SSEID 005.5TRANSMOUNTAINPIPELINEALIGNMENT

WHITEMUD CREEKFLOWDIRECTION ATCO GAS20"PIPELINECENTRELINE(APPROX.) 680

28+600

680 685 ELEVATION (masl)

685 KP 28+525 BH COLLAR ELEVATION (m) 682.3 667.0 605 620 640 660 680 700 036-0+300 -0+326 HORIZONTAL SCALE:1:2,500 VERTICAL SCALE:1:1,250(2xEXAGGERATION) (E: 329,381;N:5,923,190)

KP 28+500

POTENTIAL TO INTERSECT 28+500 -

COAL SEAMS (AER 2017) A INFERRED WATER

685 LEVEL (mbgs) HDD ENTRY HDD ENTRY 11.6 ? 7.7 OF COALSEAMUNKNOWN ? DEPTH ANDTHICKNESS BH-BGC14-WM-02 (OFFSET=23mN) ELEVATION (masl) NORTHWEST WATER LEVEL

KP 28+400 28+400 -0+200 670.7 659.3

25 E 329,500

GROUNDWATER OBSERVATIONS E 329,500 BH-BGC14-WM-02 (400 mmTHICK) 0 SCALE 1:2,500 MEASURED ONJULY5,2014,WHEN BOREHOLEWASADVANCEDTOFINALDEPTHOF61.0 m bgs MEASURED ONJULY1,2014,WHENBOREHOLEWASADVANCED TOFINALDEPTHOF50.0mbgs COAL SEAM METRES (1.1 mTHICK) COAL SEAM ? ? 25

KP 28+300 680 28+300 -0+100 755025

0 675

SCALE 1:2,500 680 EXISTING GROUND (SEPT 2014) METRES HDD 0+00POINT

670 675

665 ? 670 665 660 (656.0 masl) 200-YEAR SCOURELEVATION 755025 COMMENTS

KP 28+200 ?

660 28+200 660 (663.2 masl) 200-YEAR RETURNPERIODFLOOD 0+000

HDD 0+00POINT 665 660 PROPOSED HDDCHAINAGE(m) POSSIBLE COARSEGRAINED CHANNEL MATERIAL

COAL SEAM(100mmTHICK) COAL SEAM(200mmTHICK) E 329,750 CROSS-SECTION Combined PDF Pages Combined THIS DRAWINGMAY HAVEBEENREDUCEDORENLARGED. ALL FRACTIONALSCALE NOTATIONSINDICATEDARE

Page 30 of 36 665 E 329,750 BH-BGC14-WM-01 BASED ON ORIGINALFORMAT DRAWINGS. 670

KP 28+100 28+100 0+100 WHITEMUD CREEK A - ? 670 ?

BH-BGC14-WM-01 (OFFSET=22mN) 670 670 COAL SEAM(1.5mTHICK)

KP 28+000 28+000 0+200 675 ?

APPROVED: CHECKED: DRAWN: DATE: SCALE: 675

LEGEND -CROSS-SECTION 680 ? 680 ? ? MAR 2018 INFERRED BEDROCKCONTACT INFERRED GEOLOGICALINTERFACE INFERRED WATERLEVEL PROPOSED HDDENTRY/0+00 /EXITPOINT BGC BOREHOLE PROPOSED HDDPROFILE (ADVISIAN) (APPROXIMATELOCATION) ATCO GAS20"HDDPROFILE(APPROX.) 1:2,500 SAA

CR KP 27+900 E 330,000 27+900 - DEPTH ANDTHICKNESS OF COALSEAMUNKNOWN 0+300 CLIENT: B G

C E 330,000 BGC ENGINEERINGINC. AN APPLIEDEARTHSCIENCES COMPANY EAST

KP 27+800 27+800 0+400 (E: 330,168;N:5,923,276) HDD EXIT HDD EXIT

675 BOREHOLE PROJECT No.: TITLE: PROJECT: GEOTECHNICAL HDDFEASIBILITYASSESSMENT - WHITEMUDCREEKATSSEID005.5KP28.2 INTERPRETED GEOLOGIC CROSS-SECTION 0095-150 POTENTIAL TO INTERSECT KP 27+725 0+474 INTERPRETED GEOLOGY

COAL SEAMS (AER 2017) 27+600 27+700 A - 605 620 640 660 680 700 FORMATION BEDROCK HORSESHOE CANYON LOW RECOVERY COAL SEAM GLACIOLACUSTRINE SAND BED- ANTHROPOGENIC (FILL) ELEVATION (m) ? DWG No.:

685 675

680

E 330,250

02 N 5,923,250 N

E 330,250 Trans Mountain Expansion 19731-506-RPT-00080 Project

Feasibility Report for the Rev Date Whitemud Creek Crossing 0 04/27/2018

E. Appendix E – HDD Crossing Plan and Profile, Whitemud Creek 0A

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Feasibility Report for the Rev Date Whitemud Creek Crossing 0 04/27/2018

F. Appendix F – Calculated Fracture Pressure for Whitemud Creek

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Feasibility Report for the Rev Date Whitemud Creek Crossing 0 04/27/2018

G. Appendix G – Whitemud Creek - Contingency Design

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