Contractor 2018-03-29 Trans Mountain Expansion Project Revision Geotechnical HDD Feasibility Contractor 0 Blackmud Creek at Revision SSEID 005.5 KP 24.2
Page 1 of 104 TMEP18-026
Trans Mountain Expansion Project
Geotechnical HDD Feasibility Blackmud Creek at SSEID 005.5 KP 24.2
KMC Document #01-13283-S1-0000-PL-RPT-0034 R0
Reviewed by Pages Rev No. Prepared by / Date Reviewed by / Date Approved by / Date Issued Type TMEP Revised
Patrick Nolan 2018-03-29 0 Issued for Use Pete Quinn Alex Baumgard 2018-03-29 2018-03-29
Leo Moreno 2018-03-29
TRANS MOUNTAIN PIPELINE ULC
TRANS MOUNTAIN EXPANSION PROJECT
GEOTECHNICAL HDD FEASIBILITY ASSESSMENT BLACKMUD CREEK AT SSEID 005.5 KP 24.2
PROJECT NO.: 0095150-14 DOCUMENT NO.: TMEP18-026 DATE: March 29, 2018
Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
EXECUTIVE SUMMARY
As part of the engineering design and assessment for the Trans Mountain Expansion Project (TMEP), BGC Engineering Inc. (BGC) has been retained to complete geotechnical feasibility assessments for trenchless crossings at select watercourse and overland crossings along the proposed pipeline corridor. In June 2013, WorleyParsons, completed geophysical surveys along the proposed TMEP alignment under subcontract to BGC. In June and July of 2014, BGC monitored the drilling of two geotechnical boreholes adjacent to the proposed TMEP alignment at Blackmud Creek. The primary crossing method was originally planned to be a conventional trench, with horizontal directional drilling (HDD) identified as a contingency crossing method. A letter report (BGC 2015) provided geotechnical drilling data collected during the investigative drilling program. HDD has recently been selected as the primary crossing method. This report provides a feasibility-level geotechnical assessment for an HDD at Blackmud Creek crossing located at approximately Kilometre Post (KP) 24.2, in south Edmonton, Alberta. The scope of work for this assessment included a desktop review of the relevant regional and local geological settings, results from two geotechnical boreholes drilled in 2014 and geophysical surveys completed in 2013, and the compilation and interpretation of this data to provide an indication, from a geotechnical perspective, of the feasibility of the proposed 616 m long HDD crossing. The conclusions presented herein are based solely on the scope of the investigation undertaken at this time for the purpose of obtaining information for the feasibility study. Results of geotechnical drilling and electrical resistivity tomography (ERT) survey indicate the subsurface soils consist of silts, sands and clays with trace gravels that were soft to stiff at shallow depths, becoming hard below 12 to 17 m depth. Bedrock (interbedded sandstone, mudstone and siltstone – Horseshoe Canyon Formation) was encountered at an approximate depth of 17 m in both boreholes. The depth of this contact has been inferred from visual examination of recovered core and is uncertain due to the gradual transition from very stiff soil to very weak rock; the geophysical surveys suggest that the bedrock contact could be deeper than interpreted from drilling, and as such the actual contact depth may vary by up to approximately 5 to 10 m. While coal mining has occurred historically in some nearby areas in Edmonton (e.g., Whitemud Creek approximately 3 km west of the crossing), available records do not suggest that coal mining has taken place at the location of the Blackmud Creek HDD crossing, and no evidence of significant coal deposits or associated workings was found during the geotechnical drilling or geophysical survey investigation. Historical mining infrastructure is therefore not expected to be encountered along the HDD borepath. Given the above, and based on the desktop study, available third-party data and results of the geotechnical site investigation and geophysical survey, an HDD at this location can be considered feasible from a geotechnical perspective provided the following challenges can be addressed during detailed design and construction:
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek Page i BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Sloughing, hole collapse: As drilling is undertaken, potential for sloughing and hole collapse may occur in the glaciolacustrine deposit at an elevation of about 667 to 672 masl, where the sand content increases, and the consistency decreases from very stiff to stiff. Such horizons may be encountered along the borepath where it passes through the glaciolacustrine unit. While the fully cased geotechnical drilling process did not allow for direct observation of sloughing or hole collapse, the lower observed core recovery and non-cemented nature of the sandier beds suggest that sloughing and hole collapse are possible within these zones. Possible mitigation includes careful drill fluid management (i.e., variation of viscosity and pressure) or use of surface casing to advance the HDD bore past these horizons. Loss of drilling fluids: Drilling fluid loss could occur in the sand beds encountered in the glaciolacustrine deposit. This is expected to be mitigatable by surface casing or adapting the drill mud mixes. Encounter with cobbles or boulders: While no cobbles or boulders were encountered during the geotechnical drilling, the proposed bore path could encounter glacial till, which was not encountered during geotechnical drilling, but is commonly observed below or within glaciolacustrine soils in the area. The possible presence of larger clasts should therefore not be discounted. Highly plastic material: High plasticity clay beds were occasionally encountered in the bedrock; this has the potential to thicken drill mud and impact cuttings management (causing mud rings). Such conditions can potentially be mitigated by adapting the drill mud mixes. Steering difficulties: The HDD borepath is expected to encounter Horseshoe Canyon Formation bedrock, potentially intersecting it at a shallow angle. Bedrock strengths are anticipated to be similar to, but higher than, those of the overlying glaciolacustrine soils in the vicinity of the contact. Significant steering issues are not anticipated, but some extra effort and care may be required.
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek Page ii BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
TABLE OF CONTENTS EXECUTIVE SUMMARY ...... i TABLE OF CONTENTS ...... iii LIST OF TABLES ...... iv LIST OF FIGURES ...... iv LIST OF DRAWINGS ...... v LIST OF APPENDICES ...... 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 3.2.1. Regional ...... 4 3.2.2. Local ...... 4 3.3. Historic Coal Mining in Edmonton Area ...... 8 3.4. Bedrock Geology...... 9 3.5. Terrain Mapping ...... 9 3.5.1. Terrain Types ...... 9 3.6. Hydrotechnical Assessment ...... 10 3.6.1. Flood Frequency Analysis ...... 10 3.6.2. Scour ...... 11 3.6.3. Bank Erosion ...... 11 3.6.4. Encroachment ...... 12 3.6.5. Avulsion ...... 12 4.0 SITE INVESTIGATION ...... 13 4.1. Geotechnical Drilling and Laboratory Testing ...... 13 4.1.1. Groundwater Observations ...... 14 4.1.2. Borehole Stability ...... 15 4.1.3. Circulation and Loss of Fluids ...... 15 4.2. Geophysical Survey Data ...... 15 5.0 INFERRED GEOTECHNICAL CONDITIONS ALONG THE HDD BOREPATH ...... 17 5.1. Geotechnical Conditions Along the Borepath ...... 18 6.0 GEOTECHNICAL FEASIBILITY ASSESSMENT ...... 20 6.1. General Considerations ...... 20 6.2. Steering Difficulties...... 20 6.3. Borepath Stability...... 21 6.4. Circulation and Potential for Loss of Fluids ...... 21 6.5. Geotechnical Feasibility ...... 21 7.0 CLOSURE ...... 23 REFERENCES ...... 24
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek Page iii BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
LIST OF TABLES
Table 3-1. Peak instantaneous flow estimates (QIMAX) for the Blackmud Creek [KP 24.2] crossing...... 10 Table 3-2. Blackmud Creek historical imagery database...... 11 Table 4-1. Borehole depths and locations...... 13 Table 4-2. Groundwater observations in BH-BGC14-BM-01 and BH-BGC14-BM- 02...... 14
LIST OF FIGURES
Figure 3-1. Location of the proposed Blackmud Creek crossing...... 3 Figure 3-2. Surficial geology of the Edmonton area (Kathol and McPherson 1975)...... 5 Figure 3-3. Index map illustrating the location of the Blackmud Creek crossing relative to relevant geological cross-sections (modified from Kathol and McPherson 1975)...... 6 Figure 3-4. Select portion of geological cross-section #1 – east to west (modified, from Kathol and McPherson 1975)...... 7 Figure 3-5. Thalwegs of pre-glacial valley in the Edmonton Area (modified from Kathol and McPherson 1975). Approximate location of proposed HDD crossing is shown as a red rectangle...... 8
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek Page iv BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
LIST OF DRAWINGS
DRAWING 01A TERRAIN MAP DRAWING 01B TERRAIN MAP LEGEND DRAWING 02A INTERPRETED GEOLOGIC CROSS-SECTION DRAWING 03 BANK EROSION AND AVULSION REVIEW DRAWING 04 GEOPHYSICS RESULTS DRAWING 05 FIELD PHOTOS DRAWING 06A PHOTOGRAPHIC LOG OF BH-BGC14-BM-01 (1 OF 2) DRAWING 06B PHOTOGRAPHIC LOG OF BH-BGC14-BM-01 (2 OF 2) DRAWING 07 PHOTOGRAPHIC LOG OF BH-BGC14-BM-02
LIST OF APPENDICES
APPENDIX A HYDROTECHNICAL ASSESSMENT METHODOLOGY APPENDIX B BGC BOREHOLE LOGS APPENDIX C LABORATORY TEST RESULTS
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek Page v BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
LIMITATIONS
BGC Engineering Inc. (BGC) prepared this document for Trans Mountain Pipeline ULC (Trans Mountain). The material in this report reflects the judgment of BGC staff based upon the information made available to BGC at the time of preparation of the report, including that information provided to it by Trans Mountain. Any use which a third-party makes of this report or any reliance on decisions to be based on it is the responsibility of such third parties. BGC accepts no responsibility whatsoever for damages, loss, expenses, loss of profit or revenues, if any, suffered by any third-party as a result of decisions made or actions based on this report. As a mutual protection to our client, the public and BGC, the report, and its drawings are submitted to Trans Mountain as confidential information for a specific project. Authorization for any use and/or publication of the report or any data, statements, conclusions or abstracts from or regarding the report and its drawings, through any form of print or electronic media, including without limitation, posting or reproductions of same on any website, is reserved by BGC, and is subject to BGC's prior written approval. Provided however, if the report is prepared for the purposes of inclusion in an application for a specific permit or other government process, as specifically set forth in the report, then the applicable regulatory, municipal, or other governmental authority may use the report only for the specific and identified purpose of the specific permit application or other government process as identified in the report. If the report or any portion or extracts thereof is/are issued in electronic format, the original copy of the report retained by BGC will be regarded as the only copy to be relied on for any purpose and will take precedence over any electronic copy of the report, or any portion or extracts thereof which may be used or published by others in accordance with the terms of this disclaimer.
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek Page vi BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
1.0 PROJECT DESCRIPTION Trans Mountain Pipeline ULC (Trans Mountain) is a Canadian corporation with its head office located in Calgary, Alberta. Trans Mountain is a general partner of Trans Mountain Pipeline L.P., which is operated by Kinder Morgan Canada Inc. (KMC), and is fully owned by Kinder Morgan Energy Partners, L.P. Trans Mountain is the holder of the National Energy Board (NEB) certificates for the Trans Mountain pipeline system (TMPL system). The TMPL system commenced operations in 1953 and now transports a range of crude oil and petroleum products from Western Canada to locations in central and southwestern British Columbia (BC), Washington State, and offshore. The TMPL system currently supplies much of the crude oil and refined products used in BC. In December 2016, the NEB granted approval for the Trans Mountain Expansion Project (referred to as “TMEP” or “the Project”) under Section 52 of the National Energy Board Act (NEB Act). The proposed expansion will comprise the following: Pipeline segments that complete a twinning (or “looping”) of the pipeline in Alberta (AB) and BC with about 987 km of new buried pipeline New and modified facilities, including pump stations and tanks Three new berths at the Westridge Marine Terminal in Burnaby, BC, each capable of handling Aframax class vessels. As part of the design process for the twinning of the pipeline, geotechnical and hydrotechnical investigations are being undertaken at watercourse crossings to support feasibility assessments for establishing the preferred crossing methodology, and where appropriate, contingency options. Known reference points along the existing TMPL system are commonly referred to as Kilometer Post or “KP”. KP 0.0 is located at the Edmonton Terminal in Edmonton, AB, where the existing Trans Mountain system originates. KPs are approximately 1 km apart and are primarily used to describe features along the pipeline for operations and maintenance purposes. All references to KPs along the TMEP corridor are for the Route SSEID 005.5 alignment provided by UniversalPegasus International (UPI) in March 2018.
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek Page 1 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
2.0 SCOPE OF WORK As part of the engineering design and assessment for installing new sections of pipeline, Trans Mountain have retained BGC Engineering Inc. (BGC) to complete geotechnical feasibility assessments for trenchless crossings at select locations along the proposed pipeline corridor. A trenchless crossing by horizontal directional drilling (HDD) is proposed for the Blackmud Creek crossing, located at SSEID 005.5 KP 24.2, in Edmonton, Alberta. A 608-m long HDD crossing is proposed for this site (2D length in plan view), as illustrated in the preliminary design drawing for the proposed HDD crossing (UPI 2018). BGC’s scope of work for the feasibility assessment of the Blackmud Creek crossing consisted of the following: Desktop study including: ○ A review of the regional geology and the local geological setting at the HDD crossing in published literature. ○ A review of information pertaining to historic underground coal mining in the area (BGC 2016). ○ A review of the terrain mapping assessment (Trans Mountain 2014) along the pipeline corridor at a scale of 1:20,000. Drilling of two geotechnical boreholes adjacent to the proposed TMEP alignment (under BGC supervision). Geophysical survey completed by WorleyParsons along the proposed TMEP alignment under BGC supervision. Compilation and interpretation of this data, and assessment of geotechnical feasibility for the proposed HDD crossing. Planning for contingency construction methods is outside the scope of this study and will be addressed by the pipeline design engineer for the portion of the route under consideration, in this case, UPI. As such, no comments on the applicability of the current route to alternate crossing methods are provided herein. The purpose of this report is to summarize the anticipated geotechnical site conditions at the proposed Blackmud Creek crossing and to provide an indication, from a geotechnical perspective, of the feasibility of an HDD crossing at this location.
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek Page 2 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
3.0 SITE DESCRIPTION, GEOLOGY, AND HYDROTECHNICAL ASSESSMENT
3.1. Overview The proposed Blackmud Creek crossing is located in south Edmonton, Alberta, approximately 120 to 225 m south of Anthony Henday South Highway (HWY 216) and the 0+00 chainage directly below Blackmud Creek, is approximately 520 m east of 111 Street NW. The location of the proposed TMEP alignment and HDD are shown in Figure 3-1.
Figure 3-1. Location of the proposed Blackmud Creek crossing.
The TMEP alignment at the proposed crossing (UPI 2018) is oriented nearly east to west and crosses Blackmud Creek at about a 75 ° angle. The proposed HDD entry and exit points are
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek Page 3 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14 located approximately 290 m west and 320 m east of Blackmud Creek thalweg, respectively. From entry to exit point, the proposed HDD borepath is approximately 616 m long (608 m horizontal length in plan view), and crosses approximately 27 m below the creek bed.
3.2. Surficial Geology
3.2.1. Regional The proposed HDD crossing is within the Central Parkland natural subregion, which lies within the Eastern Alberta Plains physiographic region. This area is primarily characterized by undulating till plains. Additionally, approximately 30 percent of the region consists of hummocky uplands with more pronounced topographic relief. The vegetation of the region consists of either a patchwork of aspens and native prairie vegetation or cultivated agricultural fields and urban areas (Downing and Pettapiece 2006). The dominant surficial materials in this region are thick glaciolacustrine sediments and glacial till with lesser glaciofluvial, fluvial, colluvial and eolian soils, and bedrock outcrops (Shetsen 1990). Glaciolacustrine and till deposits overlie discontinuous pre-glacial Saskatchewan Sands and Gravels, and sedimentary bedrock (Edwards et al. 2006). Overburden depth is variable, and generally thins to the west. Surficial material in this physiographic region is controlled by the glacial history of the Laurentide Ice Sheet during the Wisconsin Glaciation (Young et al. 1994). The Edmonton region was submerged beneath Glacial Lake Edmonton, a large lake that formed as the Laurentide Ice Sheet retreated and downwasted to the north and east, blocking the eastward drainage system. Sediment-rich post-glacial streams deposited clays, silts, and sands into the Edmonton area. Glaciolacustrine deposits are characterized as dark sands, silts, and clays (Shetsen 1990). Glaciofluvial deposits, both pre- and post-glacial, contain gravels, sands, and silts. Tills are medium to moderately fine textured, and moderately calcareous (Downing and Pettapiece 2006). The Alberta Geological Survey surficial geology maps display glaciolacustrine deposits in the general vicinity of the proposed Blackmud Creek crossing at (Fenton et al. 2013).
3.2.2. Local Kathol and McPherson (1975) completed an urban geology study, which includes a summary of the basic geologic data available for the Edmonton area. The approximate location of the proposed HDD alignment at the Blackmud Creek crossing is shown in plan view overlying the surficial geology of Edmonton mapped by Kathol and McPherson (1975) in Figure 3-2. This map suggests the presence of glaciolacustrine silt and clay deposits with minor sand, and the presence of a creek valley with thin alluvial material along streams. The urban geology study also includes geological cross-sections, and the proposed HDD alignment at the Blackmud Creek crossing is located approximately 700 m north of geological cross-section #1 (see Figure 3-3 and Figure 3-4).
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Approximate location of proposed HDD drill path
Figure 3-2. Surficial geology of the Edmonton area (Kathol and McPherson 1975).
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Approximate location of proposed HDD drill path
Cross Section #1 1 1
Figure 3-3. Index map illustrating the location of the Blackmud Creek crossing relative to relevant geological cross-sections (modified from Kathol and McPherson 1975).
Based on cross-section #1, as illustrated in Figure 3-4, the following deposit types may be encountered by the drill path, in descending order from the ground surface: a. Lacostro-till (unit 7 in Figure 3-4): glaciolacustrine sediments mixed with pebbles and till- like layers, deposited by mud-flows into a glacial lake or by ice rafting or by both. b. Glaciolacustrine (unit 8 in Figure 3-4): bedded sands, silts, and clays deposited in a large pre-glacial lake called Glacial Lake Edmonton. c. Glacial till (unit 5 in Figure 3-4): unstratified sediment deposited by a glacier; lenses of outwash sand or gravel or disturbed bedrock are common.
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d. Bedrock (unit 1 in Figure 3-4): Edmonton Formation, also known as Horseshoe Canyon Formation, composed of interbedded bentonitic shales, siltstones, and sandstones with numerous coal seams.
Approximate location of proposed HDD drill path
Figure 3-4. Select portion of geological cross-section #1 – east to west (modified, from Kathol and McPherson 1975).
As part of their geologic study of the Edmonton area, McPherson and Kathol (1972) and Kathol and McPherson (1975) also mapped the presence of buried valley gravels. These are pre-glacial valleys that have been partially or fully infilled with glacial or other materials during the Wisconsin glaciation. These materials pre-date the glacial deposits and are referred to in the literature as Tertiary-Quaternary gravels. A review of the mapped buried valley thalwegs indicates that the nearest pre-glacial valleys, the New Sarepta and Ellerslie Valleys, do not intersect the proposed Blackmud Creek crossing. Figure 3-5, modified from Kathol and McPherson (1975), shows the location of the proposed HDD crossing relative to the New Sarepta Valley and Ellerslie Valley. The New Sarepta Valley is the largest of the Stony Valley tributaries and is 2 km wide with valley depths ranging from 8 to 15 m, side slopes from 1.5 to 6 percent and a valley gradient of 2.4 m per km (Kathol and McPherson 1975). The Ellerslie Valley, the nearest mapped valley to the proposed Blackmud Creek crossing, is estimated to be approximately 0.8 km wide with side slopes varying from 0 to 4 percent and a valley gradient that exceeds 5 m per km. Its mapped thalweg is offset approximately 1.5 km from the proposed Blackmud Creek crossing, and is therefore not expected to overlap the proposed crossing.
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New Sarepta Valley
Ellerslie Valley
Figure 3-5. Thalwegs of pre-glacial valley in the Edmonton Area (modified from Kathol and McPherson 1975). Approximate location of proposed HDD crossing is shown as a red rectangle.
3.3. Historic Coal Mining in Edmonton Area Underground coal mining has been undertaken in Alberta, and specifically in the Edmonton region, since the late 1800s (City of Edmonton Archives). The Alberta Energy Regulator (AER) has developed an online atlas of historic coal mines. Data provided by the atlas includes the approximate footprints of recorded mines, their years of operation, the target seam thicknesses, and the approximate depths of mining below ground surface. While coal mining has occurred historically in some nearby areas in Edmonton (e.g., Whitemud Creek area approximately 3 km west of the Blackmud Creek crossing), available records do not suggest that coal mining has taken place at the location of the Blackmud Creek crossing, and no evidence of significant coal deposits or associated workings were found during the geotechnical drilling. Historical mining infrastructure is therefore not expected to be encountered along the HDD borepath (BGC 2016).
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3.4. Bedrock Geology The proposed Blackmud Creek crossing is in an area underlain by Horseshoe Canyon Formation bedrock of the Upper Cretaceous to Tertiary Edmonton Group. These rock units are generally very gently dipping to the west and have not been tectonically deformed although minor folds and faults are known (Dawson et al. 1994). Bedrock is generally of decreasing age to the west within this physiographic region. The Horseshoe Canyon Formation is characterized as interbedded non-marine sandstone, siltstone, and shale, with numerous coal and bentonite beds (Hamblin 1998). Sandstones are soft, light-grey to greenish grey, poorly sorted, very fine to medium grained, feldspathic, and argillaceous (Hamblin 1998). Mudstones are grey-green or brown, argillaceous and bentonitic, and also carbonaceous. Units usually contain wood fragments, thin coal streaks, ironstone concretions, and beds with plant and dinosaur fossils (Hamblin 1998). Coal beds in this unit were historically mined in the Edmonton area using underground room and pillar techniques. Subsidence within the mined seams has historically caused damage to the surface and buildings in the Edmonton area (Edwards et al. 2006). Ice-shoved bedrock is also common in the Edmonton area and may be present within this subregion. This consists of blocks of bedrock that have been displaced laterally and deposited by glacial action within or above other glacial deposits (typically tills or sands and gravels; Kathol and McPherson 1975).
3.5. Terrain Mapping As part of an overall terrain assessment for TMEP, BGC produced terrain maps along the proposed pipeline corridor at a nominal scale of 1: 20,000 from the analysis of air photos, satellite imagery, and LiDAR topography. Terrain mapping was spot-checked by site visits and field observations (Trans Mountain 2014). Local variations in terrain over areas of about 2 to 3 hectares, or over distances of less than approximately 150 m, may not be captured in the scale of terrain mapping. Terrain mapping for the Blackmud Creek crossing is shown in Drawing 01A, and a terrain legend for this is shown in Drawing 01B.
3.5.1. Terrain Types Terrain types mapped at the Blackmud Creek crossing and shown on Drawing 01A include glaciolacustrine, till and fluvial deposits as described below: a. Glaciolacustrine: the dominant mapped surficial materials along the Blackmud Creek crossing are glaciolacustrine sediments. Glaciolacustrine soils typically consist of silts, clays, and fine sands deposited in glacial lakes. Higher energy deposition that occurred at the margins of glacial lakes could also result in coarser deposits. Deposits are often layered due to seasonal variations in stream flow and sediment grain size. b. Fluvial: Fluvial terrace deposits are predominately composed of sand and gravel deposited by surface water and meltwater streams. Overbank fluvial deposits consist of finer grained materials (i.e. silt) than typical fluvial deposits and are placed when the river floods and rises above its normal banks. Cobbles and boulders may also be present.
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c. Till: Tills are generally over consolidated, very dense and contain a range of particles sizes from clays and silts to boulders and cobbles. BGC completed a terrain stability analysis in conjunction with terrain mapping of the TMEP route (Drawing 01A). This analysis classified a range of stability classes for the regions along the proposed HDD crossing. The terrain near the HDD entry and exit points are classified as a Stability Class I, suggesting that no significant stability problems exist at those locations.
3.6. Hydrotechnical Assessment LiDAR imagery, historical air photographs, 2014 survey data and site observations were used to assess the potential for hydrotechnical hazards to impact the proposed pipeline. Hazards evaluated by BGC included scour, bank erosion, encroachment and avulsion. The methodologies used to complete this hazard assessment are presented in Appendix A.
3.6.1. Flood Frequency Analysis Flood quantiles for the Blackmud Creek crossing were estimated using a flood frequency analysis (FFA). The drainage area at the crossing was estimated to be 662 km2 and a prorated FFA was used to estimate peak instantaneous streamflow (QIMAX) for various return periods. This FFA used reported flood quantiles from NHC (2014), based on Water Survey of Canada (WSC) hydrometric stations Blackmud Creek near Ellerslie (05DF003) and Whitemud Creek near Ellerslie (05DF006). The Blackmud Creek near Ellerslie (05DF003) station is located approximately 2.1 km upstream (south) of the proposed crossing. This station has a record length of 34 years between 1978 and 2011 and has a published watershed area of 643 km2. The flood quantiles reported by NHC (2014) include an estimated peak flow from a historic 1974 flood, which was provided by Alberta Environment and had a return period in excess of 100-years. The flood quantiles reported by NHC (2014) were prorated to the proposed crossing along with a climate change allowance of +10% based on guidance by APEGBC1 (2012). Peak instantaneous streamflow estimates at the Blackmud Creek crossing for various return periods and the 1974 flood are as listed in Table 3-1:
Table 3-1. Peak instantaneous flow estimates (QIMAX) for the Blackmud Creek [KP 24.2] crossing.
3 Basin QIMAX for Given Return Periods (m /s) Pipeline Area Crossing 50- 200-yr 1974 (km2) 2-yr 5-yr 10-yr 25-yr 100-yr yr Flood1 Blackmud 662 11 27 40 58 73 87 103 97.5 Creek 1. Estimated instantaneous peak flow from historic 1974 flood provided by Alberta Environment (NHC 2014).
Average cross-sectional flow hydraulics for the crossing were estimated using Manning’s equation, a surveyed cross-section, a channel gradient of 0.3% and the peak flows listed in Table
1 The Association of Professional Engineers and Geoscientists of BC (APEGBC) recently changed its name to Engineers & Geoscientists British Columbia (EGBC).
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3-1. The channel gradient was estimated from LiDAR topography coverage flown by Airborne Imaging Inc., and received from UPI on April 18, 2014. The cross-section used for the evaluation is based on a surveyed cross-section by Opus Stewart Weir from June 2014. The corresponding water elevation for the 200-year return period flood is 669.1 masl as shown on Drawing 02. The proposed HDD entry and exit points are located at elevations of approximately 683.1 masl and 683.0 masl, respectively, and are located outside the confined valley, approximately 14 m above the 200-year return period flood. Therefore, submergence of the proposed HDD entry and exit points is not considered a hazard for the proposed HDD borepath.
3.6.2. Scour BGC completed a scour analysis for the site to evaluate general scour conditions over the point at which the proposed HDD alignment crosses below Blackmud Creek. The scour analysis was conducted using the estimated peak flows presented in Table 3-1, and the channel cross-section from the survey completed by Opus Stewart Weir in June 2014. Results from the analysis suggest a maximum scour depth of approximately 1.5 m below the channel thalweg (deepest elevation of the channel) elevation of 666.6 masl during a 200-year flood event, corresponding to a maximum scour elevation of 665.1 masl. The depth of cover above the proposed HDD borepath to the maximum scour elevation is greater than 25 m. Given this result, scour is not considered a hazard for the proposed HDD borepath.
3.6.3. Bank Erosion BGC completed an evaluation of the historical lateral erosion of Blackmud Creek at the crossing by comparing aerial imagery from 1949 and 2011 (Table 3-2). The 1949 aerial photograph was georeferenced to make the comparison with the 2011 orthoimage and Drawing 03 demonstrates how the channel planform has changed over the 62-year period.
Table 3-2. Blackmud Creek historical imagery database. Date Ref No. Photo No. Scale Source 1949 A0137 97 1:40,000 Alberta Environment and Parks (AEP)1
2011 - - City of Edmonton
Notes: 1. AEP was previously known as Alberta Environment and Sustainable Resource Development (AESRD). A comparison of the channel thalweg location between 1949 and 2011 illustrates that progressive lateral erosion is occurring at meander bends, with approximately 10 to 15 m of erosion over the 62-year period (Drawing 03). Blackmud Creek meanders through a vegetated, active floodplain along the valley bottom formed from alluvial sediments, and is constrained by high, steep valley walls composed of glaciolacustrine deposits and glacial till (Section 3.2.2). During a site visit on August 2, 2014 by BGC, the left (west) bank, which is approximately 5 m high, was actively eroding and undercut; however, this erosion is minor, and is not expected to
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek Page 11 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14 impact the proposed HDD alignment within its operational life span. No erosion was observed along the right bank, which is approximately 1 m high. Both banks of Blackmud Creek near the Blackmud Creek crossing are well vegetated, which also contributes to bank stability. Given that the proposed HDD entry and exit points are located outside of the confined valley and are set back approximately 125 m and 250 m from the crests of the west and east valley walls, bank erosion is not considered a hazard for the proposed HDD borepath.
3.6.4. Encroachment The proposed Blackmud Creek crossing is located along a relatively straight reach with the tortuously meandering Blackmud Creek (Drawing 03). Further upstream and downstream, larger severe meander bends represent an encroachment hazard to the pipeline 100 m to the west of the proposed crossing. The proposed HDD crossing passes under the “neck” between the two meander bends. The current minimum perpendicular distance to the creek is approximately 18 m to the south and 24 m to the north of the proposed pipeline alignment. Comparison between the 1949 and 2011 aerial imagery indicates that progressive lateral migration erosion has occurred, and there is potential for future meander migration to intercept the pipeline alignment and for a meander cutoff to develop between the two meander bends. However, the two meander bends are separated by high ground composed of glaciolacustrine deposits and glacial till (Section 3.2.2), and therefore the potential meander cutoff at this location is considered by BGC to represent a long-term geomorphic process. If a meander migration or a meander cutoff were to develop, the estimated depth of cover above the proposed HDD borepath would remain greater than 15 m, and therefore, encroachment is not considered a hazard for the proposed HDD borepath.
3.6.5. Avulsion At the proposed crossing, Blackmud Creek is contained between a 5 m high left bank composed of glaciolacustrine and glacial till deposits, and a 1 m high alluvial right bank that forms part of the active floodplain (Drawing 02). No active side channels are evident within the active floodplain at the proposed crossing. A secondary channel is evident 60 m downstream of the proposed crossing, which could potentially develop into a cutoff channel. However, given the depth of cover to the proposed HDD borehole of more than 25 m, channel avulsions within the meander belt would not affect the proposed crossing. Given that Blackmud Creek is confined within a valley with steep slopes and the entry and exit points are located outside of the valley, avulsion is not considered a hazard for the proposed HDD borepath.
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4.0 SITE INVESTIGATION In June 2013, WorleyParsons completed geophysical surveys along an earlier TMEP alignment version, under subcontract to BGC. The geophysical surveys included both electrical resistivity tomography (ERT) and seismic refraction along the alignment shown in Drawing 02 and 04. Terrestrial ERT was carried out along a total length of approximately 850 m, offset up to approximately 100 m south of the proposed HDD alignment for the Blackmud Creek crossing. Seismic refraction survey was conducted along approximately the same line as the east half of the ERT survey, extending east from Blackmud Creek. In June and July of 2014, BGC monitored the drilling of two geotechnical boreholes adjacent to the proposed HDD alignment. A letter report (BGC 2015) provided geotechnical drilling data collected during the investigative drilling program. Drawing 05 contains site photographs of drilling activities during the 2014 site investigation.
4.1. Geotechnical Drilling and Laboratory Testing
Borehole BH-BGC14-BM-01 was drilled above and east of the east bank of Blackmud Creek, approximately 80 m east of the creek thalweg, offset 8 m south of the proposed HDD alignment, and 240 m west of the HDD exit point, at an elevation of 684 masl. Borehole BH-BGC14-BM-02 was drilled above and west of the west bank of Blackmud Creek, approximately 280 m west of the creek thalweg, offset 21 m north of the proposed HDD alignment, and 10 m east of the HDD entry point. The ground surface elevation of BH-BGC14-BM-02 is also 684 masl. Drilling was completed to depths of 48.6 mbgs and 28.0 mbgs in boreholes BH-BGC14-BM-01 and BH- BGC14-BM-02, respectively.
Soils encountered during the investigative drilling at Blackmud Creek were interpreted to be glaciolacustrine in origin, consisting of silts, sands and clays with trace gravels, having soft to stiff consistency at shallow depths, and becoming harder below 12 m depth. Sand beds were encountered in both boreholes near the contact with bedrock. Bedrock (interbedded sandstone, mudstone and siltstone – Horseshoe Canyon Formation) was encountered at an approximate depth of 17 m in both boreholes and was extremely weak (R0) to a depth of about 22 m, becoming very weak (R1) or weak (R2) at greater depth. Details concerning the locations, ground surface elevations, and final depths of the boreholes are listed in Table 4-1.
Table 4-1. Borehole depths and locations.
Coordinates Ground Surface Final Borehole UTM NAD 83 Zone 12U Elevation1 Elevation/Depth Easting (m) Northing (m) masl masl mbgs BH-BGC14-BM-01 333,263 5,923,419 684.0 635.4 48.6 BH-BGC14-BM-02 332,928 5,923,355 684.0 656.0 28.0 1. Inferred based on LiDAR provided by UPI, 2014.
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The drilling method used to advance each borehole consisted of mud rotary and triple tube coring, with SPTs completed during mud rotary drilling in soil or extremely weak rock every 1.5 m. Both boreholes were advanced to their planned target depths. Data collected during geotechnical investigation included the following: Pocket penetrometer tests on recovered soil and bedrock core at various depths. SPTs (ASTM D1586) at 1.5 m intervals. The SPT casing was 60 cm (24-in) long with a 5 cm (2-in) outside diameter, driven by a 63-kg automatic trip hammer that was dropped 76 cm above the anvil. Description of soil units in terms of lithology, colour, grain size, bedding, and structural features based on visual examination of material retrieved in the SPT and core samples (ASTM D2487, ASTM D2488, and the Unified Soil Classification System). Visual description of bedrock units (e.g., lithology, colour, grain size, strength, structure). Moisture content (ASTM D2216), grain size distribution (ASTM D422), hydrometer (ASTM D7928), and Atterberg limits (ASTM D4318) of selected samples, based on laboratory testing of recovered samples obtained from the SPTs. Uniaxial compression strength (ASTM D7012-14 Method C) of selected rock core samples. Core recovery (%) and rock quality designation (RQD; source: Deere 1988). Depth to water level as observed upon completion of drilling and during drilling (typically at the beginning of shift), when applicable. Geotechnical borehole logs and results from laboratory analyses are provided in Appendix A and Appendix B, respectively. Drawing 05 presents site photographs of drilling activities during the 2014 site investigation. Drawings 06A, 06B and 07 provide photographic logs of recovered SPT and core samples.
4.1.1. Groundwater Observations Water levels were measured in both BGC boreholes prior to the completion of drilling after the boreholes had been left open overnight for approximately 12 hours, and on the mornings of the final day of drilling, where possible. The groundwater elevations measured in BH-BGC14-BM-01 and -02 are described below in Table 4-2.
Table 4-2. Groundwater observations in BH-BGC14-BM-01 and BH-BGC14-BM-02. Inferred Water Level Borehole Comments mbgs masl Observed on June 29, 2014, when borehole was advanced BH-BGC14-BM-01 16.2 667.8 to final depth of 48.6 mbgs, while casing was installed to 40.5 m depth. Observed on July 1, 2014, when borehole was advanced BH-BGC14-BM-02 7.9 676.1 to final depth of 28.0 mbgs, while casing was installed to 16.7 m depth.
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4.1.2. Borehole Stability In general, both borehole walls remained stable. HWT casing was installed in BH-BGC14-BM-01 to a depth of 40.5 m due to some loss of circulation during drilling above that depth and squeezing of the borehole. The borehole had to be re-reamed from 18.9 to 28.0 mbgs due to squeezing of the borehole walls. HWT casing was also installed in BH-BGC14-BM-02 to a depth of 16.7 m to near the bedrock contact due to some wall collapse in the sand bedding layer noted and overall borehole stability for several metres above the bedrock contact.
4.1.3. Circulation and Loss of Fluids High drilling fluid returns were generally observed during investigative drilling. However, loss of fluid circulation (as much as 50% to 70%) was noted in the glaciolacustrine sandy silt and clay (6.7 mbgs to 9.8 mbgs) at BH-BGC14-BM-01.
4.2. Geophysical Survey Data The geophysics survey for the Blackmud Creek crossing included provision of the following from WorleyParsons:
Terrestrial ERT surveys along an earlier TMEP alignment version, in a total length of approximately 850 m, and to variable imaging depths of up to approximately 80 mbgs (600 masl). A seismic refraction survey along 350 m east of Blackmud Creek. Interpretations of the anticipated subsurface geology based on both aforementioned survey methods. The observed resistivity values, in ohm-m, give an indication of the possible nature of the subsurface materials. The range of recorded resistivity values at the Blackmud Creek crossing, as shown in Drawing 04 is indicated in Figure 4-1 below.
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BLACKMUD CREEK RESISTIVITY RANGE
Figure 4-1. The Electrical Resistivity Range for the Blackmud Creek ERT Survey (Palacky 1987).
Electrical resistivity values at the Blackmud Creek crossing range from about 7 to 45 ohm-m. This is indicative of fine-grained sedimentary bedrock and clay rich glacial soils commonly found in Alberta and described in Section 3.0 above. For the Blackmud Creek ERT survey, the resistivity survey values are interpreted, from Palacky (1987) to indicate the presence of the following materials: 8 to 16 ohm-m: Fine-grained sedimentary bedrock. 8 to 40 ohm-m: Fine grained cohesive soils (e.g. Glaciolacustrine clay deposits). > 40 ohm-m: Medium to coarse grained soils (e.g. Fluvial deposits).
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5.0 INFERRED GEOTECHNICAL CONDITIONS ALONG THE HDD BOREPATH Based on the results of the geotechnical drilling, and geophysical survey completed as part of this investigation, a summary of the inferred geological units identified during BGC’s geotechnical investigation is provided below, along with a description of the drilling conditions encountered within those units. Geotechnical borehole logs and results from laboratory analyses are provided in Appendices B and C, respectively. An interpreted geological cross-section along the proposed HDD crossing has been developed (Drawing 02), along with a summary of field photos of select, representative core samples (Drawing 05), and photographic logs of the materials encountered in each borehole (Drawings 06A, 06B, 7). Similar geologic units were identified at boreholes BH-BGC14-BM-01 and -02. The following units were observed: ANTHROPOGENIC/FILL In borehole BH-BGC14-BM-01 approximately 0.3 m of fill material was encountered. The thickness of this unit may vary up to several metres along the proposed alignment and near the entry and exit points. The material was low plasticity clayey silt and contained some organic matter.
GLACIOLACUSTRINE (Silts and Clays) Soils encountered during investigative drilling at Blackmud Creek were glaciolacustrine in origin, consisting primarily of silts, sands and clays with trace gravels. This interpretation is consistent with the relevant surface geology literature for the area, and BGC terrain mapping. This glaciolacustrine unit was identified in both logs. A glaciolacustrine layer approximately 17 m thick was observed above the east and west banks of Blackmud Creek, outside the creek valley. A thinner glaciolacustrine layer, likely covered by a veneer of fluvial sediments, is inferred from the geophysics survey within the creek valley. Characteristics of the glaciolacustrine soils observed at the Blackmud Creek crossing included silt, clay, sand, and trace gravel, with low plasticity and weak cementation. Occasional pockets of silty fine to medium sand (10 mm to 50 mm thick) were also observed based on samples retrieved and drilling action. Atterberg limits performed on samples retrieved from this unit indicate a low plastic material and yielded an average liquid limit (LL) of 43.4%, an average plastic limit (PL) of 26.2%, and a wetter than plastic limit average moisture content (36.4%). The soil consistency varied from soft to stiff at shallow depths, becoming very stiff below 12 m depth. SPT N values ranged from 3 to 51. The SPT and core recovery was generally high (90-100%) while drilling throughout the glaciolacustrine deposit, with the exception of SPT 10 (14.3 m depth) at BH-BGC14-BM-01 with 0% of recovery, and 35% recovery of SPT 11 (15.9 m depth) at BH-BGC14-BM-02, which coincides with sand beds noted in Drawing 02. There was some loss of return water circulation in this unit noted between 3 to 10 m depth, and squeezing of borehole BH-BGC15-BM-01 between 18.9 to 28.0 mbgs.
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BEDROCK (Interbedded Sandstone, Siltstone, and Mudstone) Horseshoe Canyon Formation bedrock was encountered at both geotechnical boreholes drilled at the Blackmud Creek crossing at approximately 667 masl (17 mbgs). The bedrock consisted of highly weathered to fresh, poorly lithified, interbedded sandstone, siltstone and mudstone, with strength grade varying from extremely weak (R0) to very weak (R1) in the top 5 m of bedrock and increasing to weak (R2) below 40 mbgs. The sandstone was extremely weak to weak, grey to dark brown, and fine- to medium-grained. The siltstone consisted of extremely weak to weak, dark grey fine-grained deposits. The mudstone observed was extremely weak, dark grey and fine-grained. In general, core recovery was moderate to high (greater than 80%). SPTs in the bedrock at BH-BGC14-BM-01 resulted in refusal in all of the thirteen tests. The depth of the bedrock contact, at approximately 17 mbgs, has been inferred from visual examination of recovered core and is uncertain due to the gradual transition from very stiff soil to very weak rock; the geophysical surveys suggest that the bedrock contact is deeper than interpreted from drilling, and as such the actual contact depth may vary by up to approximately 5 to 10 m.
5.1. Geotechnical Conditions Along the Borepath The proposed HDD entry point is situated approximately 290 m west of Blackmud Creek thawleg, at an elevation of approximately 683.1 masl. ERT results and observations made in BH-BGC14-BM-02 suggest that the HDD will enter a layer of low plastic, soft to firm glaciolacustrine layer of silty clay for 70 m length (2D length in plan). Below the glaciolacustrine unit, the borepath is expected to pass through bedrock. This contact is expected to be a lateral distance of approximately 65 to 85 m from the HDD entry point. The strength and stiffness change from the overlying glaciolacustrine soils to the underlying bedrock may be relatively gradual, transitioning from very stiff or hard soil to extremely weak to weak rock. Borehole BH-BGC14-BM-02 encountered sand beds just above the extremely weak to weak weathered bedrock. The borepath may intercept similar geotechnical conditions when passing through an approximate lateral distance of 65 to 85 m from the entry point. The proposed HDD borepath is expected to be in interbedded extremely weak to weak sandstone, mudstone and siltstone for most of its length, from approximately 90 m (2D length in plan view) east of the HDD entry to 80 m west of the HDD exit. The borepath passes below the Blackmud Creek thawleg at a vertical distance of 27 m below the thalweg (valley bottom). When ascending to the exit point, the HDD borepath may again intercept weaker bedrock and sand beds encountered in BH-BGC14-BM-01 from 14 to 22 mbgs. This bedrock unit varies in strength and may contain beds of high plasticity mudstone.
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Upon exiting the bedrock unit, the borepath is expected to re-enter low plastic glaciolacustrine silty clay. Soil consistency approaching the HDD exit point is uncertain, as the nearest borehole BH-BGC14-BM-01 is located approximately 240 m west of the HDD exit point.
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6.0 GEOTECHNICAL FEASIBILITY ASSESSMENT The following conclusions can be drawn from the regional surficial and bedrock geology, terrain mapping, available third-party borehole data, and the results of the subsurface investigations completed along the proposed HDD crossing, and are based solely on the limited scope of the investigation undertaken at this time.
6.1. General Considerations
The banks of Blackmud Creek appear stable with regards to bank erosion and avulsion and the proposed HDD alignment is not expected to be compromised by these hydrotechnical hazards. The HDD entry and exit points are located approximately 14 m above the estimated 200-year flood level, and therefore flood submergence during construction is not considered a hazard. The 200-year scour depth is estimated to be approximately 1.5 m below the average channel bed. Under this event, the HDD borepath is expected to maintain adequate cover, therefore scour is not considered a hazard for the proposed HDD. Coal mine workings are not expected along the borepath proposed for the Blackmud Creek crossing. Poor recovery (less than 35%) noted in both boreholes at elevation 667 to 670 masl which coincides with the sand beds noted in Drawing 02. High plasticity clay beds were occasionally encountered in the bedrock; this has the potential to thicken drill mud and impact cuttings management (causing mud rings). Such conditions can be mitigated by adapting the drill mud mixes. While no cobbles or boulders were encountered during the geotechnical drilling, the proposed bore path could encounter glacial till, which is commonly observed below or within glaciolacustrine soils in the area. The possible presence of larger clasts should therefore not be discounted. The HDD borepath is expected to encounter extremely weak to weak bedrock, and encounters with occasional stronger, more lithified intervals of interbedded sandstone and siltstone are possible. Geological conditions between BH-BGC14-BM-01 and the HDD exit point area based on geophysics and extrapolation of one borehole, further investigation should be considered as part of detailed design.
6.2. Steering Difficulties Bedrock was observed to be poorly lithified (soil-like) with extremely weak to weak strength, in the upper 5 m of bedrock below the interpreted soil-bedrock contact, with the potential for sudden strength increases at harder beds, which would be encountered at flat angles. This suggests that steering issues may be a possibility (i.e., bit skipping on the lower harder material). Significant steering issues are not anticipated, but some extra effort and care may be required.
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6.3. Borepath Stability As drilling is undertaken, potential for sloughing and hole collapse may occur in the glaciolacustrine deposit between approximately 667 to 672 masl, where the sand content increases, and the consistency decreases from very stiff to stiff. Such horizons may be encountered along the borepath where it passes through the glaciolacustrine unit. While the fully cased geotechnical drilling process did not allow for direct observation of sloughing or hole collapse, the lower observed core recovery and non-cemented nature of the sand beds suggest that sloughing and hole collapse are a possibility within these zones. Squeezing of the HDD bore is possible based on observations made in BH-BGC14-BM-01 where reaming of the borehole was required prior to casing installation. The potential for the rock to swell after reaming the HDD borepath should be addressed in detailed design. Possible mitigation includes casing through low recovery and geological layers with squeezing noted during investigation and careful drill fluid management (viscosity and pressure).
6.4. Circulation and Potential for Loss of Fluids Drilling fluid loss could occur in the sand beds encountered in the glaciolacustrine deposit from 6.7 mbgs to 9.8 mbgs at BH-BGC14-BM-01. This is expected to be mitigatable by adapting the drill mud mixes.
6.5. Geotechnical Feasibility Given the above, and based on the desktop study, and results of the geotechnical and geophysical site investigation, an HDD at this location can be considered feasible from a geotechnical perspective provided the following concerns are addressed during detailed design and construction: Sloughing, hole collapse: As drilling is undertaken, potential for sloughing and hole collapse may occur in the glaciolacustrine deposit at an elevation of about 667 to 672 masl, where the sand content increases, and the consistency decreases from very stiff to stiff. Possible mitigation includes careful drill fluid management (i.e., variation of viscosity and pressure). Loss of drilling fluids: Drilling fluid loss could occur in the sand beds encountered in the glaciolacustrine deposit. This is expected to be mitigatable by adapting the drill mud mixes. Encounter with cobbles or boulders: While no cobbles or boulders were encountered during the geotechnical drilling, the proposed bore path could encounter glacial till, which was not encountered during geotechnical drilling, but is commonly observed below or within glaciolacustrine soils in the area. The possible presence of larger clasts should therefore not be discounted. Highly plastic material: High plasticity clay beds were occasionally encountered in the bedrock; this has the potential to thicken drill mud and impact cuttings management (causing mud rings). Such conditions can potentially be mitigated by adapting the drill mud mixes.
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Steering difficulties: The HDD borepath is expected to encounter Horseshoe Canyon Formation bedrock, potentially intersecting it at a shallow angle. Bedrock strengths are anticipated to be similar to, but higher than, those of the overlying glaciolacustrine soils in the vicinity of the contact. Significant steering issues are not anticipated, but some extra effort and care may be required.
Uncertain geological conditions: Between BH-BGC14-BM-01 and the HDD exit point additional investigation could mitigate the uncertainty. 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 may be considered as part of detailed design.
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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:
Leonardo Moreno, P.Eng (BC, AB), Ing. Civil Patrick Nolan, P.Eng. (BC) Senior Civil/Geotechnical Engineer Civil Engineer
Reviewed by:
Pete Quinn, Ph.D., ing., P.Eng. (BC, YT, ON, NL) Principal Geotechnical Engineer
LM/PN/pq/ksj/pg
APEGA Permit to Practice: 5366
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REFERENCES
Alberta Energy Regulators. 2017. AER Coal Mine Web Map. Online database (http://mapviewer.aer.ca/Html5/Index.html?viewer=aercoalmine) consulted in July 2017. American Society for Testing and Materials. Standard D2487-11: Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System). Developed by Sub-Committee D18.07. West Conshocken, PA. American Society for Testing and Materials. Standard D2488-09a: Standard Practice for Description and Identification of Soils (Visual-Manual Procedure). Developed by Sub-Committee D18.07. West Conshocken, PA. City of Edmonton, 2012. American Society for Testing and Materials. Standard D422-63(2007)e2: Standard Test Method for Particle-Size Analysis of Soils (Withdrawn 2016). Developed by Sub-Committee D18.03. West Conshocken, PA. American Society for Testing and Materials. Standard D7928-17: Standard Test Method for Particle-Size Distribution (Gradation) of Fine-Grained Soils Using the Sedimentation (Hydrometer) Analysis. Developed by Sub-Committee D18.03. West Conshocken, PA. American Society for Testing and Materials. Standard D1586-11: Standard Test Method for Standard Penetration Test (SPT) and Split Barrel Sampling of Soils. Developed by Sub- Committee D18.02. West Conshocken, PA. American Society for Testing and Materials. Standard D2216-10: Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass. Developed by Sub-Committee D18.03. West Conshocken, PA. American Society for Testing and Materials. Standard D4318-17: Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils. Developed by Sub-Committee D18.03. West Conshocken, PA. Association of Professional Engineers and Geoscientists of BC (APEGBC). 2012. Professional Practice Guidelines – Legislated Flood Assessments in a Changing Climate in BC. Version 1.1. June 2012. BGC Engineering Ltd. (BGC) 2015. Blackmud Creek, Whitemud Creek, Wedgewood Creek, and Little Brule Creek – Geotechnical Core Logging Results for HDD Contingency Crossing Sites, dated July 8, 2015.
BGC Engineering Inc., 2016. Preliminary Assessment of Coal Mine Related Hazards KP26 to KP 29 (South Edmonton), dated April 6, 2016. Dahlin, T. 1996. 2D Resistivity Surveying for Environmental and Engineering Applications. Vol. 14, No. 7. Dawson, F.M., Evans, C.G., Marsh, R., and Richardson, R. 1994. Uppermost Cretaceous and Tertiary strata of the Western Canadian Sedimentary Basin. In Geological atlas of the Western
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Canada Sedimentary Basin Edited by G.D. Mossop and I. Shetsen. Canadian Society of Petroleum Geologists and Alberta Research Council, pp. 387-406. Downing, D.J. and Pettapiece, W.W. 2006. Natural regions committee 2006. Natural regions and subregions of Alberta. T/852, Government of Alberta, Edmonton. Edwards, W.A.D., Magee, D., Langenberg, C.W., Grobe, M., and Mussieux, R. 2006. Geoscape Edmonton information series 126. Alberta Geological Survey. Fenton, M.M., Waters, E.J., Pawley, S.M., Atkinson, N., Utting, D.J., Mckay, K. 2013. Surficial Geology of Alberta, Generalized Digital Mosaic (DIG 2013-0002). http://geology-ags- aer.opendata.arcgis.com/datasets/745bb49973194f46b19d5ad2f84afd61_0 Hamblin, A.P. 1998. Edmonton Group/St. Mary river formation: Summary of literature and concepts open file. GSC Open File 3578, Geological Survey of Canada. Kathol, C.P., and McPherson, R.A. 1975. Urban Geology of Edmonton, Alberta Research Council, Bulletin 32. pp. 92. McPherson, R.A., and Kathol, C.P. 1972. Stratigraphic Sections and Drill Hole Logs, Edmonton Area, Alberta. Alberta Research Council Report 72-6. Northwest Hydraulic Consultants (NHC). 2014. Nisku Flood Hazards Study Blackmud Creek. Prepared for Alberta Environment and Sustainable Resources Development. Palacky, G.J, 1987, Resistivity Characteristics of Geologic Targets, Society of Exploration Geophysics, v. 1. Pettapiece, W.W. 1986. Physiographic subdivisions of Alberta. Agriculture Canada, Ottawa. Shetsen, I. 1990. Quaternary geology, Central Alberta. Alberta Research Council. Trans Mountain Pipeline ULC. 2014. Trans Mountain Expansion Project Application to the National Energy Board. Terrain Mapping and Geohazard Inventory - Revision 1, filed as part of NEB Technical Update #1, August 1, 2014. Universal Pegasus International (UPI). 2018, Trans Mountain Expansion Project, Plans and Profiles, City of Edmonton, Blackmud Creek, NE-28-51-24-W4M, Preliminary HDD Drill Path Drawing No 01-13283-M002-XD00024 Rev A, issued February 18, 2018 Young, R.R., Burns, J.A., Smith, D.G., Arnold, L.D., and Rains, R.B. 1994. A single, late Wisconsin, Laurentide glaciation, Edmonton area and Southwestern Alberta. Geology, 22: 683- 686.
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek Page 25 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
DRAWINGS
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek BGC ENGINEERING INC. 333,000 333,500 5,923,750
5,923,750 LGks-VR"sm Edmonton VM ^_! SITE ³ LOCATION ! ³
Calgary!
BLACKMUD CREEK ANTHONY HENDAY DRIVE NORTH-WEST
! zcLGbm
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SCALE 1:10,000,000
BH-BGC14-BM-02 KP 0024.6 ! A@ BH-BGC14-BM-01 KP 0024.4 KP 0024.2 KP 0024.0 ! ! ! ! ! HDD ENTRY A@ POINT KP 0023.8 5,923,250 gsMakm ! IVL zcLGpm HDD EXIT Fpt-Mm-i IL POINT IL
1 !
1
1
S
T LGks-VR"sm R E VM E T LEGEND S
O U SCALE 1:2,500 ! KILOMETRE POSTS PRIMARY SURFICIAL ! T
H (KPS) MATERIAL TYPE "
50 - 0 50 100
W
E ! PROPOSED HDD FLUVIAL S ENTRY/EXIT POINTS T METRES BLACKLOCK WAY SOUTH-WEST LABEL LEGEND GLACIOLACUSTRINE 10Cb-Rs TERRAIN LABEL A@ BGC BOREHOLE THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. GLACIAL TILL ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE III M TERRAIN STABILITY CLASS AND BASED ON ORIGINAL FORMAT DRAWINGS. " 333,000 5,923,250 NATURAL HAZARD CLASS 333,500 FLOW DIRECTION
740 740 730 730 ELEVATION PROFILE - NO VERTICAL EXAGGERATION (m) 720 720 710 710 700 HDD EXIT 700 690 BH-BGC14-BM-02 BH-BGC14-BM-01 POINT 690 ! A@ A@ ! 680 680 670 HDD ENTRY 670 660 POINT 660 650 0+000 650 SCALE 1:2,500 640 ! 640 ELEVATION (masl) ELEVATION 50 25 0 50 100 630 630 620 620 610 METRES 610
-400 -300 -200 -100 0 100 200 300 400 KP DISTANCE (m) NOTES: SCALE: 1:2,500 PROJECT: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED "GEOTECHNICAL HDD FEASIBILITY ASSESSMENT BLACKMUD CREEK AT SSEID 005.5 KP 24.2", AND DATED MARCH 2018. DATE: BLACKMUD CREEK AT SSEID 005.5 KP 24.2 3. PROPOSED TMEP SSEID 005.5 PIPELINE ALIGNMENT PROVIDED BY KMC, DATED MARCH, 2018. MAR 2018 BGC ENGINEERING INC. AN APPLIED EARTH SCIENCES COMPANY TITLE: 4. PROPOSED HDD ALIGNMENT PROVIDED BY UPI, DRAWING NO. M002-XD0002401 RA, ISSUED FEBRUARY 7, 2018. DRAWN: LL, MIB B GC TERRAIN MAP 5. FOR A FULL EXPLANATION OF THE TERRAIN MAPPING TERMS AND SYMBOLS SEE THE COMPLETE LEGEND IN DRAWING 01B. TERRAIN POLYGONS BASED ON TERRAIN MAPPING COMPLETED UP TO JULY 2015 BY BGC. CLIENT: 6. THIS MAP IS A SNAPSHOT IN TIME. CHANGES IN LAND USE (E.G. DEVELOPMENT, RIVER MIGRATION) MAY WARRANT RE-DRAWING OF CERTAIN AREAS. CHECKED: 7. PROJECTION IS NAD 1983 UTM ZONE 12N. SAA PROJECT No.: DWG No.: 8. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH BGC GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS APPROVED: 0095-150 01A ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT NOT AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. X:\Projects\0095\150\GIS\Production\Reports\20180313_Geotechnical_HDD_Feasibility_Assessment_Blackmud_Creek_at_SSEID_005_KP_24pt2\01A_Terrain_Mapping_Blackmud_Creek10-31.mxd Date:4, April Time: 2018 8:35 AM Terrain Mapping Legend Geomorph olog icProcesses SoilDrainag eClasses R R apidlandslide (runout zone) V Gullyerosion SimpleTerrain Symbols U sedwh enone surficial material ispresent within apolyg on R “ R apidlandslide (initiation zone) F“ Slowlandslide (initiation zone) r R apidlydrained: W aterisremov edfrom the soilrapidly inrelation tosupply. H Kettled L Seepag e Example: zCb –Rb U Flooding E Meltwater ch annels w W ell-drained: W aterisremov edfrom the soilreadily but not rapidly. Material Texture A SnowAvalanch es B BraidedChannel m Moderatelywell-drained: W aterisremov edfrom the soilsomew h atslow inrelation ly tosupply. SurficialMaterial Geomorph olog icalprocess sub-type M MeanderingChannel I Irreg ularChannel Surface expression Geomorph Surface expression olog ical process (up mayto 3 be assigned) Imperfectlydrained: W aterisremov edfrom the soilsufficiently slow inrelation ly tosupply J AnastamosingChannel K Karst i N Nivation P P iping tokeep the soilwet for asignificant part ofthe grow ingseason. CompositeTerrain Symbols U sedwh enorterrain2 3 types are present within apolyg on S Solifluction W W ash ing P oorlydrained: W aterisremov edso slow inrelation ly tosupply that the soilremains X P ermafrost Z P eriglacialProcesses p Cv.Mv indicatesthat and‘C’ ‘M’are roug hequal ly inextent G Anthropog enicmodification w etfor acomparatively large part ofthe time the soilis not frozen. Cv/Mv indicatesthat isgreater‘C’ inextent than ‘M’(about 60:40) v V erypoorly drained: W aterisremov edfrom the soilso slow that ly the water tab remains le Cv//Mv indicatesthat ismuch‘C’ greater inextent than ‘M’(about 80:20) Cv.Rs/Mv indicatesthat and‘C’ are‘R’ roug hequal ly inextent and both are gre aterinextent than Mv (about 40:40:20) Geomorph olog icalProcess Subtypes atoron the surface for the greater part ofthe time the soilis not frozen.
b R ockfall r R ockslides e Earthflow Stratigraph icTerrain Symbols d Debrisflow s m Bedrockslump k Tensioncracks/sackung s Debrisav alanch es u Surficialmaterial slump Ud Debrisfloods Cv|Mj indicatesthat ‘Cv’ov erlies‘Mj’ a Channelav ulsion c Soilcreep g R ockcreep
SurficialMaterial Types Examples
C Colluvium R Bedrock LG Glaciolacustrine R s//Cv–VR ”bd Steepbedrock slope with <20% cov erofa colluvial veneer; L Lacustrine M Glacial Till W G Glaciomarine g ulliedwith initiation zones for rockfall and debris flow s. F Fluvial O O rganic U Glaciolacustrine, Till, Glaciofluvial (interbedded) FAp–U Activefloodplain potentially subject toflooding E Eolian FG Glaciofluvial D W eatheredbedrock –F”g Cj Thick,gentle colluvium forming arock glacier A Anthropog enic Cf–Rd Colluvialfan subject todebris flow s Ck–Rb Colluvialslope subject torockfall (talus slope)
SurfaceExpressions TerrainStability Class p P lain(0-3°) v V eneermthick (0-2 deposit) j j GentleSlope (4-14°) b Blanketmthick (>2 deposit) I Nosignificant stability problems exist. a ModerateSlope (15-26°) w V ariableThickness Deposit) II Thereis avery low likelihood of landslides follow ingtimber harvesting orroad construction. Minor slumping isexpected k ModeratelySteep Slope (27-35°) m R olling alongroad cuts, especially foror years1 2 follow ingconstruction s SteepSlope (>35°) h H ummocky c Cone(>15°) f Fan(<15°) III Thereisa low (<30%) likelihood of landslide initiation follow ingtimber harvesting orroad construction. Minor slumping is r R idg e u U ndulating expectedalong road cuts, especially foror years1 2 follow ingconstruction. t Terrace d Depression IV Expectedto contain areas with amoderate (30-70%)likelihood of landslide initiation follow ingtimber harvesting orroad construction.Wet season construction significantly will increase the potential for road-related landslides.
TexturalTerms and Symbols V Expectedto contain areas with a high (>70%) likelihood of landslide initiation follow ingtimber harvesting orroad construction.Wet season construction significantly will increase the potential for road-related landslides. a blocks b boulders k cobbles p pebbles s sand z silt c clay d mixedfrag ments x ang ularfrag ments NaturalHazard Class g g rav el m mud r rubble L Noexisting hazard, or hazard is dormant, hazard i.e. has not been active inthe lastyearsto100 1,000 orit has dev elopedunder different climatic conditions. ActivityLev el M H azardisinactive. Veg etatedtracks can be observed inairph otos.Smaller more frequent ev ents,such as rockmay fall, affectasmallarea of the polyg on.No ev idencethat the hazard has been active within the years20 but trigg erispresent. FAp ‘AIndicates’ active floodplain (subject toch annelch ang es) H azardisunlikely tooccur within the lifeof the project. CIf ‘I’ Indicatesinactive fan H H azardiscurrently active orsh ow sev idenceofactivity inthe lastyears.20 Hazard likelyto occur within lifeof project.
SCALE: P R O J ECT: NO TES: NTS GEO TECH NICALHDD FEASIBILITY ASSESSMENT 1. THISDR 1. AW INGMU STBEREAD COIN NJU NCTIONWITH BGC'S REPO RTITLED T "GEO TECH NICALHDD FEASIBILITY ASSESSMENT BLACKMU CR D EEKAND ATSSEIDKPDATED 005.5 24.2", MAR CH2018. DATE: BLACKMU DCR EEKSSEIDATKP 005.5 24.2 2. UNLESS 2. BGC AGR EESOTH ERWWRIN ISE THISDR ITING, AW INGSH ALLNO BEMO T DIFIEDOR USED FO RANY PU R P O SEOTHER THAN THE PU R P O SEFO RWH ICHBGC GENER BGC ATED SHIT. ALL MAR2018 BGCENGINEERING INC. HAVE NO LIABILITYFO RANY DAMAGES OR LO SSARISING ANYIN WAY FRO MANY USE OR MO DIFICATIONOF THISDO CU MENTNO AU T THO R IZEDBY BGC. ANY USE OF OR RELIANCE UP OTHIS N ANAPP LIEDEARTH SCIENCES CO MP ANY TITLE: DR AW N: DO CU MENTOR COITS NTENTBY THIRD PAR SH TIES ALLBESUAT CHTHIRD PAR SO TIES' LERISK. JVC B GC TER RMAP AIN LEGEND CLIENT: CH ECKED: SAA P R O J ECTNo.: DW GNo.: APP R O V ED: 0095-150 01B X :\P rojects\0095\150\GIS\P roduction\R eports\20180313_Geotech nical_H DD_Feasibility_Assessment_Blackmud_Creek_at_SSEID_005_KP_24pt2\01B_Terrain_Leg end.mxd Date: April 4, 2018 Time: 8:28 AM 8:28 Time: 2018 4, April Date: end.mxd DD_Feasibility_Assessment_Blackmud_Creek_at_SSEID_005_KP_24pt2\01B_Terrain_Leg nical_H eports\20180313_Geotech roduction\R rojects\0095\150\GIS\P X :\P N 5,923,500 N
E 332,750 E 333,000 E 333,250 E 333,500
680
680 685 670
670 685
675
680
A 680 675
- BH-BGC14-BM-02 HDD 0+00 POINT 670 HDD EXIT
24+600 HDD ENTRY
A
-
24+500
24+400
24+300
24+200
24+100
24+000 23+900
N 5,923,250E 332,750
BH-BGC14-BM-01 23+800
N 5,923,500 685 670 23+700 670
685
680 675 BLACKMUD CREEK LEGEND - PLAN 675 SSEID 005.5 TRANS MOUNTAIN PIPELINE ALIGNMENT 680 PROPOSED HDD BOREPATH KILOMETRE POSTS (KP) BGC BOREHOLE
PROPOSED HDD ENTRY / 0+00 / EXIT POINT E 333,000 670 685 ERT SURVEY ALIGNMENT SCALE 1:2,500 685 SEISMIC SURVEY ALIGNMENT 25 0 755025 02.dwg Layout: RM-B-SIZE Plot Date Apr 4 18 Time: 8:44 AM Layout: Time: Plot Date 02.dwg RM-B-SIZE Apr 4 18 BLACKMUD CREEK FLOW DIRECTION N 5,923,250 METRES E 333,750
E 333,250 E 333,500 (E: 332,817; N: 5,923,328) NORTHWEST EAST (E: 333,543; N: 5,923,497) 700 700 BH-BGC14-BM-02 BH-BGC14-BM-01 HDD ENTRY (OFFSET = 21 m N) (OFFSET = 8 m S) HDD EXIT HDD 0+00 POINT ? 680 ? 680
? ? ? ? ? 660 660 ELEVATION (m) ELEVATION (m)
640 640
630 630 -0+390 -0+300 -0+200 -0+100 0+000 0+100 0+200 0+300 0+360 HORIZONTAL SCALE: 1:2,500 SCALE 1:2,500 PROPOSED HDD CHAINAGE (m) VERTICAL SCALE: 1:1,250 (2x VERTICAL EXAGGERATION) 25 0 755025 A LEGEND - CROSS-SECTION BOREHOLE INTERPRETED GEOLOGY CROSS-SECTION - METRES CROSS-SECTION AT BEARING 074.3° PROPOSED HDD PROFILE ANTHROPOGENIC (FILL) GROUNDWATER OBSERVATIONS BGC BOREHOLE GLACIOLACUSTRINE BH COLLAR INFERRED WATER WATER LEVEL INFERRED WATER LEVEL HORSESHOE CANYON BOREHOLE COMMENTS ELEVATION (m asl) LEVEL (m bgs) ELEVATION (m asl) ? INFERRED GEOLOGICAL INTERFACE FORMATION BEDROCK PROPOSED HDD ENTRY / 0+00 / EXIT POINT SAND BED - BH-BGC14-BM-01 684.0 16.2 667.8 MEASURED ON JULY 1, 2014, WHEN BOREHOLE WAS ADVANCED TO FINAL DEPTH OF 50.0 m bgs 200-YEAR FLOOD ELEVATION (669.1 m asl) LOW RECOVERY BH-BGC14-BM-02 684.0 7.9 676.1 MEASURED ON JULY 5, 2014, WHEN BOREHOLE WAS ADVANCED TO FINAL DEPTH OF 61.0 m bgs 200-YEAR SCOUR ELEVATION (665.1 m asl) NOTES: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. INTERPRETED BEDROCK CONTACT BOUNDARY FROM GEOPHYSICS 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - BLACKMUD CREEK AT SSEID 005.5 KP 24.2”, AND DATED MARCH 2018. SCALE: 1:2,500 PROJECT: 3. BASE TOPOGRAPHIC DATA BASED ON LIDAR PROVIDED BY UPI, DATED SEPTEMBER 2014. CONTOUR INTERVAL IS 1.0 m. BLACKMUD CREEK WATER SURFACE PROFILE AT TIME OF LIDAR SURVEY IS SHOWN IN CROSS-SECTION. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT 4. IMAGE SOURCE: ESRI WORLD IMAGERY SERVER RETRIEVED FROM BING IMAGERY. DATE: - BLACKMUD CREEK AT SSEID 005.5 KP 24.2 5. PROPOSED TMEP SSEID 005.5 PIPELINE ALIGNMENT PROVIDED BY KMC, DATED MARCH 2018. PROPOSED HDD ALIGNMENT PROVIDED BY UPI, DRAWING NO. M002-XD0002401 RA, ISSUED FEBRUARY 07, 2018. MAR 2018 BGC ENGINEERING INC. TITLE: 6. PROJECTION IS UTM NAD83 ZONE 12. BGC AN APPLIED EARTH SCIENCES COMPANY DRAWN: CR INTERPRETED GEOLOGIC CROSS-SECTION 7. SPECIFIC OBSERVATIONS PERTAINING TO THE WATER LEVEL MEASUREMENTS ARE AVAILABLE IN THE REPORT. CLIENT: 8. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH BGC THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. CHECKED: SAA PROJECT No.: DWG No.: GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT NOT ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE 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. BASED ON ORIGINAL FORMAT DRAWINGS. APPROVED: 0095-150 02 T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\BLACKMUD_CREEK_KP_24.2\ 1949IMAGERY IMAGERY2011 ³ 333,000 E 333,250 E 333,500 E 333,000 E 333,250 E 333,500 E
N5,923,750 N5,923,750
690 680 680
680 EST O RTH-W DRIV E N HENDAY ANTHO NY EST A RTH-W NTHO NY HENDAY DRIV E NO RTH-W EST RIV E NO ENDAY D HO NY H HDDEXIT ANT HDDEXIT ANTHO NY HEN PO INT DAY DRIV E NO RTH-W EST PO INT
N5,923,500 KP0023.8 KP0023.8 N5,923,500 ! ! ! 680 ! ! ! 680 KP0024.0 670 KP0024.0 ! !
BLACKMCREEK U D BLACKMCREEK U D
670
680 KP0024.2 ! ! HDDENTRY HDDENTRY KP0024.2 PO INT PO INT KP0024.4 KP0024.4 ! ! ! KP0024.6 ! KP0024.6 ! ! ! !
N5,923,500 N5,923,500
670 1 1 1 S T R E E T
S
O 1 1 U 1 T
S H - TR W
E E 670
E S
T T
S
O
U
T
H
- W
E
S
T
N5,923,000 N5,923,000
LEGEND SCALE1:5,000 200 100 0 200 FLOWDIRECTION PRO PO SEDHDD M ETRES HISTORICALCHANNEL (1949) THISDRAW INGMAY HAVE BEEN REDU CEDOR ENLARGED. ALLFRACTIONAL SCALE NO TATIONSINDICATED ARE PRO PO SEDTM EPALIGNM ENT BASEDON ORIGINAL FORM ATDRAW INGS. V ERSIONSSEID 005.5 E 333,250 E 333,500 E 333,000 E 333,250 E 333,500 E
SCALE: PRO JECT: NO TES: 1:5,000 GEO TECHNICALHDD FEASIBILITYASSESSM ENT– 1. ALLDIMENSIONS 1. AREMETRES IN UNLESS OTHERW NO ISE TED. AU THO RIZEDBYBGC. ANY USE OF OR RELIANCE UPO NTHISDO CU M ENTOR DATE: BLACKM U DCREEK SSEIDATKP24.2 005.5 2. THISDRAW 2. INGMU STBEREAD COIN NJU NCTIONWITH BGC'S REPO RTTITLED "GEO TECHNICALHDD FEASIBILITY ASSESSM ENT–BLACKM U D COITS NTENT BY THIRD PARTIES SHALL BEATSU CHTHIRD PARTIES' SO LERISK. M AR2018 CREEK AND AT SSEID DATEDKP 24.2," 005.5 MARCH 2018. PRO 7. PO SEDTM EPSSEIDPIPELINE 005.5 ALIGNM ENTPRO V IDEDBYKM C BGCENGINEERING INC. ANAPPLIED EARTH SCIENCES CO M PANY TITLE: DRAW N: 3. BASE TOPO 3. GRAPHICDATA BASED ON LiDAR PRO V IDEDBYAIRBO RNEIMAGING DATED JUNE CO 2009. NTOU RINTERV m.5 ALIS DATED MARCH, 2018. M IB B GC BANKERO SIONAND AVU SIONREVIEW 4. PRO 4. JECTIONUTM IS NAD ZO83 NE12. PRO 8. PO SEDHDD ALIGNM ENTPRO V IDEDDRAWBYUPI, INGNO . CLIENT: 5. ORTHO 5. IMAGEON RIGHT MAP PRO V IDEDBYKINDER MO RGANCANADA, FRO MCITYOF EDM O NTON,DATED IMAGE 2011. ON LEFT MAP PRO V IDEDBYALBERTA M002-XD00024-01 ISSURA, EDFEBRU .2018 ARY 7, CHECKED: ENV IRO NM ENTAND PARKS, DATED 1949. DT PRO JECTNo.: DW GNo: 6. UNLESS 6. BGC AGREES OTHERW WRITING,IN ISE THISDRAW INGSHALL NO BE TMO DIFIEDOR USED FOR ANY PU RPO SEOTHER THAN THE PU RPO SEFOR WHICH BGC APPRO V ED: 0095-150 03 GENERATED BGC SHALLIT. HAVE NO FOLIABILITY ANY R DAM AGESOR LOSS ARISING ANYIN WAY FRO MANY USE OR MO DIFICATIONOF THISDO CU M ENTNO T X:\Projects\0095\150\GIS\Production\Reports\20180313_Geotechn ical_HDD_ Feasibility_ Assessmen t_Blackm ud_ Creek_ at_SSEID_005_KP_24pt2\03_Bank_ Erosion_ Avulsion_ Review.mxd Date: April 4, 2018 Time: 8:57 AM 8:57 Time: 2018 4, April Date: Review.mxd Avulsion_ Erosion_ at_SSEID_005_KP_24pt2\03_Bank_ Creek_ ud_ t_Blackm Assessmen Feasibility_ ical_HDD_ X:\Projects\0095\150\GIS\Production\Reports\20180313_Geotechn
N 5,923,500 24+600
24+700 N 680 685
E 332,750 E 333,000 680 E 333,250 E 333,500 675
BH-BGC14-BM-02 670
670 HDD 0+00 POINT 680 HDD EXIT B HDD ENTRY 675
- 680
24+500
24+400
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24+000 23+900
N 5,923,250 23+800 BH-BGC14-BM-01
N 5,923,500 685 670 23+700 670
685 B - E 332,750 680 675 SCALE 1:2,500 BLACKMUD CREEK 25 0 755025 675 N 5,923,250 METRES E 333,000 680 E 333,250 E 333,500 (E: 332,812; N: 5,923,305) SOUTHWEST EAST (E: 333,630; N: 5,923,445) 700 700
1000 675 1500 675
650 2000 650
625 625 ELEVATION (m) ELEVATION (m)
2500 600 600
580 580 04.dwg Layout: RM-B-SIZE Plot Date Apr 4 18 Time: 8:42 AM Layout: Time: Plot Date 04.dwg RM-B-SIZE Apr 4 18 0 100 200 300 400 500 600 700 800 831 DISTANCE (m) SCALE 1:2,500 B 25 0 755025 CROSS-SECTION - CROSS-SECTION AT BEARING 078.4° METRES FIELD PARAMETERS: DATA COLLECTED: JUNE-19-2013 ELECTRODE CONFIGURATION: GRADIENT PLUS (E: 333,205; N: 5,923,377) (E: 333,630; N: 5,923,445) MINIMUM ELECTRODE SPACING: 5 m 700 700
1000 675 1500 675
LEGEND - PLAN 650 2000 650 SSEID 005.5 TRANS MOUNTAIN PIPELINE ALIGNMENT PROPOSED HDD BOREPATH KILOMETRE POSTS (KP) 625 625 BGC BOREHOLE
PROPOSED HDD ENTRY / 0+00 / EXIT POINT ELEVATION (m) 2500 ELEVATION (m) ERT SURVEY ALIGNMENT 600 600 SEISMIC SURVEY ALIGNMENT BLACKMUD CREEK FLOW DIRECTION 575 575
LEGEND - CROSS-SECTION 560 560 400 500 600 700 800 831 EXISTING GROUND (2014) FIELD PARAMETERS: SCALE 1:2,500 DISTANCE (m) P-WAVE VELOCITY CONTOURS 25 0 755025 B DATA COLLECTED: SEPTEMBER-3-2013 CROSS-SECTION INTERPRETED CONTACT - GEOPHONE SPACING: 5 m BOUNDARY FROM GEOPHYSICS METRES CROSS-SECTION AT BEARING 078.4° SHOT SPACING: 20 m SOURCE: SLEDGEHAMMER NOTES: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - BLACKMUD CREEK AT SSEID 005.5 KP 24.2”, AND DATED MARCH 2018. SCALE: 1:2,500 PROJECT: 3. BASE TOPOGRAPHIC DATA BASED ON LIDAR PROVIDED BY UPI, DATED SEPTEMBER 2014. CONTOUR INTERVAL IS 1.0 m. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT 4. IMAGE SOURCE: ESRI WORLD IMAGERY SERVER RETRIEVED FROM BING IMAGERY. DATE: - BLACKMUD CREEK AT SSEID 005.5 KP 24.2 5. GEOPHYSICS SURVEY INTERPRETATION AND GROUND PROFILE PROVIDED BY WORLEY PARSONS, RECIEVED ON APRIL 23, 2014. MAR 2018 BGC ENGINEERING INC. TITLE: 6. PROPOSED TMEP SSEID 005.5 PIPELINE ALIGNMENT PROVIDED BY KMC, DATED MARCH 2018. PROPOSED HDD ALIGNMENT PROVIDED BY UPI, DRAWING NO. M002-XD0002401 RA, ISSUED FEBRUARY 07, 2018. BGC AN APPLIED EARTH SCIENCES COMPANY DRAWN: CR GEOPHYSICS RESULTS 7. PROJECTION IS UTM NAD83 ZONE 12. CLIENT: 8. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH BGC THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. CHECKED: SAA PROJECT No.: DWG No.: GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT NOT ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE 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. BASED ON ORIGINAL FORMAT DRAWINGS. APPROVED: 0095-150 04 T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\BLACKMUD_CREEK_KP_24.2\ 02
PHOTO 1: VIEW OF THE BH-BGC14-BM-01 DRILL SETUP PHOTO 2: BH-BGC14-BM-01 SAMPLE SPT 7 FROM 11.28 m - 11.88 m SILTY CLAY (CL) PHOTO 3: BH-BGC14-BM-01 FROM 40.23 m - 48.62 m INTERBEDDED EXTREMELY WEAK (R0) TO ENCOUNTERED DURING DRILLING WEAK (R2) MUDSTONE, SILTSTONE, AND SANDSTONE ENCOUNTERED DURING DRILLING 05.dwg Layout: RM-B-SIZE Plot Date Apr 4 18 Time: 8:47 AM Layout: Time: Plot Date 05.dwg RM-B-SIZE Apr 4 18
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PHOTO 4: BH-BGC14-BM-01 SAMPLE SPT 24 FROM 35.66 m - 35.84 m INTERBEDDED PHOTO 5: BH-BGC14-BM-02 SAMPLE SPT 9 FROM 13.11 m - 13.64 m POORLY GRADED CLAYEY PHOTO 6: BH-BGC14-BM-02 FROM 21.95 m - 28.04 m INTERBEDDED EXTREMELY WEAK (R0) SANDSTONE, SILTSTONE, AND MUDSTONE [HORSESHOE CANYON FORMATION] SILT SAND (SC) ENCOUNTERED DURING DRILLING TO WEAK (R2) MUDSTONE, SILTSTONE, AND SANDSTONE ENCOUNTERED DURING ENCOUNTERED DURING DRILLING DRILLING
SCALE: N.T.S PROJECT: GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - BLACKMUD CREEK AT SSEID 005.5 KP 24.2 DATE: MAR 2018 BGC ENGINEERING INC. NOTES: BGC AN APPLIED EARTH SCIENCES COMPANY TITLE: 1. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - BLACKMUD CREEK AT DRAWN: CR FIELD PHOTOS SSEID 005.5 KP 24.2”, AND DATED MARCH 2018. CLIENT: THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. CHECKED: 2. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH BGC ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE PN PROJECT No.: DWG No.: GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT NOT BASED ON ORIGINAL FORMAT DRAWINGS. APPROVED: 0095-150 05 AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\BLACKMUD_CREEK_KP_24.2\ 06.dwg Layout: 6A Plot Date Apr 4 18 Time: 8:47 AM Time: Layout: Plot Date 06.dwg 6A Apr 4 18
NOTES: SCALE: N.T.S PROJECT: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - BLACKMUD CREEK AT DATE: BLACKMUD CREEK AT SSEID 005.5 KP 24.2 MAR 2018 BGC ENGINEERING INC. SSEID 005.5 KP24.2”, AND DATED MARCH 2018. BGC AN APPLIED EARTH SCIENCES COMPANY TITLE: 3. THIS PHOTOGRAPHIC LOG DOES NOT REPRESENT A COMPLETE CONTINUOUS PROFILE OF THE MATERIAL ENCOUNTERED. THE INDICATED DEPTHS ARE DRAWN: CR PHOTOGRAPHIC LOG OF BH-BGC14-BM-01 (1 OF 2) APPROXIMATE AND SHOULD BE TREATED AS A GENERAL GUIDELINE. CLIENT: THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. 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 ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE SAA PROJECT No.: DWG No.: BGC GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT BASED ON ORIGINAL FORMAT DRAWINGS. APPROVED: 0095-150 06A NOT AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\BLACKMUD_CREEK_KP_24.2\ 06.dwg Layout: 6B Plot Date Apr 4 18 Time: 8:47 AM Time: Layout: Plot Date 06.dwg 6B Apr 4 18
NOTES: SCALE: N.T.S PROJECT: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - BLACKMUD CREEK AT DATE: BLACKMUD CREEK AT SSEID 005.5 KP 24.2 MAR 2018 BGC ENGINEERING INC. SSEID 005.5 KP 24.2”, AND DATED MARCH 2018. BGC AN APPLIED EARTH SCIENCES COMPANY TITLE: 3. THIS PHOTOGRAPHIC LOG DOES NOT REPRESENT A COMPLETE CONTINUOUS PROFILE OF THE MATERIAL ENCOUNTERED. THE INDICATED DEPTHS ARE DRAWN: CR PHOTOGRAPHIC LOG OF BH-BGC14-BM-01 (2 OF 2) APPROXIMATE AND SHOULD BE TREATED AS A GENERAL GUIDELINE. CLIENT: THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. 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 ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE SAA PROJECT No.: DWG No.: BGC GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT BASED ON ORIGINAL FORMAT DRAWINGS. APPROVED: 0095-150 06B NOT AUTHORIZED BY BGC. ANY USE OF OR RELIANCE UPON THIS DOCUMENT OR ITS CONTENT BY THIRD PARTIES SHALL BE AT SUCH THIRD PARTIES' SOLE RISK. T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\BLACKMUD_CREEK_KP_24.2\ 07.dwg Layout: 07A Plot Date Apr 4 18 Time: 8:45 AM Time: Plot Date Layout: Apr 4 18 07.dwg 07A
NOTES: SCALE: N.T.S PROJECT: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - BLACKMUD CREEK AT DATE: BLACKMUD CREEK AT SSEID 005.5 KP 24.2 MAR 2018 BGC ENGINEERING INC. SSEID 005.5 KP 24.2”, AND DATED MARCH 2018. BGC AN APPLIED EARTH SCIENCES COMPANY TITLE: 3. THIS PHOTOGRAPHIC LOG DOES NOT REPRESENT A COMPLETE CONTINUOUS PROFILE OF THE MATERIAL ENCOUNTERED. THE INDICATED DEPTHS ARE DRAWN: CR PHOTOGRAPHIC LOG OF BH-BGC14-BM-02 APPROXIMATE AND SHOULD BE TREATED AS A GENERAL GUIDELINE. CLIENT: THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. 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 ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE SAA PROJECT No.: DWG No.: BGC GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT BASED ON ORIGINAL FORMAT DRAWINGS. APPROVED: 0095-150 07 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. T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\BLACKMUD_CREEK_KP_24.2\ Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
APPENDIX A HYDROTECHNICAL ASSESSMENT METHODOLOGY
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
A.1. INTRODUCTION
This appendix documents the methodology followed by BGC Engineering Inc. (BGC) to complete hydrotechnical assessments at pipeline watercourse crossings. A description of hydrotechnical hazards is provided in Section A.2, followed by the flood frequency analysis (FFA) methodology in Section A.3. The hydrotechnical assessment methods specific to each hydrotechnical hazard are presented in Sections A.4 (scour), A.5 (bank erosion and encroachment), and A.6 (avulsion). Several industry terminology conventions are used in this methodology report, and in supporting hydrotechnical reports. Definitions of the terminology are as follows: Downstream Direction of water flow. Upstream Direction opposite to water flow. Right & left banks Reference convention for banks when facing downstream. DoC Depth of cover (burial depth) over the pipeline. RoW Pipeline right of way. Thalweg Line defining the lowest points along the length of a river bed or valley. Hazards Characterisation of hydrotechnical processes such as scour, channel bed degradation, and bank erosion that could result in a loss of DoC. Likelihood Qualitative assessment of how often an event may occur (e.g., the likelihood of scour hazard occurring is high). Probability Quantitative assessment of how often an event may occur (e.g., the probability of scour hazard occurring is 0.05 yr -1). Return Period The inverse of probability, it gives the estimated average time interval between events of a similar intensity (e.g., 1/[0.05 yr -1] = 20 yr return period). A.2. HYDROTECHNICAL HAZARDS
The following hydrotechnical hazards are included as part of the hydrotechnical assessment: • Scour of the channel bed; • Bank erosion caused by lateral channel migration or channel widening; • Encroachment of the channel towards the pipeline due to bank erosion; and • Avulsion of the channel within the floodplain.
A.2.1. Scour
Scour is the localized removal of granular bed material from the channel substrate by hydrodynamic forces during a flood event. Scour can happen at any location where local flow velocities increase within an otherwise uniform flow situation. Scour also occurs when the
Appendix A_Hydrotechnical Assessment Methodology A-2 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14 direction of flow changes at channel bends, confluences, constrictions, obstructions, and impingements. There are two types of scour: general scour and local scour. General scour occurs due to the complex interaction between flow rates and volumes, sediment transport rates, and channel morphology. Intermittent general scour occurs when a mobile-bed watercourse floods and the channel bed degrades (lowers) to accommodate the increased flow. Pipelines can become exposed or undermined during an intermittent flood event, becoming vulnerable to damage. The channel bed can experience significant scour during a flood event but this is often not detected because of compensating deposition that can occur as the flood flows decline (Leopold et al. 1964). Local scour results from acceleration of flow due to an obstruction or constriction to flow near piers, abutments, riprap revetments, large woody debris or other structures obstructing or constricting the flow. These obstructions cause vortices with accelerated flow that erode the surrounding bed and bank sediments. Contraction scour is a form of local scour where acceleration of flow is caused by a local narrowing of the channel. Local and general scour depths are shown in the schematic in Figure A-1. General scour depth is measured relative to the design flood water level and local scour depth is measured from the bottom of the general scour elevation. Both general and local scour contribute to the total scour depth below the design flood water level.
Figure A-1. Schematic of general and local scour (reproduced from Veldman 2008).
A.2.2. Bank Erosion and Encroachment
Patterns of sediment transport and deposition naturally cause the channel banks to migrate laterally, resulting in bank erosion. Erosion can take place slowly over a period of years or suddenly during a single flood event. Gradual bank erosion most often occurs on outer bends of low gradient, meandering river channels. Large flood events may cause sudden widening, particularly in braided or wandering rivers, as the channel geometry adjusts to convey the
Appendix A_Hydrotechnical Assessment Methodology A-3 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14 additional flow. Bank migration (erosion) at a pipeline crossing, either through lateral migration or episodic widening, can result in exposure of the sagbends and overbends of the pipeline. Encroachment may be a hazard to the pipeline where bank erosion is occurring along a section of the channel that flows parallel and adjacent to the pipeline RoW. Bank erosion can lead to lateral movement of the watercourse toward the pipeline, potentially leading to exposure and freespan of a section of the pipeline outside of a designed watercourse crossing.
A.2.3. Avulsion
Avulsion, also referred to as outflanking or abandonment, occurs when streams leave their present channel and establish a new channel. This process can lead to pipe exposure if the new channel intersects the pipeline outside of the designed watercourse crossing where the top of pipe elevation may be higher. Avulsion frequently takes place on alluvial fans that carry high loads of bed material. It may also occur where rivers meander on a wide floodplain, although in this case the avulsion is typically into an existing side channel or abandoned channel. For the latter scenario, avulsion typically occurs progressively over a period of years rather than suddenly during a large flood event (although the large flood event may be the final tipping point for the avulsion to occur). In braided channels, the term avulsion is sometimes used to describe a shift in the main thread of current to the other side of a mid-channel bar, but in general, is intended to denote a complete shift of the main channel. Avulsions commonly result when an event (usually a flood) of sufficient magnitude occurs along a reach of river that is at or near an avulsion threshold (Schumm 2005). Avulsion channels can be characterized as active, transitional, or inactive based on the hydrological regime. Active avulsions are characterized by the presence of standing or flowing water. Transitional avulsions are dry without established vegetation. Inactive avulsions are dry and vegetated in the channel suggesting conditions have remained constant for several years. A.3. FLOOD FREQUENCY ANALYSIS
Flood discharge magnitudes and frequencies are estimated using a flood frequency analysis (FFA). Flood discharge quantiles are estimated for one or several representative hydrometric gauge stations, which are then related to the pipeline crossing using a site-specific relationship to estimate flood discharge quantiles at the crossing. This relationship could be a proration using a station on the same watercourse or a regression using several representative stations near the crossing. The flood discharge quantiles estimated using an FFA form the basis for the hydrotechnical hazard assessment for scour, bank erosion, encroachment, and avulsion. The methods used to conduct an FFA are described herein. The FFA is based on an approach known as Annual Maximum Series (AMS), which uses the maximum discharge value over a period of time. The selected AMS is the maximum peak instantaneous streamflow for each year on record, which is assumed to be a random sample from the underlying population of hydrological events and can thus be estimated by the selection of an appropriate statistical distribution.
Appendix A_Hydrotechnical Assessment Methodology A-4 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Extreme value statistics are used to estimate flood discharge quantiles from the AMS. A distribution known as the Generalized Extreme Value (GEV) distribution, which is described by location, scale, and shape parameters, is fitted to the AMS to estimate the flood discharges associated with selected event probabilities (Gilleland and Katz 2006). This statistical analysis is conducted using the Extremes package in R, a non-proprietary software environment for statistical computing and graphics (Gilleland 2016).
A.3.1. Historical Peak Flow Records
The FFA requires the input of streamflow data. In Canada, the Water Survey of Canada (WSC) monitors and manages hydrometric stations and publishes their data. The hydrometric stations for FFA are selected based on proximity to the crossing, available streamflow data (i.e., record length), drainage basin area, station elevation, hydro-climatic zone, and regulation type.
The preferred input to the FFA is peak instantaneous streamflow (QIMAX) for each available year on record. However, peak streamflow records at hydrometric stations are often limited to maximum average daily streamflow (QMAX) which are lower in magnitude than QIMAX. The difference between peak instantaneous and average daily flows are typically greater for small basins than for very large drainage areas. In some cases, QIMAX values may be estimated from available QMAX records using regression analyses techniques.
A.3.2. Prediction Limit of Dataset
The maximum return period for which a peak streamflow can be estimated reliably (i.e., the prediction limit) at a given hydrometric station is limited by the record length of the dataset defined by the number of years with a complete peak streamflow record. Generally, in cases where the record length of the station of interest is too short, the dataset can sometimes be extended using a correlation analysis with another nearby hydrometric station to estimate flood frequencies of higher return periods.
A.3.3. Climate Change
Flood frequency analyses use extreme value statistics that rely on assumptions of stationarity and homogeneity in the hydrologic data; however, climate change may invalidate the assumption of stationarity by producing a temporal trend in flood magnitude over time. Flood magnitude may be directly influenced by changes in annual precipitation or intensity, but is also indirectly affected by changes in precipitation phase related to temperature fluctuations (e.g., greater frequency of rain-on-snow events). The assumption of homogeneity in flow records will also be invalidated in many regions, as hydrologic regimes may shift from snowmelt-dominated or hybrid to rainfall- dominated, creating mixed populations of data. The impacts of climate change on hydrology are expected to vary regionally based on differences in temperature and precipitation changes across Canada. Potential impacts are described in the following sub-sections for select regions according to Canadian Ecozones (i.e., broad ecological units) (Li and Hélie 2014), as shown in Error! Reference source not found.. These regions were
Appendix A_Hydrotechnical Assessment Methodology A-5 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14 selected to capture the geographic range of hydrotechnical assessments for the Trans Mountain Expansion Project. The magnitude and timing of climate change impacts on hydrology in these different regions are uncertain. It is expected that some areas will experience more frequent, high-intensity flood events while others will experience less frequent flood events of the same intensity. These descriptions are intended to serve as general information only. Statistical analyses have not been incorporated in the FFAs to account for regional climate change impacts on hydrology at this time. Instead, flood quantiles for sites in all ecozones are conservatively increased by 10% to account for this uncertainty.
BRITISH COLUMBIA ALBERTA N
Edmonton
Vancouver
300 km
Figure A-2. Geographic map of Canadian ecozones across the geographic range of the Trans Mountain Expansion Project.
A.3.3.1. Pacific Maritime The dominant form of precipitation dictates runoff patterns throughout much of Canada (Whitfield 2001). Thus, although changes in the annual volume of precipitation due to climate change are uncertain (e.g., Zwiers et al. 2011), much of the Pacific Maritime region will experience changes in runoff timing as a result of increased winter temperature, as the contribution of snowmelt to annual runoff decreases. As a result, many streams in the Pacific Maritime region will shift from nival (i.e., snowmelt-dominated) to hybrid regimes, which are characterized by earlier snowmelt and more frequent rain-on-snow events (Loukas and Quick 1999; Whitfield 2001). Meanwhile hybrid streams are anticipated to transition to a fully pluvial regime, as the
Appendix A_Hydrotechnical Assessment Methodology A-6 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14 importance of the spring freshet decreases due to a loss of winter snowpack, especially in coastal areas (Zwiers et al. 2011; Schnorbus et al. 2014). As nival watersheds trap precipitation from winter storms in the snowpack, releasing it gradually during the spring freshet, this transition may be accompanied by an increase in the size and variability of floods (Pitlick 1994). To date, the impacts appear to be greatest in headwater streams; the Columbia River, for example, has shown little change in runoff magnitude or timing (Hatcher and Jones 2013), though this resilience is in part due to an increase in snowpack at high elevations (Schnorbus et al. 2014).
A.3.3.2. Semi-Arid Plateaux A decrease in the number and magnitude of flood events is predicted for many snowfall- dominated watersheds, particularly in the semi-arid interior regions of British Columbia (Loukas et al. 2002). In drier climates, evaporation from water surfaces and from the land as well as transpiration from vegetation make up a large component of the regional water balance suggesting that temperature changes have the potential to affect runoff. Trends suggest that the Okanagan Basin is getting warmer and wetter with minimum temperatures and the number of frost-free days increasing (Cohen and Kulkarni 2001). Climate change scenarios predict an increase in winter temperature of 1.5 to 4.0 ⁰C and an increase in summer temperatures by approximately 2 to 4 ⁰C by the 2050s compared to the 1961 to 1990 baseline (Merritt et al. 2006). Taylor and Barton (2004) analyzed precipitation records from six sites in the Okanagan Basin and identified statistically significant positive trends in spring-time and summer precipitation for most stations. In contrast, climate change scenarios show precipitation increases on the order of 5 to 20% during the winter season and more variable predictions in the summer with changes ranging from no change to a 35% decrease by the 2050s compared to the 1961to1990 baseline, depending on the Global Climate Model and emission scenario (Merritt et al. 2006). Despite the warmer and wetter climate, little impact on the total water supply has been observed to date, which likely reflects a cancellation of the increase in precipitation inputs versus evapotranspiraton losses (Fleming and Barton 2015). Most studies seem to agree that climate change is resulting in an earlier onset of the spring freshet, a more rainfall-dominated hydrograph, and reduction in the annual and spring flow volumes with large variation in the flow volume and magnitude of the timing shift (Cohen and Kulkarni 2001; Merritt et al. 2006; Fleming and Barton 2015).
A.3.3.3. Montane Cordillera Extreme flooding in the Montane Cordillera is often associated with rain-on-snow events during the spring freshet (Harder et al. 2015). Although the effects of climate change on precipitation are not clear in this region, projected increases in temperature are expected to have the largest impact on annual minimum temperatures occurring in the winter months (Harder et al. 2015). As a result, the temperature rise will dramatically impact the ratio of rainfall to snowfall throughout the winter and spring, leading to a decrease in snowpack accumulation and changes in melt timing (Farjan et al. 2016). Researchers anticipate that streamflow will increase in the winter and spring in this region due to earlier snowmelt and more frequent rain-on-snow events (Schnorbus et al. 2014; Farjan et al. 2016).
Appendix A_Hydrotechnical Assessment Methodology A-7 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
The effects of temperature change differ throughout the region, however, based on watershed elevation; high elevation regions throughout parts of the Montane Cordillera are projected to experience increases in snowpack, which would limit changes to peak flow in high elevation basins (Loukas and Quick 1999). To date, the sustained snowpack accumulation in some watersheds has limited changes in peak flows from climate change (Schnorbus et al. 2014, Harder et al. 2015). For example, Whitfield and Pomeroy (2016) recently studied the historical flow record for the upper Bow River, which contains over 100 years of records, and found that when flood events generated by different processes (snowmelt versus rain-on-snow) are analyzed separately, there are no clear trends in flood magnitude associated with climate index. The continued resilience of high elevation watersheds to future change is uncertain, though, as climate change is anticipated to affect snowpack accumulation at increasingly higher elevation regions throughout the century (Schnorbus et al. 2014, Harder et al. 2015).
A.3.3.4. Boreal Plains Global Circulation Model predictions are in general agreement that the climate in the southern boreal forest will likely become warmer and drier in the future, especially in the summer due to greater water loss by evapotranspiration (Cubasch et al. 2001; Gregory et al. 1997). Regional climate models indicate that the predicted warming could increase evaporation by up to 55% in certain areas of Alberta, Saskatchewan, and Manitoba (Schindler and Donahue 2006). Paleolimnological studies have shown a drying trend with reduced flood frequency and intensity in the northern Boreal Plains since 1850 (Wolfe et al. 2006). In contrast to temperature, precipitation trends are weaker and less certain. None of the data from reference climate stations within the Boreal Plains show significant trends in total precipitation over the time period 1950 to 2010 (Ireson et al. 2015). Data from some stations show a decline in annual snowfall and consequently a reduction in the fraction of precipitation that falls as snow due to the shortening cold season (Mekis and Vincent 2011). The response of hydrological processes to winter warming is highly uncertain. Earlier spring snowmelt and delayed autumn snowfall are predicted to be very likely but the impacts are not clear due to the complex runoff generation mechanisms in the Boreal Plains. For example, earlier melt could mean a shift to an earlier peak in streamflow and less water available in the late summer or it could mean more soil infiltration due to the increased proportion of rainfall over snowmelt which could increase soil moisture, stream baseflow, and hydraulic connectivity between wetland and streams (Barnett et al. 2005). Nevertheless, the net effect will be warmer and drier over time due to an increase in air temperature (Ireson et al. 2015).
A.3.3.5. Prairies Peak runoff in the Canadian Prairies is primarily a result of spring snowmelt over frozen soils but can also be caused by intense rainfall from summer storms (Shook and Pomeroy 2012). The fraction of spring snowmelt forming runoff is strongly influenced by the rate of melt and the presence of ice layers near the surface in frozen soils or at the base of the snowpack, all of which can be influenced by rainfall in the spring and late fall. In 2008, earlier occurrence of spring runoff
Appendix A_Hydrotechnical Assessment Methodology A-8 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14 and decreasing trends in the spring snowmelt runoff volume, magnitude of peak flow, and summer baseflows were attributed to a combination of a reduction in snowfall and increases in temperatures during the winter months (Burn et al. 2008). More recently, the fraction of monthly precipitation falling as rain was found to increase at many locations in the Canadian Prairies over the periods 1901 to 2000 and 1951 to 2000 (Shook and Pomeroy 2012). Short-duration summer convective rainfall events show significant decreases in frequency while multiple-day rainfall events have significantly increased in frequency at many locations in the Canadian Prairies over these time periods. Longer rainfall events strongly suggest greater spatial extents for storms and increasing tendencies for basin-scale rainfall– runoff events (Shook and Pomeroy 2012). Warming air temperatures, increased rainfall fraction in peak flows, earlier snowmelt, and higher occurrence of multiple-day rainfall events have, along with extensive wetland drainage (and corresponding reduction in runoff storage within basins), have resulted in an increase in flows generated from snowmelt, rain-on-snow, and rainfall runoff processes, with the greatest increases for rainfall runoff and a relative decline in the proportion of streamflow derived from snowmelt from over 85% in the 20th century to less than 50% in the last 5 years (Dumanski et al. 2015).
A.3.4. Pro-rated FFA
In cases where a single representative station is located along the same watercourse as the proposed pipeline crossing, a pro-rated FFA can be conducted by transposing the flood quantiles from the station to the crossing. This type of FFA uses a pro-rated calculation to relate the QIMAX quantiles at the hydrometric station to the pipeline crossing based on basin area. The equation used for this relation is as follows (Eq. A-1):
n QU AU [Eq. A-1] QG AG
3 where QU and QG are the peak instantaneous flow estimates (m /s) at the ungauged site (pipeline crossing) and gauged site (hydrometric station) respectively, AU and AG are the drainage basin areas (km2) for the ungauged and gauged sites respectively, and n is a site-specific exponent that relates peak streamflow data at both sites (Transportation Association of Canada [TAC] 2004). The value of n is selected based on the drainage area, as shown in Table A-1. The drainage area at the pipeline crossing is typically estimated by BGC using available topographic datasets while drainage areas for the hydrometric stations are obtained from WSC records.
Table A-1. Approximate drainage area exponents for prorating flood quantiles (from TAC 2004) Drainage Area (km2) Exponent, n
10 to 100 0.8
100 to 1000 0.65
Appendix A_Hydrotechnical Assessment Methodology A-9 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
1000 to 10,000 0.5
10,000 to 100,000 0.35
100,000 to 1,000,000 0.2
A.3.5. Regional FFA
A regional FFA approach is used to estimate design flood flows at the proposed pipeline crossing when there are several representative hydrometric stations in the area, either along the crossing watercourse or on nearby watercourses with similar catchment characteristics. A regional FFA is conducted using regression analysis, where QIMAX quantiles are estimated from a regression with the form of a power law, which is described by equation (Eq. A-2):
b Qp aA [Eq. A-2]
where Qp is the peak flood estimate at the pipeline crossing, A is the upstream drainage area for the crossing, and a and b are regression coefficients developed from the estimated QIMAX and calculated drainage area of several regional hydrometric stations (TAC 2004). A.4. SCOUR ANALYSIS
Scour is the localized removal of granular bed material from the channel substrate by hydrodynamic forces during a flood event. The likelihood of a pipeline becoming exposed due to scour in a flood event is assessed by estimating the maximum scour depth associated with a range of return period floods. If the pipe’s crown elevation within the bankfull channel is higher than the estimated scour elevation, then the pipe is considered to be susceptible to exposure for that particular magnitude of flood event. The scour elevation is estimated by subtracting the predicted scour depth from the design flood elevation, which is generated using an estimate of channel hydraulics with Manning’s equation.
A.4.1. Channel Hydraulics
As part of the scour assessment, hydraulic parameters (i.e., water surface elevation, average flow depth etc.) are estimated at the pipeline crossing site for the design flood. The hydraulics are assessed by modeling flow through the study reach, or by applying Manning’s equation at the pipeline crossing. Manning’s equation is an empirical formula for open channel flow, and it is applicable in cases where flow is driven by gravity and is considered uniform. Manning’s equation is defined in equation A-3.
1 푉 = 푅 2/3 ∙ 푆1/2 푛 ℎ [Eq. A-3] where V is the cross-sectional average velocity (m/s), n is Manning’s roughness coefficient (unitless), Rh is the hydraulic radius (m), and S is the slope of the water surface (m/m). The
Appendix A_Hydrotechnical Assessment Methodology A-10 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14 hydraulic radius, Rh, is calculated as the cross-sectional area of the flow divided by the wetted perimeter. The slope of the water surface is generally assumed to be comparable to the regional slope of the channel bed for uniform flow. Manning’s coefficient values typically range from 0.025 to 0.07 for streams with boulder to sand substrates; selection of an appropriate value is based on professional judgment.
A.4.2. General Scour Equations
Various empirical hydraulic equations have been developed to estimate general scour depth during a peak flow event (Table A-2). The selection and use of these equations requires engineering judgment, resulting in semi-quantitative results. Each method was designed by its authors based on a specific range of boundary conditions, and care must be taken to select appropriate methods for the site under study.
Table A-2. Methods for estimating the potential depth of general scour. Method Reference
Lacey’s Regime Lacey (1930)
Blench Regime Blench (1969)
Yaremko and Cooper Yaremko and Cooper (1983)
A.4.2.1. Lacey’s Regime Most of the work on general scour can be traced back to the concept of channel regime, starting with Lacey in 1930. The regime concept is generally considered synonymous with that of equilibrium or balance, and was a concept that originated with British engineers working in India from the study of the dimensions of stable alluvial, irrigation canals. The regime concept was originally formalized by Lindley (1919) who noted that “when an artificial channel is used to convey silty water, both bed and banks scour or fill, changing depth, gradient, and width, until a state of balance is attained at which the channel is said to be in regime.” Lacey (1930) expanded on the regime concept of Lindley by quantifying it. He defined a regime channel as a channel carrying a constant discharge under uniform flow in an unlimited incoherent alluvium having the same characteristics as that transported without changing the bottom slope, shape, or size of the cross-section over a period of time. Using data from irrigation canals on the Indian subcontinent, Lacey developed equations that related hydraulic parameters – namely wetted perimeter, velocity, hydraulic radius, and channel slope – to discharge and a silt factor (f), which takes into consideration the effect of sediment size on the channel dimensions. Lacey’s regime equation for mean depth is shown in Equation A-4.
푄 1/3 푑 = 0.47 ( ) 푚 푓 [Eq. A-4] where:
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• dm is the mean hydraulic depth of the main channel at the design discharge (m) • Q is the design discharge (m3/s) 1/2 -1 • f is Lacey’s silt factor = 1.76 (D50) , (s ) • And D50 is the median bed particle size (mm).
The regime method of Lacey is limited to channels with a sand1 bed, similar to conditions observed at the irrigation canals. However, Lacey also stated he was “inclined to believe that his formulas were general for all channels in the alluvium with which the engineer may be called upon to deal.” While the equation was developed from canal data, it has since been checked against data from a number of stable bridge sites on large sand-bed rivers, with remarkably good agreement (Neill 1964). The silt factor was introduced to account for differences in velocity-depth relations between different canal systems and was initially assumed to be a function of the grain size of transported sediment. For standard “silt” (actually medium sand) of 0.4 mm, the silt factor was taken as 1. The above equation only gives an estimated mean depth across the channel. To estimate the maximum general scour depth for a given flow, a multiplying factor must be applied. Lacey (1930) stated that “in a river flowing through a stable reach the maximum depth should approximate to the mean depth multiplied by 1.273 (elliptical section). For moderate, severe and right-angled bends, he recommended replacing the multiplier by 1.5, 1.75, and 2.0 m (the last based on a triangular section), respectively. However, Lacey (1930) gave no numerical guidance as to sharpness of curvature. Table A-3 gives coefficients (Zf factors) recommended by the Indian bridge code (1966), which are based mainly on consideration of the local channel morphology.
Table A-3. Empirical Lacey Z factors for maximum scour depth (after Neill 1973). Correction Factor Channel Morphology (Zf Factor)
Straight reach 1.25 Moderate bend 1.5 Severe bend 1.75 Right-angled abrupt turn 2.0 Noses of piers 2.0 Alongside cliffs and weirs 2.25 Noses of guide banks 2.75
The resulting equation is then:
푑푠 = 푍푓푑푚 [Eq. A-5]
1 The term “silt” was used at that time in India for canal sediment (Neill 1964).
Appendix A_Hydrotechnical Assessment Methodology A-12 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14 where ds is the scour depth below the channel bed (m) and Zf is the correction factor (Table A-3). The average depth, dm (m), is assumed to be the hydraulic depth over the incised portion of the channel. It is further noted that the above equations are based on an unconstrained river, where the width is not constricted or imposed. As an example, if the mean channel depth for a given flow is estimated by Equation A-4 to be 2.0 m and the site is at a moderate bend, then the maximum scour depth estimated using Equation A.5 would be 1.5 times the mean depth, or 3.0 m, as measured from the water level for the given flow. Most subsequent regime equations for estimating general scour are variants of Lacey’s equations.
A.4.2.2. Blench Regime Depth Blench (1969) extended previous regime methods to include cases of different bank material. With this method, the bed factor is similar to Lacey’s silt factor. Blench defined the regime depth as follows:
2/3 1/3 푑푟 = 푞 /퐹푏 [Eq. A-6]
Where dr = regime depth (m) q = Q/b = unit discharge (m3/s/m) Q = design discharge (m3/s) b = water surface width (m)
Fb = Fbo (1 + 0.12 C) = bed factor (m/s2)
Fbo = zero bed factor (m/s2) C = bed load charge.
The value of Fbo is the larger of the values determined from Equation A-7, which has been converted by BGC to metric units, or from Figure A-3:
0.5 퐹푏표 = 14.63 (퐷50/푑푟) [Eq. A-7] where D50 = median diameter of bed material (m).
Appendix A_Hydrotechnical Assessment Methodology A-13 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Figure A-3. Blench’s zero bed factor, Fbo, versus particle diameter, D50, from Pemberton and Lara (1984).
Fbo is the zero bed factor, or the value to which the bed factor tends as C tends to zero. Because the value of Fbo is calculated using the regime depth, solving the equation is an iterative process. The estimated bed load charge, C, is essentially an adjustment factor to dampen estimated scour depths when significant bed load transport occurs; under these conditions a portion of the stream’s energy is committed to sediment transport rather than to scour of the channel bed. BGC’s does not generally adjust for bed load charge as this leads to less conservative results. Finally, similar to Lacey’s method, the regime depth is multiplied by a Z factor to calculate the scour depth as per Equation A-8:
푑푠 = 푍푓푑푟 [Eq. A-8] where ds is the scour depth relative to the design flood stage (m), Zf is the empirical correction factor, and dr is Blench’s regime depth (m). Northwest Hydraulic Consultants Ltd. (NHC) (1973) investigated Zf factors to be applied to the Blench regime equation using both field and model results, and recommended the values shown in Table A-4.
Appendix A_Hydrotechnical Assessment Methodology A-14 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Table A-4. Zf factors for scour depth applied to Blench’s regime equation (after NHC 1973). Correction Factor Channel Morphology (Zf factor) Forced, Rigid Bends 1.4 – 2.5 Free, Eroding Bends 1.4 – 1.75 Confluence 1.5 – 2.0 Tip of Spurs 2.0 – 2.75 Braided Channel1 2.5 – 3.0 Note: 1. Applicable to the bankfull mean depth of the largest existing channel in the vicinity of the crossing.
There is considerable range in Zf factors for a given channel morphology, and NHC noted that selection of appropriate Zf factors requires considerable experience in river engineering design. A conservative Zf factor at the upper end of the range is typically selected to account for uncertainty in the scour analysis inputs and empirical methods.
A.4.2.3. Yaremko and Cooper Yaremko and Cooper’s (1983) scour equation assumes that scour depth is proportional to the mean channel depth for a given flow event. Essentially, the Yaremko and Cooper equation is a simplification of other regime equations, with the assumption that the mean depth is an approximation of the regime depth (Figure A-4). The mean channel depth is assumed to be the hydraulic depth (wetted area/top width). The Yaremko and Cooper scour equation is defined by equation A-9.
푑푠 = 푍푓푑푟 [Eq. A-9] where ds is the depth of maximum scour relative to the design flood stage (m), dr is defined as the hydraulic depth over the main (incised) portion of the channel, and Zf is the correction factor. For appropriate Zf factors, the authors quote the values shown in both Table A-3 and Table A-4.
Appendix A_Hydrotechnical Assessment Methodology A-15 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Figure A-4. Application of estimated scour depths relative to the design flood stage (after Yaremko and Cooper 1983).
Yaremko and Cooper (1983) note that on northern pipeline projects, a great deal of attention was focused on the importance of accurately estimating an appropriate design discharge for use in determining depth of scour. However, the authors note that the design procedure for estimating scour is much more sensitive to the selection of an appropriate Z factor, than it is to the accurate determination of a design flood discharge.
A.4.2.4. BGC Z Factors As a general rule, BGC uses the Z factors specified in Table A-3 and Table A-4. An atypical example might be a braided river, where a local multiplier of 3 is used to account for increased scour at confluences, which are characteristic features of such rivers due to multiple channels and mid-channel bars. The mid-channel bars add geomorphic complexity that results in convergent flow downstream of these deposits, which can cause localized changes in bed planform, including scour holes (Ashworth 1996). Galay et al. (1987) indicate that scour multipliers for braided rivers can be as high as 5 under certain circumstances.
A.4.3. Maximum Bed Mobility
Channel bed mobility controls the adjustment of alluvial river channels and is driven by scour and entrainment. The maximum mobile particle size is estimated based on a combination of the shear velocity (u*) and channel bed shear stress (휏푏), which are calculated using Equations A-10 and A-11, respectively.
푢∗ = (푔푅푆)1/2 [Eq. A-10]
휏푏 = 푔휌푅푆 [Eq. A-11]
Appendix A_Hydrotechnical Assessment Methodology A-16 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14 where g is acceleration due to gravity (9.81 m/s2), R is the hydraulic radius (m), S is the regional channel slope (m/m), and 휌 is the density of water (1000 kg/m3). Shear velocity is expressed in units of m/s. Several empirical equations are available to estimate the maximum mobile particle size and each is considered a check on the others (Table A-5) (Pemberton and Lara 1984). The methods described below use channel hydraulic flow parameters, shear velocity, and channel bed shear stress. The maximum mobile particle size in a channel is estimated by taking the average of the different methods.
Table A-5. Methods for estimating bed material mobility. Method Reference
Shields’ Incipient Motion Shields (1936)
Lane’s Tractive Force Theory Pemberton and Lara (1984)
Borah Bed Armouring Borah (1989)
Meyer-Peter Muller Pemberton and Lara (1984)
The estimated maximum mobile particle size is used to assess the mobility of the bed material in the channel by comparison with an estimate of the median particle size present in the channel. Under conditions where the maximum mobile particle size is greater than the median particle size of the channel bed, the bed material is considered to be frequently mobile. Alternatively, in cases where the maximum mobile particle size is less than the median particle size of the channel bed, bed mobility is considered infrequent.
A.4.4. Wolman Sampling
Various regime and scour equations require an estimation of the median diameter of the bed material (D50). For gravel-bed rivers, the D50 of the bed material is assessed using field data collected following the standardized Wolman river bed material sampling method (Wolman 1954). This technique involves randomly picking up and measuring at least 100 pebbles from the river bed at the pipeline crossing or in a representative location in the same reach). The pebbles are measured and classified by size, then counts of pebbles in each size class are compiled to develop a grain size distribution, from which the D50 particle size is estimated.
A.4.5. Channels with Cohesive Beds
Conventional approaches to scour prediction were developed from field observations and laboratory experiments in non-cohesive soils, and are generally regarded as overly conservative when applied to cohesive soils. Accurate and accepted methods for predicting scour depths in the more scour-resistant cohesive soils are not yet available to practicing geomorphologists and engineers. The lack of an accurate predictive method often results in an overly conservative design scour depth for cohesive bed channels.
Appendix A_Hydrotechnical Assessment Methodology A-17 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Quantification of channel bed resistance to erosion is site specific and requires laboratory analysis on in-situ samples. Given that the cohesiveness and scour resistance of the substrate is generally not quantified, it is typically assumed by BGC that the bed materials at the pipeline crossings are non-cohesive. In cases where the channel bed material is obviously cohesive, scour depth results may be overestimates. A.5. BANK EROSION AND ENCROACHMENT ANALYSIS
Much of the methodology presented in the following section has been developed by BGC, and rely significantly on engineering judgement. Bank erosion occurs when bank locations change due to erosion at the channel margins, generally due to channel widening or progressive, gradual erosion from lateral migration of the channel. Channel widening occurs in response to flood events where the channel is forced to convey large flows. Bank erosion may also occur in the absence of large flow events and as a result of gradual erosion along one bank; in this case, the erosion typically occurs along the outer bank of a meander bend and is systematically balanced by the deposition of a point bar on the opposite bank, thus maintaining the channel width (Figure A-5) (Fuller 2007). Encroachment occurs when bank erosion results from migration of the channel bank toward a pipeline that travels parallel and adjacent to the channel flow direction.
Figure A-5. Illustration of gradual lateral channel migration in meandering rivers (Church 2006).
Figure A-6 illustrates different channel planforms as related to sediment supply and channel stability. These channel types can similarly be related to different forms of bank erosion; erosion due to channel widening is typically associated with inherently unstable channels such as braided
Appendix A_Hydrotechnical Assessment Methodology A-18 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14 or wandering rivers, whereas progressive lateral channel migration is commonly observed in unconfined to semi-confined meandering rivers. The following sections describe the methods used by BGC to assess and quantify bank erosion.
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Figure A-6. Illustration of channel planform and related sediment supply and stability (Church 2006).
A.5.1. Historical Assessment of Channel Changes
A channel’s susceptibility to lateral migration can be assessed by looking at changes in channel position over time. Historical aerial photographs and satellite imagery can be used to compare and measure changes in the channel position and planform over time. The oldest available aerial photograph is compared to the most recent available imagery (satellite image or orthophoto) to observe noticeable trends in channel stability and lateral movement over a period of decades. This method will generally provide more accurate and reliable results for medium to large rivers (> 15-20 m width) due to limitations in the spatial scale of available imagery and the precision of mapping techniques. Historical aerial photographs at a scale of 1:30,000 or larger are preferred for this assessment. Aerial photographs are manually georeferenced to enable 2-dimensional (2D) comparison. Georeferencing is done using control points that are constant over time; where possible, a higher density of control points near the watercourse or in the valley is used to minimize distortion near the river banks. For some sites where adequate control data such as LiDAR are available, high- precision orthorectified models are created that are viewable in 3-dimensional (3D) space using the program Summit EvolutionTM. In both 2D and 3D cases, banks are delineated from the aerial photographs or models using geographic information system (GIS) software, and the differences in bank locations, which represent erosion or deposition, can be observed and quantified, as relevant. When multiple sets of LiDAR topographic data are available, change analysis techniques can be used to obtain higher precision estimates of recent channel change. Similar methodologies for historical imagery comparison using both aerial photographs and LiDAR imagery have resulted in spatial error of +/- 2.5 m (Fuller 2007). The spatial accuracy in the BGC method is estimated to be typically about +/-15 m because aerial photographs were not flown specifically for the proposed pipeline crossings and therefore may not be centered, resulting in potential distortion near the crossing location during the georeferencing process.
A.5.2. Encroachment
Progressive lateral movement of the channel toward the pipeline as a result of bank erosion can be evaluated using the same qualitative and quantitative methods as outlined for bank erosion described in the section above. An example of an encroachment hazard is shown in (Figure A-7).
Appendix A_Hydrotechnical Assessment Methodology A-20 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Encroachment Hazard
Figure A-7. Example of an encroachment hazard. The blue arrow indicates the channel centerline and flow direction and the red line shows a pipeline centerline location (imagery source: Google Earth, 2004).
A.6. AVULSION ANALYSIS
A.6.1. Background
Avulsion is the creation of a new channel on a floodplain or alluvial fan adjacent to the existing channel location. Scour within an avulsion channel could expose a pipeline, especially where the pipeline rises (and DoC decreases) outside of the boundaries of the main channel or existing channel location. Figure A-8 depicts a typical avulsion hazard in plan view and cross-section.
Appendix A_Hydrotechnical Assessment Methodology A-21 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Figure A-8. Example of avulsion in plan view (left) and cross-section (right).
Avulsions in floodplains tend to occur within a limited area known as the channel migration zone (Olson et al. 2014). This zone comprises the modern valley bottom as well as adjacent areas that could be incorporated into the valley bottom through erosion and it can be defined based largely on historical landforms visible in aerial photographs and satellite imagery; however, in streams subject to post-glacial incision, distinguishing between recent and historical landforms that may be abandoned (e.g., oxbow lakes on floodplain surface versus those on elevated terraces) can require considerable judgement. Within the channel migration zone, the likelihood of island-forming avulsions to occur is highest in previously abandoned secondary channels (Konrad 2012). In meandering streams, avulsion is most likely to occur between meander bends from the formation of neck and chute cutoffs (Slingerland and Smith 2004). Avulsions typically occur in response to a trigger, such as channel blockage (e.g. a log jam) or overland flooding, and the likelihood of avulsion will be greatest when at least one of these triggers is present. According to Schumm (2005), the underlying causes of avulsions can be organized into four groups as shown in Table A-6. The groupings represent different processes and events that create instability and can lead to avulsion. Generally, increases in the ratio of the potential avulsion path gradient (Sa) to the gradient of existing main channel (Se) the lead to greater instability and potentially to avulsion. Slingerland and Smith (1998) observed that avulsion tends to occur when the Sa/Se ratio is greater than 4. Therefore, Groups 1 and 2 include processes or events that affect the Sa/Se ratio in different ways, while processes and events in Group 3 and 4 are not related to the Sa/Se ratio.
Appendix A_Hydrotechnical Assessment Methodology A-22 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Table A-6. Causes of avulsions according to Schumm (2005). Ability of the existing main Processes and events that create instability and lead to avulsion channel to transport sediment and/or discharge Group 1 a) Sinuosity increases Decrease Avulsion due to increased ratio of b) Delta growth (lengthening of channel) Decrease Sa/Se resulting from a c) Base level fall Decrease decrease in Se d) Tectonic uplift Decrease Group 2 Avulsion due to a) Natural levee/alluvial ridge growth No change increased ratio of b) Alluvial fan and delta growth (convexity) No change Sa/Se resulting from an increase in Sa c) Tectonism (resulting in lateral tilting) No change Group 3 a) Hydrologic change in flood peak discharge Decrease Avulsion not b) Increased sediment load Decrease associated with a c) Vegetative encroachment Decrease change in ratio of Sa/Se d) Log Jams Decrease e) Ice Jams Decrease Group 4 a) Animal trails No Change Other avulsions b) Capture (diversion into adjacent drainage) No Change
Note: Se is the gradient of the existing (main) channel and Sa is the gradient of the potential avulsion course. Avulsion potential is assessed with qualitative consideration for various factors. Without a floodplain or fan, for example, the potential for avulsion is restricted spatially; channel patterns formed through avulsion (streams with multiple adjacent channels) generally occur in floodplains that are at least four times wider than the bankfull channel width (Beechie and Imaki 2014). Avulsion therefore poses little hazard in entrenched streams as it requires flooding onto elevated terraces, which would only be possible under extreme flows. In reaches bounded by floodplains, avulsion is most likely to occur within the channel migration zone, typically through the reoccupation of abandoned side channels or as cutoffs between successive meander bends. Avulsion is of greatest concern in aggrading streams, often typified by braided or anabranching channel patterns, where sediment deposition and other triggering factors such as large woody debris may force flows onto the adjacent floodplain (Slingerland and Smith 2004).
Appendix A_Hydrotechnical Assessment Methodology A-23 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Another factor that influences avulsion is the resistance of the valley bottom to vertical erosion. Factors that influence erosion resistance include the nature and abundance of vegetation and the composition and cohesion of floodplain sediments (Constantine et al. 2009; Dunne et al. 2010). Avulsion channels may be more likely to develop in areas with sparse vegetation, such as tilled agricultural fields, than in those with forest cover (Olson et al. 2014).
Olson et al. (2014) recommend that the following factors be considered in an assessment of avulsion potential: • Cross-valley gradients relative to main channel gradients; • Areas at lower elevations than the main channel with downstream outlets; • The presence of abandoned, side or secondary channels that have steeper slopes than the main channel; • The composition and cohesion of the floodplain and valley bottom sediments; • Abundance and type of vegetation in potential avulsion pathways; • Indications of active channel aggradation; and • Accumulations of large woody debris and channel-spanning log jams.
A.6.2. Assessment
The first step in assessing the potential avulsion hazard for proposed crossings is to delineate the floodplain or fan extents, if relevant, and to identify any contributing factors such as levees, cutoff structures, debris jams, sediment accumulation, beaver dams, debris flow potential, or extreme flooding. Next, the threshold flow depth for avulsion to occur is quantitatively defined based on the bank elevations at the crossing, which are obtained from survey and LiDAR data. The bank elevation is determined visually as the maximum elevation of the land that separates the stream channel from the floodplain, or the height of the terrace if no floodplain is present. The minimum bank elevation, which is the elevation of the lower of the two banks, defines the threshold flow depth needed to cause overbank flooding and to enable avulsion at the crossing. If this threshold is high, which is typically the case for entrenched reaches, then the design flow does not overtop the banks and avulsion cannot develop in the absence of a blockage. This is common in many Canadian streams, where they flow through valleys carved by larger glacial meltwater channels and are bounded by glaciofluvial terraces. Due to the complex nature of the combination of mechanisms that can initiate avulsion, it is difficult to predict exact avulsion flow paths through a floodplain or fan, even with detailed topographic information for the entire study area. In addition to establishing an elevation threshold for avulsion at the proposed crossing, avulsion is assessed qualitatively with consideration for additional contributing factors at the reach scale. Avulsion most often initiates at locations with triggering factors (e.g. log jams), or in existing or abandoned side channels that begin in locations where bank elevations are lower than at the crossing; therefore, if active or abandoned side channels are evident in imagery or on the crossing elevation profile, then this may indicate that the elevation threshold for avulsion is lower in a location upstream of the crossing.
Appendix A_Hydrotechnical Assessment Methodology A-24 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
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.
Barnett, T.P., Adam, J.C., and Lettenmaier, D.P. 2005. Potential impacts of a warming climate on water availability in snow-dominated regions. Nature 438: 303–309. Beechie, T. and Imaki, H. 2014. Predicting natural patterns based on landscape and geomorphic controls in the Columbia River basin, USA. Water Resources Research 50: 39-57. Blench, T. 1969. Mobile-bed Fluviology. University of Alberta Press, Edmonton, Alberta. Borah, D.K. 1989. Scour depth prediction under armouring conditions. Journal of Hydraulic Division, ASCE 115 (HY10):1421-1425. Burn, D. 1994. Hydrologic effects of climatic change in west-central Canada. Journal of Hydrology 160: 53-70. Burn, D., Fan, L., and Bell, G. 2008. Identification and quantification of streamflow trends on the Canadian Prairies. Hydrological Sciences 53: 538-549. Church, M. 2006. Bed material transport and the morphology of alluvial river channels. Annual Review of Earth and Planetary Sciences 34: 325-354. Cohen, S., and Kulkarni, T. (Eds.), 2001. Water management and climate change in the Okanagan Basin. Final Report, Climate Change Action Fund Project A206, 75 pp. Constantine, J.A., McLean, S.R., and Dunne, T. 2009. A mechanism of chute cutoff along large meandering rivers with uniform floodplain topography. Geological Society of America Bulletin 122: 855–869. Cooper, R., Peterson A. and Blench T. 1973. Critical review of sediment transport experiments. Proceedings of the American Society of Civil Engineers, Vol. 98, No. HY5. May 1972. Cubasch, U., Meehl, G.A., Boer, G.J., Stouffer, R.J., Dix, M., Noda, A., Senior, C.A., Raper, S., and Yap, K.S. (eds) 2001. Projections of future climate change. Cambridge University Press, Cambridge, United Kingdom. Dumanski, S., Pomeroy, J. W., and Westbrook, C. J. 2015. Hydrological regime changes in a Canadian Prairie basin. Hydrological Processes 29: 3893–3904. Dunne, T., Constantine, J.A., and Singer, M.B. 2010. The role of sediment transport and sediment supply in the evolution of river channel and floodplain complexity. Transactions, Japanese Geomorphological Union 31: 155–170. Farjan, B., Gupta, A., and Marceau, D.J. 2016. Annual and seasonal variations of hydrological processes under climate change scenarios in two sub-catchments of a complex watershed. Water Resources Management, 30(8): 2851-2865.
Appendix A_Hydrotechnical Assessment Methodology A-25 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Ferguson, R.I. 2003. The missing dimension: effects of lateral variation on 1-D calculations of fluvial bedload transport. Geomorphology 56: 1-14. Fleming, S.W. and Barton, M. 2015. Climate trends but little net water supply shift in one of Canada’s most water stressed regions over the last century. Journal of the American Water Resources Association 51: 833-841. Fuller, I.C. 2007. Geomorphic work during a “150-Year” storm: contrasting behaviors of river channels in a New Zealand catchment. Annals of the Association of American Geographers 97(4): 665-676. Galay, V.J., Yaremko, E.K., and Quazi, M.E. 1987. River bed scour and construction of stone rip rap protection. In: Sediment Transport Gravel Bed Rivers. Edited by: C.R. Thorne, J.C. Bathurst and R.D. Hey. John Wiley and Sons Ltd., p. 353-382. Gilleland, E. and Katz, R.W. 2006. Analyzing Seasonal to Interannual Extreme Weather and Climate Variability with the Extremes Toolkit. Research Applications Laboratory, National Center for Atmospheric Research. Gilleland, E. 2016. Package ‘extRemes’ Extreme Value Analysis [software package]. Version 2.0-8. CRAN. Available from: https://cran.r-project.org/web/packages/extRemes/extRemes.pdf Gregory, J.M., Mitchell, J.F.B., and Brady, A.J. 1997. Summer drought in northern midlatitudes in a time-dependent CO2 climate experiment. Journal of Climate 10: 662-686. Harder, P., Pomeroy, J.W., and Westbrook, C.J. 2015. Hydrological resilience of a Canadian Rockies headwaters basin subject to changing climate, extreme weather, and forest management. Hydrological Processes 29: 3905-3924. Haschenburger, J.K. and Wilcock, P.R. 2003. Partial transport in a natural gravel bed channel. Water Resources Research 39(1): 1020. Hatcher, K.L. and Jones, J.A. 2013. Climate and streamflow trends in the Columbia River Basin: evidence for ecological and engineering resilience to climate change. Atmosphere-Ocean, 51(4): 436-455. Indian Roads Congress. 1966. Standard Specifications and Code of Practice for Bridges. India. Ireson, A. M., Barr, A. G., Johnstone, J. F., Mamet, S. D., van der Kamp, G., Whitfield, C. J., Michel, N. L., North, R. L., Westbrook, C. J., DeBeer, C., Chun, K. P., Nazemi, A., and Sagin, J. 2015. The changing water cycle: The Boreal Plains ecozone of Western Canada. WIRES Water doi: 10.1002/wat2.1098. Konrad, C.P. 2012. Reoccupation of floodplains by rivers and its relation to the age structure of floodplain vegetation. Journal of Geophysical Research 117: G00N13. Lacey, G. 1930. Stable Channels in Alluvium. In Proceedings of the Institution of Civil Engineers. Volume 229.
Appendix A_Hydrotechnical Assessment Methodology A-26 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Leopold, L.B., Wolman, M.G., and Miller, J.P. 1964. Fluvial Processes in Geomorphology. San Francisco: W.H. Freeman. Li, T., and Hélie, R. 2014. Ecozones of Canada. Update Version – 2014.02. 1:1,000,000. Canadian Council on Ecological Areas (CCEA). Lindley, E.S. 1919. Regime Channels. Proceedings, Punjab Engineering Congress, 7. Lindley, E.S. 1919. Regime channels. In Proceedings of the Punjab Engineering Congress, Lahore, Pakistan, Vol. 7. pp. 63-74. Loukas, A., and Quick, M.C. 1999. The effect of climate change on floods in British Columbia. Nordic Hydrology 30: 231-256. Loukas, A., Vasiliades, L., and Dalezios, N.R. 2002. Potential climate change impacts on flood producing mechanisms in southern British Columbia, Canada using the CGCMA1 simulation results. Journal of Hydrology 259: 163–188. McParland, D.J., Eaton, B. and Rosenfeld, J. 2014. At-a-station hydraulic geometry simulator. River Research and Applications, doi:10.1002/rra. Mekis, É., and Vincent, L.A. 2011. An overview of the second generation adjusted daily precipitation dataset for trend analysis in Canada. Atmos Ocean 49: 163–177. Merritt, W.S., Younes, A., Barton, M., Taylor, B., Cohen, S., and Neilsen, D. 2006. Hydrologic response to scenarios of climate change in subwatersheds of the Okanagan basin, British Columbia. Journal of Hydrology 326: 79-108. Neill, C.R. 1964. River-bed Scour: A Review for Bridge Engineers. Research Council of Alberta. Canadian Good Roads Association. Technical Publication No. 23. pp.47. Neill, C.R. [Editor]. 1973. Guide to Bridge Hydraulics. University of Toronto Press, Toronto, Canada. Northwest Hydraulic Consultants Ltd. 1973. Hydraulic model study of scour in gravel-bed rivers. Report prepared for Alyeska Pipeline Service Company. April 1973. Olson P., Legg, N., Abbe, T., and Reinhardt, M., 2014. A methodology for delineating planning- level channel migration zones. Publication no. 14-06-025, Washington State Department of Ecology, Olympia, Washington. Pemberton, E.L. and Lara, J.M. 1984. Computing degradation and local scour. Technical Guideline for Bureau of Reclamation, Denver, Colorado, United States. Pitlick, J. 1994. Relation between peak flows, precipitation, and physiography for five mountainous regions in the western USA. Journal of Hydrology 158: 219-240. Schindler, D.W., and Donahue, W.F. 2006. An impending water crisis in Canada's western prairie provinces. Proceedings of the National Academy of Science USA 103: 7210-7216.
Appendix A_Hydrotechnical Assessment Methodology A-27 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Schnorbus, M., Werner, A., and Bennett, K. 2014. Impacts of climate change in three hydrologic regimes in British Columbia, Canada. Hydrological Processes 28: 1170-1189. Schumm, S. A. 2005. River Variability and Complexity. Mussetter Engineering, Inc., USA. Cambridge University Press. Chapter 3, pp 31. Shields, I.A. 1936. Application of similarity principles and turbulence research to bed-load movement. United States Department of Agriculture Soil Conservation Service, Pasadena, California. Shook, K. and Pomeroy, J. 2012. Changes in hydrological character of rainfall on the Canadian prairies. Hydrological Processes 26: 1752-1766. Slingerland, R. and Smith, N.D. 2004. River avulsions and their deposits. Annual Review of Earth and Planetary Sciences 32: 257-285. Slingerland, R., and Smith, N.D. 1998. Necessary conditions for a meandering-river avulsion: Geology 26, p. 435, doi: 10.1130/0091-7613(1998). Transportation Association of Canada. 2004. Guide to Bridge Hydraulics, 2nd ed. Thomas Telford Publishing, London, U.K. Taylor, B., and Barton, M., 2004. Chapter 4. Climate. In Cohen, S., Neilsen, D., and Welbourn, R. (Eds.) Expanding the dialogue on climate change and water management in the Okanagan Basin, British Columbia, Final Report, 24–45. Veldman, W. 2008. Pipeline Geo-Environmental Design and Geohazard Management. Chapter 3, Open Cut and Elevated River Crossings. Edited by Moness Rizkalla. ASME. Whitfield, P.H. 2001. Linked hydrologic and climate variations in British Columbia and Yukon. Environmental Monitoring and Assessment 67: 217-238. Whitfield, P.H., and Pomeroy, J.W. 2016. Changes to flood peaks of a mountain river: implications for analysis of the 2013 flood in the Upper Bow River, Canada. Hydrological Processes, 30(25): 4657–4673. doi:10.1002/hyp.10957. Wilcock, P.R. and Crowe, J.C. 2003. Surface-based transport model for mixed-size sediment. Journal of Hydraulic Engineering 129: 120-128. Wolfe, B.B., Hall, R.I., Last, W.M., Edwards, T.W.D., English, M.C., Karst-Riddoch, T.L., Paterson, A., and Palmini, R. 2006. Reconstruction of multi-century flood histories from oxbow lake sediments, Peace-Athabasca Delta, Canada. Hydrological Processes 20: 4131–4153. Wolman, M. 1954. A method of sampling coarse river-bed material. Transactions of the American Geophysical Union 35(6): 951-956. Yaremko, E.K., and Cooper, R.H. 1983. Influence of Northern Pipelines on River Crossing Design. In: Pickell, M.B. (Ed.). Proceedings of the Conference on Pipelines in Adverse Environments II, American Society of Civil Engineers. San Diego, California, November 14-16, 1983. pp. 49-63.
Appendix A_Hydrotechnical Assessment Methodology A-28 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
Zwiers, F.W., Schnorbus, M.A., and Maruszeczka, G.D. 2011. Hydrologic impacts of climate change on BC water resources. Summary Report for the Campbell, Columbia and Peace River Watersheds. Pacific Climate Impacts Consortium.
Appendix A_Hydrotechnical Assessment Methodology A-29 BGC ENGINEERING INC. Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
APPENDIX B BGC BOREHOLE LOGS
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek BGC ENGINEERING INC. SYMBOLS AND TERMS FOR SOIL DESCRIPTIONS ON BOREHOLE LOGS
Project Name: Trans Mountain Expansion Project Project Number: 0095-150-14 USCS CLASSIFICATION (1) PROPORTION OF MINOR COMPONENTS (4) GROUP GROUP NAME BY WEIGHT MAJOR DIVISIONS SYMBOL “and” > 35% Coarse Clean gravel Well graded gravel, fine Gravel GW “y/ey” 20% to 35% grained <5% smaller to coarse gravel > 50% of “Some” 10% to 20% soils — than No. 200 coarse fraction Poorly graded gravel more sieve GP “Trace” > 0% to 10% retained on No. than 50% 4 (4.75 mm) Gravel with GM Silty gravel (2) retained PARTICLE SHAPE sieve >12% fines GC Clayey gravel on No. Flat Particles with width/thickness > 3 200 Clean sand SW Well graded sand, fine Particles with length/width > 3 (0.075 Sand to coarse sand Elongated >= 50% of < 5% passes Flat and Particles that meet both criteria mm) No. 200 sieve SP Poorly graded sand sieve coarse fraction Elongated passes No. 4 Silty sand Sand with SM (2) sieve >12% fines SC Clayey sand ANGULARITY Fine ML Silt Angular Particles have sharp edges and rela- Inorganic tively planar sides with unpolished grained Silt and clay CL Clay soils — surfaces. Liquid limit < 50 OL Organic silt, organic more Organic Particles are similar to angular de- than 50% clay Subangular passes MH High plasticity silt scription but have some rounded Silt and clay Inorganic edges. No. 200 CH High plasticity clay sieve Liquid limit Organic clay, organic Subrounded Particles have nearly planar sides but >= 50 Organic OH silt have well rounded corners and edg- Highly organic soils PT Peat es. (1) Rounded Particles have smoothly curved sides CLASSIFICATION BY PARTICLE SIZE and no edges. SIZE RANGE DENSITY OF GRANULAR SOILS(4) US STANDARD SIEVE SIZE DESCRIPTION SPT N FIELD (6, 9) IDENTIFICATION NAME (mm) (3) Retained Passing None Boulders >300 12 inch - “Very Loose” 0-4 Cobbles 75 - 300 3 inch 12 inch “Loose” 4-10 Easily penetrated by 13 mm Gravel: Coarse 19 - 75 0.75 inch 3 inch rod pushed by hand Fine 4.75 - 19 No. 4 0.75 inch “Compact” 10-30 Easily penetrated by 13 mm rod driven by hammer Sand: Coarse 2 - 4.75 No. 10 No. 4 Medium 0.43 - 2 No. 40 No. 10 “Dense” 30-50 Penetrated 0.3 m by 13 mm Fine 0.075 - 0.43 No. 200 No. 40 rod driven by hammer
Fines (Silt or Clay)(4) <0.075 - No. 200 “Very dense” >50 Penetrated few cm by 13 mm rod driven by hammer CONSISTENCY OF COHESIVE SOILS GRADE DESCRIPTION SPT UNDRAINED SHEAR FIELD IDENTIFICATION (8, 9) (7) “N” STRENGTH - “Su” kPa S1 “Very soft” <2 <12 Easily penetrated several cm by the fist. S2 “Soft” 2-4 12-25 Easily penetrated several cm by the thumb. S3 “Firm” 4-8 25-50 Can be penetrated several cm by the thumb with moder- ate effort. S4 “Stiff” 8-15 50-100 Readily indented by the thumb but penetrated only with great effort. S5 “Very Stiff” 15-30 100-200 Readily indented by the thumb nail. S6 “Hard” >30 >200 Indented with difficulty by the thumbnail. SYMBOLS AND TERMS FOR SOIL DESCRIPTIONS ON BOREHOLE LOGS
Project Name: Trans Mountain Expansion Project Project Number: 0095-150-14 PLASTICITY OF COHESIVE SOILS (10) DESCRIPTION SILT CLAY CRITERIA (10) High WL >50% WL >50% It takes considerable time rolling and kneading to reach the plastic limit. The thread can be rerolled several times after reaching the plastic limit. The lump can be formed without crumbling when drier than the plastic limit. (4) Intermediate - 30%< WL<50% The thread is easy to roll and not much time is required to reach the plastic limit. The lump crumbles when drier than the plastic limit.
Low WL<50% WL<30% The thread can barely be rolled and the lump cannot be formed when drier than the plastic limit. Non-Plastic NP - A 1/8 inch (3 mm) thread cannot be rolled at any water content. PLASTICITY OF COHESIVE SOILS(10) MOISTURE CONDITION (2) Description Criteria Dry Absence of moisture
Moist Damp but no visible water Wet Visible free water, usually soil is below water table
CEMENTATION (2) Description Criteria Weak Crumbles or breaks with handling or little pressure (12) DILATANCY Moderate Crumbles or breaks Description Criteria with considerable None No visible change in the spec-men during shaking or squeezing finger pressure Slow Water appears slowly on the surface of the specimen during shaking and disappears slowly upon squeezing Strong Will not crumble or break with finger Rapid Water appears quickly on the surface of the specimen during shaking pressure and disappears quickly upon squeezing
Notes: (1) ASTM D2487-11, Unified Soil Classification System (USCS). (2) ASTM D2488-09a. (3) Approximate metric conversion. (4) Canadian Foundation Engineering Manual (CFEM), 2006. (5) Fines are classified as silt or clay on the basis of Atterberg limits (refer to Plasticity Chart). (6) Standard Penetration Test (SPT) blow count uncorrected, after Terzaghi and Peck, 1948. (7) Undrained shear strength can be estimated by shear vane (gives Su), pocket penetrometer (gives unconfined compressive strength, qu = 2 * Su), or unconfined compression test (gives qu = 2 * Su). (8) Approximate correlation with Standard Penetration Test blow counts, after Terzaghi and Peck, 1948. (9) “R” represents sampler refusal during Standard Penetration Test. (10) This plasticity classification conforms to the Unified Soil Classification System (USCS) and to ASTM D-2487 (11) WL = Liquid Limit (%) (12) Test for dilatancy conducted by shaking and squeezing a moulded ball of soil that is 12 mm in diameter. (13) Test for dry strength conducted on natural soil pieces or moulded balls about 25 mm in diameter that have been dried at less than 60°C. SYMBOLS AND TERMS FOR SOIL DESCRIPTIONS ON BOREHOLE LOGS
Project Name: Trans Mountain Expansion Project Project Number: 0095-150-14 STRUCTURE (2) Soil Symbols Legend Description Criteria High Plastic Clay Low Plastic Clay Stratified Alternating layers of varying material or colour with layers at least 6 mm thick; note thickness Silt/Clay High Plastic Silt Laminated Alternating layers of varying material or colour with the layers less than 6 mm thick; note thickness Low Plastic Silt Clay/Sand Fissured Breaks along definite planes or fracture with little re- sistance to fracturing Slickensided Fracture planes appear polished or glossy, some- Silt/Sand Poorly-graded Sand times striated
Blocky Cohesive soil that can be broken down into small Well-graded Sand Clay/Gravel angular lumps which resist further breakdown
Lensed Inclusion of small pockets of different soils, such as Silt/Gravel Sand/Gravel small lenses of sand scattered through a mass of clay; note thickness Homogeneous Same colour and appearance throughout Well-graded Gravel Poorly-graded Gravel Heterogeneous Colour and appearance vary throughout High Plastic Organic Low Plastic Organic (2) SENSITIVITY Soil Soil St = Ratio of intact to remoulded strength Fill Peat/Topsoil St Sensitivity
St < 2 Low Sensitivity Boulders and Cobbles 2 < St < 4 Medium Sensitivity 4 < St < 8 Sensitive 8 < St < 16 Extra Sensitive Simplified Soil Symbols St > 16 Quick Clay Clay Sand DRY STRENGTH (2) Description Criteria(13) Silt Gravel None The dry specimen crumbles into powder upon applying pressure or handling Testing Results Legend Low The dry specimen breaks into pieces or crumbles with considerable finger pressure High The dry specimen cannot be broken with finger pres- sure. Specimen will break into pieces between thumb and a hard surface Very High The dry specimen cannot be broken between the thumb and a hard surface Sample Symbols SYMBOLS AND TERMS FOR ROCK DESCRIPTIONS ON BOREHOLE LOGS
Project Name: Trans Mountain Expansion Project Project Number: 0095-150-14
WEATHERING/ALTERATION (14) GRADE Description Field Identification A/W 1 Fresh and Unweathered No visible sign of rock material weathering A/W 2 Slightly Weathered or Discolouration indicated weathering of rock material and discontinuity surfaces. All Altered rock material may be discoloured by weathering and may be weaker than in its fresh condition. A/W 3 Moderately Weathered Less than 50% of rock material decomposed and/or disintegrated to soil. Fresh/ or Altered discoloured rock present as a continuous framework or corestones. A/W 4 Highly Weathered or More than 50% rock material is decomposed or disintegrated to soil. Fresh/ Altered Discoloured rock present as discontinuous framework or corestones. A/W 5 Completely Weathered All rock material decomposed and/or disintegrated to soil. Original mass structure or Altered still largely intact A/W 6 Residual Soil All rock material converted to soil; mass structure and material fabric destroyed. HARDNESS CLASSIFICATION FOR ROCK (15) GRADE Description Field Identification R6 Extremely Strong Specimen can only be chipped with flat end of geological hammer R5 Very Strong Specimen requires many blows of flat end of geological hammer to fracture R4 Strong Specimen requires more than one blow of flat end of geological hammer to fracture R3 Medium Strong Cannot be scraped or peeled with pocket knife; can be fractured with single firm blow of flat end of the geologic hammer R2 Weak Can be peeled with pocket knife with difficulty; shallow indentation made by firm blow with point of geological hammer R1 Very Weak Crumbles under firm blow with point of geological hammer; can be peeled by a pocket knife R0 Extremely Weak Indented by thumbnail JOINT CONDITION(16) Condition of Joints Rating Very rough surfaces. Not continuous. No 25 separation. Hard joint wall rock. Slightly rough surfaces. Separation 20 <1mm. Hard joint wall rock. Slightly rough surfaces. Separation 12 <1mm. Soft joint wall rock. Slickensided surfaces or gouge <5mm 6 thick or joints open 1-5mm. Continuous joints. Soft gouge >5mm thick or joints open 0 >5mm. Continuous joints. (14) After ISRM, 1981. (15) ISRM, 1977 (16) Joint condition is a numerical index that summarizes the typical surface properties and infilling of discontinuities within an interval (Bieniawski, 1976). SYMBOLS AND TERMS FOR ROCK DESCRIPTIONS ON BOREHOLE LOGS
Project Name: Trans Mountain Expansion Project Project Number: 0095-150-14
Lithological Graphic Log Legend Texture (14) Rock Term Particle Size Examples Very Coarse > 60 mm Porphyritic Shale Sandstone Coarse 2 - 60 mm Breccia, Gneiss (measurable grains) Medium 0.06 - 2 mm Sandstone, Gabbro, Granite, Schist Coal, Lignite Breccia (visible grains) Fine 0.002 - 0.06 mm Tuff, Siltstone, Claystone, Mudstone, Siltstone Mudstone Very Fine < 0.002 mm Basalt Fabric Conglomerate Limestone Term Description Homogeneous/ Equigranular or homogeneous grains Granite Rhyolite Uniform Bedded Deposited in layers, can be sedimentary or volcaniclastic rocks Dolomite Chalk Foliated Minerals are aligned due to shearing or metamorphism Gneissic Alternating layers of different colour or texture with mineral Chert, Flint Halite alignment and typically parts along layers Porphyritic Crystalline texture with bimodal grain size distribution, fine to medium grained groundmass with coarse to very coarse Gypsum Anhydrite phenocrysts Stockwork Veins (typically quartz, calcite, or gypsum/anhydrite) make up greater than 10% of the rock mass, they may be aligned Diorite, Syenite Andesite, Trachyte with foliation or irregularly oriented Microfractured Hairline fractures are the primary fabric of the rock, typically oriented in all directions and intersecting one another Gabbro Basalt Brecciated Healed or welded angular clasts with matrix, may be matrix – or clast-supported
Peridotite Granite Porphyry, (17) Felsite Rock Mass Rating
Porphyrite, Porphyry Dolerite/Diabase RMR Rock Quality 81-100 Very Good Slate, Phyllite Schist 61-80 Good
Migmatite Gneiss 41-60 Fair
21-40 Poor Quartzite Serpentinite 0-20 Very Poor
Marble Amphibolite, Eclogite
(17) The Rock Mass Rating (RMR) system, published by Bieniawski (1976) classifies Fault Zone Bedrock rock on a linear scale of 0-100 based on the sum of the ratings given to five parameters. The five parameters are: rock quality designation, facture intercept, joint condition, intact strength, and groundwater conditions. For core logging purposes, the value of the groundwater condtions parameter is assumed to be 10. The sum of the rating may then be used to assess the quality of the rock based on the classification table. SYMBOLS AND TERMS FOR ROCK DESCRIPTIONS ON BOREHOLE LOGS
Project Name: Trans Mountain Expansion Project Project Number: 0095-150-14
REFERENCES
American Society for Testing and Materials. Standard D2487-11: Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System). West Conshohocken, PA. American Society for Testing and Materials. Standard D2488-09a: Standard Practice for Description and Identification of Soils (Visual-Manual Procedure). West Conshohocken, PA.
Bieniawski, Z.T. 1976. Rock Mass Classification in Rock Enginereing. Proceedings of the Symposium on Exploration for Rock Engineering. Cape Town, Balkema, 1, 97-106. Canadian Geotechnical Society 2006. Canadian Foundation Engineering Manual 4th Edition. pp. 488. International Society of Rock Mechanics (ISRM). 1977. International Society for Rock Mechanics Com- mission of Standardization of Laboratory and Field Tests: Suggested Methods for the Quantitative Description of Discontinuities in Rock Masses. Committee on Field Tests, Document No. 4, pp. 319-368. International Society of Rock Mechanics (ISRM). 1981. International Society for Rock Mechanics: Com- mission of Classification of Rocks and Rock Masses, Basic Geotechnical Description of Rock Masses. International Journal of Rock Mechanics, Mineral Science, and Geomechanics. Vol. 18, pp. 85-110. Terzaghi, K., and Ralph B. Peck, 1948, Soil Mechanics in Engineering Practice, John Wiley and Sons, New York
Revision: June 11, 2015 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 1 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 0 SILT (ML) Clayey, trace sand, low plasticity, stiff, brown, no odour, moist, homogeneous, weak cementation, low dry strength, no dilatancy, roots and organic material. [ANTHROPOGENIC/FILL] CLAY (CL) SPT 01 silty, sandy, low plasticity, stiff, light brown, no odour, moist, 4 1 homogeneous, weak cementation, low dry strength, no dilatancy. 5 [GLACIOLACUSTRINE] 7 SPT 01 - Recovered 0.10 m.
2
SPT 02 - Recovered 0.38 m. SPT 02 3 5 4 3
3.66 - 4.57 m - 15% loss of circulation.
4 SPT 03 - Recovered 0.37 m. Changes to trace to some clay, firm, blocky SPT 03 0 and fissured, strong cementation, low to medium dry strength. 3 4
5 SPT 04 - Recovered 0.60 m. Changes to weak cementation. Grainsize SPT 04 distribution: 0.1% gravel, 20.3% sand, 79.6% fines. 0 2 4 6
6.71 - 8.23 m - 50% loss of circulation. 7 SPT 05 SPT 05 - Recovered 0.60 m. 1 2 3
8 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 2 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 8
SPT 06 - Recovered 0.60 m. Trace gravel. SPT 06 8.23 - 9.75 m - 70% loss of circulation. 3 5 6 9
SPT 07 - Recovered 0.48 m. Grainsize distribution: 4.5% gravel, 33.7% 10 SPT 07 sand, 43.6% silt, 18% clay. 4 9.75 m - Gained back 100% circulation. 5 7
11
SPT 08 - Recovered 0.60 m. Very stiff, blocky, medium dry strength. SPT 08 5 9 7 12
SPT 09 - Recovered 0.50 m. Changes to grey brown, homogeneous. 13 SPT 09 3 7 8
14
SPT 10 20 SPT 10 - No Recovery. 26 24
15
16 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 3 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 16 SPT 11 SPT 11 - Recovered 0.35 m. Fine SAND(SP) lenses 5 cm thick, very 4 hard dry strength. 7 8
17
SPT 12 Interbedded SANDSTONE, SILTSTONE, and MUDSTONE, 20 >> SANDSTONE, fine to medium grained, bedded, dark brown to grey, 34 slightly weathered, extremely weak (RO), close to moderate joint spacing, R 1-2 joint sets, some silt infill. 18 SILTSTONE, very fine to fine grained, bedded, dark grey, highly weathered, extremely weak (RO), close to moderate joint spacing, 1-2 joint sets, some silt infill. MUDSTONE, very fine grained, bedded, dark grey, highly weathered, extremely weak (RO), close to moderate joint spacing, 1-2 joint sets, some silt infill. 19 SPT 13 From 17.3 to 22 m the material is weathered and extremely weak (R0). 41 >> SPT 12 - Recovered 0.30 m - SILT (ML) Sandy, trace to some clay, trace 50 gravel, low plasticity, hard, grey brown, no odour, moist, slightly blocky to R homogeneous, strong cementation, medium dry strength, no dilatancy. 18.28 - 28.04 m - Had to re-ream hole, due to squeezing in of materials. SPT 13 - Recovered 0.26 m. Changes to dry, grey, no gravel. 20
SPT 14 - Recovered 0.40 m. Clay, high plasticity, hard (S6), grey, dry to moist, weak cementation. Grainsize distribution: 22.6% sand, 77.4% SPT 14 fines. 50 >> 50 R 21
22 SPT 15 39 R
23
SPT 16 - Recovered 0.50 m. SPT 16 20 >> 37 24 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 4 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 24 R
25 SPT 17 SPT 17 - Recovered 0.20 m. Coal seam approximately 1 cm thick R
26
SPT 18 SPT 18 - Recovered 0.31 m. 28 R 27
28 SPT 19 SPT 19 - Recovered 0.20 m. 50 R
29
SPT 20 - Recovered 0.41 m. SPT 20 40 >> 40 30 R
31 SPT 21 SPT 21 - Recovered 0.30 m. 32 >> 50 R
32 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 5 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 32
SPT 22 SPT 22 - Recovered 0.19 m. R
33
34 SPT 23 SPT 23 - Recovered 0.18 m. R
35
SPT 24 SPT 24 - Recovered 0.18 m. R 36
37 R SPT 25 SPT 25 - Recovered 0.10 m.
38
SPT 26 SPT 26 - Recovered 0.17 m. R 39
40 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 6 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 40 R SPT 27 Interbedded SILTSTONE, and SANDSTONE SILTSTONE, very fine to fine grained, bedded, dark grey, slightly weathered to fresh, weak (R2), close to moderate joint spacing, 1-2 joint sets, some silt infill. 41 SANDSTONE, fine to medium grained, bedded, dark brown to grey, slightly weathered, extremely weak (RO) to weak (R2), close to moderate joint spacing, 1-2 joint sets, some silt infill. SPT 27 - Recovered 0.10 m. 40.23-45.57 m - Siltstone, very stiff.
42
43
44
45
45.57-48.62 m - Sandstone, extremely weak.
46
47
48 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 7 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 48
RC 1 48.3-48.5 m - Unconfied Compressive Strength test completed on core by Golder Ltd.. Sample properties were 61 mm diameter, 125 mm height, wet density 2152 kg/m3, 6.9% moisture content. Maximum load was 32.1 kN, stress was 11.1 MPa. Failure mode was a diagonal shear plane at 24 49 degrees from the core axis. Borehole completed at target depth of 48.6 m below ground surface. Borehole grouted to surface with bentonite grout. No instrumentation installed.
SPT Sampler Details: 60 cm (24") length, 5 cm (2") diameter, driven by automatic trip hammer. All SPT sampling was carried out in accordance 50 with ASTM D1586.
Borehole coordinates acquired by a Garmin GPSMAP 62s handheld GPS.
Pocket penetrometer tests conducted on base of SPT sample when 51 possible and on opened face of SPT sample as appropriate. Elevation based on LiDAR provided by UPI, dated September 16, 2014.
Groundwater observed at a depth of 16.2 m below ground surface on June 29, 2014 with the drill hole at a final depth of 48.6 m, while casing was installed to 40.5 m depth. 52 HWT casing was installed to a depth of 40.5 m due to some loss of circulation and wall squeezing.
53
54
55
56 TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-02 Page 1 of 4 Location: Blackmud Creek - West Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 30 Jun 14 Co-ordinates (m): 332,928E, 5,923,355N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 28.0 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 16.70 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.5 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 0 CLAY (CL) silty, trace sand, low plasticity, stiff, light brown, no odour, dry, blocky, weak cementation, low dry strength, no dilatancy. [GLACIOLACUSTRINE]
>> 1 SPT 01 - Recovered 0.36 m. SPT 01 3 4 6
2
SPT 02 - Recovered 0.55 m. SPT 02 3 5 3 5
SPT 03 - Recovered 0.53 m. Lenses of 5 cm thick blocky soft SILT(ML), SPT 03 changes to homogeneous and firm. 0 4 2 2
5
SPT 04 - Recovered 0.61 m. Changes to soft, wet, homogeneous, SPT 04 moderate cementation, moderate dry strength, slow dilatancy. Grainsize 0 distribution: 10.8% sand, 89.2% fines. 1 6 2
7 SPT 05 - Recovered 0.60 m. Changes to trace sand, firm, lenses of coal SPT 05 3 cm thick. 2 3 5
8 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-02 Page 2 of 4 Location: Blackmud Creek - West Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 30 Jun 14 Co-ordinates (m): 332,928E, 5,923,355N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 28.0 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 16.70 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.5 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 8
SPT 06 - Recovered 0.57 m. Changes to some sand, trace gravel. Some SPT 06 SAND (SP-SM) lenses 0.5 cm thick. 3 10 9 12
10 SPT 07 - Recovered 0.60 m. Changes to lenses of rust coloured SPT 07 SAND(SP) 1 cm thick, some gravel, fragments of coal 5 mm in diameter. 7 10 12
11
SPT 08 - Recovered 0.60 m. SPT 08 9 12 SAND (SC) 13 Fine to medium grained, clayey, silty, poorly graded, dense, max. particle 13 size < 1mm, subangular, light grey, no odour, dry, homogeneous, moderate cementation, fragments of coal 5 mm in diameter. [GLACIOLACUSTRINE]
13 SPT 09 - Recovered 0.53 m. Changes to very dense. Grainsize SPT 09 distribution: 60.7% sand, 39.3% fines. 12 19 32
14
SPT 10 - Recovered 0.45 m. Changes to compact to dense. SPT 10 10 15 15 15
4 16 SPT 11 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-02 Page 3 of 4 Location: Blackmud Creek - West Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 30 Jun 14 Co-ordinates (m): 332,928E, 5,923,355N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 28.0 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 16.70 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.5 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 16 SPT 11 - Recovered 0.17 m. Lenses of SILT(ML) 1 cm thick. 7 9
17
SPT 12 - Recovered 0.60 m. Grainsize distribution: 18.7% sand, 81.3% SPT 12 fines. 8 Interbedded MUDSTONE, SILTSTONE, and SANDSTONE 37 31 18 MUDSTONE, slightly weathered to fresh, extremely weak (RO) to weak (R2), light to dark grey, fine, bedded, moderately fractured. SILTSTONE, slightly weathered to fresh, extremely weak (RO) to weak (R2), light to dark grey, fine, bedded, moderately fractured. SANDSTONE, slightly weathered to fresh, extremely weak (RO) to weak (R2), light to dark grey, medium grained, bedded to massive, moderately fractured. 19 17.4 to 22.5 m logged as a soil. Rock strength generally increased with depth. RC 1 18.07 m - Lenses of SAND(SP-SM) 5 cm thick.
20
21
22
23
>> 24 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18 Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-02 Page 4 of 4 Location: Blackmud Creek - West Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 30 Jun 14 Co-ordinates (m): 332,928E, 5,923,355N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 28.0 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 16.70 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.5 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 24
25
26
27
28 Borehole completed at target depth of 28.04 m below ground surface. Borehole grouted to surface with bentonite grout. No instrumentation installed.
SPT Sampler Details: 60 cm (24") length, 5 cm (2") diameter, driven by automatic trip hammer. All SPT sampling was carried out in accordance 29 with ASTM D1586.
Borehole coordinates acquired by a Garmin GPSMAP 62s handheld GPS.
Pocket penetrometer tests conducted on base of SPT sample when 30 possible and on opened face of SPT sample as appropriate. Elevation based on LiDAR provided by UPI, dated September 16, 2014.
Groundwater observed at a depth of 7.9 m below ground surface on July 1, 2014 with the drill hole at a final depth of 28.0 m, while casing was installed to 16.7 m depth. 31 No loss of circulation noted.
HWT casing was installed to a depth of 16.7 m due to some wall collapse in the sand bedding layer noted and overall borehole stability for several metres above the bedrock contact. 32 TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18 Trans Mountain Pipeline ULC, Trans Mountain Expansion Project March 29, 2018 Geotechnical HDD Feasibility Assessment, Blackmud Creek at SSEID 005.5 KP 24.2 Project No.: 0095150-14
APPENDIX C LABORATORY TEST RESULTS
0095-150-14 HDD Geotechnical Feasibility Report - Blackmud Creek BGC ENGINEERING INC. SIZE OF OPENING (in) U.S. STANDARD SIEVE SIZE 3 3 " 24" 12" 6" 4" 3" 1" /4" /8 #4 #6 #10 #20 #40 #100 #200 100
90
80
70
60
50 f r 40 2018.g _ GSA PERCENT FINER THAN FINER PERCENT _ 30 eek\BM r 20
10
0 1000 100 10 1 0.1 0.01 0.001 0.0001 GRAINSIZE (mm)
GRAVEL SAND BOULDER COBBLE FINES
oject\04 Assessment\labHDD data\Blackmud C COARSE FINE COARSE MEDIUM FINE r
NOTE: Material classification plotted according to the Unified Soil Classification System (USCS). Testing completed by Shelby Engineering Ltd. gan\150 - TMEP Pipeline P PipelineTMEP gan\150 -
r NTS SZ GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - Mo r MARCH 2018 SAA BLACKMUD CREEK AT SSEID 005.5 KP 24.2 BGC ENGINEERING INC. GRAIN SIZE ANALYSIS RESULTS NW LDM BGC AN APPLIED EARTH SCIENCES COMPANY BH-BGC14-BM-01, & -02 DWG TO BE READ WITH BGC REPORT TITLED ojects\0095 Kinde r "GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - BLACKMUD CREEK AT SSEID 005.5 KP 24.2", DATED C-01 0 MARCH 2018 N:\BGC\P 50
40
30 f r
g_2018.g 20 r be r PLASTICITY INDEX (%) PLASTICITY eek\BM_Atte r 10
0 0 102030405060708090100 LIQUID LIMIT (%) oject\04 HDD Assessment\lab data\Blackmud C data\Blackmud Assessment\lab HDD oject\04 r
NOTE: Testing completed by Shelby Engineering Ltd. gan\150 - TMEP Pipeline P Pipeline TMEP - gan\150 r NTS SZ GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - Mo r BLACKMUD CREEK AT SSEID 005.5 KP 24.2 MARCH 2018 SAA BGC ENGINEERING INC. LDM ATTERBERG LIMIT ANALYSIS RESULTS NW BGC AN APPLIED EARTH SCIENCES COMPANY BH-BGC14-BM-01 AND BM-02 DWG TO BE READ WITH BGC REPORT TITLED ojects\0095 Kinde ojects\0095 r "GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - BLACKMUD CREEK AT SSEID 005.5 KP 24.2", DATED C-02 0 MARCH 2018. N:\BGC\P
Golder Associates Ltd. - Burnaby Lab #300 - 3811 North Fraser Way Burnaby, B.C. Canada V5J 5J2
Reference Unconfined Compressive Strength of Intact Rock Core Specimens ASTM D7012-14 Method C Project No.: 1408883 Failure Mode Project: Trans Mountain Expansion Project (1) Diagonal shear plane(s) (5) Conical Client: BGC Engineering Inc. (2) Vertical fracture(s) (6) Spalling Location: Not Provided (3) Vertical splitting (7) Other Lab ID 244 (4) Shear along foliation / discontinuit Note: (deg) measured from core axis Wet Dry Maximum Stress No. Borehole Sample Depth Dia Ht A V Mass Density W Density Load V Rock Type Failure Mode # # (m) (mm) (mm) (cm2)(cm3) (g) (kg/m3) (%) (kg/m3) (kN) (MPa) Type (deg) 1 BH-BGC14-BM-01 1 48.30-48.50 60.63 124.59 28.87 359.66 774.30 2153 6.89 2014 32.11 11.1 Not Provided 1 24
2 BH-BGC14-BM-02 2 19.23-19.39 Sample received broken - not suitable for testing
3 BH-BGC14-LB-01 3 28.66-28.91 60.34 129.01 28.59 368.86 788.60 2138 4.90 2038 56.40 19.7 Not Provided 1/5 14
4** BH-BGC14-LB-02 4 32.45-32.72 60.35 126.45 28.60 361.67 786.30 2174 4.57 2079 111.30 38.9 Not Provided 6/2 N/A
5 BH-BGC14-WLF-01 5 40.08-40.33 60.41 126.43 28.67 362.41 751.00 2072 3.11 2010 57.60 20.1 Not Provided 1 19
6 BH-BGC14-WLF-02 6 42.90-43.20 60.35 128.10 28.60 366.40 777.90 2123 5.03 2021 46.80 16.4 Not Provided 114
7 BH-BGC14-LB-02 7 19.55-19.78 Sample received broken - not suitable for testing
Note: ** UCS 07 arrived broken, UCS 04 selected as replacement
G. Patton August 22, 2014 E. Kostyukov August 25, 2014 TESTED BY DATE CHECKED BY DATE Golder Associates Ltd. - Burnaby Lab #300 - 3811 North Fraser Way Burnaby, B.C. Canada V5J 5J2
Reference Unconfined Compressive Strength of Intact Rock Core Specimens ASTM D7012-14 Method C Project No.: 1408883 Borehole: BH-BGC14-BM-01 Project: Trans Mountain Expansion Project Sample Number: 1 Location: Not Provided Depth (m): 48.30-48.50 Client: BGC Engineering Inc. Lab ID No: 244
Testing Results Sample Measurements
Max Load (kN) 32.11 Diameter (mm) 60.63 Height (mm) 124.59 6WUHVVı 03D 11.1 Area (cm2) 28.87 Volume (cm3) 359.66 Pace Rate (kN/s) N/A Mass (g) 774.30 Moisture Content (%) 6.89 Lithology Not Provided Wet Density (kg/m3) 2152.88 Dry Density (kg/m3) 2014.11
Failure Mode Notes
- Water content as received Type: 1 Mode: (1) Diagonal shear plane(s) BEFORE TEST Degrees:*24 (2) Vertical fracture(s) (3) Vertical splitting (4) Shear along foliation /discontinuity (5) Conical * Degrees measured with respect to (6) Spalling core axis. (7) Other
Comments
* The test data given herein pertain to the sample provided only. This report constitutes a testing service only. Interpretation of the data given here may be AFTER TEST provided upon request.
G. Patton August 22, 2014 E. Kostyukov August 25, 2014
TESTED BY DATE CHECKED BY DATE
\\golder.gds\gal\Burnaby\Active\_2014\1417\1408883 BGC Trans Mountain Expansion\UCS\BGC UCS (2)
Trans Mountain Expansion 19731-506-RPT-00079 Project
Feasibility Report for the Rev Date Blackmud Creek Crossing 0 04/27/2018
Table of Contents 1.0 INTRODUCTION...... 1 2.0 SITE VISIT ...... 1 3.0 GEOTECHNICAL INVESTIGATIONS ...... 1 4.0 REVIEW OF AVAILABLE WATERCOURSE CROSSING METHODOLOGIES...... 1 4.1 Horizontal Directional Drill...... 1 4.2 Direct Pipe® ...... 2 4.3 Bore...... 2 4.4 Isolated Crossing Techniques ...... 2 4.5 Open Cut...... 2 5.0 GEOTECHNICAL/GEOPHYSICAL PROGRAM ...... 3 6.0 CROSSING DESIGN ...... 3 6.1 Primary Crossing Method - HDD Crossing Design...... 3 6.2 Contingency Crossing Method - Isolated In-stream Crossing Design...... 4 7.0 RECOMMENDATIONS...... 4
Appendices A. Appendix A – Abbreviations and Acronyms...... A-1 B. Appendix B – Mean Monthly Flows for Blackmud Creek...... B-1 C. Appendix C – Geotechnical Borehole Logs at Blackmud Creek ...... C-1 D. Appendix D – Interpreted Geological Section at Blackmud Creek ...... D-1 E. Appendix E – HDD Crossing Plan and Profile, Blackmud Creek...... E-1 F. Appendix F – Calculated Fracture Pressure for Blackmud Creek ...... F-1 G. Appendix G – Blackmud Creek - Contingency Design ...... G-1
Combined PDF Pages Page 3 of 31 Pages Trans Mountain Expansion 19731-506-RPT-00079 Project
Feasibility Report for the Rev Date Blackmud Creek Crossing 0 04/27/2018
Disclaimer
This report represents the work of UniversalPegasus International (UPI) performed to recognized engineering principles and practices appropriate for engineering work and the terms of reference provided by UPI’s contractual Customer. This report may not be relied upon for any other purpose not specifically identified within this report. This report is confidential and prepared solely for the use of the Customer. The contents of this report may not be used or relied upon by any party other than the Customer, and neither UPI, its sub- consultants nor their respective employees assume any liability for any reason, including, but not limited to, negligence, to any other party for any information or representation herein. The extent of any warranty or guarantee of this report or the information contained therein in favour of the Customer is limited to the warranty or guarantee, if any, contained in the contract between the Customer and UPI.
Combined PDF Pages Page 4 of 31 Pages Trans Mountain Expansion 19731-506-RPT-00079 Project
Feasibility Report for the Rev Date Blackmud Creek Crossing 0 04/27/2018
1.0 INTRODUCTION UniversalPegasus International (UPI) has been retained by Kinder Morgan Canada Inc. (KMC) to undertake the routing and engineering design for the Trans Mountain Expansion Project (TMEP) pipeline. As part of this work, a number of watercourse crossings have been identified as potential candidates for a trenchless crossing methodology. This report evaluates the Blackmud Creek Crossing KP 24.2 SSEID 005.5 with the intent of determining the feasibility of an HDD. The applicability of several other crossing methodologies has been considered in this study. The purpose of this feasibility report is to evaluate existing information and the results of the geotechnical and geophysical investigations that have been completed at Blackmud Creek for the TMEP, in order to provide an assessment of the feasibility of the selected crossing methodology for this crossing. Appendix A lists the abbreviations and acronyms used in this report.
2.0 SITE VISIT Site visits and investigations were carried out at the Blackmud Creek Crossing by BGC Engineering Inc. (BGC) in June 2014 to ascertain an understanding of the subsurface conditions at this site.
3.0 GEOTECHNICAL INVESTIGATIONS As part of the HDD feasibility evaluation process BGC has completed geotechnical and geophysical investigations at several major water crossing locations, specifically to determine which of the trenchless technologies could be a viable crossing methodology at these locations. BGC issued the “Geotechnical HDD Feasibility Blackmud Creek at SSEID 005.5 KP 24.2” (KMC Document #01-13283-S1-0000-PL-RPT-0034 R0) on March 29th, 2018, which detailed the results and recommendations from their investigations at the Blackmud site. From the hydrological data attached, Appendix B, Mean Monthly Flows for Blackmud Creek Crossing, April is the month with the highest flow, and the winter months (November to February) have the lowest flow.
4.0 REVIEW OF AVAILABLE WATERCOURSE CROSSING METHODOLOGIES A number of watercourse crossing methodologies, including trenchless techniques (HDD, Direct Pipe®, and Bore), isolated crossing technique and open cut are typically considered for crossing watercourses such as the Blackmud Creek. These methodologies include both primary methods as well as contingency methods. These methodologies are described below
4.1 HORIZONTAL DIRECTIONAL DRILL Horizontal Directional Drilling is one of the most commonly accepted trenchless methods for a pipeline watercourse crossing. The method involves setting up an HDD drill rig and drilling a pilot hole with subsequent reaming passes to enlarge the borehole to an adequate diameter for pull-in of carrier pipe. The make-up section is typically fabricated in one piece, hydrostatically tested, and then pulled into the bore. Buoyancy water within the pipe is normally used to minimize pull forces for larger diameter pipes. The constructability of an HDD typically ranges from 400 m to 3,500 m in length for NPS 36 pipe. In some instances, the HDD methodology may also require a large diameter surface casing if sands or gravels are encountered near surface. The feasibility of utilizing an HDD method is normally compromised where large boulders or deep deposits of gravel containing cobbles and boulders are encountered. Topography, geometry, and available workspace may also impact the feasibility of using an HDD. Potential obstacles for HDD: Loss of drilling fluid circulation in a sand and gravel stratum; Pilot hole steering problems when encountering boulders;
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Need for additional workspace for the pullback area; and Cobbles and boulders which may be present.
® 4.2 DIRECT PIPE The Direct Pipe® method involves attaching a Micro-Tunnel Boring Machine (MTBM) in front of the product pipe (or a casing). The MTBM and product pipe are then “thrust” into the ground using the Herrenknecht ‘thruster’. This technique can be utilized to tunnel through soft or hard ground below the water table. The excavated material is mixed with water or drilling mud in the micro-tunnelling cutting head and pumped back to surface to be cleaned and reused, much like the HDD method. Gravel and cobbles which are able to enter the MTBM, are crushed and mixed with the drilling mud and then pumped back up to surface. Small to medium sized boulders that are able to enter the MTBM may also be broken down by disk cutters on the cutter head. Larger boulders that are unable to be broken down need to be pushed away from the bore alignment. Boring through large boulders or numerous boulders would not be feasible. This has been seen on a recent project North East of Hope, BC on a crossing of the Coquihalla River. This methodology has length limitations of approximately 500 m for NPS 36 and 800 m for NPS 42. The size and number of boulders encountered also limits the feasibility of using this technique. The use of the Direct Pipe® method in Europe has been growing rapidly over the last 10 years. To date, a number of relatively straight forward crossings have been completed in Canada using this methodology. Potential obstacles for Direct Pipe®: Quantity and size of boulders present along the drill path; Complicated entry pit setup; and Possibly requires additional geotechnical information.
4.3 BORE This is a common crossing technique that utilizes a boring machine operating within an excavation to advance a casing pipe and auger beneath a road. Length is normally limited to a maximum of approximately 100m but some contractors now state that advances in equipment capabilities can increase this maximum length limit. This technique is generally not ideal for watercourse crossing due to the difficulties with controlling water migration into the bell holes but is very well suited to road and rail crossings. Proper procedural criteria need to be maintained to minimize the formation of voids during the bore. Potential obstacles for Bored methodology: Large boulders which the boring equipment is not capable of handling; and High water table in coarse granular soils.
4.4 ISOLATED CROSSING TECHNIQUES Isolated crossing techniques (which are in-stream bypass techniques) typically involve isolating the location of the work from the water flow by the use of temporary dams or steel plates and then diverting the water using a pump, a flume or by excavating a side channel. The dam and pump method generally works well for maximum flows up to approximately 1.2 to 1.4 m³/s for summer construction and up to approximately 1.0 m³/s for winter construction. The flume method works well for maximum flows up to approximately 8.0 m³/s (i.e. double super flume). After the crossing location is isolated the pipeline trench is excavated followed by pipe placement and backfill. The final steps include re-contouring the riverbed and restoration of the banks.
4.5 OPEN CUT The Open Cut method involves excavating a trench through the watercourse (without isolation) to the required depth, installing the pipe and then backfilling. The final steps include re-contouring the riverbed and restoration of the banks. This method is best used when flows are at their lowest point.
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Potential obstacles for Open Cut: Unexpected soil conditions within the riverbed; Lack of available workspace; Fisheries sensitivity; and Unanticipated high water conditions.
5.0 GEOTECHNICAL/GEOPHYSICAL PROGRAM The Blackmud Creek site has been geotechnically investigated by BGC. BGC drilled two boreholes in June 2014. Borehole BH-BGC14-BM-01 was drilled approximately 80 from the east bank of the creek, and BH- BGC14-BM-02 approximately 240m from the west bank. (See Appendix C - Geotechnical Borehole Logs at Blackmud Creek) The soil strata is shown in Appendix D – Interpreted Geological Section at Blackmud Creek. Based on the information obtained, and the geophysical survey results, the borepath is expected to pass through varying depths of silts, sands, and clays prior to encountering siltstone, sandstone, and mudstone bedrock of the Horseshoe Canyon formation at a depth of ~22mbgs. The majority of the drill profile will pass through that siltstone/sandstone bedrock. Losses in HDD drilling circulation may be encountered in the upper portion of the sandy silt and clay layer (6.7mbgs to 9.7 mbgs), and if encountered, would have to be addressed through the use of appropriate drilling fluids, casing, or by other techniques. The conclusion from the results of the geotechnical and geophysical investigation is that, from a geotechnical perspective, an HDD at this location is considered feasible but somewhat challenging due to some concerns associated with a potential for loss of circulation in the upper soil layers. It is recommended that the geotechnical report be provided to the HDD contractor for planning purposes and for considering the use of appropriate loss control materials.
6.0 CROSSING DESIGN
6.1 PRIMARY CROSSING METHOD - HDD CROSSING DESIGN As a result of the TMEP constructability meetings with the contractor, the primary crossing method has been confirmed to be HDD. The proposed NPS 36 TMEP pipeline crosses Blackmud Creek at about KP 24.2 SSEID 005.5. The pipeline alignment is from East to West and will cross the river at approximately 40°. The river flows from North to South at the location of the crossing. The HDD crossing plan and profile drawing for the Blackmud Creek has been prepared and is included in this report as Appendix E. A hydrofracture analysis diagram is also presented in Appendix F. The ground profile utilized in the design was derived from LiDAR dated November 2007, June 2009, and November 2012. As shown in the HDD crossing plan and profile, Drawing M002-XD-00024, the drill path for the NPS 36 pipeline will be about 616m long. The pipe will cross the creek at a depth of about 27 m below the bottom elevation of the creek. This design profile has an entry angle of 12° and an exit angle of 12°. The setback from the creek centre is about 288 m on the West side and 320 m from the East side. The West side has been selected as the entry primarily because the make-up section of pipe will be located on the East side of the crossing and the entry and exit elevations are approximately the same. There is sufficient workspace available on the East side to accommodate two sections of pipe in the make-up area. This design has placed the drill profile approximately 5m or more below the bedrock profile highpoints for the majority of the crossing. Casing, if required, is anticipated to have a minimum diameter of about 1,524 mm OD (NPS 60) to accommodate the anticipated final ream size of 1,219 mm (NPS 48). The calculated pull force for the 914 mm OD (NPS 36) pipe is estimated to be approximately 1,868 kN (420,000 lbf) without buoyancy water, and 712 kN (160,000 lbf) by utilizing 100% buoyancy control. Based on the length and overall geometry of this crossing we would recommend a drill rig size of at least 2,224 kN (500,000 lbf).
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NPS 36 pipe is normally installed using buoyancy control to minimize the pull force. The initial hydrofracture analysis (Appendix F), illustrates that this HDD crossing should be feasible at the depth shown. Construction of the Blackmud Creek Crossing may require a drilling schedule of 4-5 weeks for the 914 mm OD (NPS 36) pipe, excluding the time that may be required to install casing (if required). This duration is based on the HDD Contractor working twenty four (24) hours per day, 7 days per week, to complete the installation.
6.2 CONTINGENCY CROSSING METHOD - ISOLATED IN-STREAM CROSSING DESIGN The contingency crossing method for Blackmud Creek was determined to be an isolated in-stream crossing method with water quality monitoring. The contingency crossing drawing appears in Appendix G. The construction window for the contingency crossing method is currently planned to occur during low flow conditions (outside RAP).
7.0 RECOMMENDATIONS Based on the geotechnical and geophysical information provided for this feasibility report, the following is recommended: The Blackmud Creek Crossing location is a feasible candidate for an HDD crossing method, based on the results and recommendations included in the BGC Feasibility Assessment. The following difficulties, while generally surmountable, may be encountered: Steering difficulties: Bedrock was observed to be weak and poorly lithified (soil-like) in the upper 5m of bedrock, with the potential for sudden strength changes at harder beds. Also, the HDD borepath potentially intersects the bedrock layer at a shallow angle. This may lead to some increased steering effort and care, but significant steering issues are not expected. Sloughing, hole collapse: Some sloughing or hole collapse may occur in the sandy deposits. If encountered, this may be mitigated via managing the drill fluid mix design. Loss of drilling fluids: Highly permeable sands are present and could cause circulation losses. If encountered, this may be mitigated via proper drill mud mixes or casing. Encounter with cobbles or boulders: While no cobbles or boulders were encountered during the geotechnical drilling, it is still possible the proposed bore path could encounter glacial till, which is common in the area. The possible presence of larger clasts should not be discounted. Highly plastic material: Some high-plasticity clay beds may be encountered, which may impact drill mud consistency and cuttings management. If encountered, this may be mitigated via drill fluid mix design.
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A. Appendix A – Abbreviations and Acronyms The following is a list of abbreviations and acronyms used in this report.
Term Meaning o degree % percent BGC BGC Engineering Inc. DWG Drawing ERT Electrical Resistivity Tomography HDD Horizontal Directional Drill KMC Kinder Morgan Canada Inc. kN kilonewton KP Kilometer Post KPa kilopascal lbf Pounds force LiDAR Light Detection and Ranging m metre m3/s cubic metres per second mm millimeter MTBM micro-tunnel boring machine NPS nominal pipe size OD outside diameter ® Registered Trademark symbol SPT Standard Penetration Test TMEP Trans Mountain Expansion Project TMPL Trans Mountain Pipeline UPI UniversalPegasus International
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B. Appendix B – Mean Monthly Flows for Blackmud Creek
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Combined PDF Pages Page 10 of 31 Pages Crossing Name Blackmud Creek Crossing Catchment Area (km2) 633 Reference Gauge 05DF003 Catchment Area (km2) 513
Mean Monthly Flows - Blackmud Creek 3
2.5 NOV DEC
2
1.5 Flow(m3/s)
1
0.5
0 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Mean Monthly Median Upper Discharge Discharge Lower Quartile Quartile in m3/s in m3/s in m3/s in m3/s JAN #N/A #N/A #N/A #N/A FEB 0 0 0 0 MAR 0.86 0 0 0.74 APR 2.71 1.36 0.25 3.83 MAY 0.74 0.25 0 0.62 JUN 0.49 0.12 0 0.25 JUL 1.11 0.12 0 0.86 AUG 0.37 0 0 0.25 SEP 0.25 0 0 0.12 OCT 0.12 0 0 0.12 NOV 0 0 0 0 DEC #N/A #N/A #N/A #N/A
Daily streamflow records used in the calculation of monthly flow statistics are recorded by hydrometric stations that have been established and are operated across Canada by the Water Survey Canada (WSC) to help understand and manage water resources.
N/A denotates that no records were available at the hydrometric gauges for that month.
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C. Appendix C – Geotechnical Borehole Logs at Blackmud Creek
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Combined PDF Pages Page 12 of 31 Pages Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 1 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 0 SILT (ML) Clayey, trace sand, low plasticity, stiff, brown, no odour, moist, homogeneous, weak cementation, low dry strength, no dilatancy, roots and organic material. [ANTHROPOGENIC/FILL] CLAY (CL) SPT 01 silty, sandy, low plasticity, stiff, light brown, no odour, moist, 4 1 homogeneous, weak cementation, low dry strength, no dilatancy. 5 [GLACIOLACUSTRINE] 7 SPT 01 - Recovered 0.10 m.
2
SPT 02 - Recovered 0.38 m. SPT 02 3 5 4 3
3.66 - 4.57 m - 15% loss of circulation.
4 SPT 03 - Recovered 0.37 m. Changes to trace to some clay, firm, blocky SPT 03 0 and fissured, strong cementation, low to medium dry strength. 3 4
5 SPT 04 - Recovered 0.60 m. Changes to weak cementation. Grainsize SPT 04 distribution: 0.1% gravel, 20.3% sand, 79.6% fines. 0 2 4 6
6.71 - 8.23 m - 50% loss of circulation. 7 SPT 05 SPT 05 - Recovered 0.60 m. 1 2 3
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Combined PDF Pages Page 13 of 31 Pages Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 2 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 8
SPT 06 - Recovered 0.60 m. Trace gravel. SPT 06 8.23 - 9.75 m - 70% loss of circulation. 3 5 6 9
SPT 07 - Recovered 0.48 m. Grainsize distribution: 4.5% gravel, 33.7% 10 SPT 07 sand, 43.6% silt, 18% clay. 4 9.75 m - Gained back 100% circulation. 5 7
11
SPT 08 - Recovered 0.60 m. Very stiff, blocky, medium dry strength. SPT 08 5 9 7 12
SPT 09 - Recovered 0.50 m. Changes to grey brown, homogeneous. 13 SPT 09 3 7 8
14
SPT 10 20 SPT 10 - No Recovery. 26 24
15
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Combined PDF Pages Page 14 of 31 Pages Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 3 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 16 SPT 11 SPT 11 - Recovered 0.35 m. Fine SAND(SP) lenses 5 cm thick, very 4 hard dry strength. 7 8
17
SPT 12 Interbedded SANDSTONE, SILTSTONE, and MUDSTONE, 20 >> SANDSTONE, fine to medium grained, bedded, dark brown to grey, 34 slightly weathered, extremely weak (RO), close to moderate joint spacing, R 1-2 joint sets, some silt infill. 18 SILTSTONE, very fine to fine grained, bedded, dark grey, highly weathered, extremely weak (RO), close to moderate joint spacing, 1-2 joint sets, some silt infill. MUDSTONE, very fine grained, bedded, dark grey, highly weathered, extremely weak (RO), close to moderate joint spacing, 1-2 joint sets, some silt infill. 19 SPT 13 From 17.3 to 22 m the material is weathered and extremely weak (R0). 41 >> SPT 12 - Recovered 0.30 m - SILT (ML) Sandy, trace to some clay, trace 50 gravel, low plasticity, hard, grey brown, no odour, moist, slightly blocky to R homogeneous, strong cementation, medium dry strength, no dilatancy. 18.28 - 28.04 m - Had to re-ream hole, due to squeezing in of materials. SPT 13 - Recovered 0.26 m. Changes to dry, grey, no gravel. 20
SPT 14 - Recovered 0.40 m. Clay, high plasticity, hard (S6), grey, dry to moist, weak cementation. Grainsize distribution: 22.6% sand, 77.4% SPT 14 fines. 50 >> 50 R 21
22 SPT 15 39 R
23
SPT 16 - Recovered 0.50 m. SPT 16 20 >> 37 24 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18
Combined PDF Pages Page 15 of 31 Pages Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 4 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 24 R
25 SPT 17 SPT 17 - Recovered 0.20 m. Coal seam approximately 1 cm thick R
26
SPT 18 SPT 18 - Recovered 0.31 m. 28 R 27
28 SPT 19 SPT 19 - Recovered 0.20 m. 50 R
29
SPT 20 - Recovered 0.41 m. SPT 20 40 >> 40 30 R
31 SPT 21 SPT 21 - Recovered 0.30 m. 32 >> 50 R
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Combined PDF Pages Page 16 of 31 Pages Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 5 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 32
SPT 22 SPT 22 - Recovered 0.19 m. R
33
34 SPT 23 SPT 23 - Recovered 0.18 m. R
35
SPT 24 SPT 24 - Recovered 0.18 m. R 36
37 R SPT 25 SPT 25 - Recovered 0.10 m.
38
SPT 26 SPT 26 - Recovered 0.17 m. R 39
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Combined PDF Pages Page 17 of 31 Pages Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 6 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 40 R SPT 27 Interbedded SILTSTONE, and SANDSTONE SILTSTONE, very fine to fine grained, bedded, dark grey, slightly weathered to fresh, weak (R2), close to moderate joint spacing, 1-2 joint sets, some silt infill. 41 SANDSTONE, fine to medium grained, bedded, dark brown to grey, slightly weathered, extremely weak (RO) to weak (R2), close to moderate joint spacing, 1-2 joint sets, some silt infill. SPT 27 - Recovered 0.10 m. 40.23-45.57 m - Siltstone, very stiff.
42
43
44
45
45.57-48.62 m - Sandstone, extremely weak.
46
47
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Combined PDF Pages Page 18 of 31 Pages Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-01 Page 7 of 7 Location: Blackmud Creek - East Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 26 Jun 14 Co-ordinates (m): 333,263E, 5,923,419N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 29 Jun 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 48.6 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 40.50 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.4 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 48
RC 1 48.3-48.5 m - Unconfied Compressive Strength test completed on core by Golder Ltd.. Sample properties were 61 mm diameter, 125 mm height, wet density 2152 kg/m3, 6.9% moisture content. Maximum load was 32.1 kN, stress was 11.1 MPa. Failure mode was a diagonal shear plane at 24 49 degrees from the core axis. Borehole completed at target depth of 48.6 m below ground surface. Borehole grouted to surface with bentonite grout. No instrumentation installed.
SPT Sampler Details: 60 cm (24") length, 5 cm (2") diameter, driven by automatic trip hammer. All SPT sampling was carried out in accordance 50 with ASTM D1586.
Borehole coordinates acquired by a Garmin GPSMAP 62s handheld GPS.
Pocket penetrometer tests conducted on base of SPT sample when 51 possible and on opened face of SPT sample as appropriate. Elevation based on LiDAR provided by UPI, dated September 16, 2014.
Groundwater observed at a depth of 16.2 m below ground surface on June 29, 2014 with the drill hole at a final depth of 48.6 m, while casing was installed to 40.5 m depth. 52 HWT casing was installed to a depth of 40.5 m due to some loss of circulation and wall squeezing.
53
54
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56 TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18
Combined PDF Pages Page 19 of 31 Pages Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-02 Page 1 of 4 Location: Blackmud Creek - West Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 30 Jun 14 Co-ordinates (m): 332,928E, 5,923,355N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 28.0 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 16.70 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.5 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 0 CLAY (CL) silty, trace sand, low plasticity, stiff, light brown, no odour, dry, blocky, weak cementation, low dry strength, no dilatancy. [GLACIOLACUSTRINE]
>> 1 SPT 01 - Recovered 0.36 m. SPT 01 3 4 6
2
SPT 02 - Recovered 0.55 m. SPT 02 3 5 3 5
SPT 03 - Recovered 0.53 m. Lenses of 5 cm thick blocky soft SILT(ML), SPT 03 changes to homogeneous and firm. 0 4 2 2
5
SPT 04 - Recovered 0.61 m. Changes to soft, wet, homogeneous, SPT 04 moderate cementation, moderate dry strength, slow dilatancy. Grainsize 0 distribution: 10.8% sand, 89.2% fines. 1 6 2
7 SPT 05 - Recovered 0.60 m. Changes to trace sand, firm, lenses of coal SPT 05 3 cm thick. 2 3 5
8 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18
Combined PDF Pages Page 20 of 31 Pages Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-02 Page 2 of 4 Location: Blackmud Creek - West Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 30 Jun 14 Co-ordinates (m): 332,928E, 5,923,355N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 28.0 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 16.70 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.5 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 8
SPT 06 - Recovered 0.57 m. Changes to some sand, trace gravel. Some SPT 06 SAND (SP-SM) lenses 0.5 cm thick. 3 10 9 12
10 SPT 07 - Recovered 0.60 m. Changes to lenses of rust coloured SPT 07 SAND(SP) 1 cm thick, some gravel, fragments of coal 5 mm in diameter. 7 10 12
11
SPT 08 - Recovered 0.60 m. SPT 08 9 12 SAND (SC) 13 Fine to medium grained, clayey, silty, poorly graded, dense, max. particle 13 size < 1mm, subangular, light grey, no odour, dry, homogeneous, moderate cementation, fragments of coal 5 mm in diameter. [GLACIOLACUSTRINE]
13 SPT 09 - Recovered 0.53 m. Changes to very dense. Grainsize SPT 09 distribution: 60.7% sand, 39.3% fines. 12 19 32
14
SPT 10 - Recovered 0.45 m. Changes to compact to dense. SPT 10 10 15 15 15
4 16 SPT 11 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18
Combined PDF Pages Page 21 of 31 Pages Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-02 Page 3 of 4 Location: Blackmud Creek - West Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 30 Jun 14 Co-ordinates (m): 332,928E, 5,923,355N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 28.0 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 16.70 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.5 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 16 SPT 11 - Recovered 0.17 m. Lenses of SILT(ML) 1 cm thick. 7 9
17
SPT 12 - Recovered 0.60 m. Grainsize distribution: 18.7% sand, 81.3% SPT 12 fines. 8 Interbedded MUDSTONE, SILTSTONE, and SANDSTONE 37 31 18 MUDSTONE, slightly weathered to fresh, extremely weak (RO) to weak (R2), light to dark grey, fine, bedded, moderately fractured. SILTSTONE, slightly weathered to fresh, extremely weak (RO) to weak (R2), light to dark grey, fine, bedded, moderately fractured. SANDSTONE, slightly weathered to fresh, extremely weak (RO) to weak (R2), light to dark grey, medium grained, bedded to massive, moderately fractured. 19 17.4 to 22.5 m logged as a soil. Rock strength generally increased with depth. RC 1 18.07 m - Lenses of SAND(SP-SM) 5 cm thick.
20
21
22
23
>> 24 (Continued on next page) TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18
Combined PDF Pages Page 22 of 31 Pages Project: Trans Mountain Expansion Project DRILL HOLE # BH-BGC14-BM-02 Page 4 of 4 Location: Blackmud Creek - West Bank Project No.: 0095-150-14
Survey Method: Handheld GPS Drill Designation: HT 750 Start Date: 30 Jun 14 Co-ordinates (m): 332,928E, 5,923,355N Drilling Contractor: Foundex Exploration Ltd. Finish Date: 01 Jul 14 Ground Elevation (m): 684.0 Drill Method: Mud Rotary/Coring Final Depth of Hole (m): 28.0 Datum: NAD83 UTM Zone 12U Fluid: Bentonite Mud/Water Logged by: BNM Dip (degrees from horizontal): 90 Casing: HWT Cased To (m): 16.70 Reviewed by: PN Direction: N/A Depth To Rock (m): 17.5 Approved by: LDM
Su - kPa
40 80 120 160
% Fines UCS/2 Lithologic Description Vane Field Peak Pocket Pen /2 Vane Field Remold DCT (blows/300mm) RQD SPT (blows/300mm) Moisture Content & SPT N Core Recovery WP% W% WL%
Depth (m) Depth Type Sample No. Sample Symbol 150mm per Blows SPT Details Install 20 40 60 80 20 40 60 80 24
25
26
27
28 Borehole completed at target depth of 28.04 m below ground surface. Borehole grouted to surface with bentonite grout. No instrumentation installed.
SPT Sampler Details: 60 cm (24") length, 5 cm (2") diameter, driven by automatic trip hammer. All SPT sampling was carried out in accordance 29 with ASTM D1586.
Borehole coordinates acquired by a Garmin GPSMAP 62s handheld GPS.
Pocket penetrometer tests conducted on base of SPT sample when 30 possible and on opened face of SPT sample as appropriate. Elevation based on LiDAR provided by UPI, dated September 16, 2014.
Groundwater observed at a depth of 7.9 m below ground surface on July 1, 2014 with the drill hole at a final depth of 28.0 m, while casing was installed to 16.7 m depth. 31 No loss of circulation noted.
HWT casing was installed to a depth of 16.7 m due to some wall collapse in the sand bedding layer noted and overall borehole stability for several metres above the bedrock contact. 32 TMEP (SOIL & ROCK W INSTRUMENTS) TMEP_SOILROCK.GDL BGC.GDT 4/4/18
Combined PDF Pages Page 23 of 31 Pages Trans Mountain Expansion 19731-506-RPT-00079 Project
Feasibility Report for the Rev Date Blackmud Creek Crossing 0 04/27/2018
D. Appendix D – Interpreted Geological Section at Blackmud Creek 0A
UniversalPegasus International Page D-1
Combined PDF Pages Page 24 of 31 Pages N 5,923,500 N
E 332,750 E 333,000 E 333,250 E 333,500
680
680 685 670
670 685
675
680
A 680 675
- BH-BGC14-BM-02 HDD 0+00 POINT 670 HDD EXIT
24+600 HDD ENTRY
A
-
24+500
24+400
24+300
24+200
24+100
24+000 23+900
N 5,923,250E 332,750
BH-BGC14-BM-01 23+800
N 5,923,500 685 670 23+700 670
685
680 675 BLACKMUD CREEK LEGEND - PLAN 675 SSEID 005.5 TRANS MOUNTAIN PIPELINE ALIGNMENT 680 PROPOSED HDD BOREPATH KILOMETRE POSTS (KP) BGC BOREHOLE
PROPOSED HDD ENTRY / 0+00 / EXIT POINT E 333,000 670 685 ERT SURVEY ALIGNMENT SCALE 1:2,500 685 SEISMIC SURVEY ALIGNMENT 25 0 755025 02.dwg Layout: RM-B-SIZE Plot Date Apr 4 18 Time: 8:44 AM Layout: Time: Plot Date 02.dwg RM-B-SIZE Apr 4 18 BLACKMUD CREEK FLOW DIRECTION N 5,923,250 METRES E 333,750
E 333,250 E 333,500 (E: 332,817; N: 5,923,328) NORTHWEST EAST (E: 333,543; N: 5,923,497) 700 700 BH-BGC14-BM-02 BH-BGC14-BM-01 HDD ENTRY (OFFSET = 21 m N) (OFFSET = 8 m S) HDD EXIT HDD 0+00 POINT ? 680 ? 680
? ? ? ? ? 660 660 ELEVATION (m) ELEVATION (m)
640 640
630 630 -0+390 -0+300 -0+200 -0+100 0+000 0+100 0+200 0+300 0+360 HORIZONTAL SCALE: 1:2,500 SCALE 1:2,500 PROPOSED HDD CHAINAGE (m) VERTICAL SCALE: 1:1,250 (2x VERTICAL EXAGGERATION) 25 0 755025 A LEGEND - CROSS-SECTION BOREHOLE INTERPRETED GEOLOGY CROSS-SECTION - METRES CROSS-SECTION AT BEARING 074.3° PROPOSED HDD PROFILE ANTHROPOGENIC (FILL) GROUNDWATER OBSERVATIONS BGC BOREHOLE GLACIOLACUSTRINE BH COLLAR INFERRED WATER WATER LEVEL INFERRED WATER LEVEL HORSESHOE CANYON BOREHOLE COMMENTS ELEVATION (m asl) LEVEL (m bgs) ELEVATION (m asl) ? INFERRED GEOLOGICAL INTERFACE FORMATION BEDROCK PROPOSED HDD ENTRY / 0+00 / EXIT POINT SAND BED - BH-BGC14-BM-01 684.0 16.2 667.8 MEASURED ON JULY 1, 2014, WHEN BOREHOLE WAS ADVANCED TO FINAL DEPTH OF 50.0 m bgs 200-YEAR FLOOD ELEVATION (669.1 m asl) LOW RECOVERY BH-BGC14-BM-02 684.0 7.9 676.1 MEASURED ON JULY 5, 2014, WHEN BOREHOLE WAS ADVANCED TO FINAL DEPTH OF 61.0 m bgs 200-YEAR SCOUR ELEVATION (665.1 m asl) NOTES: 1. ALL DIMENSIONS ARE IN METRES UNLESS OTHERWISE NOTED. INTERPRETED BEDROCK CONTACT BOUNDARY FROM GEOPHYSICS 2. THIS DRAWING MUST BE READ IN CONJUNCTION WITH BGC'S REPORT TITLED “GEOTECHNICAL HDD FEASIBILITY ASSESSMENT - BLACKMUD CREEK AT SSEID 005.5 KP 24.2”, AND DATED MARCH 2018. SCALE: 1:2,500 PROJECT: 3. BASE TOPOGRAPHIC DATA BASED ON LIDAR PROVIDED BY UPI, DATED SEPTEMBER 2014. CONTOUR INTERVAL IS 1.0 m. BLACKMUD CREEK WATER SURFACE PROFILE AT TIME OF LIDAR SURVEY IS SHOWN IN CROSS-SECTION. GEOTECHNICAL HDD FEASIBILITY ASSESSMENT 4. IMAGE SOURCE: ESRI WORLD IMAGERY SERVER RETRIEVED FROM BING IMAGERY. DATE: - BLACKMUD CREEK AT SSEID 005.5 KP 24.2 5. PROPOSED TMEP SSEID 005.5 PIPELINE ALIGNMENT PROVIDED BY KMC, DATED MARCH 2018. PROPOSED HDD ALIGNMENT PROVIDED BY UPI, DRAWING NO. M002-XD0002401 RA, ISSUED FEBRUARY 07, 2018. MAR 2018 BGC ENGINEERING INC. TITLE: 6. PROJECTION IS UTM NAD83 ZONE 12. BGC AN APPLIED EARTH SCIENCES COMPANY DRAWN: CR INTERPRETED GEOLOGIC CROSS-SECTION 7. SPECIFIC OBSERVATIONS PERTAINING TO THE WATER LEVEL MEASUREMENTS ARE AVAILABLE IN THE REPORT. CLIENT: 8. UNLESS BGC AGREES OTHERWISE IN WRITING, THIS DRAWING SHALL NOT BE MODIFIED OR USED FOR ANY PURPOSE OTHER THAN THE PURPOSE FOR WHICH BGC THIS DRAWING MAY HAVE BEEN REDUCED OR ENLARGED. CHECKED: SAA PROJECT No.: DWG No.: GENERATED IT. BGC SHALL HAVE NO LIABILITY FOR ANY DAMAGES OR LOSS ARISING IN ANY WAY FROM ANY USE OR MODIFICATION OF THIS DOCUMENT NOT ALL FRACTIONAL SCALE NOTATIONS INDICATED ARE 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. BASED ON ORIGINAL FORMAT DRAWINGS. APPROVED: 0095-150 02
T:\Geomatics\Projects\0095\CAD\Production\Report-Memo\20170720_GEOTECHNICAL_HDD_FEASIBILITY_ASSESSMENT_DRAWINGS\BLACKMUD_CREEK_KP_24.2\ Combined PDF Pages Page 25 of 31 Pages Trans Mountain Expansion 19731-506-RPT-00079 Project
Feasibility Report for the Rev Date Blackmud Creek Crossing 0 04/27/2018
E. Appendix E – HDD Crossing Plan and Profile, Blackmud Creek 0A
UniversalPegasus International Page E-1
Combined PDF Pages Page 26 of 31 Pages
Combined PDF Pages Page 27 of 31 Pages Trans Mountain Expansion 19731-506-RPT-00079 Project
Feasibility Report for the Rev Date Blackmud Creek Crossing 0 04/27/2018
F. Appendix F – Calculated Fracture Pressure for Blackmud Creek
UniversalPegasus International Page F-1
Combined PDF Pages Page 28 of 31 Pages · · · ·
Combined PDF Pages Page 29 of 31 Pages Trans Mountain Expansion 19731-506-RPT-00079 Project
Feasibility Report for the Rev Date Blackmud Creek Crossing 0 04/27/2018
G. Appendix G – Blackmud Creek - Contingency Design
UniversalPegasus International Page G-1
Combined PDF Pages Page 30 of 31 Pages
Combined PDF Pages Page 31 of 31 Pages