TRANS MOUNTAIN PIPELINE ULC

TRANS MOUNTAIN EXPANSION PROJECT

GEOTECHNICAL HDD FEASIBILITY ASSESSMENT NORTH THOMPSON RIVER (AT CHAPPELL) AT SSEID 005.11 KP 577.1

PROJECT NO.: 0095150-14 DATE: October 31, 2018 DOCUMENT NO.: TMEP18-084

Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

EXECUTIVE SUMMARY

As part of the engineering design and assessment of the Trans Mountain Expansion Project (TMEP), BGC Engineering Inc. (BGC) has been retained to complete geotechnical feasibility assessments for horizontal directional drilling (HDD) at select river crossings along the proposed pipeline corridor. In August of 2013 and September and November of 2014, BGC supervised the drilling of three boreholes adjacent to the proposed TMEP HDD crossing of the North Thompson River near the confluence with Chappell Creek, south of Blue River, BC. WorleyParsons, under subcontract to BGC, completed geophysical surveys at the same site in August of 2013. Analysis of historical aerial photographs shows active erosion of the right bank of the North Thompson River confined within the floodplain. Given the proposed locations of entry and exit points, the proposed HDD alignment is not expected to be compromised by either bank erosion or avulsion. The HDD entry and exit points are significantly higher than the 200-year flood level and are therefore not expected to be at risk to flooding during construction or operation. The 200-year scour depth is estimated to be approximately 2.5 m below the channel thalweg (deepest point in the channel) elevation, corresponding to a 200-year scour elevation of 699.2 masl. During this event, the full HDD borepath is expected to maintain adequate cover. In general, soils encountered during investigative drilling were fluvial, glaciofluvial, or glaciolacustrine in origin, consisting primarily of silts, sands, and gravels with coarser sediments (cobbles) inferred from drilling action within the fluvial unit. The density of the soil ranged from loose/soft near surface to very dense/hard with depth. Generally high to very high (95% to 100%) drilling mud circulation returns were observed throughout investigative drilling with the exception of a brief period of low circulation return (10%) while advancing through a gravel lens on the east bank. Soils on the east and west banks of the North Thompson River appear stable with no borehole instabilities observed. Borehole collapse was observed near the valley center, within 100 m of the North Thompson River, within a unit of poorly graded glaciofluvial sand that led to filling of approximately 40% of the unsupported borehole following completion. Curvature of the HDD borepath may contribute to caving and stability issues within the fluvial and glaciofluvial units. Bedrock was not encountered during investigative drilling and, based on geophysical survey and drilling results, is not expected to be encountered along the proposed HDD borepath. The difference between the anticipated drilling fluid pressures and the confining stresses provided by the unconsolidated overburden sediments is small enough to warrant careful consideration. As such, the risk of drilling fluid release into the river needs to be carefully assessed by the HDD design team using the borepath geometry for frictional losses and the HDD rig and pumping characteristics. Based on the observations from three boreholes and the geophysics, an HDD crossing at this location is considered feasible from a geotechnical perspective provided concerns associated with borepath stability, the presence of coarse grained material in the fluvial (gravel and

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page i BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14 cobbles) and glaciofluvial (gravel) deposits, and the potential loss of drilling fluid containment are addressed during detailed design and construction of the HDD. The conclusions presented herein are based solely on the limited scope of the investigation undertaken at this time for the purpose of obtaining preliminary information, and additional investigation should be considered as part of detailed design.

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page ii BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

TABLE OF CONTENTS

EXECUTIVE SUMMARY ...... i TABLE OF CONTENTS ...... iii LIST OF FIGURES...... iv LIST OF TABLES ...... i v LIST OF DRAWINGS ...... iv LIST OF APPENDICES ...... iv AMENDMENTS...... v LIMITATIONS ...... vi 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 3.3. Bedrock Geology ...... 4 3.4. Terrain Mapping ...... 5 Terrain Types ...... 5 3.5. Hydrotechnical Assessment ...... 6 Flood Frequency Analysis ...... 6 Scour ...... 7 Bank Erosion ...... 7 Avulsion ...... 8 4.0 SITE INVESTIGATION ...... 9 4.1. Geotechnical Drilling Data ...... 9 4.2. Geophysical Survey Data ...... 10 5.0 INFERRED GEOTECHNICAL CONDITIONS ALONG THE HDD BOREPATH ..... 11 5.1. Groundwater Conditions ...... 12 5.2. Inferred Geology along HDD Borepath ...... 1 2 6.0 GEOTECHNICAL FEASIBILITY ASSESSMENT ...... 13 6.1. General Considerations ...... 13 6.2. Borepath Stability ...... 13 6.3. Circulation and Potential for Loss of Fluids ...... 14 7.0 CLOSURE ...... 15 REFERENCES ...... 1 6

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page iii BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

LIST OF FIGURES

Figure 3-1. Location of the proposed North Thompson River Chappell pipeline crossing point...... 3 Figure 4-1. The Electrical Resistivity Range for the North Thompson River Chappell ERT Survey...... 10

LIST OF TABLES

Table 3-1. Peak instantaneous flow estimates (QIMAX) for the North Thompson River Chappell site...... 6 Table 3-2. Historical aerial photographs at North Thompson crossing ...... 7

LIST OF DRAWINGS

DRAWING 01A Bank Erosion & Avulsion Review DRAWING 01B Avulsion Review DRAWING 02A Terrain Mapping DRAWING 02B Terrain Mapping Legend DRAWING 03 Interpreted Geological Section DRAWING 04 Geophysics Results DRAWING 05 Field Photos

LIST OF APPENDICES

APPENDIX A HYDROTECHNICAL INVESTIGATION AND ANALYSIS METHODOLOGY APPENDIX B BOREHOLE LOGS APPENDIX C LABORATORY TEST RESULTS

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page iv BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

AMENDMENTS

This report is an update to BGC Engineering Inc. (February 20, 2015) report entitled "Geotechnical HDD Feasibility Assessment – North Thompson River (at Chappell) at V10 RK 581.1". This revision utilizes the current (August 15, 2018) SSEID alignment (SSEID 005.11): Title Page: Report title renamed to reference the current SSEID alignment. Section 1.0: Revised text to reference the current SSEID alignment and project ownership and approval status. Section 3.0: Figure 3-1 has been updated to show the current SSEID alignment. Drawings: Drawings 01A, 01B, 02A, 03 and 04 have been updated to show the revised SSEID alignment. Content of Drawing 02B (Terrain Map Legend) has been updated. All drawing title blocks have been updated (e.g., new SSEID name, updated reference dates, no ‘draft’ stamp)

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page v BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 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 - North Thompson Chappell Page vi BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 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 (AB). Trans Mountain is operated by Trans Mountain Canada (TMC) and is fully owned by the Canada Development Investment Corporation. 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 British Columbia. 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 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 watercourse crossings to support feasibility assessments for establishing the preferred crossing methodology, and where appropriate, contingency options. Known reference points along the existing Trans Mountain pipeline system are commonly referred to as Kilometer Post or “KP”. KP 0.0 is located at the Edmonton Terminal 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 005.11 alignment provided by Universal Pegasus International Ltd. (UPI) in August 2018.

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page 1 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 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 have retained BGC Engineering Inc. (BGC) to complete geotechnical feasibility assessments for horizontal directional drilling (HDD) at select stream crossings along the proposed pipeline corridor. The scope of work for the feasibility assessment of the North Thompson River crossing (near the confluence with Chappell Creek) included the following: • Desktop study of regional geology and the geological setting for the crossing site • Hydrological analysis of the site including flood frequency and scour analyses • Geotechnical borehole drilling adjacent to the proposed crossing path (supervised by BGC) • Geophysical surveys along the proposed crossing path (by WorleyParsons). Planning for contingency river crossing 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, Universal Pegasus International Ltd. (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 site conditions at the proposed North Thompson River crossing (near the confluence of Chappell Creek) (hereafter referred to as North Thompson River Chappell) and provide an indication, from a geotechnical perspective, on the feasibility of HDD technology as a crossing method.

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page 2 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

3.0 SITE DESCRIPTION, GEOLOGY AND HYDROTECHNICAL ASSESSMENT

3.1. Overview The North Thompson River (at Chappell) site is situated within the Rocky Mountains, approximately 35 kilometers north of Blue River, BC. The proposed TMEP pipeline corridor runs parallel to the Southern Yellowhead Hwy (BC-5), and the North Thompson River within the North Thompson River Valley and crosses the North Thompson River several times. At this crossing location, the meandering North Thompson River has a bankfull width of approximately 75 m and is located within a floodplain approximately 350 m wide and confined by alluvial fans to the north and south. The western and eastern floodplain margins, at the toes of the fans, are at elevations of approximately 705 m above sea level (masl). The location of the site along the proposed TMEP alignment is shown in Figure 3-1 below.

Figure 3-1. Location of the proposed North Thompson River Chappell pipeline crossing point.

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The proposed HDD entry and exit points are located on the surface of alluvial fans, above the active floodplain, on gentle slopes (< 15°). Preliminary HDD design drawings of the proposed HDD borepath were issued by UPI on May 29, 2013. The crossing covers a horizontal distance of approximately 675 m and passes 30 m beneath the North Thompson River. The proposed HDD borepath falls outside of the existing TMPL right of way, which lies to the west of the crossing.

3.2. Surficial Geology The North Thompson River Chappell site is located within the Caribou Mountains ecosection, a subsection of the Columbia Mountains physiographic region (Holland, 1976). The dominant surficial materials in this region are colluvium, till, glaciofluvial, fluvial, and organic deposits, as well as bedrock outcrops (Trans Mountain, 2013). The North Thompson and its tributary valleys typically display classic glacially formed U-shaped morphology. The main valley is characterized by its broad floor (up to 1 km across), and the North Thompson is a sinuous to meandering river that winds across a sand and gravel floodplain (Seemann and Blyth, 2000). Depth of surficial materials generally thins with increased elevation up the valley sides, and higher elevations largely comprise exposed bedrock. These weathered bedrock outcrops may produce active colluvial deposits (Seemann and Blyth, 2000; Madrone 2007). The landscape of the North Thompson valley has been, and continues to be, sculpted by on-going geomorphic processes. Modern fluvial processes have eroded and redistributed much of the material in the North Thompson valley forming plains, terraces, bars, fans and gullies (Seemann and Blyth, 2000), composed of sand, gravel and silt up to 20 m thick (Fulton et al., 1986). Post-glacial glaciofluvial outwash sediments deposited during glacial retreat are most prevalent along the valley floor and lower slopes of the North Thompson valley, in some areas greater than 50 m thick (Seemann and Blyth, 2000). Glaciofluvial deposits generally form terraces above the active floodplain, and are typically composed of non-cohesive well sorted sands, gravels, and minor silts (Fulton et al., 1986; Madrone, 2007). Colluvial deposits are also common along valley slopes and in fans and cones. Colluvium is typically composed of sub-angular to sub-rounded clasts in a silty sand matrix (Madrone, 2007). Near the North Thompson River Chappell site, modern fluvial deposits blanket the valley floor, and valley slopes typically comprise glacial till and colluvium with lesser amounts of glaciofluvial sediment and bedrock outcrops (Trans Mountain, 2014).

3.3. Bedrock Geology The North Thompson River Valley is a fault-controlled valley consisting of the Cariboo Mountains to the west, and the Monashee Mountains to the east. The fault separating the valley exhibits normal, extensional displacement and runs parallel to the North Thompson River, approximately 550 m east of the proposed HDD crossing. The dominant rock types within the down-dropped block to the west, within the vicinity of the proposed HDD crossing

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are quartzite and quartz arenite sedimentary rocks of the Horsethief Creek Group (Massey et al., 2005). The eastern block is dominantly composed of metamorphic rocks of the Mica Creek Succession (Massey et al., 2005). Regional metamorphism is generally amphibolite facies, with some variation within units.

3.4. Terrain Mapping As a part of the overall terrain assessment for TMEP, BGC mapped the terrain along the proposed pipeline corridor at a scale of 1:20,000 by analyzing 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 resolved due to limitations in data resolution and field work. Terrain mapping for the North Thompson River Chappell crossing is shown in Drawing 02A, and a terrain code legend is shown in Drawing 02B. A terrain stability analysis was carried out by BGC in conjunction with terrain mapping of the TMEP route (Drawing 02A). This analysis classifies the regions surrounding the entry and exit points as Terrain Stability Class I (no significant stability problems exist), though some of the deposits on the valley slopes have Terrain Stability Class ratings at high as V, as detailed in Section 3.4.1 (see Drawing 02B for full descriptions of Terrain Stability Classes).

Terrain Types Terrain types mapped at the North Thompson River Chappell crossing and shown on Drawing 02A include fluvial and glaciofluvial, colluvium, and glacial till deposits described below: a. Fluvial and Glaciofluvial Fluvial material is predominantly composed of sand and gravel deposited by moving surface water. Cobbles and boulders may also be present. Fluvial and glaciofluvial deposits are the primary soil types mapped along the valley floor at the North Thompson River Chappell crossing. b. Colluvium Colluvium consists of surficial materials transported downslope by gravity through a range of processes including gradual downslope creep, landslides, rockfall, and debris flows. Aprons of colluvium line the valley margins to the east and west of the proposed crossing c. Glacial Till Till material is deposited through the movement of glacial ice. It is often consolidated by the weight of the glacier, and is usually poorly sorted (i.e. well graded) and most often matrix supported. Glacial till is found in discontinuous blankets of variable thickness along the valley margins behind and beneath colluvial aprons.

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3.5. Hydrotechnical Assessment LiDAR coverage, historical air photographs, bathymetric survey data, and site observations were used to assess the potential for bank erosion, scour, and avulsion. Hazards evaluated by BGC included bank erosion, scour, and avulsion. The methodologies used to complete this hazard assessment are presented in Appendix A.

Flood Frequency Analysis Flood quantiles at the HDD crossing site were estimated using a flood frequency analysis (FFA). The drainage area at the crossing was estimated to be 1,470 km2 and a prorated FFA

was used to estimate peak instantaneous streamflow (QIMAX) for various return periods. This FFA is based on the gauging station: North Thompson River at Birch Island (08LB047), which is located approximately 130 km downstream of the proposed crossing. This station has a record length of 51 years between 1960 and 2011 and has a published watershed area of 4,490 km2. These records allow for a prediction of flood quantiles up to a return period of 200 years. Peak instantaneous streamflow estimates at the North Thompson River Chappell site for various return periods are as follows:

Table 3-1. Peak instantaneous flow estimates (QIMAX) for the North Thompson River Chappell site.

3 Basin QIMAX for Given Return Periods (m /s) Pipeline Area Crossing (km2) 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 200-yr North Thompson 1470 300 350 380 420 450 470 500 River Chappell Flow values are rounded to the nearest 10 m3/s.

Average cross sectional flow hydraulics for the crossing were estimated using Manning’s equation, a surveyed cross-section, a channel gradient of 0.15%, and the peak flows listed in Table 3-1. The cross-section and channel gradient used for the evaluation are based on a bathymetric survey by Opus Stewart Weir in August 2014. The corresponding water elevation for the 200-year return period flood is estimated at 705.1 masl (see Drawing 03). The HDD exit point is located on the left (northeast) bank at the margin of what appears to be an inactive alluvial fan, approximately 340 m away from the active channel and at an approximate elevation of 719 masl. The CN railway runs in between the active channel of the river and the exit point at an approximate elevation of 713 masl. The entry point is located on the right (southwest) bank, also at the margins of what appears to be an inactive alluvial fan. This point lies approximately 245 m from the active channel at an approximate elevation of 712 masl (see Drawing 01B).

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Scour BGC completed a detailed scour analysis to evaluate general scour conditions at the proposed crossing of the North Thompson River at Chappell. The scour analysis was conducted using the estimated peak flows presented in Table 3-1 above and a channel cross-section derived from the bathymetric survey. Results from the analysis estimate a maximum scour depth of approximately 2.5 m below the channel thalweg (deepest point in the channel) elevation of 701.7 masl during a 200-year flood event. The elevation of maximum scour is shown on Drawing 03 and the depth of cover above the HDD borepath remains greater than 25 m should this amount of scour occur. Given these results, scour is not considered a hazard for the HDD borepath.

Bank Erosion BGC completed an evaluation of the historical lateral stability of the North Thompson River using a comparison of historical aerial photographs between the years 1953 and 2010. Table 3-2 lists the photographs used in this analysis. The aerial photographs were georeferenced to make the comparison, and Drawing 01A demonstrates how the channel planform has changed.

Table 3-2. Historical aerial photographs at North Thompson crossing Ref No. Photo No. Date Scale BCC05117 005 2005 1:20,000 BCC97118 165 1997 1:15,000 BCC91094 205 1991 1:15,000 BC85083 260 1985 1:15,000 BC80044 94 1980 1:20,000 BC7812 106 1975 1:20,000 BC5394 117 1970 1:80,000 BC4395 236 1966 1:16,000 BC1740 80 1953 1:15,000 X193R 4,5 1948 N/A The 2010 aerial photograph is considered a current image and is not included in the historic database

The channel of the North Thompson River exhibits a slight bend to the left (southeast) at the proposed crossing, followed by a moderate bend to the right (southwest) approximately 280 m downstream of the crossing when it abuts against the embankment of the CN railway. Drawing 01A illustrates that the planform of the 200 m long reach upstream of the crossing has remained relatively stable over the 57-year period covered by the aerial photographs. However, the active channel has migrated to the south along the right bank up to 130 m immediately downstream of the proposed crossing. Ongoing active erosion of the right bank was observed by BGC during a ground inspection of the site conducted in July 2014.

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The HDD exit point is located approximately 340 m away from the active channel on an alluvial fan and is separated from the river by the embankment of the CN railway. The HDD entry point is also located on the outer margin of an alluvial fan complex, approximately 220 m away from the active channel. These fan deposits located on opposite sides of the valley provide limitations on the potential extent of lateral migration by the river. Therefore bank erosion is not considered a hazard to the HDD borepath.

Avulsion The channel of the North Thompson River is incised about 3 m into fluvial and glacio-fluvial sediments. The left (northeast) floodplain could be inundated during a 200-year flood event but the flooding would be contained by the embankment of the CN railway and adjacent fluvial fan. The right (southwest) floodplain is at a slightly higher elevation than the left side, but it would be inundated by a 200-year flood event with flooding extending approximately 100 m beyond the top of bank. Neither the LiDAR data nor the satellite imagery show abandoned channel scars or side channels within the floodplain. In addition, there are no signs of channel aggradation or of active bank erosion along either bank that could indicate avulsion during flood events. These observations support a very limited capacity for an avulsion channel to develop on either floodplain. Regardless, the entry and exit points are not located on the active floodplain and therefore, avulsion is not considered a hazard to the HDD borepath at this time.

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4.0 SITE INVESTIGATION In August of 2013 and September and November of 2014, BGC supervised the drilling of three boreholes adjacent to the proposed TMEP HDD alignment at the North Thompson River Chappell site. The target borehole depths extended at least 10 m below the proposed HDD borepath depth in the vicinity of the borehole. WorleyParsons carried out geophysical surveys at the proposed HDD crossing in August 2013, using both electrical resistivity tomography (ERT) and seismic refraction survey methodologies. ERT was carried out along the entire length of the proposed HDD route, extending approximately 100 m beyond the entry and exit points. Two seismic refraction surveys were carried out along portions of this alignment: an approximately 350 m section across the west bank in 2013 and an approximately 475 m section across the east bank in 2014. The locations of the boreholes and geophysical surveys with respect to the proposed HDD crossing are shown in Drawings 03 and 04.

4.1. Geotechnical Drilling Data Borehole BH-BGC13-NTC-01 was drilled on the west bank of the river upon a fluvial fan to a depth of 42.4 meters below ground surface (mbgs) (665.1 masl) at an offset of 31 m southeast of the proposed HDD crossing. Drilling was performed using a combination of mud rotary and air rotary methods with Standard Penetration Tests (SPTs) completed every 1.5 m. Boreholes BH-BGC14-NTC-02 and BH-BGC14-NTC-03 were drilled on the east bank of the river within the river floodplain and upon a fluvial fan to depths of 40.8 mbgs (665 masl) and 46.4 mbgs (674 masl) respectively. Both borehole BH-BGC14-NTC-02 and BH-BGC14-NTC-03 were drilled at an offset to the southeast of the proposed HDD crossing by 77 m and 26 m respectively. Mud rotary drilling methods with SPTs completed every 1.5 m were used to advance the boreholes to their respective target depths. Data collected includes the following: • SPT blow counts and visual description of soil units based on visual examination of material retrieved in the SPT sampler (according to the Unified Soil Classification System) • Moisture content, grain size and Atterberg limits of selected soil samples, based on laboratory testing • Depth to static water table as observed near or upon completion of drilling. BGC notes that the drilling and sampling methods used do not retrieve particles larger than gravel size (50 mm), so the percentage of larger sized clasts has to be inferred from drilling results. Appendix B contains the borehole logs for BH-BGC13-NTC-01, BH-BGC14-NTC-02, and BH-BGC14-NTC-03. Laboratory testing results are included in Appendix C and Figures C-01 and C-02 provide the results from the sieve analyses and Atterberg limits tests respectively. Drawing 05 contains site photographs of drilling activities and SPT samples during the 2013 and 2014 site investigation.

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4.2. Geophysical Survey Data The geophysics survey scope for the North Thompson River Chappell crossing included provision of the following from WorleyParsons: • An ERT survey along the entire accessible length of the proposed HDD alignment to a depth exceeding that of the maximum borepath depth (Drawing 04). • A seismic refraction survey along a 350 m portion of the west bank of the proposed HDD alignment as well as approximately 475 m along the east bank. This serves to provide some quality assurance to the ERT results and can also be used to draw inferences on subsurface geology. • Interpretations of the anticipated subsurface geology based on both aforementioned survey methods. In order to draw inferences from the ERT data, the resistivity scale shown on each survey is unique. The electrical resistivity range shown in Drawing 04 is indicated in Figure 4-1 below:

Figure 4-1. The Electrical Resistivity Range for the North Thompson River Chappell ERT Survey.

The electrical resistivity values found at the North Thompson River Chappell site are from approximately 80 to 1500 ohm-m. These values are indicative of gravel, sand, silt and clay sediments, glacial till, sandstone, and weathered felsic igneous and metamorphic rocks.

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5.0 INFERRED GEOTECHNICAL CONDITIONS ALONG THE HDD BOREPATH Based on the results obtained from the geotechnical site investigation described above, BGC has developed a geological section of the proposed HDD crossing (Drawing 03). The ERT data was calibrated with borehole data and assisted in the interpretation of unit boundaries between boreholes in this section. For the North Thompson River Chappell ERT survey, the resistivity survey values are interpreted to indicate the presence of the following materials: • < 350 ohm-m: Saturated fines (e.g. glaciolacustrine sediments). • 350 – 800 ohm-m: Saturated sand and fines (e.g. glaciofluvial sediments). • > 800 ohm-m: Sand and gravel (e.g. fluvial sediments). Although ERT results clearly show the extent of the fluvial sediment, the contrast between the glaciofluvial and glaciolacustrine sediments is less distinct. For further information on geophysics methodology the following literature may be referred to: “2D Resistivity Surveying for Environmental and Engineering Applications”, Torleif Dahlin, 1996. Three primary geological units have been interpreted in the section: • FLUVIAL SAND AND GRAVEL – Well graded gravels were encountered in all three boreholes, to depths ranging from 2 to 10 mbgs. This unit is described as fine to coarse gravel and sand to sandy, trace fines; loose to very dense. The presence of cobbles and coarse gravel beds was interpreted through drill action within this unit. Generally high to very high (95% to 100%) drilling mud returns and stable borehole walls were observed while drilling through this unit and the borehole walls remained stable (no borehole sloughing occurred). ERT results showed the thickness of this unit to range from < 5 m in the river floodplain to 20 m below the proposed HDD exit point. • GLACIOLACUSTRINE SILT AND CLAY – This unit was encountered in all three boreholes (BH-BGC13-NTC-01, BH-BGC14-NTC-02, and BH-BGC14-NTC-03) underlying the fluvial sand and gravel described above, below depths of 10.1 mbgs, 10.8 mbgs, and 5.6 mbgs respectively, with a variable thickness ranging from greater than 30 m thick, to 6 m thick, to greater than 15 m thick, respectively. This unit is described as low plasticity silt and/or clay, trace sand to sandy; firm to hard. Silt and clay commonly appeared interbedded with fine sands. Generally high to very high drilling mud returns (95% to 100%) and stable borehole walls were experienced while drilling through these materials (no borehole sloughing occurred). • GLACIOFLUVIAL SAND – This unit was encountered in both BH-BGC14-NTC-02 and BH-BGC14-NTC-03 below depths of 16.9 mbgs and 21.5 mbgs respectively, underlying the glaciolacustrine silt and clay described above. This unit is described as a poorly graded, fine to medium grained, silty sand; very loose to dense. Sands were observed to grade from clean to silty with depth and commonly interbedded with strata of silt. Generally high to very high (95% to 100%) drilling mud returns were observed

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page 11 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

while drilling through this unit. A brief period of low (10%) drilling mud return was observed across 10 cm of a gravel lens approximately 1 m thick that was encountered in this unit while drilling BH-BGC14-NTC-03. Upon completion, approximately 40% of BH-BGC-NTC-02 collapsed in this unit while the borehole was unsupported.

5.1. Groundwater Conditions Stabilized water levels were observed at 5.4 mbgs, 1.7 mbgs, and 4.5 mbgs for BH-BGC13- NTC-01, BH-BGC14-NTC-02, and BH-BGC14-NTC-03 respectively, measured approximately 12 hours following drilling activity.

5.2. Inferred Geology along HDD Borepath The proposed HDD entry point is situated at an elevation of approximately 712 masl, approximately 250 m southwest of the North Thompson River. Subsurface conditions surrounding the HDD entry point consist of fluvial sand and gravel underlain by glaciolacustrine silt and clay. ERT survey results suggest the HDD borepath will encounter this glaciolacustrine silt and clay at a depth of approximately 13 mbgs, or 70 m laterally from the entry point. Drilling and geophysical survey results indicate that the glaciolacustrine silt and clay is greater than 50 m thick in the vicinity of the HDD entry point, and the HDD borepath is expected to remain within this unit for a lateral distance of about 170 m. Beneath the glaciolacustrine silt and clay, at an elevation of approximately 675 masl and 240 m from the HDD entry point, the borepath is expected to encounter a unit of glaciofluvial silty sand of unknown thickness. However, the location of this contact is uncertain, and the glaciofluvial silty sand and glaciolacustrine silt and clay deposits may be intermixed. ERT results and investigative drilling suggest that the borepath will remain in this unit for approximately 300 m as it advances laterally beneath the North Thompson River and east bank. ERT results and borehole observations indicate that the borepath may re-enter a glaciolacustrine silt and clay approximately 125 m from the HDD exit point at an elevation of approximately 695 masl and remain in this unit for approximately 65 m. Within approximately 45 m of the HDD exit point the borepath is expected to re-enter fluvial fan-derived sands and gravels, and remain in this unit until it exits to the surface at an elevation of approximately 719 masl. ERT results suggest that there may be pockets of coarser sediment (gravel) within the glaciolacustrine and glaciofluvial units, particularly in the vicinity of the HDD exit point. The exact extent and composition of these materials is unknown. Bedrock was not encountered during investigative drilling, or inferred from geophysical survey results and is not expected to be encountered by the HDD borepath.

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page 12 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

6.0 GEOTECHNICAL FEASIBILITY ASSESSMENT The following conclusions can be drawn from the preceding information, including from the regional surficial and bedrock geology, local hydrology as well as the results from the subsurface investigation on site.

6.1. General Considerations • Analysis of historical aerial photographs shows active erosion of the right bank of the North Thompson River confined within the floodplain. This analysis also supports a very limited capacity for an avulsion channel to develop. Given the proposed locations of entry and exit points, the proposed HDD alignment is not expected to be compromised by bank erosion and avulsion. The HDD entry and exit points are located above the 200-year flood level and are not expected to be at risk of flooding during construction or operation. • The 200-year scour depth is estimated to be approximately 2.5 m below the channel thalweg elevation of 701.7 masl, corresponding to a 200-year scour elevation of 699.2 masl. Under this event the HDD borepath is expected to maintain adequate cover. • The presence of cobbles was inferred during investigative drilling of the fluvial deposits, and gravel lenses were observed during investigative drilling of the glaciofluvial units. Given the lateral variability of these deposits, cobbles and gravel lenses are likely to be encountered by the borepath in the fluvial and glaciofluvial units respectively. • Bedrock was not encountered during drilling, and is not expected to be encountered by the HDD borepath.

6.2. Borepath Stability • Upon completion, approximately 40% of BH-BGC14-NTC-02 collapsed while unsupported. Although no caving was observed in the other boreholes, challenges with borepath stability may be experienced while drilling through the fluvial and glaciofluvial units and should be addressed by the HDD design team through fluid management, the use of casing, or other measures. • Curvature of the HDD borepath may contribute to borehole stability issues within the poorly graded fluvial and glaciofluvial deposits. • Squeezing of the borepath may occur from approximately 50 to 250 m and 550 to 625 m laterally from the proposed HDD entry point where the borepath is interpreted to pass through the glaciolacustrine silt and clay unit. Squeezing is more likely in the upper portion of this unit where the glaciolacustrine material has the softest consistency.

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page 13 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

6.3. Circulation and Potential for Loss of Fluids • Significant fluid losses were encountered across a 10 cm interval while advancing BH-BGC14-NTC-03 through a gravel lens. No significant fluid losses were observed during investigative drilling of the other boreholes. Fluid losses may occur within similar materials, particularly within the fluvial sand and gravel near surface, or within coarser zones within the glaciofluvial unit and should be addressed during HDD construction through the use of appropriate drilling fluids, casing, or other means. • The minimum depth between the proposed HDD borepath and the river bed is 30 m. Assuming hydrostatic pressures and accounting for the elevation difference between the entry and exit points and along the HDD borepath, the difference between the anticipated drilling fluid pressures and the confining stresses provided by the unconsolidated overburden sediments is small enough to warrant careful consideration. As such, the risk of drilling fluid release into the river needs to be carefully assessed by the HDD design team using the borepath geometry for frictional losses and the HDD rig and pumping characteristics. Given the above, and based on the observations from three boreholes and the geophysics, an HDD at this location can be considered feasible from a geotechnical perspective provided concerns associated with borepath stability, the presence of coarse grained fluvial and glaciofluvial deposits, and the potential loss of drilling fluid containment are addressed during detailed design and construction of the HDD. The conclusions presented herein are based solely on the limited scope of the investigation undertaken at this time for the purpose of obtaining preliminary information, and additional investigation should be considered as part of detailed design.

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page 14 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 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:

Katherine Johnston, M.Sc., P.Eng., P.Geo. Chris Pederson, M.Sc., E.I.T. Senior Geological Engineer Junior Geotechnical Engineer

Reviewed by: Dr. Alex Baumgard, P.Eng., P.Geo. Senior Geotechnical Engineer

KSJ/AJB/mp/sjk

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page 15 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

REFERENCES

Dahlin, T. 1996. 2D Resistivity Surveying for Environmental and Engineering Applications, Vol. 14, No. 7. Fulton, R. J., Alley, N. F., and Achard, R. A. 1986: Surficial geology, Seymour Arm, British Columbia; Geological Survey of Canada Map 1609A, scale 1:250,000. Holland, S.S. 1976. Landforms of British Columbia: a physiographic outline. Bulletin 48, The Government of the Province of British Columbia. Madrone Environmental Services. 2007. Terrain classification and terrain stability mapping Albreda and Messiter project areas. 06.0419, Madrone Environmental Services Ltd. Massey, N.W.D., MacIntyre, D.G., Desjardins, P.J., and Cooney, R.T. 2005. Digital geology map of British Columbia: Whole province. 2005-1, B.C. Ministry of Energy and Mines, Victoria, B.C. Murphy, D.C. 2007. Geology Canoe River Open File 2110A. Geological Survey of Canada. Palacky, G.J, 1987, Resistivity Characteristics of Geologic Targets, Society of Exploration Geophysics, v. 1.Seeman, M. and Blyth, H. 2000. Detailed terrain stability mapping of the Upper North Thompson watershed: Lebher creek - Miledge creek. Quaterra Environmental Consulting Ltd. Comox, British Columbia. Seemann, M., and H. Blyth. 2000. Detailed terrain stability mapping of the upper North Thompson watershed: Lebher Creek – Miledge Creek. Prepared for Tolko Industries Limited, Louis Creek Division. Louis Creek, British Columbia. Trans Mountain Pipeline ULC. 2013. Trans Mountain Expansion Project Application to the National Energy Board. Volume 4A – Appendix I: Route Physiology and Hydrology. 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.

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell Page 16 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

DRAWINGS

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell BGC ENGINEERING INC. PAGE: 1 OF 1 NAME: 581.1 DESC: NORTH THOMPSON RIVER AT CHAPPELL

715 715 1953710 IMAGERY 2010710 IMAGERY755 815 E 351,500 E 352,000 E 352,500 E 351,500 E 352,000 E 352,500 E

E 352,250 E 352,250 E N5,814,750 N5,807,500 352,500 E 352,750 E 352,500 E 352,750 E

845

745 805

845

805

855 ER 855 ER IV IV N5,807,250 R R N5,807,250 ³ N N 745 O O S S 725 725 P 735 P 735 M M

O 795 O 795

H 835 H 835 NT ORT HTHOMPSON RIVER 775 NT ORT HTHOMPSON RIVER 775 H H T T R 715 !KP576.0 R 715 !KP576.0

O 870 O 870 N N N5,807,000 N5,807,000 750 750 N5,807,000 N5,807,000

765 765

785 785

825 825

? ? 865 865

710 710

730 730

S S

N5,806,750 E 830 E 830 N5,806,750 770 790 770 790 R R HDDEXITPOINT P P 710 E 710 E N N T T I I N N ! E ! E C HDDEXITPOINT C R R E E E E K K

705 705

Y A

W H N5,806,500 N5,806,500 G N5,806,500 I H

705 ! D 705 ! KP577.0 A KP577.0 E CN H CN 745 W 745 725 O 705 L 705

E 353,000 E E 352,500 E 352,750 E 352,500 E 352,750 E L E Y

715 715

750 750 735 735

755 755 735 735 E 351,250 E 351,250 E E 351,500 E 351,750 E HDDEN T RYPOINT 351,500 E 351,750 E HDDEN T RYPOINT ! ! 730 730

785 785

C H A P P E LL C R E E K C H A P P E LL C R E E K 725 725

N5,806,000N 5,806,000 N5,806,000 N5,806,000 705

725 725 705 710 710

770 770

735 735

? ?

N5,805,750 N5,805,750

755 745 !KP578.0 !KP578.0 730 730

815 815

795 785 N5,805,500 N5,805,500 N5,805,500 715 L EGEND 715 N5,805,500 765 765

750 750 PROPOSEDHDD BOREPAT H

785 ? N ORTTHOMPSON H RIVER FLOWDIRECT ION N ORTTHOMPSON H RIVER 770 790 770 755 745 SCALE 1:10,000 705 HISTORICALCHANN EL 705 800 800 100 0 100 710 200 300 710 T HISDRAWING MAY HAVE BEEN REDU CEDOR ENL ARGED. RAILWAY ALLFRACT ION ALSCALE NOT ATION SINDICATED ARE N5,805,250 N5,805,250 MET RES BASEDON ORIGINAL FORMAT DRAWINGS. T MPLRoW 775

E 352,500 E 353,000 E 351,500 E 352,500 E 353,000 E E 352,000 E 352,000 E SCALE: PROJECT : N OT ES: 1:10,000 GEOT ECHN CIALHDD FEASIBILITY ASSESSMENT 1. ALL DIMENSION 1. SARE METIN RESUN L ESSOT HERWISENOT ED. N ORTTHOMPSON H RIVER AT CHAPPELL DATE: 2. THIS DRAWING 2. MU STBEREAD CONIN JUN CT IONWITH BGC'S REPORT TITL ED"GEOT ECHN CIALHDD FEASIBILITY ASSESSMENT NORT THOMPSON H RIVER AT CHAPPELL AT SSEID –REVISIONKP577.1 005.11 AND 0", DATED OCT OBER2018. OCT2018 BGCENGINEERING INC. ATSSEID –REVISIONKP577.1 005.11 0 3. PROPOSED 3. HDD PROFILE PROV IDEDBY UPILTON NOV D., EMBER2016. 17, ANAPPLIED EART HSCIENCES COMPANY T ITL E: DRAWN : 4. BASE TOPOGRAPHIC 4. DATA BASED ON LIDAR PROV IDEDBY McELHANN EYCON SU L T INGSERV ICESLTAND D., DATED SEPTEMBER 2014. 16, MIB, JVC B GC BANKEROSION AND AVU L SIONREVIEW CLIENT : 5. ORT HOIMAGE5. PROV IDEDBY KINDER MORGAN CANADA FROM I-CU BED:INFORMATION INT EGRATIONIMAGING,& LLDATED C., BETWEEN JANU ARY2008THROU GHAU GU ST2010. CHECKED: CAP, MT 6. PROJECT 6. IONNADIS 1983UT MZON 11N. E PROJECTNo.: DWGNo.: 7. UN L7. ESSBGC AGREES OT HERWISEWRITING,IN THIS DRAWING SHALL NOT BEMODIFIED OR USED FOR ANY PU RPOSEOT HERTHAN THE PURPOSE FOR WHICH BGC GENERATED BGC IT. SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS APPROV ED: ARISING ANY IN WAY FROM ANY USE OR MODIFICATION OFTHIS DOCU MENTNOT AUT HORIZEDBY BGC.ANY USE OFOR RELIANCE UPON THIS DOCU MENTOR ITSCON T ENTBY THIRD PART IESSHALL BEAT SU CHTHIRD PART SOLE IES' RISK. KSJ 0095-150 01 :Poet\0510GSPouto\eot\0807Goehia_D_esblt_ses n\ rhTo snRvraCapl_SI_0p1_P57t\1Bn_rso_vlinRve_ot_hmpson_atChappell.mxd pson_River_atChappell_SSEID_005pt11_KP_577pt1\01_Bank_Erosion_Avulsion_Review_North_Thom orth_Thom ent\N X:\Projects\0095\150\GIS\Production\Reports\20181017_Geotechnical_HDD_Feasibility_Assessm

! ! ! 351,500 352,000 352,500 353,000 5,807,000 5,807,000 735 800

875 720

835 715 760 765 770 775 875 780 785 745 790

820

850 725 865

710 755

795

³ 825 840 750 845 880 855

870

895

890 HDDEXITPOINT 860

705 830 ! N ORT H 710 715

T HOMPSON 805 RIVER 715 795

740

740

740

Y 5,806,500 A 750 5,806,500 W H KP577.0 G ! I CN H

D A 705 705 S 730 ERPE E N T IN E CRE H EK W 745 O 705 L L E 705 Y 705 705

755

755

750

760 K 765 E 735 E CHA R P PEL L C

775

725 ! HDDEN T RYPOINT 785

730

720 780

715 770

740

L EGEND 5,806,000 5,806,000 T HISDRAWING MAY HAVE BEEN 710 PROPOSEDHDD BOREPAT H REDU CEDOR ENL ARGED. 705 ALLSCALE NOT ATION SINDICATED 725 PROPOSEDTMEP ALIGN MENT AREBASED ON ORIGINAL 720 V ERSIONSSEID 005.11 FORMATDRAWINGS.

735 FLOWDIRECT ION SCALE1:5,000 770 RAILWAY 100 50 0 100 200 WATERBODY

765

740730 T MPLRoW

MET RES 351,500 352,000 352,500 353,000

SCALE: PROJECT : N OT ES: 1:5,000 GEOT ECHN CIALHDD FEASIBILITY ASSESSMENT 1. ALL DIMENSION 1. SARE METIN RESUN L ESSOT HERWISENOT ED. N ORTTHOMPSON H RIVER AT CHAPPELL DATE: 2. THIS DRAWING 2. MU STBEREAD CONIN JUN CT IONWITH BGC'S REPORT TITL ED"GEOT ECHN CIALHDD FEASIBILITY ASSESSMENT NORT THOMPSON H RIVER AT CHAPPELL AT SSEID –REVISIONKP577.1 005.11 AND 0", DATED OCT OBER2018. OCT2018 BGCENGINEERING INC. ATSSEID –REVISIONKP577.1 005.11 0 3. PROPOSED 3. HDD PROFILE PROV IDEDBY UPILTON NOV D., EMBER2016. 17, ANAPPLIED EART HSCIENCES COMPANY T ITL E: DRAWN : 4. BASE TOPOGRAPHIC 4. DATA BASED ON LIDAR PROV IDEDBY McELHANN EYCON SU L T INGSERV ICESLTAND D., DATED SEPTEMBER 2014. 16, LL, JVC B GC BANKEROSION AND AVU L SIONREVIEW CLIENT : 5. ORT HOIMAGE5. PROV IDEDBY KINDER MORGAN CANADA FROM I-CU BED:INFORMATION INT EGRATIONIMAGING,& LLDATED C., BETWEEN JANU ARY2008THROU GHAU GU ST2010. CHECKED: 6. PROJECT 6. IONGCSIS NORT AMERICAN H 1983UT MZON 11U E (CALCU L ATED). CAP, MT PROJECTNo.: DWGNo.: 7. UN L7. ESSBGC AGREES OT HERWISEWRITING,IN THIS DRAWING SHALL NOT BEMODIFIED OR USED FOR ANY PU RPOSEOT HERTHAN THE PURPOSE FOR WHICH BGC GENERATED BGC IT. SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS APPROV ED: ARISING ANY IN WAY FROM ANY USE OR MODIFICATION OFTHIS DOCU MENTNOT AUT HORIZEDBY BGC.ANY USE OFOR RELIANCE UPON THIS DOCU MENTOR ITSCON T ENTBY THIRD PART IESSHALL BEAT SU CHTHIRD PART SOLE IES' RISK. KSJ 0095-150 01B :Poet\0510GSPouto\eot\0807Goehia_D_esblt_ses n\ rhTo snRvraCapl_SI_0p1_P57t\1_akEoinAuso_eiwNrh hom pson_atChappell.mxd pson_River_atChappell_SSEID_005pt11_KP_577pt1\01B_Bank_Erosion_Avulsion_Review_NorthT orth_Thom ent\N X:\Projects\0095\150\GIS\Production\Reports\20181017_Geotechnical_HDD_Feasibility_Assessm

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350,500 351,000 351,500 Cvb Cv 352,000 Cv Ov|Fp 352,500 353,000 gsCv/Rs 353,500 354,000 w III L w IV L w IV L p I L w IV L Mw//Rra w III L Cb KP576.0 Mw//Rk m III L ! Cv-V 5,807,000 w III L 5,807,000 w IV L Mw.Cv-V Cv.Rs-R"b ³ FGkf-V w IV L w-r V H m III L Mb-VRd At m IV L m I L sFAf-UaUd Mv w-m I M w III L

Mb Cb m III L m III L sFt w-m I M 5,806,500 5,806,500 ! Cv KP577.0 Cv//Rs w IV L Cv w IV L w IV L FAp Cv i I H m III L L EGEND PROPOSEDTMEP ALIGN MENTVERSION SSEID005.11 Cv-V w IV M EXIST INGTMPL 24" sgFAf-Ud mm(610 Ø)PIPELINE Ms/Rs-VR"s Cv-VR"s m I M T MPLRoW w V H 5,806,000 w V M Mw RAILWAY 5,806,000 w III L PRIMARYSURFICIAL MATERIALTY PE Cv Mv-V w IV L ANT HROPOGENIC SCALE1:10,000 Mw|Rua w-m IV L COLL U V IUM 200 100 0 200 w II L 400 600 FLU V IAL MET RES GLACIOFLU V IAL Cv|Mvb/Mvb !KP578.0 T HISDRAWING MAY HAVE BEEN REDU CEDOR ENL ARGED. w-m III L GLACIALTILL ALLFRACT ION ALSCALE NOT ATION SINDICATED ARE BASEDON ORIGINAL FORMAT DRAWINGS.

350,500 351,000 351,500 352,000 352,500 353,000 353,500 ORGANIC 354,000

780 ELEVATIONPROFILEVERT - ICALEXAGGERAT ION(m) 760

! 740 RK576

A@ 720 ! RK578 A@ SCALE1:10,000 ! !! A@ ELEVATION (masl) ELEVATION 700 200 100 0 200 400 600 RK577

680 MET RES

N OT ES: KPDIST ANCE(m) 1. ALL DIMENSION 1. SARE METIN RESUN L ESSOT HERWISENOT ED. 2. THIS DRAWING 2. MU STBEREAD CONIN JUN CT IONWITH BGC'S REPORT TITL ED"GEOT ECHN CIALHDD FEASIBILITY ASSESSMENT –NORT THOMPSON H RIVER AT CHAPPELL AT SSEID –REVISIONKP577.1 005.11 AND 0", DATED OCT OBER2018. 3. PROPOSED 3. PIPELINE CENT RELINEVERSION SSEID PROV005.11 IDEDBY UPILTRECEIVED D., AU GU ST2018 15, SCALE: PROJECT : 4. WATERBODY 4. AND ST REAMDATA FROM NRCAN CANV EC. 1:10,000 GEOT ECHN CIALHDD FEASIBILITY ASSESSMENT N ORTTHOMPSON H RIVER AT CHAPPELL 5. ORT HOIMAGE5. PROV IDEDBY KINDER MORGAN CANADA FROM I-CU BED:INFORMATION INT EGRATIONIMAGING,& LLDATED C., BETWEEN JANU ARY2008THROU GHAU GU ST2010. DATE: 6. BASE TOPOGRAPHIC 6. DATA BASED ON LIDAR PROV IDEDBY McELHANN EYCON SU L T INGSERV ICESLTAND D., DATED SEPTEMBER 2014. 16, OCT2018 BGCENGINEERING INC. ATSSEID –REVISIONKP577.1 005.11 0 ANAPPLIED EART HSCIENCES COMPANY T ITL E: 7. PROPOSED 7. HDD PROFILE PROV IDEDBY UPILTON NOV D., EMBER2016. 17, DRAWN : M IB, JVCMIB, B GC T ERRAINMAP 8. FOR FULA 8. LEXPLANATION OFTHE TERRAIN MAPPING TERMS AND SY MBOLSSEE THE COMPLET LEGEND E DRAWINGIN TERRAIN02B. POLY GON SBASED ON TERRAIN MAPPING COMPLETED UP TO JUL Y2015BY BGC. CLIENT : 9. THIS MAP SN A9. IS APSHOTTIME.INCHANGES LANDIN USE DEVELOPMENT (E.G. RIVER , MIGRATION MAY ) WARRANT RE-DRAWING OFCERT AINAREAS. CHECKED: CAP, MT 10. PROJECT 10. IONNADIS 1983UT MZON 11N. E PROJECTNo.: DWGNo.: 11. UN 11. L ESSBGC AGREES OT HERWISEWRITING,IN THIS DRAWING SHALL NOT BEMODIFIED OR USED FOR ANY PU RPOSEOT HERTHAN THE PU RPOSEFOR WHICH BGC GENERATED BGC IT. SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS APPROV ED: KSJ 0095-150-14 02A ARISING ANY IN WAY FROM ANY USE OR MODIFICATION OFTHIS DOCU MENTNOT AUT HORIZEDBY BGC.ANY USE OFOR RELIANCE UPON THIS DOCU MENTOR ITSCON T ENTBY THIRD PART IESSHALL BEAT SU CHTHIRD PART SOLE IES' RISK. :Poet\0510GSPouto\eot\0807Goeh clHDFaiiiyAssmntNorth_Thompson_River_atChappell_SSEID_005pt11_KP_577pt1\02A_Terrain_Map_North_Thompson_atChappell.mxd t\N ical_HDD_Feasibility_Assessmen X:\Projects\0095\150\GIS\Production\Reports\20181017_Geotechn Terrain Mapping Legend

SimpleTerrain Symbols: U se dwhen one surficial mate rialisprese ntwithin apolygon GeomorphologicProce sses NaturalHazard Classe s

Exam ple: Cb–Rb A SnowAvalanches M Me ande ringChanne l B Braide dChanne l N Nivation L Noexisting hazard, or hazard isdormant. hazard i.e. has not be e nactive inthe last to1001,000 yearsor ithas de ve lope dunde diffe r rentclimatic conditions. SurficialMate rial Geomorphological proce sssub-type E Me ltwate channe r ls P P iping Surface expression Geomorphological proce ss(uptomay 3 be assigne d) F Slowlandslide (runout zone ) R R apidlandslide (runout zone ) M H azardisinactive Ve . ge tate dtracks can be obse rve dinairphotos. Smaller more freque nteve nts, F” Slowlandslide (initiation zone ) R ” R apidlandslide (initiation zone ) suchas rock fall,may affe ctasmall area ofthe polygon. No evide ncethat the hazard has be e n G Anthropoge nicground disturbance S Solifluction CompositeTerrain Symbols: U se dwhen orte2 3 rraintype sare prese ntwithin apolygon activewithin years20 but trigge is rprese Hazard nt. isunlikely tooccur within the life ofthe H Kettled U Flooding project. I IrregularChanne l V Gullyerosion Cv.Mv indicate sthat ‘C’ and ‘M’ are roughly equal inexte nt J Anastam osingChanne l W W ashing H H azardiscurrently active or shows evide nceofactivity inthe last years.20 Hazard likely to Cv/Mv indicate sthat ‘C’ isgreate in rexte ntthan ‘M’ (about 60:40) K Karst X P e rmafrost occurwithin the life ofthe project. Cv//Mv indicate sthat ‘C’ ismuch greate in rexte ntthan ‘M’ (about 80:20) L See page Z P e riglacialProce sses SoilDrainage Classe s StratigraphicTerrain Symbols GeomorphologicalProce ssSubtype s r R apidlydraine d W ateis rrem ove dfrom the soil rapidly inrelation tosupply. Cv|Mj indicate sthat ‘Cv’ ove rlies‘Mj’Note is]also[ : use dinste adofa ve rticalline on some maps w W e ll-draine d W ateis rrem ove dfrom the soil readily but not rapidly. /Cv|Mj indicate sthat ‘Cv’ partially ove rlies‘Mj’ W ateis rrem ove dfrom the soil some w hatslowly inrelation to a channeavulsion l g R ockcree p s Debrisavalanches m Mode rate lywe ll-draine d b R ockfall k te nsioncracks/sacking u Surficialmate rialslum p supply. SurficialMate rialType s c soilcree p m Bedrockslum p Ud de brisfloods W ateis rrem ove dfrom the soil sufficiently slowly inrelation to d Debrisflows r R ockslide s x slum p/earthflow combine d i Impe rfe ctlydraine d supplytokee pthe soil we for t asignificant part ofthe growing A Anthropoge nic I Ice R Bedrock e Earthflow se ason. C Colluvium L Lacustrine W G Glaciomarine W ateis rrem ove dso slowly inrelation tosupply that the soil D W e atheredbedrock LG Glaciolacustrine U Till,Glaciolacustrine Glaciofluvial , (inte rbedde d) p P oorlydraine d rem ainswe for t acomparative lylarge part ofthe time the soil is E Eolian M GlacialTill notfrozen. F Fluvial N Notmappe d(usually alake or large rive r) TexturalTerms and Symbols W ateis rrem ove dfrom the soil so slowly that the wate table r FG Glaciofluvial O O rganic v V e rypoorly draine d rem ainsator on the surface for the greate part r ofthe time the a blocks g grave l s sand soilisnot frozen. boulde rs hum icorganics m e sicorganics SurfaceExpressions b h u c clay k cobbles x angularfragm e nts Exam ples m ixedfragm e nts m ud silt a Mode rateSlope (15-26°) p P lain(0-3°) d m z fibricorganic Ste e pbe drockslope with <20% cove of ra colluvial ve ne egullied r; with initiation zone sfor rockfall and b Blanketmthick (>2 deposit) r R idge e p pe bbles R s//Cv–VR ”bd VH de brisflows. Expe cte dtocontain areas with ahigh likelihood oflandslide initiation following road c Cone(>15°) s Ste e pSlope (>35°) construction.Debris flows and rock fall are likely tooccur within the life ofthe project. f Fan (<15°) t Terrace h H um m ocky u U ndulating FAp-U Activefloodplain pote ntiallysubject toflooding. No significant stability problem sexist. Inactive flood j j GentleSlope (4-14°) v V e nemthick e (0-2 rdeposit) TerrainStability Class M I hazardisunlikely tooccur during the life timeofthe project k Mode rate lySte e pSlope (27-35°) w V ariableThickne ssDeposit) m R olling x ve rythin ve nethick e (0-.5m rdeposit) I Nosignificant stability problem sexist. LGks-VR ”s Mode rate lyste e ptoste e pglaciolacustrine slope with gullies. High likelihood ofde brisavalanches V MV followingmajor landform change Small s. natural de brisslide sare possible within years.20 II Thereis ave rylow likelihood of landslide sfollowing right of way clearing, pipe lineand road construction. Minorinstability isexpe cte dalong cut slope espe s, ciallyforor years1 2 following construction LabeLege l nd ActivityLeve l III Thereisa low likelihood of landslide initiation following right ofway clearing, pipe lineand road construction. Minorinstability isexpe cte dalong cut slope espe s, ciallyforor years1 2 following construction. 10Cbs-Rsw TERRLABEL AIN AND DR AIANGE FAp ‘AIndicate’ sactive floodplain (subject tochanne change l s) III M III TERRSTABILITY AIN CLASS AND NATU R ALHAZARD CLASS CIf ‘I’ Indicate sinactive fan IV Expe cte dto contain areas with amode ratelikelihood of landslide initiation following right ofway clearing, pipe lineand road construction. We se t asonconstruction will significantly increase the pote ntialfor construction- relate dlandslide s.

SACKU NG V Expe cte dtocontain areas with ahigh likelihood oflandslide initiation following right ofway clearing, pipe line androad construction. W eand t or winte rseason construction will significantly increase the pote ntialfor LANDSLIDESCAR P construction-relate dlandslide s. LANDSLIDEPATH

SCALE: P R O J ECT: NO TES: NTS GEO TECH NCIALHDD FEASIBILITY ASSESSMENT 1. THISDR AW1. INGMU STBEREAD COIN NJU NCTIONWITH BGC'S REPO RTITLED T "GEO TECH NCIALHDD FEASIBILITY ASSESSMENT NO R THTHO MP SO NRIVER ATCH APP ELLATSSEIDKP 005.11 577.1 NO R THTHO MP SO NRIVER ATCH APP ELL DATE: –REVISION AND DATED 0", OCTO BER2018. O CT2018 BGCENGINEERING INC. SSEIDATKP–REVISION 005.11 577.1 0 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 ATEDSHIT. ALL ANAPP LIEDEARTH SCIENCES CO MP ANY TITLE: DR AW N: HAVE NO LIABILITYFO RANY DAMAGES OR LO SSAR ANY ISINGIN WAY FRO MANY USE OR MO DIFICATIONOF THISDO CU MENTNO AU T THO R IZEDBY BGC. ANY USE OF OR RELIANCE UP OTHIS N JVJDC C, B GC TER RMAP AIN LEGEND CLIENT: DO CU MENTOR COITS NTENTBY THIRD PAR SH TIES ALLBESUAT CHTHIRD PAR SO TIES' LERISK. CH ECKED: SHSAA , P R O J ECTNo.: DW GNo.: APP R O V ED: CB 0095-150 02B \ oet\0510GSPrdcinReprs2111_eoecnclHD_esblt_sesm tNrhTopo_ v _thpel_SI_0p1_P57t\2_eri_eend.mxd ll_SSEID_005pt11_KP_577pt1\02B_Terrain_Lege r_atChappe ive ssme nt\North_Thompson_R DD_Feasibility_Asse ote chnical_H e ports\20181017_Ge roduction\R rojects\0095\150\GIS\P X :\P N 5,806,250 N 5,806,500 N N PROPOSED TMEP E 352,000 RIVER CROSSING E 351,750

SCALE 1:1,000,000 NORTH E 352,250 10,000 0 10,000 20,000 30,000 RIVER THOMPSON

METRES BLUE RIVER BC THIS DRAWING MAY HAVE BEEN REDUCED. ALL SCALE NOTATIONS INDICATED ARE BASED ON ORIGINAL FORMAT DRAWINGS. N 5,806,750 HDD ENTRY POINT A - HDD EXIT POINT

BH-BGC13-NTC-01 BH-BGC14-NTC-03

NORTH THOMPSON RIVER SCALE 1:2,500 BH-BGC14-NTC-02 25 0 755025

N 5,806,250 N 5,806,500 N 5,806,750 METRES THIS DRAWING MAY HAVE BEEN REDUCED. ALL SCALE NOTATIONS INDICATED ARE BASED ON ORIGINAL FORMAT DRAWINGS. E 352,000 E 352,250 03_NTC_(RK_581.1)_INTERPRETED_GEOLOGICAL_SECTION.dwgOct 19 18 Layout: 5:18 PM 03 Time: Plot Date

SOUTHWEST ELECTRICAL RESISTIVITY TOMOGRAPHY SURVEY NORTHEAST 750 750 BATHYMETRIC SURFACE BH-BGC14-NTC-03 EXISTING GROUND SURFACE (SEE NOTE 4) (OFFSET = 26 m SE) (UPI, LIDAR, APRIL 2014) HDD ENTRY POINT BH-BGC13-NTC-01 BH-BGC14-NTC-02 HDD EXIT POINT 725 NOVEMBER 30, 2014 725 (OFFSET = 31 m SE) 200-YEAR STREAM FLOW (OFFSET = 77 m SE) OCTOBER 22, 2013 EL. 705.1 m Xref .\XREF\BH-BGC13-NTC-01.dwg AUGUST 31, 2014 700 700

ELEVATION (m) 675 675 ELEVATION (m) ? ? ? 650 650 -100 0 100 200 300 400 500 600 700 800 SCALE 1:2,500 BOREHOLE DISTANCE (m) 25 0 755025 A CROSS-SECTION - METRES THIS DRAWING MAY HAVE BEEN REDUCED. ALL SCALE NOTATIONS INDICATED ARE BASED ON ORIGINAL FORMAT DRAWINGS.

LEGEND PLAN INTERPRETED TOP OF SCOUR NOTES: 1. GROUND SURFACE PROFILE BASED ON LIDAR, PROVIDED BY UPI, AND DATED APRIL 18, PROPOSED HDD ENTRY / EXIT POINTS INFERRED GEOLOGY CONTACT 2014. 2. PROPOSED HDD ALIGNMENT AND PROFILE PROVIDED BY UPI LTD. ON MAY 29, 2013. EXISTING BOREHOLE LOCATION BOREHOLE INFERRED GEOLOGY 3. BASE TOPOGRAPHIC DATA BASED ON LIDAR PROVIDED BY UPI, AND DATED APRIL 18, 2014. CONTOUR INTERVAL IS 1.0 m. PROPOSED HDD BOREPATH FLUVIAL SAND AND GRAVEL 4. BATHYMETRIC DATA PROVIDED BY OPUS STEWART WEIR, AND DATED AUGUST 26 AND 27, PROPOSED TMPL ALIGNMENT (GW AND SP-SM) 2014. (SSEID 005.11) 5. ORTHOIMAGE PROVIDED BY KINDER MORGAN CANADA, FROM I-CUBE: INFORMATION GLACIOLACUSTRINE SILT AND INTEGRATION & IMAGING, LLC., DATED BETWEEN JANUARY 2008 THROUGH AUGUST 2010. 200-YEAR FLOW EXTENT 6. PROPOSED SSEID 005.11 PIPELINE ALIGNMENT PROVIDED BY UPI, AND RECEIVED CLAY (ML AND CL) AUGUST 15, 2018. SECTION 7. PROJECTION IS NAD 83 UTM ZONE 11U. GROUNDWATER OBSERVATIONS 200-YEAR FLOW ELEVATION GLACIOFLUVIAL SAND (SM) 8. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. 9. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT BOREHOLE DEPTH (mbgs) ELEVATION (m) COMMENTS SCALE: AS SHOWN PROJECT: GEOTECHNCIAL HDD FEASIBILITY ASSESSMENT - TITLED “GEOTECHNCIAL HDD FEASIBILITY ASSESSMENT - NORTH THOMPSON RIVER AT NORTH THOMPSON RIVER AT CHAPPELL AT CHAPPELL AT SSEID 005.11 KP 577.1 - REVISION 0” DATED OCTOBER 2018. 5.4 704.66 DATE: SSEID 005.11 KP 577.1 - REVISION 0 10. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR BH-BGC13-NTC-01 STABILIZED FOLLOWING BH COMPLETION OCT 2018 TITLE: USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH BGC GENERATED IT. DRAWN: AH INTERPRETED GEOLOGICAL SECTION BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM BH-BGC14-NTC-02 1.66 703.34 STABILIZED FOLLOWING BH COMPLETION CLIENT: ANY USE OR MODIFICATION OF THIS DOCUMENT NOT AUTHORIZED BY BGC. ANY USE OF CHECKED: CAP PROJECT No.: DWG No.: OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT BH-BGC14-NTC-03 4.5 716.18 STABILIZED FOLLOWING BH COMPLETION 0095-150 03 SUCH THIRD PARTIES' SOLE RISK. APPROVED: KSJ X:\Projects\0095\150\CAD\OVERALL\PRODUCTION\REPORT\20181017_PRELIMINARY_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_-_NORTH_THOMPSON_RIVER_AT_CHAPPEL_AT_RK_581.1\ N 5,806,500 N 5,806,750 N N 5,806,250

E 352,000 E 352,250

HDD ENTRY POINT HDD EXIT POINT

BH-BGC13-NTC-01 BH-BGC14-NTC-03

SCALE 1:2,500

25 0 755025 NORTH THOMPSON RIVER N 5,806,250 N 5,806,500 N 5,806,750 METRES BH-BGC14-NTC-02 THIS DRAWING MAY HAVE BEEN REDUCED. ALL SCALE NOTATIONS INDICATED ARE BASED ON ORIGINAL FORMAT DRAWINGS. E 352,000 E 352,250 SOUTHWEST NORTHEAST ELECTRICAL RESISITIVITY TOMOGRAPHY SURVEY 750 750 EXISTING GROUND SURFACE BH-BGC14-NTC-03 HDD EXIT POINT HDD ENTRY POINT (WORLEY PARSONS FIELD SURVEY, AUGUST 2013) (OFFSET = 26 m E) (OFFSET = 1 m W) BH-BGC13-NTC-01 (OFFSET = 2 m E) 725 BH-BGC14-NTC-02 725 (OFFSET = 31 m E) (OFFSET = 79 m E)

700 1500 1500 700 1750 1500 1750 675 675 ELEVATION (m) ELEVATION (m) 04_NTC_(RK_581.1)_GEOPHYSICS_RESULTS.dwg5:24 PM 04 Time: Plot Date Oct 19 18 Layout: 650 650 1750 2000 2000 2250 625 625 -102-102-100 -100 0 100 200 300 400 500 600 700 800800809 809 SCALE 1:2,500 BOREHOLE DISTANCE (m) 25 0 755025 ELECTRICAL RESISIVITY FIELD PARAMETERS: (ohm-m) DATA COLLECTED: AUGUST-18-2013 METRES ELECTRODE CONFIGURATION: GRADIENT PLUS THIS DRAWING MAY HAVE BEEN REDUCED. ALL SCALE NOTATIONS INDICATED ARE BASED ON ORIGINAL FORMAT DRAWINGS. MINIMUM ELECTRODE SPACING: 5 m 2014 SEISMIC SURVEY 750 750 EXISTING GROUND SURFACE 2013 SEISMIC SURVEY (WORLEY PARSONS FIELD SURVEY, AUGUST 2013) 725 725 725 725

700 1500 700 700 1500 700 1500 1750 1750

ELEVATION (m) 675 675 ELEVATION (m) 675 675 -102-102-100 -100 0 100 200 260 BOREHOLE DISTANCE (m) P-WAVE VELOCITY 650 650 (m/s) 1750

625 625 2000

FIELD PARAMETERS: GEOPHONE SPACING: 5 m ELEVATION (m) ELEVATION (m) DATA COLLECTED: SHOT SPACING: 20 m 2250 AUGUST-18 TO 19-2013 SOURCE: SLEDGEHAMMER 600 600

LEGEND 2500 575 575 PLAN SECTION SCALE 1:2,500 FIELD PARAMETERS: PROPOSED HDD ENTRY / EXIT POINTS P-WAVE VELOCITY CONTOURS 25 0 755025 DATA COLLECTED: OCTOBER-16-2014 EXISTING BOREHOLE LOCATION BOREHOLE GEOLOGY 550 GEOPHONE SPACING: 5 m 550 METRES SHOT SPACING: 20 m PROPOSED TMPL ALIGNMENT FLUVIAL SAND AND GRAVEL (GW AND SP-SM) THIS DRAWING MAY HAVE BEEN REDUCED. ALL SCALE NOTATIONS SOURCE: BUFFALO GUN (SSEID 005.11) INDICATED ARE BASED ON ORIGINAL FORMAT DRAWINGS. GLACIOLACUSTRINE SILT AND CLAY (ML AND CL) 525 525 SEISMIC SURVEY ALIGNMENT 325 400 500 600 700 800800809 809 BOREHOLE DISTANCE (m) ERT SURVEY ALIGNMENT GLACIOFLUVIAL SAND (SM)

NOTES: 6. PROJECTION IS NAD 83 UTM ZONE 11U. 1. GEOPHYSICS SURVEY INTERPRETATION AND GROUND SURFACE PROFILE PROVIDED BY WORLEY 7. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. SCALE: PROJECT: GEOTECHNCIAL HDD FEASIBILITY ASSESSMENT - PARSONS FIELD SURVEY, DATED AUGUST 18-19, 2013 AND OCTOBER 29, 2014. 1:2,500 8. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNCIAL HDD NORTH THOMPSON RIVER AT CHAPPELL AT 2. PROPOSED HDD ALIGNMENT AND PROFILE PROVIDED BY UPI LTD. ON MAY 29, 2013. FEASIBILITY ASSESSMENT - NORTH THOMPSON RIVER AT CHAPPELL AT DATE: SSEID 005.11 KP 577.1 - REVISION 0 3. BASE TOPOGRAPHIC DATA BASED ON LIDAR PROVIDED BY UPI, AND DATED APRIL 18, 2014. SSEID 005.11 KP 577.1 - REVISION 0” DATED OCTOBER 2018. OCT 2018 TITLE: CONTOUR INTERVAL IS 1.0 m. 9. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED DRAWN: AH GEOPHYSICS RESULTS 4. ORTHOIMAGE PROVIDED BY KINDER MORGAN CANADA, FROM I-CUBE: INFORMATION FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH BGC GENERATED IT. BGC SHALL HAVE CLIENT: INTEGRATION & IMAGING, LLC., DATED BETWEEN JANUARY 2008 THROUGH AUGUST 2010. NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION CHECKED: CAP PROJECT No.: DWG No.: 5. PROPOSED SSEID 005.11 PIPELINE ALIGNMENT PROVIDED BY UPI, AND RECEIVED AUGUST 15, OF THIS DOCUMENT NOT AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT 0095-150 04 2018. OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. APPROVED: KSJ X:\Projects\0095\150\CAD\OVERALL\PRODUCTION\REPORT\20181017_PRELIMINARY_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_-_NORTH_THOMPSON_RIVER_AT_CHAPPEL_AT_RK_581.1\ 05_NTC_(RK_581.1)_FIELD_PHOTOS.dwg Plot Date Oct 17 18 Layout: 11:22 AM 05 Time:

PHOTO 1: LOOKING NORTHWEST TO SOUTHEAST OF A PANORAMA OF THE PHOTO 2: BH-BGC14-NTC-02 SPT SAMPLE FROM 5.13 m - 5.74 m. PHOTO 3: BOTTOM HALF BH-BGC13-NTC-01 SPT SAMPLE FROM 10.06 m - 10.67 m. TRANSMISSION LINE ROW AND PROPOSED HDD BOREPATH RUNNING TYPICAL FLUVIAL SAND AND GRAVEL FOUND NEAR SURFACE TYPICAL THIN, LOW PLASTIC CLAY ZONE BENEATH THE WATER TABLE PERPENDICULAR TO IT

PHOTO 4: BH-BGC14-NTC-02 SPT SAMPLE FROM 21.89 m - 22.58 m. PHOTO 5: BH-BGC14-NTC-03 SPT SAMPLE FROM 24.38 m - 24.99 m. PHOTO 6: BH-BGC14-NTC-02 SPT SAMPLE FROM 26.47 m - 27.08 m. DETAIL OF DILATENT SILT. LOWER OF 2 HALVES SHAKEN IN PALM FOR A FEW TYPICAL GLACIOFLUCIAL SAND AND SILT ENCOUNTERED NEAR THE TYPICAL FLUVIAL/GLACIOFLUVIAL SAND AND SILT ENCOUNTERED NEAR THE SECONDS. BEFORE AGITATION (LEFT) AND AFTER AGITATION (RIGHT). PROPOSED EXIT POINT. PROPOSED HDD INFLECTION POINT.

SCALE: N.T.S. PROJECT: GEOTECHNCIAL HDD FEASIBILITY ASSESSMENT - NOTES: NORTH THOMPSON RIVER AT CHAPPELL AT SSEID 1. PIPELINE RK BASED ON THE V10 CORRIDOR CENTERLINE. DATE: OCT 2018 005.11 KP 577.1 - REVISION 0 2. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. TITLE: 3. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNCIAL HDD FEASIBILITY ASSESSMENT - NORTH THOMPSON RIVER AT DRAWN: AH FIELD PHOTOS CHAPPELL AT SSEID 005.11 KP 577.1 - REVISION 0” DATED OCTOBER 2018. CLIENT: CHECKED: 4. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH CAP 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 APPROVED: 0095-150 05 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. KSJ X:\Projects\0095\150\CAD\OVERALL\PRODUCTION\REPORT\20181017_PRELIMINARY_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_-_NORTH_THOMPSON_RIVER_AT_CHAPPEL_AT_RK_581.1\ Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

APPENDIX A HYDROTECHNICAL INVESTIGATION AND ANALYSIS METHODOLOGY

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

APPENDIX A HYDROTECHNICAL INVESTIGATION AND ANALYSIS METHODOLOGY

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell - Rev 0 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14

TABLE OF CONTENTS

TABLE OF CONTENTS ...... 1 LIST OF TABLES ...... 2 LIST OF FIGURES...... 2 A.1. INTRODUCTION ...... 3 A.2. HYDROTECHNICAL HAZARDS ...... 4 A.2.1. Scour ...... 4 A.2.2. Channel Degradation ...... 5 A.2.3. Bank Erosion ...... 5 A.2.4. Avulsion ...... 5 A.2.5. Encroachment ...... 6 A.3. FLOOD FREQUENCY ANALYSIS (FFA) ...... 6 A.3.1. Monitoring Agencies ...... 7 A.3.2. Historical Peak Flow Records ...... 7 A.3.3. Prediction Limit of Dataset ...... 8 A.3.4. Statistical Validity of Dataset ...... 8 A.3.5. Randomness...... 8 A.3.6. Independence ...... 8 A.3.7. Stationarity ...... 8 A.3.8. Homogeneity...... 9 A.3.9. Statistical Tests ...... 9 A.3.10. Regional FFA ...... 9 A.3.11. Pro-rated FFA ...... 10 A.4. HYDROTECHNICAL HAZARD ASSESSMENT ...... 10 A.4.1. Scour ...... 10 A.4.1.1. Channel Hydraulics ...... 11 A.4.1.2. General Scour Equations ...... 11 A.4.1.3. Maximum Bed Mobility ...... 16 A.4.1.4. Local Scour ...... 17 A.4.1.5. Factor of Safety ...... 18 A.4.1.6. Channels with Cohesive Beds ...... 18 A.4.2. Channel Degradation ...... 18 A.4.3. Bank Erosion ...... 19 A.4.4. Avulsion ...... 20 A.4.5. Encroachment ...... 22 APPENDIX A REFERENCES ...... 24 https://coreshack.bgcengineering.ca/projects/tmepprelimeng/HDDAss/CrossingReports/Appendix A_Hydrotech Methodology Report.docx BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14

LIST OF TABLES

Table A.3-1. Statistical Criteria and Corresponding Statistical Test ...... 9 Table A.4-1. Methods for Estimation of Potential Depth of General Scour ...... 12 Table A.4-2. Empirical Multiplying Factors for Maximum Scour Depth (Joyce and Chandler, 2004) ...... 13 Table A.4-3. Empirical Multiplying Factors for Maximum Scour Depth (Pemberton and Lara, 1984) ...... 13 Table A.4-4. Methods for Estimation of Bed Material Mobility ...... 17 Table 4-A.4-5. Causes of Avulsions According to Schumm (2005) ...... 22

LIST OF FIGURES

Figure A.2-1. Schematic of General and Local Scour (as per Veldman, 2008) ...... 5 Figure A.4-1. Hypothetical Scour Analysis for a Given Design Flood ...... 11 Figure A.4-2. Cross-sectional Channel Changes on the Lillooet River in Response to Meander Cutoffs and Base Level Lowering (after Weatherly and Jakob, 2013) ...... 19 Figure A.4-3 Multi-temporal Ground and Pipe Profile Surveys at a Watercourse Crossing ...... 20 Figure A.4-4. Example of Avulsion in Plan View (left) and Cross-section (right) ...... 21 Figure A.4-5. Example of an Encroachment Hazard (Google Earth imagery year: 2004) ...... 23

https://coreshack.bgcengineering.ca/projects/tmepprelimeng/HDDAss/CrossingReports/Appendix A_Hydrotech Methodology Report.docx BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14

A.1. INTRODUCTION The following appendix describes the different types of hydrotechnical hazards and outlines the methodology followed by BGC during the hazard assessment process. The methodology presented in this appendix includes a brief description of sites selection and terminology conventions and hydrotechnical hazards (Section A.2.) followed by a detailed description of the flood frequency analysis (FFA) (Section A.3.) and scour analysis (Section A.4.1.). Finally, a description of the hydrotechnical assessment specific to each hazard is presented in Section A.4.

Several industry terminology conventions are used herein and within hydrotechnical reports and the definitions are presented here:

Downstream The direction of water flow. Upstream The direction opposite to water flow. Upflow The direction of decreasing pipeline chainage. Downflow The direction of increasing pipeline chainage. Right & left banks Looking downstream. DoC Depth of cover (burial depth) over the pipeline. RoW Pipeline right of way. Thalweg The line defining the lowest points along the length of a river bed or valley. Hazard A characterisation of the hydrotechnical event such as scour, degradation, and bank erosion. The characterisation does not consider the protection around the pipeline (e.g. scour hazard is active at the crossing). Likelihood A qualitative assessment of how often an event may occur (i.e. the likelihood of scour hazard occurring is high). Probability A semi-quantitative assessment of how often an event may occur (i.e. the annual probability of scour hazard occurring is 0.05).

Appendix A_Hydrotech Methodology Report Page 3 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14

A.2. HYDROTECHNICAL HAZARDS Channel geometry and site observations are used to subjectively assess the likelihood of exposure of the pipe from the following hydrotechnical hazards:

 scour of the channel bed;  degradation of the channel bed;  bank erosion caused by lateral channel migration;  avulsion; and  encroachment on the pipeline.

A.2.1. Scour Scour can happen at any location where local flow velocities increase as a result of secondary currents developing within a uniform flow situation. Scour also occurs when the direction of flow is changed at channel bends, confluences, constrictions, obstructions, and impingements. There are two types of scour; general scour and local scour. General scour is the natural variation in bed levels that 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 (Joyce and Chandler, 2001). The channel bed can experience significant scour during a flood event but is often not detected because of compensating deposition that can occur as the flood flows decline (Leopold et al., 1964). General scour typically requires a qualitative geomorphic analysis to quantify. Local scour occurs 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 like at the confluence of two separate channels. 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. Generally, depths of local scour are larger than general scour. Figure A.2-1 shows a schematic of general and local scour. The scour depths shown in the diagram are relative to the design flood water surface level. The calculations carried out by BGC to predict scour depths are relative to the bed of the channel.

Appendix A_Hydrotech Methodology Report Page 4 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14

Figure A.2-1. Schematic of General and Local Scour (as per Veldman, 2008)

A.2.2. Channel Degradation While scour is considered event-based, channel degradation occurs over a long time and along relatively long stream reaches. Degradation is the process of a general lowering of the channel bed, and is the result of the process of channel morphology reaching equilibrium with the existing flow regime (Ulrich et al., 2005). The degradation of a stream channel can be caused by gullying, the presence of downstream obstructions such as beaver dams, and erosion as a result of bed steepening. Degradation may also occur due to an increase in average discharge, a reduction in average bed material load or diverting and confining flows into a single channel where there had previously been multiple channels (alluvial fans). Degradation is a very common fluvial hazard.

A.2.3. Bank Erosion Patterns of sediment transport and deposition naturally cause the channel banks to migrate laterally. Bank migration (erosion) at a pipeline crossing can result in exposure of the sag- bends and over-bends of the pipeline. Bank erosion most often occurs on outer bends of meandering river channels and along braided rivers. Erosion can take place slowly over a period of years or suddenly during a single flood event. Bank erosion is the most recognizable of all five river hazards.

A.2.4. Avulsion Avulsion, also referred to as outflanking, or abandonment, may occur when streams have the potential to leave their channel upstream of a crossing and establish a new channel where the pipeline has insufficient cover. Avulsion is predominantly a concern on alluvial fans that carry high bed material loads. Avulsion 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

Appendix A_Hydrotech Methodology Report Page 5 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14 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, should be limited to 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).

Avulsions 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.

A.2.5. Encroachment Encroachment to the pipeline may occur on a meandering watercourse when a section of the channel flows parallel with the pipeline right of way. Bank erosion can lead to lateral movement of the watercourse towards the pipeline. Encroachment is typically a concern where rivers meander along a wide floodplain.

A.3. FLOOD FREQUENCY ANALYSIS (FFA) Flood discharge magnitude and frequencies are estimated using a flood frequency analysis (FFA). A popular approach in hydrologic frequency modeling is the Annual Maximum Series (AMS) where the maximum value over a period of time is used for analysis. In this case, the AMS consists of the maximum peak instantaneous streamflow for each year on record. The AMS is assumed to be a random sample from the underlying population of hydrological events and can thus be predicted by the selection of an appropriate distribution. In extreme value statistics, data follow one of three extremal types of distributions: Gumbel, Fréchet, or Weibull (Coles, 2001). These three distributions can be expressed as a single formula and are considered a family of distributions known as the Generalized Extreme Value (GEV) distribution. The GEV distribution is described by a location, scale, and shape parameter where the three extremal types are determined by the sign of the shape parameter (Gilleland and Katz, 2006). For example, when the shape parameter is negative, the distribution is described by the Weibull type. As the shape parameter approaches zero, the distribution is described by the Gumbel type. When the shape parameter is positive, the distribution is described by the Fréchet type. The GEV distribution is selected for the AMS approach to frequency analysis. The GEV distribution is generally suited for large design flood predictions (i.e. >100-year return period). In cases where lower return period events are required for analysis, other specified theoretical probability distributions may be selected for analysis. These distributions include but are not limited to the following: Normal (N), Log Normal (LN),

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Pearson Type III, (P3), Log Pearson Type III (LP3), Gamma, Log Gamma, Gumbel, and Weibull. The Aquarius Standard Edition program incorporates these distributions and is only used for the AMS approach to FFA. There is no standard distribution that describes all peak flow events thus the distribution selected for analysis is done on case by case basis. While the AMS is easily obtained from a hydrologic time series, it does not consider the possibility that secondary events in one year may exceed the annual maxima in other years (Madsen et al., 1997). Furthermore, annual maxima selected during dry years may be very small resulting in a bias of the extreme value statistic outcome. As such, the AMS approach may not be appropriate in all cases. An alternative to AMS is the Peaks Over Threshold (POT) approach, also known as the Partial Duration Series. For the POT approach, data above a threshold are fit to the Generalized Pareto Distribution (GPD). The choice of threshold is critical to the analysis because a value that is too high discards too much data resulting in high variance of the estimate and too low of a threshold can bias the estimate. The thresholds are selected using a graphical approach (i.e. the Mean Residual Life Plot) combined with an assessment of the stability of the GPD parameters (Gilleland and Katz, 2006). The FFA using the GEV and GPD distributions is carried out using the Extremes package in the software R. R is a free software environment for statistical computing and graphics. The Extremes package is specifically designed for extreme value statistics and provides the option to carry out the analysis using the AMS or the POT approach. The approach to FFA is selected on a case by case basis.

A.3.1. Monitoring Agencies The FFA requires the input of streamflow data. The two agencies that monitor and manage hydrometric stations for Canada and the United Stated include:  Water Survey of Canada (WSC); and  United States Geological Survey (USGS). The hydrometric stations for FFA are selected based on available streamflow data (i.e. record length), drainage basin area, station elevation, hydro-climatic zone, geology, and regulation type.

A.3.2. Historical Peak Flow Records

The metric used for the FFA is peak instantaneous streamflow (QIMAX) for each available year on record. Peak streamflow records at hydrometric stations are often limited to maximum average daily streamflow (QMAX) which are lower in magnitude than peak instantaneous streamflow, except for very large drainage areas. In some cases, QIMAX values may be estimated from available QMAX using regression analyses techniques.

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A.3.3. Prediction Limit of Dataset The maximum return period for which a peak streamflow can be predicted (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. In cases where the record length of the station of interest is too short, the dataset can be extended using a correlation analysis with a nearby hydrometric station in order to predict flood frequencies of higher return periods. Generally, flood quantiles are reported to the 100-year return period for Alberta and the United States while the 200-year return period event is reported for British Columbia.

A.3.4. Statistical Validity of Dataset The streamflow dataset needs to satisfy four statistical criteria in order to be valid for an FFA. The four statistical criteria include the following:

 Randomness  Independence  Stationarity  Homogeneity.

A.3.5. Randomness In a hydrological context, randomness implies that the fluctuations in streamflow occur in response to natural causes. The term natural flow always means that the data series is not regulated and may be considered random. Alternatively, if the flood flows are altered by regulation (i.e. reservoir operations, water diversions, water extractions, major land-use changes etc.) the streamflow record cannot be considered random unless the regulation has been accounted for in some way. Note that some flow records may be published as regulated however, the level of regulation may not be significant. Even when statistical tests indicate that randomness has not been met, the flow data may result in an unbiased estimation of frequency if the other assumptions are valid (USGS, 1982). However, a non- random sample increases the degree of uncertainty in the relation.

A.3.6. Independence Random events in a data series do not imply that they are independent. For example, large natural storage like surface water bodies may cause high flows to follow high flows and low flows to follow low flows. The dependence between successive daily flows tends to be strong where the dependence between annual maxima tends to be weak.

A.3.7. Stationarity The stationarity criterion implies that the data series does not change with respect to time. Examples that violate the stationarity criterion include trends, jumps and cycles. Trends may reflect a gradual change in land-use influencing the data series over time. Jumps in the data series resulting from an abrupt change in the basin or river due to the construction of a hydraulic structure is another example of non-stationarity. The last factor that can violate the

Appendix A_Hydrotech Methodology Report Page 8 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14 stationarity criterion is the presence of cycles such as long-term climate fluctuations. However, no method is available for testing the influence of cycles adequately (Watt et al., 1989).

A.3.8. Homogeneity Homogeneity indicates that the data series making up the sample originates from a single population. For example, a series containing a combination of snowmelt and rainfall floods may not be homogeneous and may result from different types of events (i.e. mixed populations of data). However, it may be acceptable to treat the sample as homogeneous if it is supported by a statistical test. Flow conditions can be changed due to urbanization, diversions or a change in cover conditions. These changes will affect record homogeneity. These may not change the flow significantly from year to year but a cumulative effect can influence the flow after many years (USGS, 1982).

A.3.9. Statistical Tests The statistical tests to assess the four criteria are listed in Table A.3-1. These statistical tests are non-parametric which avoid assumptions of the underlying distribution, which is generally not known for flood data. An element of judgment is inevitable in the process of assessing the statistical validity of a dataset. Statistical tests only provide a probability of satisfying particular criteria and will not yield a definitive answer. Furthermore, flood data may incorporate important measurement errors resulting from human error and the difficulty in the measurement of high flows.

Table A.3-1. Statistical Criteria and Corresponding Statistical Test Statistical Criteria Statistical Test Independence Spearman Test for Independence Trend Spearman Test for Trend Randomness Runs Test for General Randomness Homogeneity Mann-Whitney Split Sample Test for Homogeneity

A.3.10. Regional FFA Transforming the predicted design flood flows from the gauge station to the pipeline crossing requires further statistical manipulation in the form of regression analysis. Regional FFAs are completed when there are several representative hydrometric stations along a watercourse of interest or along adjacent watercourses in the area. Regional flood frequencies for set return periods at the pipeline crossing are calculated using a power law combining the QIMAX data from the selected regional hydrometric stations. The power law form is described by the following equation (Eq.1):

Q  aAb (Eq. 1) p

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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 QIMAX and drainage area of several regional hydrometric stations (Watt et al., 1989). The drainage area at the pipeline crossing is typically estimated by BGC using available topographic datasets while drainage areas for the regional hydrometric stations are obtained either from WSC or USGS records.

A.3.11. Pro-rated FFA Pro-rated FFAs are carried out in cases where a single representative station is located along the watercourse of interest. Flood frequencies are calculated using a pro-rated

calculation by relating the annual QIMAX values at the hydrometric station to the basin area of the specific pipeline crossing. The equation used for this relation is as follows (Eq. 2):

n Q  A  U   U  (Eq. 2) Q  A  G  G 

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 related to peak streamflow data at both sites (Watt et al., 1989). Typically, a value of 0.8 is chosen for n.

A.4. HYDROTECHNICAL HAZARD ASSESSMENT The flood quantiles estimated using FFA are incorporated in the hydrotechnical hazard assessment for scour. The following section describes the methods used to assess the degree of scour, degradation, bank erosion, avulsion, and encroachment at each pipeline crossing.

A.4.1. Scour Scour is the general lowering of the channel bed that occurs during a flood event in a straight, uniform channel. The likelihood of a pipe becoming exposed due to scour in a flood event is assessed by estimating the maximum scour depth for each flood return period. If the pipe’s crown elevation is greater than the scour elevation, then the pipe is considered to be vulnerable to exposure for that particular magnitude of flood event. The scour elevation is estimated by subtracting the predicted scour depth from the average bed elevation. The average bed elevation is generated using an estimate of channel hydraulics with Manning’s equation (Figure A.4-1). The average bed elevation is estimated by subtracting the average flow depth from the estimate of the water surface elevation for a given flood event. The probability of exposure due to scour is determined by comparing the elevation of the pipeline at the minimum Depth of Cover (DoC) (see E in Figure A.4-1) and the average bed elevation (see C in Figure A.4-1) for each flood return period.

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Figure A.4-1. Hypothetical Scour Analysis for a Given Design Flood

A.4.1.1. Channel Hydraulics As part of the scour assessment, flood flow hydraulics (i.e. water surface elevation, average flow depth etc.) are estimated for each design flood using Manning’s equation. Manning’s equation is an empirical formula for open channel flow in cases where flow is driven by gravity and is considered uniform. Manning’s equation is defined by the following formula:

/ ∗/ (Eq. 3)

where V is the cross-sectional average velocity (m/s), n is Manning’s coefficient (unitless), Rh is the hydraulic radius (m), and S is the slope of the water surface (m/m). The slope of the water surface can be assumed to be comparable to the regional slope of the channel bed. Manning’s coefficient values typically range from 0.07 to 0.025 for streams with cobble- boulder to sand substrates. Topographic and bathymetric survey data are typically used to develop cross sections and channel gradients, which become inputs into scour depth estimations. In some cases, open channel flow modeling may be implemented if backwater effects need to be accounted for in the analysis.

A.4.1.2. General Scour Equations Following the estimate of channel hydraulics, the general scour depth is estimated for each design flood. Various hydraulic equations have been developed empirically for estimating general scour depth during a peak flow event (Table A.4-1). The selection and effective use of these equations requires considerable engineering judgment resulting in semi-quantitative

Appendix A_Hydrotech Methodology Report Page 11 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14 results. Each method was designed based on a specific range of boundary conditions and care must be taken to select appropriate methods for the site under study.

Table A.4-1. Methods for Estimation of Potential Depth of General Scour Method Reference Yaremko and Cooper Yaremko and Cooper (1983)

Neill’s Regime Neill (1964)

Lacey’s Regime Lacey (1930)

Competent Velocity MTO (1997)

Blench Zero Bed Factor Blench (1969); Pemberton and Lara (1984)

Bed Armouring Borah (1989)

Originally, some of the scour equations were intended to estimate scour relative to a design flood stage (e.g. Yaremko and Cooper). For ease of result presentation, the calculations made by BGC (described in the following sections) were manipulated to predict scour depth relative to the channel bed.

A.4.1.2.1 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 where the mean channel depth is assumed to be the hydraulic depth (Wetted Area/Top Width). The Yaremko and Cooper scour equation is defined by the following equation:

(Eq. 4) where ds is the depth of maximum scour below the stream bed, dm is defined as the hydraulic

depth over the main (incised) portion of the channel, and Zn is the correction factor (z-factor). A correction factor (z-factor) is applied to the mean channel depth to account for channel morphology such as the degree of bending in the channel (Table A.4-2).

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Table A.4-2. Empirical Multiplying Factors for Maximum Scour Depth (Joyce and Chandler, 2004)

Correction Factor Channel Morphology (z-factor)

Straight Reach 0.25

Moderate Bend 0.5

Severe Bend 0.75

A.4.1.2.2 Neill’s Regime The Neill Regime scour equation is similar to the Yaremko and Cooper Equation where the scour depth is proportional to the mean channel depth for a given flow event (Eq. 5). However, the mean channel depth is calculated using the average bankfull depth, bankfull flow, design flow, and size of bed material (Neill, 1964). The mean channel depth (dm for a given flow event is defined by the following equation: (Eq. 5)

where di is the average depth of the incised reach (m), qf is the flow event per unit width 2 2 (m /s), qi is the bankful discharge per unit width in the incised channel (m /s), and m is an exponent that ranges from 0.67 to 0.85 for coarse gravel material. The average incised channel depth (di) in this assessment is assumed to be the hydraulic depth over the main (incised) portion of the channel under bankfull condition (assumed to be 2 to 5-year return period flows). The hydraulic depth is the wetted cross-sectional area (m2) divided by the top width (m). Similar to Yaremko and Cooper, a correction factor (z-factor) is applied to the mean channel depth to account for the degree of bending (Table A.4-3). The final scour depth estimate is relative to the incised bankfull hydraulic depth.

Table A.4-3. Empirical Multiplying Factors for Maximum Scour Depth (Pemberton and Lara, 1984)

Correction Factor Channel Morphology (z-factor)

Straight Reach 0.5

Moderate Bend 0.6

Severe Bend 0.7

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A.4.1.2.3 Lacey’s Regime Lacey’s Regime was developed for large alluvial channels where total discharge and mean particle size are the driving variable (Lacey, 1930). Lacey’s Regime equation is based on the estimation of a design flow depth using the following relationship

/ 0.47 (Eq. 6) where dm in this assessment is assumed to be the hydraulic depth over the main (incised) portion of the channel (m), Q is the design discharge (m3/s), f is Lacey’s silt 1/2 factor = (1.76(D50 (mm)) )/s, and D50 (mm) is the median bed particle size (Joyce and Chandler, 2004). Lacey’s silt factor is based on the idea that silt is carried by water and kept in suspension and is derived based on grain size and total discharge through the channel. Similar to Yaremko and Cooper, a correction factor (z-factor) is applied to the average depth under design flood conditions to account for channel morphology

(Eq. 7)

where ds is the scour depth below the channel and Zf is the correction factor (z-factor)

(Table A.4-2.). The average depth (dm) is assumed to be the hydraulic depth over the incised portion of the channel. The hydraulic depth is the wetted cross-sectional area divided by the top width of the channel.

A.4.1.2.4 Blench Zero Bed Factor The Blench Zero Bed Factor method estimates the channel depth for which no material transport is observed on the channel bed. The zero bed factor method is based on Blench (1969) and the method is described in Pemberton and Lara (1984). The depth for which no material transport is observed is estimated using the following equation:

/ / (Eq. 8) where dfo is the depth for which no sediment transport is observed on the channel bed (m), qf 3 2 is the design discharge per unit width (m /s/m), fbo refers to Blench’s Zero Bed Factor (m/s ). Blench’s Zero Bed Factor follows a power relationship with the bed material particle diameter, and can be estimated directly from a graph. Similar to the other methods, the depth for zero bed transport is subsequently multiplied by a correction factor to account for the likely concentration of flood discharge in a portion of the channel. A correction factor value of 0.6 is applicable for channels ranging from straight to severe bends.

A.4.1.2.5 Competent Velocity Neill’s Competent velocity equation is based on the hypothesis that the channel cross- section will increase in size through scouring until the mean velocity is reduced to the point where no movement of bed material occurs. The average cross sectional velocity where no erosion occurs is referred to as the competent velocity and is estimated based on the bed

Appendix A_Hydrotech Methodology Report Page 14 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14 material composition. This method assumes that the composition of the bed material does not change (no bed armour layer forms) as erosion occurs.

There are several empirical equations for Vc. A simplified version assumes a specific gravity of the bed material as 2.65 and the equation is described as follows:

/ / 5.67 (Eq. 9)

where y is the flow depth (m), and D50 is the median particle size (mm). Flow depth is assumed to be the hydraulic depth over the main incised portion of the channel at the design flood flow. Hydraulic depth is the wetted cross-sectional area (m2) divided by top width (m). The wetted cross-sectional area is predicted by the flood flow hydraulics (see Section A.4.1.1) calculated using the surveyed cross-sectional data. It is assumed that the channel cross-section scours in a parabolic pattern along the original channel bed (MTO, 1997) as defined by:

(Eq. 10) where ds is the depth of scour relative to the channel bed (m), As is the scoured area (define by AT – A where AT is the total flow area with scouring and A is total flow area without 3 scouring). The total flow area with scouring (AT) is equal to the design discharge (m /s) divided by the critical velocity (Vc). The width of scour (Ts) across the channel is estimated by calculating the top flow width for a 1 m deep channel with the surveyed cross-section.

A.4.1.2.6 Depth to Bed Armouring Some watercourses are lined with a natural stable bed paving layer typically formed from cobbles and boulders. This layer is formed as the river degrades through glacial till or outwash deposits to its existing elevation and will not be transported even during extreme flood flows (Yaremko and Cooper, 1983). An armour layer is expected along highly regulated rivers. The magnitude and frequency of high flows can be significantly decreased by dams (Schmidt and Wilcock, 2008). As such, the flows released by the dams may not be able to transport sizes previously moved by higher flows. Progressive winnowing from successive flows removes finer particles from the surface of the channel bed concentrating the coarser fraction (Grant, 2012). As degradation continues, the average particle size at the surface of the channel bed can be expected to increase resulting in an armor of coarse particles that is more difficult to mobilize for a given flow. The Bed Armouring method involves first estimating the size of bed material that will remain stable during a flood event (refer to Section A.4.1.5). Following the estimation of maximum mobile particle size, the depth of scouring before the formation of a stable armour layer is calculated and is referred to as the flood scour depth. It is dependent on the proportion of stable material in the original bed where the higher the proportion of stable particles, the lower the scour depth. Borah (1989) proposed a relationship to estimate the flood scour

Appendix A_Hydrotech Methodology Report Page 15 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14 depth below a dam in a channel characterized by a well-mixed bed made of particles with the same specific gravity. Bed armouring will form based on the equations:

(Eq. 11)

and

∆∗ (Eq. 12)

which are combined together to form:

1 (Eq. 13) ∆

where Ya is the thickness of the armouring layer, Y is the depth from the original streambed to

the bottom of the armouring layer, Yd is the depth from the original streambed to top of the armouring layer and is referred to as the total depth of scour to self armouring, and ΔP is the decimal percentage of original bed material larger than the armour. The thickness of the armouring layer may vary depending on the limiting particle size and can range in thickness from one particle diameter to three particle diameters. A general guide in design suggests selecting the smallest between either 1) three times the armouring particle diameters or 0.15 m. The percentage of bed material equal to or greater than the required armour particle size can be determined from bed material size analysis as discussed in Section Error! Reference source not found..

A.4.1.3. 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 generated using an estimate of the

shear velocity (u*) and channel bed shear stress () where shear stress is expressed by the following equation:

∗ / (Eq. 14) where g is acceleration due to gravity (9.81 m/s2), R is the hydraulic radius (m), S is the regional channel slope (unitless). Shear velocity is expressed in units of m/s. Channel bed shear stress incorporates water density and is expressed by the following formula:

(Eq. 15) Where g is acceleration due to gravity (9.81 m/s2), is the density of water (1000 kg/m3), R is the hydraulic radius (m), and S is the regional channel slope (m/m).

Similar to scour, several empirical equations are available to estimate the maximum mobile particle size and each is considered a check on the others (Table A.4-4) (Pemberton and

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Lara, 1984). The methods described below use basic channel hydraulic flow parameters, shear velocity, and channel bed shear stress for 200-year flood. The maximum mobile particle size in a given channel is estimated by taking the average of the six different methods at every crossing.

Table A.4-4. Methods for Estimation of Bed Material Mobility Method Reference Shields’ Incipient Motion Shields (1936)

Yang Insipient Motion Pemberton and Lara (1984)

Competent Bottom Velocity Pemberton and Lara (1984)

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 using 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.4.1.4. Local Scour In some reaches where bends, confluences, or obstructions are present, it is necessary to consider the potential effects of local scour. Local scour is the site-specific formation of scour holes in the bed as a result of secondary currents. Local scour depth is typically larger than general scour depth. Local scour equations can be implemented to estimate local scouring around structures such as bridge piers and abutments (Melville and Coleman, 2000). Prediction of local scour depth at channel bends and confluences is more subjective than general scour estimates. A common method is to apply a multiplier to the computed general scour depth for a given reach (e.g. Table A.4-3). Scour multipliers ranging from 1.5 to 3.0 for straight channels and sharp channel confluences respectively can be experienced (Veldman, 2008). For sites where a scour estimate is carried out, BGC estimates the general scour depth by taking the average of several estimation methods listed in Table A.4-1. In reaches where local scour can be expected (at confluences, boulders, large woody debris), a multiplier is applied to the general scour estimate to estimate the potential scouring in the local scour holes along the reach. For example, BGC typically incorporates a local multiplier of 3 to 5 for scour analyses in braided rivers to account for increased scour at confluences, which are characteristic features of such rivers due to multiple channels and mid-channel bars. The

Appendix A_Hydrotech Methodology Report Page 17 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14 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.4.1.5. Factor of Safety A factor of safety is often included in the scour analysis as a conservative precaution to account for the degree of variability in channel conditions increasing the scour depth. A factor of safety equivalent to 1.3 is applied by BGC to the average of the selected scour predictions.

A.4.1.6. 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 cohesive soils that account for the soil’s greater scour resistance 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. 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 are considered overestimates and thus may not be reported by BGC.

A.4.2. Channel Degradation Various mathematical models are available for the prediction of channel degradation, but these models tend to be labour and data intensive. Furthermore, the models require some level of calibration to produce meaningful results. For the purpose of predicting long-term degradation at pipeline crossings where data and time are limited, mathematical modelling of sedimentation processes is not practical and is not implemented in this assessment. Degradation rates at pipeline crossings are typically assessed by reviewing a few “snap- shots” of historic channel morphology observations, and/or depth of cover measurements and survey data (see Figure A.4-2. ). This review provides an indication for the average rate of degradation over a given period of time.

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Figure A.4-2. Cross-sectional Channel Changes on the Lillooet River in Response to Meander Cutoffs and Base Level Lowering (after Weatherly and Jakob, 2013)

A.4.3. Bank Erosion The assessment of a channel’s susceptibility to channel migration is somewhat qualitative. Consideration of the following characteristics at a pipe crossing is required:

 discharge and flow velocity;  location of bends along the river;  bank geometry (steep slope vs. mild slope, deep banks vs. shallow banks);  presence of obstructions in the channel that can deflect flow towards the bank; and  effectiveness of bank protection (i.e. cohesive vs. non-cohesive bank material, presence of vegetation on the banks, size and integrity of bank armouring).

As with assessing degradation rates, when available, multi-temporal survey data through the channel cross section are plotted together, relative to the same datum, and compared to provide an indication of the historic average rate of channel lateral migration. Historical air photographs can also be analyzed to assess lateral channel stability, although this method is generally limited to medium to large rivers (> 20 m width). It should be noted however, that any lateral migration rates that are determined through analysis of historical observations should be applied with caution when predicting future rates of lateral migration. Some channel banks can appear to be stable for long periods of time only to be washed out in a single severe flood event (Yaremko and Cooper, 1983).

Appendix A_Hydrotech Methodology Report Page 19 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14

In the absence of previous site survey data, the most recent surveyed pipe and ground profile also gives an indication of the lateral migration that has occurred at the pipe crossing since the time of pipeline construction. The pipeline sag-bends are typically installed symmetrically such that the channel is centered equidistant from each sag-bend. When lateral migration occurs, the channel centerline is no longer positioned symmetrically between the sag-bends and over-bends. Figure A.4-3 depicts the location of sag-bends with respect to the channel banks at the time of construction, and then after a period of lateral migration.

Figure A.4-3. Multi-temporal Ground and Pipe Profile Surveys at a Watercourse Crossing

A.4.4. Avulsion If the crossing is situated on an alluvial fan, the footprint of the fan is approximated and the length of pipeline that crosses the fan is identified. If the crossing passes through a floodplain, the floodplain extents are roughly approximated. After the length of affected pipe is identified, factors such as levees, cutoff structures, debris jams, sediment accumulation, beaver dams, debris flow, or extreme flooding are considered. 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 fan or floodplain, even with detailed topographic survey data of the entire study area. The potential length of affected pipeline should be inspected following extreme flood events. In a majority of cases, avulsion hazards encountered by BGC typically occur on a wide floodplain, where the river avulses into an existing side channel or abandoned channel. A pipeline rupture on the Red Deer River in 2008 was a result of channel avulsion into a side channel, a situation that developed over a period of years. Figure A.4-4. depicts a typical avulsion hazard in plan view and cross-section.

Appendix A_Hydrotech Methodology Report Page 20 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14

Figure A.4-4. Example of Avulsion in Plan View (left) and Cross-section (right)

According to Schumm (2005), the underlying causes of avulsions can be organized into four groups (Table 4-A.4-5). In braided channels, avulsion channel creation would likely be a result of the instabilities listed in Group 1 and/or 3.

Appendix A_Hydrotech Methodology Report Page 21 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14

Table 4-A.4-5. Causes of Avulsions According to Schumm (2005) Ability of channel to Processes and events that create instability and lead toward carry sediment and avulsion discharge Group 1 a) Sinuosity increases (reduction in gradient) Decrease Avulsion from increased ratio of b) Delta growth (lengthening of channel) Decrease Sa/Se due to decrease c) Baselevel fall (Resulting in decreased slope Decrease in Se d) Tectonic uplift (Resulting in decreased Decrease slope) Group 2 Avulsion from a) Natural levee/alluvial ridge growth No change increased ratio of b) Alluvial fan and delta growth (convexity) No change Sa/Se due to increase in Sa c) Tectonism (resulting in lateral tilting) No change Group 3 a) Hydrologic change in flood peak discharge Decrease b) Increased sediment load Decrease Avulsion with no c) Vegetative encroachment Decrease change in ratio, 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.

A.4.5. Encroachment Progressive lateral movement of the channel toward the pipeline as a result of bank erosion toward the pipeline can be evaluated with similar qualitative and quantitative methods as outlined for bank erosion (Figure A.4-5).

Appendix A_Hydrotech Methodology Report Page 22 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14

Encroachment Hazard

Figure A.4-5. Example of an Encroachment Hazard (Google Earth imagery year: 2004)

Appendix A_Hydrotech Methodology Report Page 23 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14

APPENDIX A REFERENCES

Ashworth, P.J. 1996. Mid-channel bar growth and its relationship to local flow strength and direction. Earth Surface Processes and Landform 21(2): 103–123.

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. Coles, S. 2001. An Introduction to Statistical Modeling of Extreme Values. Springer Verlag London Limited. pp.208. 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. Grant, G.E. 2012. The geomorphic response of gravel-bed rivers to dams: perspectives and prospects. In: Gravel-Bed Rivers: Processes, Tools, Environments. Edited by: M. Church, P. M. Biron and A. G. Roy. John Wiley & Sons, Ltd, Chichester, UK. Ch. 15. Joyce, S. and Chandler, A. 2004. A Method for the Analysis of Scour Potential and Protective Works Design at Pipeline Crossings of Mobile-Bed Rivers. Proceedings of the Conference on Advances in Pipelines Engineering and Construction, American Society of Civil Engineers. San Diego, California, July 15-18. Lacey, G. 1930. Stable Channels in Alluvium. In Proceedings of the Institution of Civil Engineers. Volume 229. Leopold, L.B., Wolman, M.G., and Miller, J.P. 1964. Fluvial Processes in Geomorphology. San Francisco: W.H. Freeman. Madsen, H., Rasmussen, P.F., and Rosbjerg, D. 1997. Comparison of annual maximum series and partial duration series methods for modeling extreme hydrological events, 1, at- site modeling. Water Resources Research 33(4): 747-758. Melville, B. and Coleman, S. 2000. Bridge Scour. Water Resources Publications LLC. Highlands Reach, Colorado. Ministry of Transportation Ontario. (MTO) 1997. Drainage Management Manual. Ontario Ministry of Transportation, Drainage and Hydrology Section, Transportation Engineering Branch. Chapter 5: Bridges, Culverts and Stream Channels. 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.

Appendix A_Hydrotech Methodology Report Page 24 BGC ENGINEERING INC. Trans Mountain Pipeline ULC May 2014 Hydrotechnical Investigation and Analysis Methodology Project No.: 0095-150-14

Pemberton, E.L. and Lara, J.M. 1984. Computing Degradation and Local Scour. Technical Guideline for Bureau of Reclamation, Denver, Colorado, United States. 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. Schmidt, J.C. and Wilcock, P.R. 2008. Metrics for assessing the downstream effects of dams. Water Resources Research 44:1-19. Ulrich, C., Rajah, S.K., Talich, C. and Galatas, J. 2005. A Case History of Scour Impacted Pipelines in River Crossings Part I – Scour Evaluation. Proceedings of the Conference on Pipeline Design, Operations, and Maintenance in Today’s Economy, Houston, Texas. Aug. 21-24. USGS. 1982. Flood Flow Frequency. Bulletin 17B of the Hydrology Subcommittee. Interagency Advisory Committee on Water Data. Office of Water Data Coordination. Reston, Virginia. 194 pp. Veldman, W. 2008. Pipeline Geo-Environmental Design and Geohazard Management. Chapter 3, Open Cut and Elevated River Crossings. Edited by Moness Rizkalla. ASME. 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. Watt, W. E. (Editor-in Chief), 1989. Hydrology of Floods in Canada: a Guide to Planning and Design. N.R.C., Ottawa, Canada. 245 pp. Weatherly, H. and Jakob, M. 2013. Geomorphic response of Lillooet River, British Columbia, to meander cutoffs and base level lowering. Submitted to Geomorphology. Wolman, M. 1954. A method of sampling coarse river-bed material. Transactions of the American Geophysical Union. 35(6): 951-956.

Appendix A_Hydrotech Methodology Report Page 25 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

APPENDIX B BOREHOLE LOGS

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project October 31, 2018 Geotechnical HDD Feasbility Assesment North Thompson River (at Chappell) at SSEID 005.11 KP 577.1 Project No.: 0095150-14

APPENDIX B BOREHOLE LOGS

0095-150-14 HDD Geotechnical Feasibility Report - North Thompson Chappell - Rev 0 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 (2) DRY STRENGTH 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, Felsite

Porphyrite, Porphyry Dolerite/Diabase

Slate, Phyllite Schist

Migmatite Gneiss

Quartzite Serpentinite

Marble Amphibolite, Eclogite

Fault Zone Bedrock

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. Engineering classification of jointed rock masses. Trans South African Institute of Civil Engineers. 15, 335-344. 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: August 11, 2014

Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC13-NTC-01 Page 1 of 6 Location: North Thompson River (at Chappell) - Left Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT-700 Start Date: 21 Oct 13 Co-ordinates (m): 351,990E, 5,806,212N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 22 Oct 13 Ground Elevation (m): 708.0 Drill Method: Air/Mud Rotary Final Depth of Hole (m): 42.40 Datum: NAD 83 UTM Zone 11U Fluid: Bentonite Mud Logged by: SW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 10.10 Reviewed by: LDM Direction: N/A Depth To Rock (m): N/A Approved by: KWB

Su - kPa

40 80 120 160

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

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

Depth (m) Sample Type Sample No. Grade Weathering Symbol SPT Blows per 150mm 20 40 60 80 20 40 60 80 0 GRAVEL (GW) Fine to coarse, sandy, well graded, loose, maximum particle size = 23 mm, rounded to subangular, orangey brown, moist, homogeneous, weak cementation. [FLUVIAL]

1 SPT-01 - Recovered 0.33 m. SPT-01 5 4 2

2

SAND (SP-SM) Fine to coarse, trace to some gravel, trace silt, trace clay, poorly SPT-02 1 graded, loose, subangular to subrounded, orangey brown, moist, 3 3 homogeneous, weak cementation. 6 [FLUVIAL] SPT-02 - Recovered 0.30 m.

4 SPT-03 - Recovered 0.30 m, changes to some gravel, trace clay, very SPT-03 loose, maximum particle size = 40 mm. 3 1 2

5

Water table measured at a depth of 5.39 m below ground surface on October 22, 2013 with the drill hole at a depth of 27.13 m below SPT-04 surface. 6 7 6 SPT-04 - Recovered 0.23 m, changes to no clay, no gravel, compact, subangular to subrounded, brown. 10

7 SPT-05 - Recovered 0.23 m, changes to some gravel. SPT-05 10 9 9

8 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 2/13/15 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC13-NTC-01 Page 2 of 6 Location: North Thompson River (at Chappell) - Left Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT-700 Start Date: 21 Oct 13 Co-ordinates (m): 351,990E, 5,806,212N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 22 Oct 13 Ground Elevation (m): 708.0 Drill Method: Air/Mud Rotary Final Depth of Hole (m): 42.40 Datum: NAD 83 UTM Zone 11U Fluid: Bentonite Mud Logged by: SW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 10.10 Reviewed by: LDM Direction: N/A Depth To Rock (m): N/A Approved by: KWB

Su - kPa

40 80 120 160

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

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

Depth (m) Sample Type Sample No. Grade Weathering Symbol SPT Blows per 150mm 20 40 60 80 20 40 60 80 8 SAND (SP-SM) Fine to coarse, trace to some gravel, trace silt, trace clay, poorly graded, compact, subangular to subrounded, brown, moist, homogeneous, weak cementation. [FLUVIAL] SPT-06 SPT-06 - Recovered 0.61 m, changes to fine grained sand, and silt, 2 9 trace clay, poorly graded, light brown, moist, homogenous, weak 4 cementation. 7

10 CLAY (CL) SPT-07 And silt, low plasticity, firm, low sensitivity, grey, wetter than plastic 1 limit, homogeneous, weak cementation, very high dry strength, no 3 dilatancy. 4 [GLACIOLACUSTRINE] 11 SPT-07 - Recovered 0.61 m.

SPT-08 - Recovered 0.61 m. SPT-08 3 4 7 12 SILT (ML) Clayey, some sand to sandy, low plasticity, very stiff to hard, orangey brown, near plastic limit, stratified to homogenous, weak cementation, low dry strength. [GLACIOLACUSTRINE] SPT-09 - Recovered 0.61 m. 13 SPT-09 10 9 12

14

SPT-10 - Recovered 0.53 m. SPT-10 10 13 14 15

16 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 2/13/15 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC13-NTC-01 Page 3 of 6 Location: North Thompson River (at Chappell) - Left Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT-700 Start Date: 21 Oct 13 Co-ordinates (m): 351,990E, 5,806,212N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 22 Oct 13 Ground Elevation (m): 708.0 Drill Method: Air/Mud Rotary Final Depth of Hole (m): 42.40 Datum: NAD 83 UTM Zone 11U Fluid: Bentonite Mud Logged by: SW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 10.10 Reviewed by: LDM Direction: N/A Depth To Rock (m): N/A Approved by: KWB

Su - kPa

40 80 120 160

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

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

Depth (m) Sample Type Sample No. Grade Weathering Symbol SPT Blows per 150mm 20 40 60 80 20 40 60 80 16 SPT-11 SPT-11 - Recovered 0.43 m. 6 SILT (ML) 9 Clayey, some sand to sandy, low plasticity, very stiff to hard, grey, near 11 plastic limit, stratified to homogenous, weak cementation, low dry strength. [GLACIOLACUSTRINE] 17

SPT-12 - Recovered 0.61 m. SPT-12 7 11 14 18

19 SPT-13 - Recovered 0.41 m. SPT-13 7 10 10

20

SPT-14 - Recovered 0.48 m. Sand changes from fine to medium, SPT-14 dense. 11 17 21 20

22 SPT-15 - Recovered 0.51 m. SPT-15 10 17 15

23

SPT-16 - Recovered 0.61 m. SPT-16 13 15 24 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 2/13/15 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC13-NTC-01 Page 4 of 6 Location: North Thompson River (at Chappell) - Left Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT-700 Start Date: 21 Oct 13 Co-ordinates (m): 351,990E, 5,806,212N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 22 Oct 13 Ground Elevation (m): 708.0 Drill Method: Air/Mud Rotary Final Depth of Hole (m): 42.40 Datum: NAD 83 UTM Zone 11U Fluid: Bentonite Mud Logged by: SW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 10.10 Reviewed by: LDM Direction: N/A Depth To Rock (m): N/A Approved by: KWB

Su - kPa

40 80 120 160

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

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

Depth (m) Sample Type Sample No. Grade Weathering Symbol SPT Blows per 150mm 20 40 60 80 20 40 60 80 24 SILT (ML) 20 Clayey, some sand to sandy, low plasticity, compact to dense, grey, near plastic limit, stratified to homogenous, weak to moderate cementation, low dry strength. [GLACIOLACUSTRINE]

25 SPT-17 - Recovered 0.51 m. SPT-17 9 16 15

26

SPT-18 - Recovered 0.58 m. SPT-18 10 12 27 14

28 SPT-19 - Recovered 0.58 m. SPT-19 5 9 13

29

SPT-20 - Recovered 0.61 m. Density increases to dense. SPT-20 12 30 14 19

31 SPT-21 - Recovered 0.61 m. SPT-21 10 15 20

32 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 2/13/15 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC13-NTC-01 Page 5 of 6 Location: North Thompson River (at Chappell) - Left Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT-700 Start Date: 21 Oct 13 Co-ordinates (m): 351,990E, 5,806,212N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 22 Oct 13 Ground Elevation (m): 708.0 Drill Method: Air/Mud Rotary Final Depth of Hole (m): 42.40 Datum: NAD 83 UTM Zone 11U Fluid: Bentonite Mud Logged by: SW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 10.10 Reviewed by: LDM Direction: N/A Depth To Rock (m): N/A Approved by: KWB

Su - kPa

40 80 120 160

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

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

Depth (m) Sample Type Sample No. Grade Weathering Symbol SPT Blows per 150mm 20 40 60 80 20 40 60 80 32 SILT (ML) Clayey, some sand to sandy, low plasticity, compact to dense, grey, near plastic limit, stratified to homogenous, weak to moderate cementation, low dry strength. [GLACIOLACUSTRINE] SPT-22 SPT-22 - Recovered 0.48 m 11 33 16 25

34 SPT-23 - Recovered 0.61 m. SPT-23 11 15 20

35

SPT-24 - Recovered 0.61 m. SPT-24 15 36 16 22

37

SPT-25 - Recovered 0.58 m. Density increases to very dense. SPT-25 20 31 28 38

SPT-26 - Recovered 0.48 m. Density decreases to dense. 39 SPT-26 19 25 21

40 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 2/13/15 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC13-NTC-01 Page 6 of 6 Location: North Thompson River (at Chappell) - Left Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT-700 Start Date: 21 Oct 13 Co-ordinates (m): 351,990E, 5,806,212N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 22 Oct 13 Ground Elevation (m): 708.0 Drill Method: Air/Mud Rotary Final Depth of Hole (m): 42.40 Datum: NAD 83 UTM Zone 11U Fluid: Bentonite Mud Logged by: SW Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): 10.10 Reviewed by: LDM Direction: N/A Depth To Rock (m): N/A Approved by: KWB

Su - kPa

40 80 120 160

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

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

Depth (m) Sample Type Sample No. Grade Weathering Symbol SPT Blows per 150mm 20 40 60 80 20 40 60 80 40 SILT (ML) Clayey, some sand to sandy, low plasticity, compact to dense, grey, near plastic limit, stratified to homogenous, weak to moderate SPT-27 cementation, low dry strength. 16 [GLACIOLACUSTRINE] 18 SPT-27 - Recovered 0.56 m. 19 41

SPT-28 - Recovered 0.61 m. 42 SPT-28 14 20 20 Borehole completed at target depth of 42.4 m. Borehole grouted to surface with bentonite grout. No instrumentation installed.

43 SPT Sampler Details: 24" (610 mm) length, 2" (51 mm) diameter, driven by automatic trip hammer.

Pocket penetrometer tests conducted perpendicular to borehole axis. Tests were conducted on disturbed samples.

Garmin GPSMAP 62s handheld GPS accuracy +/- 3 m. Elevation 44 reported taken from LiDAR provided by Universal Pegasus International (UPI) and received on April 18, 2014.

45

46

47

48 TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 2/13/15 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-NTC-02 Page 1 of 6 Location: North Thompson River (at Chappell) - Right Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 #5 Start Date: 29 Aug 14 Co-ordinates (m): 352,203E, 5,806,420N Drilling Contractor: Foundex Finish Date: 01 Sep 14 Ground Elevation (m): 706.0 Drill Method: Mud Rotary Final Depth of Hole (m): 40.79 Datum: NAD 83 UTM Zone 11U Fluid: Bentonite Mud Logged by: CAP Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): N/A Reviewed by: LDM Direction: N/A Depth To Rock (m): N/A Approved by: KWB

Su - kPa

40 80 120 160

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

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

Depth (m) Sample Type Sample No. Grade Weathering Symbol SPT Blows per 150mm 20 40 60 80 20 40 60 80 0 SAND (SP-SM) Fine to medium, trace to some silt, poorly graded, loose, angular, light brown transitions to dark grey with depth, moist, faintly laminated to homogeneous, trace organics (roots and wood chips), mixed GRB-01 mineralogy including muscovite and quartz. [FLUVIAL] 1 GRB-01 - [Grab Sample] Recovered ~0.75 kg.

Water table measured at a depth of 1.66 m below ground surface on August 31, 2014 with the drill hole at depth of 24.9 m below surface. 2 SPT-01 - Recovered 0.30 m. SPT-01 1 2 2

3

SPT-02 - Recovered 0.43 m. SPT-02 3 4 2 3

GRAVEL (GW) Fine to coarse, sandy, compact to dense, maximum particle size 35mm, subrounded to rounded gravel, angular sand, dark grey, 5 granodiorite and quartz gravels, odourless, moist, homogeneous, no cementation. SPT-03 [FLUVIAL] 11 SPT-03 - Recovered 0.24 m. 17 22 5.74 to 6.65 m - Slow drilling progress. Interpreted coarse gravel 6 and/or cobble beds.

SPT-04 - Recovered 0.30 m. Begin transition to SAND (SP) SPT-04 12 7 10 3

8 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 2/13/15 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-NTC-02 Page 2 of 6 Location: North Thompson River (at Chappell) - Right Bank Project No.: 0095-150-04

Survey Method: Garmin GPSMAP 62s Drill Designation: HT 700 #5 Start Date: 29 Aug 14 Co-ordinates (m): 352,203E, 5,806,420N Drilling Contractor: Foundex Finish Date: 01 Sep 14 Ground Elevation (m): 706.0 Drill Method: Mud Rotary Final Depth of Hole (m): 40.79 Datum: NAD 83 UTM Zone 11U Fluid: Bentonite Mud Logged by: CAP Dip (degrees from horizontal): -90 Casing: HWT Cased To (m): N/A Reviewed by: LDM Direction: N/A Depth To Rock (m): N/A Approved by: KWB

Su - kPa

40 80 120 160

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

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

Depth (m) Sample Type Sample No. Grade Weathering Symbol SPT Blows per 150mm 20 40 60 80 20 40 60 80 8

SPT-05 - Recovered 0.33 m. SPT-05 39 41 17 8.79 to 9.70 m - Slow drilling progress. Interpreted gravel and/or 9 cobble beds. SAND (SM) Fine to medium, silty, trace gravel, poorly graded, compact, angular to subangular, grey, moist, laminated, maximum gravel size 35 mm. [FLUVIAL] SPT-06 - Recovered 0.34 m. 10 SPT-06 6 8 6

SILT (ML) 11 Sandy, low plasticity, stiff to very stiff, grey, odourless, moist, faintly laminated, weak cementation, low dry strength. [GLACIOLACUSTRINE] SPT-07 SPT-07 - Recovered 0.52 m. 4 7 7 12

SPT-08 - Recovered 0.58 m. 13 SPT-08 4 6 8

14

14.27 to 14.37 m - 0.10 m interval of highly dilatant silt, readily flowed SPT-09 when shaken. 7 SPT-09 - Recovered 0.53 m. 7 Sandy SILT (ML) fines content 67.7%. 11 15

16 (Continued on next page) TMEP (SOIL & ROCK) TMEP_SOILROCK.GDL BGC.GDT 2/13/15