APPENDIX 6D

Horizontal Directional Drilling Feasibility Report

Repor t

Horizontal Directional Drilling Feasibility Evaluation Report for Oregon LNG

Bidirectional Project

Prepared for

LNG Development Company, LLC (d/b/a Oregon LNG)

and Oregon Pipeline Company, LLC

June 2013

Prepared by

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Contents Section PageAcronymsandAbbreviations..............................................................................................................................viiExecutiveSummary.........................................................................................................................................ES11 Introduction.........................................................................................................................................11

1.1 Purpose............................................................................................................................................111.2 ProjectandSiteDescription............................................................................................................111.3 PipelineRoute..................................................................................................................................121.4 PipelineDesignandSafetyStandards.............................................................................................121.5 HorizontalDirectionalDrillingDescription......................................................................................13

1.5.1 PilotHole.............................................................................................................................131.5.2 Reaming...............................................................................................................................141.5.3 PipePullback........................................................................................................................141.5.4 AdvantagesofHorizontalDirectionalDrilling.....................................................................151.5.5 LimitationsofHorizontalDirectionalDrilling......................................................................15

1.6 ProposedHorizontalDirectionalDrillingLocations.........................................................................161.7 OtherLocationsEvaluated...............................................................................................................171.8 HorizontalDirectionalDrillingInstallationsBeneathUSACELevees...............................................181.9 InadvertentReleaseMitigationMeasures......................................................................................19

1.9.1 InadvertentReleaseContingencyPlan................................................................................191.9.2 TimingofWork....................................................................................................................191.9.3 FluidMonitoringProgramsandInadvertentReleasePreventionPlans.............................191.9.4 PrequalificationofHDDContractors...................................................................................19

1.10 Limitations.....................................................................................................................................110

2 ProjectSetting.....................................................................................................................................212.1 PhysiographicSetting......................................................................................................................21

2.1.1 CoastRangePhysiographicProvince...................................................................................212.1.2 PortlandBasinPhysiographicProvince...............................................................................21

2.2 GeologicSetting...............................................................................................................................212.2.1 ProjectGeologyOverview...................................................................................................222.2.2 QuaternaryDeposits............................................................................................................222.2.3 SedimentaryRockUnits.......................................................................................................222.2.4 IgneousRockUnits..............................................................................................................242.2.5 VolcanicRockUnits.............................................................................................................24

3 PreliminaryGeotechnicalExploration..................................................................................................313.1 FieldExplorationProgram...............................................................................................................31

3.1.1 GeotechnicalBorings...........................................................................................................313.1.2 SoilSampling........................................................................................................................323.1.3 RockCoreDrillingandSampling..........................................................................................33

3.2 GroundwaterLevels.........................................................................................................................333.3 LaboratoryTesting...........................................................................................................................34

4 HDDCrossingConditions......................................................................................................................414.1 Highway101andAdairsSlough......................................................................................................41

4.1.1 SurfaceConditions...............................................................................................................414.1.2 SubsurfaceConditions.........................................................................................................41

4.2 LewisandClarkRiveratMilepost3.................................................................................................43

CONTENTS, CONTINUED

iv ES030613113935PDX

4.2.1 Surface Conditions ............................................................................................................... 4-3 4.2.2 Subsurface Conditions ......................................................................................................... 4-3

4.3 Lewis and Clark River at Milepost 5 ................................................................................................. 4-4 4.3.1 Surface Conditions ............................................................................................................... 4-4 4.3.2 Subsurface Conditions ......................................................................................................... 4-5

4.4 Lewis and Clark River at Milepost 5.5 .............................................................................................. 4-5 4.4.1 Surface Conditions ............................................................................................................... 4-5 4.4.2 Subsurface Conditions ......................................................................................................... 4-6

4.5 Lewis and Clark River at Milepost 11 ............................................................................................... 4-7 4.5.1 Surface Conditions ............................................................................................................... 4-7 4.5.2 Subsurface Conditions ......................................................................................................... 4-7

4.6 Nehalem River at Milepost 33.5 ...................................................................................................... 4-9 4.6.1 Surface Conditions ............................................................................................................... 4-9 4.6.2 Subsurface Conditions ....................................................................................................... 4-10

4.7 Highway 26 at Milepost 41 ............................................................................................................ 4-11 4.7.1 Surface Conditions ............................................................................................................. 4-11 4.7.2 Subsurface Conditions ....................................................................................................... 4-12

4.8 Highway 26 at Milepost 43 ............................................................................................................ 4-14 4.8.1 Surface Conditions ............................................................................................................. 4-14 4.8.2 Subsurface Conditions ....................................................................................................... 4-14

4.9 Rock Creek at Milepost 57 ............................................................................................................. 4-16 4.9.1 Surface Conditions ............................................................................................................. 4-17 4.9.2 Subsurface Conditions ....................................................................................................... 4-17

4.10 Nehalem River at Milepost 64 ....................................................................................................... 4-18 4.10.1 Surface Conditions ........................................................................................................... 4-18 4.10.2 Subsurface Conditions ..................................................................................................... 4-18

4.11 Columbia River at Milepost 82.5 ................................................................................................... 4-21 4.11.1 Surface Conditions ........................................................................................................... 4-21 4.11.2 Subsurface Conditions ..................................................................................................... 4-21

4.12 Skipanon River for Terminal Utilities South of Terminal ............................................................... 4-22 4.12.1 Surface Conditions ........................................................................................................... 4-23 4.12.2 Subsurface Conditions ..................................................................................................... 4-23

5 Horizontal Directional Drilling Feasibility Assessment .......................................................................... 5-1 5.1 Adairs Slough ................................................................................................................................... 5-1 5.2 Lewis and Clark River at Milepost 3 ................................................................................................. 5-2 5.3 Lewis and Clark River at Milepost 5 ................................................................................................. 5-2 5.4 Lewis and Clark River at Milepost 5.5 .............................................................................................. 5-2 5.5 Lewis and Clark River at Milepost 11 ............................................................................................... 5-3 5.6 Nehalem River at Milepost 33.5 ...................................................................................................... 5-3 5.7 Highway 26 at Milepost 41 .............................................................................................................. 5-4 5.8 Highway 26 at Milepost 43 .............................................................................................................. 5-4 5.9 Rock Creek at Milepost 57 ............................................................................................................... 5-5 5.10 Nehalem River at Milepost 64 ......................................................................................................... 5-5 5.11 Columbia River at Milepost 82 ........................................................................................................ 5-6 5.12 Skipanon River for Terminal Utilities South of Terminal ................................................................. 5-6

6 References ........................................................................................................................................... 6-1

CONTENTS, CONTINUED

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Appendices

A Soil Boring and Rock Coring Logs B Field Exploration Photographs C Laboratory Test Results D Preliminary HDD Profile Drawings

D-1 Preliminary HDD ProfileHwy 101 and Adairs Slough at MP 01 D-2 Preliminary HDD ProfileLewis & Clark River at MP 03 D-3 Preliminary HDD ProfileLewis & Clark River at MP 5 D-4 Preliminary HDD ProfileLewis & Clark River at MP 5.5 D-5 Preliminary HDD ProfileLewis & Clark River at MP 11 D-6 Preliminary HDD ProfileNehalem River at MP 33.5 D-7 Preliminary HDD ProfileHighway 26 at MP 41 D-8 Preliminary HDD ProfileHighway 26 at MP 43 D-9 Preliminary HDD Profile Rock Creek at MP 57 D-10 Preliminary HDD Profile Nehalem River at MP 64 D-11 Preliminary HDD Profile Columbia River at MP 82 D-12 Preliminary HDD Profile Skipanon River for Terminal Utilities

Tables

ES-1 Summary of Proposed Horizontal Directional Drilling Crossings ................................................................. ES-3 1-1 Horizontal Directional Drilling Locations ...................................................................................................... 1-8 3-1 Geotechnical Boring Summary ..................................................................................................................... 3-2 3-2 Summary of Geotechnical Laboratory Tests Performed .............................................................................. 3-4

Figures (located at the end of their respective sections)

1-1 HDD Location Overview (MP 0 47.5) ....................................................................................................... 1-11 1-2 HDD Location Overview (MP 47.5 86.8) .................................................................................................. 1-13 2-1 Physiographic Provinces of Oregon and Washington ................................................................................... 2-5 2-2 Geologic Overview of Project Area ............................................................................................................... 2-7 3-1 HDD Feasibility AssessmentHwy 101 and Adairs Slough at MP 01 ........................................................... 3-5 3-2 HDD Feasibility AssessmentLewis & Clark River at MP 03 ........................................................................ 3-7 3-3 HDD Feasibility AssessmentLewis & Clark River at MP 5 and Lewis & Clark River at MP 5.5 ................... 3-9 3-4 HDD Feasibility AssessmentLewis & Clark River at MP 11 ...................................................................... 3-11 3-5 HDD Feasibility AssessmentNehalem River at MP 33.5 .......................................................................... 3-13 3-6 HDD Feasibility AssessmentHighway 26 at MP 41 .................................................................................. 3-15 3-7 HDD Feasibility AssessmentHighway 26 at MP 43 .................................................................................. 3-17 3-8 HDD Feasibility AssessmentRock Creek at MP 57 ................................................................................... 3-19 3-9 HDD Feasibility AssessmentNehalem River at MP 64 ............................................................................. 3-21 3-10 HDD Feasibility Assessment Columbia River at MP 82 ........................................................................... 3-23 3-11 HDD Feasibility Assessment Skipanon River for Terminal Utilities .......................................................... 3-25

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Acronyms and Abbreviations API American Petroleum Institute ASTM American Society for Testing and Materials ATWS Additional Temporary Workspace bgs below ground surface bpf blows per foot CFR Code of Federal Regulations DCCA Directional Crossing Contractors Association DNR Washington State Department of Natural Resources DOGAMI Department of Geology and Mineral Industries (Oregon) ESA Endangered Species Act ESP East Bank Skipanon Peninsula FERC Federal Energy Regulatory Commission GP-GM gravel with silt, sand, and cobbles GPS global positioning system HDD horizontal directional drill/drilling HDPE high density polyethylene HT high torque ID Identification kV kilovolt LNG liquefied natural gas LNGC liquefied natural gas carrier MP milepost mya million years ago NAVD88 North American Vertical Datum of 1988 NPI Northwest Pipeline Interconnect OD outside diameter ODOT Oregon Department of Transportation Oregon LNG LNG Development Company, LLC, and Oregon Pipeline Company, LLC Project Oregon LNG Terminal and Oregon Pipeline psi pounds per square inch RQD Rock Quality Designation SPCC spill prevention, control, and countermeasure SP-SM poorly graded sand with silt, gravel, and cobbles SPT standard penetration test UCS unconfined compressive strength U.S. United States USACE U.S. Army Corps of Engineers USCS Unified Soil Classification System USDOT U.S. Department of Transportation USGS U.S. Geological Survey WOEC West Oregon Electric Cooperative

ES030613113935PDX ES-1

Executive Summary Installationsofpipelineusingthehorizontaldirectionaldrilling(HDD)technologyareproposedat11locationsalongtheapproximate86.8mileLNGDevelopmentCompany,LLC,andOregonPipelineCompany,LLC(collectively,OregonLNG)liquefiednaturalgas(LNG)pipelinealignmentbetweenWarrenton,Oregon,andWoodland,Washington.OneadditionalHDDinstallationwillcrosstheSkipanonRivertocarryutilitiesfromtheCityofWarrentontotheterminalfacility(Terminal)locatedatthenortherntipoftheeastbankoftheSkipanonPeninsula.All12oftheproposedHDDinstallationswillcrossstreamsorriversthatsupportspecieslistedintheEndangeredSpeciesAct(ESA)orthathavebeendesignatedascriticalhabitat.Inaddition,threeoftheHDDinstallationswillcrossmajorhighways:Highway101(onecrossing)andHighway26(twocrossings).AllHDDsalongthepipelinealignmentwillinvolvetheinstallationof36inchdiameterweldedsteelpipe,whiletheoneHDDtobringutilitiestotheTerminalwillinvolvetheinstallationofa36inchdiameterhighdensitypolyethylene(HDPE)pipeline.

SixofthetwelveHDDinstallationswillcrossbelowfloodprotectionleveesconstructed,operated,maintainedby,orotherwiseundertheoveralljurisdictionoftheU.S.ArmyCorpsofEngineers(USACE).FederalregulationsrequirethatanymodificationstoanexistingUSACEproject(eitherfederallyorlocallymaintained)thatpassover,under,orthroughleveesbeapprovedbyeithertheUSACEdistrictengineeroratahigherlevelofthechiefofengineers.USACEguidelinesforinstallationofutilitiesbeneathCorpsofEngineersleveesusingHDDmethodswillbefollowedincompletingadditionalgeotechnicalexplorations,finaldesign,andconstructionofthesecrossings.SpecificrequirementsforHDDcrossingsofUSACEleveesarediscussedinthisreport.

OregonLNGperformedapreliminarygeologicandgeotechnicalassessmenttoevaluatethefeasibilityofsuccessfullycompletingtheproposedHDDinstallations.Thepreliminarygeotechnicalfieldexplorationprogramconsistedofadvancingatotalof20boringsinthevicinityofproposedHDDlocations.Geotechnicalboringswereadvancedfrompublichighwaysorroadsorwhereaccesstoprivatelandwasgrantedbypropertyowners.Atleastoneboringwasadvancedinthevicinityof11oftheproposedHDDlocations.BoringswerenotadvancedinthevicinityofoneproposedHDDlocationbecauseoftheinabilitytogainaccesstoprivatelyheldpropertyonwhichthelocationsaresituated.TableES1summarizestheproposedHDDlocationsandthenumberofboringsadvancedinthevicinityofthepreliminaryPipelinealignment.

AdditionalgeotechnicalexplorationsandlaboratorytestingarerecommendedtobecompletedforalloftheHDDcrossings.Inaddition,calculationstoevaluatethefactorofsafetyagainstinadvertentreleaseofdrillingfluidshouldbeperformedforeachHDDduringthefinaldesignprocess.ThesecalculationsshouldbeusedtodeterminethemaximumfluidpressurelimitationsandmodifytheverticalalignmentsofHDDs,ifnecessary,tomaintainappropriatefactorsofsafetyagainstinadvertentrelease.Additionalmeasureswillbeimplementedtoreducethepotentialforinadvertentreleaseofdrillingfluids,includingthefollowing:

Preparingspillprevention,control,andcountermeasure(SPCC)plansforeachHDDcrossing

EstablishingminimumrequirementsforHDDcontractors

RequiringHDDcontractorstodevelopandfollowfluidmonitoringprogramsandinadvertentreleasepreventionplans

ThisreporthasbeenpreparedtodocumentthepreliminaryHDDfeasibilityassessment,includingthepreliminarygeotechnicalfieldexplorationprogramperformed.AdiscussionofeachproposedHDDinstallationisprovided.Siteconditions,existinggeologicinformation,andresultsofgeotechnicalexplorations(whereperformed)arediscussed.ConclusionsaboutthefeasibilityofsuccessfullyperformingtheHDDinstallation,alongwithanassessmentoftheriskofinadvertentreleaseofdrillingfluidtostreams,rivers,orotherwaterfeaturesatthesurface,areprovidedbasedoninformationavailableatthetimeofthisreportpreparation.RecommendationsforobtainingadditionalsiteandsubsurfaceinformationtofurtherassessHDDfeasibilityandtomanageandminimizetheriskofinadvertentdrillingfluidreleaseareprovided.

EXECUTIVE SUMMARY

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Basedonexistinginformation,itappearsthateachoftheproposedHDDsisfeasiblewiththepossibleexceptionofHDDCrossingNo.8locatedatHighway26Pipelinemilepost(MP)43.ThefeasibilityofHDDCrossingNo.8isuncertainatthistimeandadditionalunderstandingofthevariabilityofsubsurfaceconditionsisneededbeforefinalfeasibilitycanbedetermined.Additionally,itappearsthat,withtheexceptionoftheSouthForkRockCreekCrossingnearMP43.1,theproposedHDDinstallationscanbecompletedwithlowriskofinadvertentreleaseofdrillingfluidtostreamsorriverswithESAlistedfish.TheriskofinadvertentreleaseofdrillingfluidisconsideredtobelowtomoderateattheSouthForkofRockCreekcrossingbecauseofrelativelylowthicknessofsoilcoverbetweenthebottomofthestreamandtheproposedHDDinstalledPipeline.Alternativesformitigatingtheriskofdrillingfluidreleaseattheselocationsarediscussedinthisreport.

EXECUTIVE SUMMARY

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TABLE ES-1 Summary of Proposed Horizontal Directional Drilling Crossings

HDD Number HDD Location

(Main Obstacle being Crossed)

MP Approximate Crossing Length

(feet) Crosses Streams with ESA

Listed Fish ID(s) of ESA Streams

Crossed

Geotechnical Borings Advanced Near

Alignment (Number) Begin End

Pipeline Alignment

1 Highway 101 and Adairs Slough at Pipeline MP 1 0.9 1.1.2 1,210 Yes S5BCL081B Yes (2)

2 Lewis and Clark River at Pipeline MP 3 2.8 3.4 2,950 Yes S40CL002 Yes (1)

3 Lewis and Clark River at Pipeline MP 5 5.0 5.5 2,450 Yes S5BCL072 No

4 Lewis and Clark River at Pipeline MP 5.5 5.6 6.0 2,100 Yes S99CL064 Yes (1)

5 Lewis and Clark River at Pipeline MP 11 10.9 11.2 1,320 Yes S99CL018 Yes (2)

6 Nehalem River at Pipeline MP 33.5 33.3 33.7 2,010 Yes S99CL108 Yes (2)

7 Highway 26 at Pipeline MP 41 40.9 41.3 1,910 Yes S8BCL005 S8BCL006 S8BCL007

Yes (2)

8 Highway 26 at Pipeline MP 43 43.1 43.6 2,920 Yes S1BCL021 S1BCL022 S1BCL023

Yes (2)

9 Rock Creek at Pipeline MP 57 57.5 58.1 3,000 Yes S3BCO101 Yes (2)

10 Nehalem River at Pipeline MP 64 63.6 64.3 3,370 Yes S3BCO014 Yes (4)

11 Columbia River at Pipeline MP 82.5 81.8 83.0 6,100 Yes S99BCO014 Yes (2)

12 Skipanon River for Terminal Utilities NA NA 1,950 Yes S5BCL075 Yes

SECTION 1

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Introduction LNG Development Company, LLC (doing business as Oregon LNG) proposes to own, construct, and operate a liquefied natural gas (LNG) bidirectional terminal (Terminal) composed of marine facilities, LNG storage tanks, LNG vaporization facilities, natural gas liquefaction facilities, and associated support facilities in Warrenton, Oregon. Natural gas will be transported to and from the Terminal via an approximately 86.8-mile-long, 36-inch outside diameter (OD) bidirectional pipeline (Pipeline) that is being developed by Oregon Pipeline Company, LLC (Oregon Pipeline with LNG Development Company, LLC, Oregon LNG).1 The Pipeline will interconnect with the interstate transmission system of Northwest Pipeline GP (Northwest), a subsidiary of the Williams Companies, at the Northwest Pipeline Interconnect (NPI) near Woodland, Washington.2

1.1 Purpose

The Pipeline will be routed through Clatsop, Tillamook, and Columbia counties in Oregon and Cowlitz County in Washington. An electrically driven gas compressor station (Compressor Station) will be constructed at milepost (MP) 80.8 of the Pipeline. The Terminal, Pipeline, and Compressor Station are collectively referred to as the Bidirectional Project or Project.

The purpose of this report is to discuss the feasibility of using the horizontal directional drilling (HDD) technique to install portions of the LNG Pipeline associated with the Oregon LNG Terminal and Oregon Pipeline (collectively, the Project). The use of HDD installation techniques is proposed at 11 separate locations along the Pipeline and at one location across the Skipanon River to provide utility services from the City of Warrenton to the Terminal. HDDs will be completed where obstacles at the ground surface, such as major roads and rivers, make traditional cut and cover pipeline installation problematic, or where major streams or rivers designated as critical habitat for species listed in the Endangered Species Act (ESA) are crossed.

This report contains a description of the proposed Project, information on the HDD installation technique, a summary of the locations where this technique is being considered, and discussions of surface and geologic conditions at each of the locations. The report also includes a discussion of subsurface conditions for potential HDD locations where site access was arranged to allow for geotechnical drilling. An assessment of the feasibility of successfully completing an HDD installation at each of the locations is provided based on all available information.

Trenchless construction methods differing from HDD are anticipated where the Pipeline crosses Highway 30 near MP 81 and Interstate 5 near MP 85. At these and other locations it is anticipated that LNG Pipeline will be installed using traditional auger bore methods. These installations are not included in this document, which is limited to HDD crossings.

1.2 Project and Site Description Oregon LNG proposes to construct and operate the onshore Terminal and associated facilities on the East Bank Skipanon Peninsula (ESP) near the confluence of the Skipanon and Columbia Rivers at Warrenton, Clatsop County, Oregon. The proposed Project includes construction of a turning basin and berth for loading LNG carriers (LNGCs), facilities to compress the gas at the terminal, facilities to transport natural gas between the existing U.S. transmission grid and the terminal through approximately 86.8 miles of new 36-inch-OD Pipeline, and construction of an interconnection with the existing gas Pipeline grid near Woodland, Washington. The Pipeline will be primarily routed through Clatsop and Columbia Counties in Oregon and Cowlitz County in Washington. The Pipeline alignment is presented in Figures 1-1 and 1-2.

1 The Terminal and Pipeline are proposed at the site, and along the route, of Oregon LNGs proposed LNG import terminal and proposed pipeline that currently are pending before the Federal Energy Regulatory Commissions (FERC) in Docket Nos. CP09-6-000 and CP09-7-000, as amended in Docket No. PF12-18-000. 2 A separate application will be filed by Northwest for the Washington Expansion Project, a capacity expansion to Northwests existing natural gas transmission facilities along the Interstate 5 corridor in the state of Washington.

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1.3 Pipeline Route The 36-inch-OD Pipeline will begin at the Terminal site. The proposed Pipeline will travel southeast, cross Oregon State Highway 101, and run by the west end of one of the Astoria Airport runways. The Pipeline will then run approximately 1.5 miles south and east around the edges of Astoria Airport, and will cross the Lewis and Clark River. The Pipeline will run about 2.2 miles south across dairy cattle pastures and then cross back over the Lewis and Clark River. The Pipeline will then run southwest for approximately a mile until it enters Weyerhaeuser property at MP 6.25. From this point, the Pipeline will run southeast across the coastal range on Weyerhaeuser property to approximately MP 33.2, which is near Jewell Junction. From approximately MP 33.3 to MP 33.7, the Pipeline will cross under the Nehalem River.

Once across the Nehalem River, the proposed Pipeline route will parallel the West Oregon Electric Cooperative (WOEC) power line. This WOEC power line is a 34.5-kilovolt (kV) line that essentially parallels Oregon State Highway 26. The proposed Pipeline alignment parallels the WOEC power line where feasible from Jewell Junction to approximately MP 47.4.

At MP47.4, the Pipeline will be near the four intersecting corners of Clatsop, Tillamook, and Columbia counties. From here the route heads northeast, generally through private timber land. Near MP 56 the Pipeline is approximately 1 mile west of the Vernonia Airfield and it passes approximately 2 miles north of the town of Vernonia between MPs 58 and 61. The Pipeline crosses Highway 47 (Nehalem Highway) in a HDD (HDD Crossing #10) at approximately MP 63.8. From this location the Pipeline travels east until it reaches the Columbia River Valley near MP 80. This portion of the route follows ridgelines where possible, but must drop down to cross Rock Creek at MP 57.5 and the Nehalem River and Highway 47 near MP 64.

The route crosses onto the Columbia River flood plain at approximately MP 80.2. From MP 80.2 to 80.75, it crosses agricultural land. At MP 80.75, the route will cross Highway 30; the crossing will most likely be completed using the auger boring trenchless installation method. Between MP 80.8 and 81.5, the route parallels Highway 30, then roughly parallels the Deer Island Dike Road across a small side channel of the Columbia River to the southern end of Deer Island. The entry point for the Columbia River HDD crossing is at the southern end of Deer Island, just north of the Dyno Nobel outfall channel. The route crosses the Columbia River by HDD, with the eastern exit point on the east side of Dike Access Road in Cowlitz County, Washington. The route passes through more floodplain agricultural land until it reaches Interstate 5 at MP 84.9.

The Interstate 5 crossing will most likely be installed by either pipe ramming or auger boring. At MP 84.9, the route would cross beneath the southbound lanes of Interstate 5. Between MP 84.9 and 85.45 there would be open trench construction in the Interstate 5 median approximately 300 feet wide and accessible from a local street that crosses beneath Interstate 5. At MP 85.45, the route would cross beneath two Burlington Northern Railroad tracks and the northbound lanes of Interstate 5.

From the eastern edge of Interstate 5 to the terminus at MP 86.8, the route passes through mixed use industrial, agricultural, and undeveloped land on the northern outskirts of Woodland, Washington.

In selecting the proposed routes for the Pipeline, Oregon LNG sought to minimize impacts to the environment and landowners by paralleling other linear features to the greatest extent possible or practical.

1.4 Pipeline Design and Safety Standards Oregon LNG will operate and maintain the proposed Pipeline in accordance with the applicable safety standards established by the U.S. Department of Transportation (USDOT), Code of Federal Regulations, Chapter 49, Part 192 (49 CFR Part 192); the Pipeline Safety Improvement Act of 2002; and Oregon LNGs operations and maintenance manual. The standards imposed are in accordance with the Natural Gas Pipeline Safety Act of 1968, as amended. The proposed Pipeline will be operated and maintained in accordance with the regulatory requirements and in a manner such that Pipeline integrity is maintained in the interest of maintaining a safe, continuous supply of natural gas.

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Key provisions of 49 CFR Part 192 that are applicable to the Pipeline include the following:

Thorough and adequate inspection, testing, maintenance, and repair (49 CFR Part 192 Subpart JTest Requirements, Subpart KUprating, and Subpart MMaintenance)

Implementation of damage prevention best practices (49 CFR Part 192.614)

Coordination and preparation for emergency response (49 CFR Part 192 Subpart LOperations)

Identification and mitigation of risks (Pipeline Integrity Management rule for gas pipelines)

Selection and use of qualified materials (49 CFR Part 192 Subpart HMaterials)

Sound system design (49 CFR Part 192 Subpart CPipe Design and Subpart DDesign of Pipeline Components)

Continuous system monitoring and control (49 CFR Part 192 Subpart ICorrosion Control and Subpart LOperations)

Proper Construction (49 CFR Part 192 Subpart EWelding of Steel in Pipelines, Subpart FJoining of Materials Other Than by Welding, and Subpart GGeneral Construction Requirements for Transmission Lines and Mains)

Operations conducted by trained and qualified workers (49 CFR Part 192 Subpart LOperations, Subpart NQualification of Pipeline Personnel, and Appendix C Qualification of Welders for Low Stress Level Pipe)

Welding of the steel pipe will be performed in accordance with API Standard 1104, safety regulations in 49 CFR 192, Transportation of Natural and Other Gas by Pipeline: Minimum Federal Safety Standards, Subpart E, Welding of Steel in Pipelines, and company welding specifications. Completed welds will be visually and radiographically inspected, with pipe welds coated in accordance with Oregon LNGs specifications. The weld joint areas will be coated and the entire pipe will be inspected for defects in the coating and repaired, as needed, prior to being lowered into the trench.

1.5 Horizontal Directional Drilling Description The HDD process involves boring under a feature and pulling the pipeline into place through the borehole that has been reamed to accommodate the diameter of the pipeline. This process has three main phases: pilot-hole drilling, subsequent reaming passes, and pipe pullback.

1.5.1 Pilot Hole The HDD process involves drilling a pilot hole into the ground and following a predetermined path made of straight tangents and long radius arcs. The pilot hole establishes the ultimate position of the installed pipeline. For this operation an initial hole is drilled from the entry point to the exit point on the opposite side of the crossing. The head of the pilot drill string contains steering head, which is an offset joint to provide the directional control of the drill string. By altering (via rotation of the offset joint) or steering the drill head, the operator can control the direction as the drill progresses. Thus, the pilot hole can be directed downward at an angle until the proper depth is achieved, then turned and directed horizontally for the required distance, and finally angled upward to the surface.

The path of the boring can be monitored during drilling by an electronics package contained near the drill bit that transmits data on the drill bits position back to the driller at the surface. Most downhole survey tools are electronic devices that give a magnetic azimuth (for right/left control) and inclination (for up/down control). Surface locators can also be used in conjunction with the downhole electronics package to provide additional information on the location of the drill bit.

As the pilot string is advanced, additional sections of drill pipe and wire are added at the drill rig located at the entry point. Advancement of the steering head and thus the entire drill string is achieved by a high-pressure jet of drilling fluid at the drill head and, in hard soil formations, use of a conventional rotary cone drill bit. The drilling

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fluid (mud) is typically a nontoxic bentonite clay mixed with freshwater to make a viscous slurry. Once the pilot hole exits in an acceptable location, the steering head is removed and the reaming operation is initiated.

1.5.2 Reaming After drilling the pilot hole, the driller typically enlarges the hole by reaming it to successively larger diameters. During the reaming phase, a reaming head is attached to the drill pipe from the opposite side of the drill rig and is pulled back through the pilot hole to enlarge it. Various reaming heads can be used, depending on the substrate encountered, with a fly cutter being the most common. High-pressure drilling fluid is jetted through the reaming head to float out drill cuttings and debris, to cool the reamer, and to provide a cake wall of semisolidified bentonite to stabilize the reamed and enlarged hole. Once the drill hole is enlarged to the proper diameter, the reamers are removed and the pipe is prepared to be pulled back through the reamed hole.

The final hole diameter is defined by a number of factors, such as geology, pipe material and diameter, and crossing length, but is typically a minimum of 12 inches larger than the pipe diameter and up to 1.5 times the pipe diameter.

1.5.3 Pipe Pullback In the final phase of HDD, the pipe is pulled back toward the drilling rig through the reamed drill hole. To facilitate pulling the pipeline into the hole, the Pipeline is typically prefabricated into one continuous string during, or in advance of, the drilling operation, coated, radiographically inspected, hydrostatically tested, and placed on rollers to reduce friction during the pullback. This operation occurs in an additional temporary workspace (ATWS) area commonly referred to the pullback area. Ideally, the ATWS is of sufficient length to allow the entire length of Pipeline being installed to be welded and tested before the start of the installation. A barrel reamer is attached to the end of the drill pipe to further condition the drill hole, and a swivel is attached between the barrel reamer and the Pipeline to abate any rotational forces generated by the rotating drill string. The barrel reamer helps to keep the hole open during the pullback and allows more lubricating drill fluid to be pumped into the hole. Once the pullback operation begins, the Pipeline is typically pulled into the exit hole in one continuous operation until it surfaces at the entry point.

Several pictures of this process, obtained from the Directional Crossing Contractors Association (DCCA, 1995), are shown in Figure 1-1.

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FIGURE 1-1 Illustration of Horizontal Directional Drilling Process

1.5.4 Advantages of Horizontal Directional Drilling If successfully completed, the main advantage of HDD is that impacts to aquatic species, sensitive resources, and water quality can be avoided, and disturbance at the ground surface is limited to the initiation and termination points of the boring. As a result, HDD is more environmentally friendly than traditional cut-and-cover pipeline installation techniques. HDD allows pipelines to be installed beneath rivers without the need to excavate in the river channel, which minimizes the potential for increasing the turbidity of the water. Depending on the obstacle being crossed, it can be easier to obtain regulatory agency approval when HDD techniques are used, and in some instances, it can be more cost effective than traditional pipeline installation techniques.

1.5.5 Limitations of Horizontal Directional Drilling The feasibility of successful HDD completion depends on the subsurface conditions, the required diameter of the bore and length of the crossing, aboveground structures, and the topography along the bore, among other factors. HDD may not be feasible where there is steep ground or constrained geometry on either or both sides of the obstacle being crossed. Additionally, the relative rigidity of the pipe requires long curvatures to navigate large elevation changes. The minimum required length of the bore is a function of the minimum acceptable depth of the bore beneath the obstacle being crossed, the diameter and material of the pipeline being installed, and the topography. For steel pressure pipe, the general rule is that the radius of the pipe curvature should not be less

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than approximately 100 feet for each diameter inch of the pipe. For 36-inch steel pipe, the maximum acceptable curvature and required depth of pipeline beneath waterbodies generally necessitates a minimum bore length of 1,500 feet or more.

Subsurface conditions that may complicate or preclude HDD installation include the presence of flowing sands, coarse-grained materials (gravels, cobbles, and boulders), the presence of wood, and extremely strong or hard bedrock. The presence of cobbles and boulders could lead to hole collapse, or cobbles and boulders could fall into the hole resulting in binding of the drilling rods. A high percentage of gravel (generally greater than 40 to 50 percent) also increases the risk that material will collapse into the bore. Coarse-grained gravel (greater than about 1-inch diameter) and cobbles can be difficult to flush out of the bore and may require the use of thick drilling fluids and high flow rates. Gravel and cobbles in the substrate can also result in difficulty or inability to steer the HDD. While these materials should be avoided, if possible, they are more easily mitigated when the deposits are near the ground surface. If, during the HDD installation, obstructions or a hole collapse occurs, the HDD method can be reattempted along a different drill path or it can abandoned in favor of an alternative crossing method. The duration of a large-diameter HDD may take weeks to months to complete.

Topography also plays an important role in selecting the entry and exit site locations. A relatively flat area that is large enough for the rig and equipment is needed. It is optimal for the entry and exit holes to be as close to the same elevation as possible to allow better circulation and return of the drill mud and cuttings and to mitigate the risk of drill failure. The ATWS is needed to weld-up and test the pipe section for the crossing it must be aligned with the drill path and should be straight. The rig and all support equipment require a good access road with large turnouts. The difficulty in completing a successful crossing becomes greater when these conditions are not present.

The potential for an unintentional escape of drilling fluid, commonly referred to as a frac-out, is another limitation of HDD. Frac-out is sometimes mistakenly associated with the term fracking, which is a common term describing the process of hydraulic fracturing used to improve recovery of oil and gas from deep shale deposits. Because of the potential for confusion, the term inadvertent release is used in this document to describe the unintentional escape of drilling fluid that can occur as part of the HDD process.

During the drilling process, it is necessary for the driller to keep the hole filled with a drilling fluid typically consisting of approximately 5 percent bentonite clay and 95 percent water. The drilling fluid is used to keep the hole open and flush out cuttings. It is important that the driller monitor the pressure of the slurry being pumped into the hole so the pressure is high enough to keep the hole open but low enough that the slurry is not forced out through the soil to the ground surface. Inadvertent releases can range from minor releases, which are easily controlled and cleaned up, to major releases (hundreds of thousands of gallons), which are difficult to clean up and may significantly affect water quality in waterbodies or upland and wetland areas. The probability of an inadvertent release increases when undertaking HDD methods in less-suitable substrates or physical design conditions.

The potential for inadvertent release of drilling fluid is greatest at the beginning and end of the HDD path, where the distance between the boring and the surface is smallest. Inadvertent release can also occur beneath obstacles being crossed, such as rivers, if the HDD path is not drilled deep enough to have sufficient soil cover. The risk of inadvertent release can be minimized before drilling by using knowledge of the subsurface conditions to establish a profile that avoids obstacles in the ground, consists of straight sections and long-radius arches (avoids tight radius curves), and allows for adequate depth of cover. The risk of inadvertent release can be minimized during drilling by developing and following a drilling fluid monitoring program, monitoring slurry pumping rates and pressures, monitoring fluid return rates, watching the ground surface for signs of leakage, prequalifying contractors so that experienced drilling crews are performing the work, and having a plan in place describing what to do if an inadvertent release occurs.

1.6 Proposed Horizontal Directional Drilling Locations The Project proposes HDD crossings at 11 separate locations along the Pipeline alignment, which coincide with 11 streams or rivers that support species listed in the ESA or that have been designated as critical habitat. In

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addition, one HDD crossing of the Skipanon River is proposed to carry utility services from the City of Warrenton to the Terminal. The proposed HDD locations are shown on Project overview maps in Figures 1-2 and 1-3. Table 1-1 presents the crossing location names (which coincide with the main obstacles being crossed), the beginning and ending MPs for each crossing, the approximate crossing length, and an indication of whether the proposed alignment crosses stream(s) with ESA-listed fish. The first column in Table 1-1 contains the HDD Identification (ID) number that correlates with the HDD ID shown in the tables in Figures 1-2 and 1-3.

1.7 Other Locations Evaluated HDDs were evaluated for several other river and stream crossings along the Pipeline alignment and determined to be either infeasible or have elevated risk of inadvertent release of drilling fluids. The feasibility of completing HDD crossings were evaluated for the following locations and the reasons for not competing HDDs at lease locations are provided below. In each of these locations the crossings can be completed using a process called fluming where water is diverted around the crossing location so that the Pipeline can be installed in dry conditions to minimize turbidity and other impacts to the creek.

North Fork Wolf Creek at MP 47.5: Very steep forested ground exists immediately to the north of the creek and continues for about 1,500 feet, at which point the ground continues to rise but on a flatter slope. The elevation difference between the stream and the top of the steep slope is about 300 feet. Highway 26 is located about 1,000 feet south of the crossing location, thereby limiting the availability of an HDD pullback ATWS. Based on these limitations, the HDD crossing was judged to be unfeasible.

Clear Creek at MP 50.5: Steep forested ground exists immediately to the northeast of the creek and continues for about 1,500 feet to a ridge line. Beyond the ridge line, the ground drops for another 300 feet. The elevation difference between the stream and the top of the steep slope is about 450 feet. Sloping ground also exists to the southwest of the crossing. Based on these limitations, the HDD crossing was judged to be unfeasible.

Claskanie River at MP 70.7: Very steep ground exists immediately to the west of the creek and continues for about 1,000 feet to a high point approximately 300 feet above the river crossing. A slope also exists to the east of the crossing and continues for a distance of about 1,000 feet. HDD pullback ATWS on either side of the crossing would be in forested areas and would require the removal of significantly more trees than a flumed crossing. Based on the ground surface limitations, the HDD crossing was judged to be impractical.

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TABLE 1-1 Horizontal Directional Drilling Locations

HDD ID Number

HDD Location (Main Obstacle being Crossed)

MP Approximate Crossing Length (feet)

Crosses Streams with ESA-Listed

Fish

Crosses USACE Flood Control Levee

Begin End

Pipeline Alignment

1 Highway 101 and Adairs Slough MP 1 0.9 1.1 1,210 Yes Yes

2 Lewis and Clark River at Pipeline MP 3 2.8 3.4 2,950 Yes Yes

3 Lewis and Clark River at Pipeline MP 5.0 5.0 5.5 2,450 Yes Yes

4 Lewis and Clark River at Pipeline MP 5.5 5.6 6.0 2,100 Yes Yes

5 Lewis and Clark River at Pipeline MP 11 10.9 11.2 1,320 Yes No

6 Nehalem River at Pipeline MP 33.5 33.3 33.7 2,010 Yes No

7 Highway 26 at Pipeline MP 41 40.9 41.3 1,910 Yes No

8 Highway 26 at Pipeline MP 43.5 43.1 43.6 2,920 Yes No

9 Rock Creek at Pipeline MP 57.5 57.5 58.1 3,000 Yes No

10 Nehalem River at Pipeline MP 64 63.6 64.3 3,370 Yes No

11 Columbia River at Pipeline MP 82.5 81.8 83.0 6,100 Yes Yes

12 Skipanon River for Terminal Utilities NA NA 1,950 Yes Yes

NA = Not Applicable

1.8 Horizontal Directional Drilling Installations Beneath USACE Levees

Six of the twelve HDD installations will cross below flood protection levees as identified in Table 1-1. Federal regulations require that any modifications to an existing USACE project (either federally or locally maintained) that pass over, under, or through levees be approved by either the USACE district engineer or at a higher level of the chief of engineers.

USACE Engineering Manual (EM) 1110-2-1913 (USACE, 2000) provides general guidance for construction of penetrations through levees. Specific guidance for installation of utilities beneath Corps of Engineers levees using HDD methods is provided in ERDC/GSL TR-02-9 document Guidelines for Installation of Utilities Beneath Corps of Engineers Levees Using Horizontal Directional Drilling (USACE, 2002).

Guidelines for penetrations below levees using HDD will be followed in completing additional geotechnical explorations, final design, and construction of HDD levee crossings. Specific items discussed in the guidance reports that will be followed are as follows:

Timing of work. HDD crossings will be completed when risks of flood events are low

The minimum set-back of entry/exit point from the levee toe will be a minimum of 300 feet on the land side of the flood protection levee

The minimum set-back of entry/exit point from the levee toe will be a minimum of 50 feet on the water side of the flood protection levee

The recommended minimum depth of the HDD installed pipe beneath the base of the levee is 15 feet for pipe diameters in excess of 24 inches

Soils investigations are required along the alignment of the proposed HDD and laboratory testing is required to determine characteristics of the stratums penetrated

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An analysis must be performed to determine the factor of safety against inadvertent release along the HDD profile. The factor of safety must be 1.5 or greater within 300 feet of the levee being crossed

In addition to these requirements, additional requirements for construction are provided in the Guidelines for Installation of Utilities Beneath Corps of Engineers Levees Using Horizontal Directional Drilling document (USACE, 2002). Contracts documents developed for construction of the HDD crossings of levees will reference the USACE guidelines and make them requirements of the contract.

1.9 Inadvertent Release Mitigation Measures The following mitigation measures will be implemented to further reduce the risk of an inadvertent release of drilling fluid to the ground surface during the HDD installation process.

1.9.1 Inadvertent Release Contingency Plan An Erosion Control Plan has also been developed for the Project and includes a detailed HDD inadvertent release contingency plan. This plan provides a detailed discussion of planning and prevention, monitoring, containment, and response and notification measures that will minimize the potential for such an occurrence and mitigate potential impacts in the unlikely event of such an occurrence.

A SPCC plan (located in Appendix 2H to Resource Report 2Water Use and Quality [Oregon LNG, 2013a]) has also been developed to address both potential modes of failure, as well as mitigation measures that would be implemented should an inadvertent release occur. The SPCC plan establishes procedures for addressing potential impacts associated with a release of drilling fluid through hydraulically induced fractures during the HDD process. Additionally, the document describes detailed mitigation measures to be implemented to minimize impacts on federally listed aquatic species in the event of an inadvertent release.

1.9.2 Timing of Work Oregon Department of Fish and Wildlife has indicated that HDD crossing streams or rivers that support species listed in the ESA or that have been designated as critical ESA habitat (that is all of the proposed HDD crossings) will be conducted only during recommended in-water work periods to minimize impacts from potential inadvertent release. In addition, HDD crossings of USACE flood control levees will be completed when the risk of flood events is low to minimize the potential negative impacts of the construction on the flood control system.

1.9.3 Fluid Monitoring Programs and Inadvertent Release Prevention Plans A fluid monitoring program and inadvertent release prevention plan will be required from all HDD contractors prior to the start of drilling. The plan will detail specific procedures that the contractor will employ to monitor the pressure, circulation, and loss of the drilling fluid during the HDD installation. The plan will document the process the contractor will follow if partial or complete loss of circulation occurs. The plan will also address the contractors plan for monitoring and testing the viscosity and composition of the drilling fluid. Changes to the drill fluid may provide early warning signs of potential problems.

Construction managers and environmental monitors will oversee HDD operations to confirm contractors are following the processes established in their monitoring programs and inadvertent release prevention plans.

1.9.4 Prequalification of HDD Contractors Minimum requirements for HDD contractors will be established for all HDD crossings associated with this project. All HDD contractors will be required to show a minimum of 3 years experience installing welded steel pipe of similar size and length using the HDD process. Additional experience requirements will be placed on contractors who complete the longer and more complicated HDD installations. It is expected that a minimum of 5 years previous experience will be required for many of the longer or potentially more complicated crossings. Up to 10 years experience may be required on some of the crossings, such as the crossing of the Columbia River.

An experienced and well qualified crew can anticipate problems based on the subsurface material being drilled and take appropriate action to prevent problems, including the inadvertent release of materials, from occurring. In addition to minimum requirements for the HDD contractors, minimum experience requirements will be

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established and enforced for key personnel including the foreman and lead drill operators of the HDD contractor crews.

1.10 Limitations This report has been prepared for specific application to the Oregon LNG Project in Oregon. It has been prepared in accordance with generally accepted geotechnical engineering practice. No other warranty, express or implied, is made.

The geotechnical data contained in this report are based on the soil and rock borings performed during the 2008, 2009, and 2012 geotechnical exploration programs. Exploration data indicate soil conditions and water levels only at specific locations and times, and only to the depths penetrated. Subsurface conditions and water levels at other locations may differ from conditions occurring at these explored locations. The passage of time may result in a change in conditions at these locations.

The opinions related to feasibility of HDD success and risk of inadvertent release of drilling fluid to the surface are provided based on the following:

Topographic, geologic, and subsurface information available at the time of the report preparation

Discussions with HDD contractors familiar with the ground conditions in northwest Oregon and southwest Washington

Capabilities of the HDD technology

Recommendations are provided for obtaining additional site and geotechnical information that will allow for a more thorough evaluation of the feasibility of the proposed HDDs.

CH2M HILL is not responsible for any claims, damages, or liability associated with interpretation of subsurface data or for reuse of subsurface data, without CH2M HILLs express written authorization.

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File Path: \\simba\proj\LNGDevelopment\355036\GIS\MapDocuments\HDD_Feasibility_Assessment\MB_HDDLocationOverview.mxd, Date: May 5, 2009 12:26:36 PM

Figure 1-2

Oregon

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Begin End12 Skipanon River for Terminal Utilities N/A N/A 1,9501 Highway 101/ Adair Slough 0.9 1.1 1,2102 Lewis and Clark River @ MP 3 2.8 3.4 2,9503 Lewis and Clark River @ MP 5.0 5 5.5 2,4504 Lewis and Clark River @ MP 5.5 5.6 6 2,1005 Lewis and Clark River @ MP 11 10.9 11.2 1,3206 Nehalem River @ 33.5 33.3 33.7 2,0107 Highway 26 @ MP 41 40.9 41.3 1,9108 Highway 26 @ MP 43 43.1 43.6 1,920

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File Path: \\simba\proj\LNGDevelopment\355036\GIS\MapDocuments\HDD_Feasibility_Assessment\MB_HDDLocationOverview.mxd, Date: May 5, 2009 12:26:36 PM

Figure 1-3

Oregon

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Tillamook

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Begin End9 Rock Creek @ MP 57.5 57.5 58.1 3,000

10 Nehalem River @ MP 64 63.6 64.3 3,37011 Columbia River @ MP 82.5 81.8 83 6,100

Site ID Drilling Location Milepost Approximate Length (feet)

SECTION 2

ES030613113935PDX 2-1

Project Setting This section describes the physiographic setting and geology along the proposed HDD installation locations. Information provided in this section is developed from published reports and mapping.

2.1 Physiographic Setting The Project will be located in the Coast Range physiographic province of Oregon and the Portland Basin physiographic province of Washington. The Terminal and the segment of Pipeline from approximately MP 0 to 82.4 will be in the Coast Range physiographic province of Oregon. The segment of Pipeline from approximately MP 82.4 to intersection with the Williams Pipeline near MP 86.8 will be in the Portland Basin physiographic province of Washington.

Oregon contains a total of nine physiographic provinces (Orr et al., 1992) and Washington contains eight (Washington State Department of Natural Resources [DNR], 2012).

Oregon and Washington are effectively divided by the north-south trending Cascade Mountain Range. Areas west of the Cascade have substantially different climate and geologic features than the east side. The Project is located in the area west of the Cascade Mountains, which receives significantly more rainfall and has a much higher population density than the area east of the mountains. The proposed Pipeline begins in the Coast Range physiographic province and transitions into the adjacent Portland Basin physiographic province at approximately MP 82.4. Maps showing the physiographic provinces of Oregon and Washington are provided in Figures 2-1 and 2-2. The transition from one physiographic province to another in both Oregon and Washington does not occur at an exact boundary as suggested by Figures 2-1 and 2-2. Rather, the transition occurs gradually over distance. Therefore, the noted MP locations where the Pipeline transitions from one physiographic province to another should be thought of as approximate zones of transition.

2.1.1 Coast Range Physiographic Province The Coast Range physiographic province is a narrow strip of land that extends along most of the Oregon coast and is bounded to the east by the Willamette Valley. It stretches from the Columbia River in the north to the Middle Fork of the Coquille River in the south. This province is approximately 200 miles long and varies in width from about 30 to 60 miles. The ground elevation varies widely across the province, from sea level along the coast to a height of 4,097 feet at Marys Peak (Orr et al., 1992). A narrow belt of mountains that runs parallel to the coast traverses the length of the province. The western slopes of the mountains receive more than 100 inches of rain per year, while the eastern slopes receive only about 30 inches of rain. As recently as 66 million years ago (mya), Oregon had no coastal mountain range. The existing mountains formed during subsequent years as a result of the Cascadia Subduction Zone, located offshore, where the Juan de Fuca plate was driven beneath the North American Plate. The nearby tectonic activity created a seismically active region that is characterized by many faults and nearby volcanoes.

2.1.2 Portland Basin Physiographic Province The Portland Basin is a relatively narrow region that is approximately 20 miles long and 2 to 10 miles wide. It is bounded by the Columbia River on the west and south and by the Cascade Range physiographic provide on the east. The Portland Basin is a lowland area that has been filled by sediment deposits of the ancestral Columbia River and also by deposits from the Lake Missoula Floods that traveled down the Columbia River Gorge. Columbia River basalt underlies much of the Portland Basin at depths around 100 feet or more. Exposures of Columbia River basalt are visible at the edges of the Portland Basin (DNR, 2012).

2.2 Geologic Setting The geology of Oregon and southwest Washington is complex and varies widely across the states. Much of this variation can be attributed to the offshore Cascadia Subduction Zone, which is where the Juan de Fuca Plate is being actively subducted beneath the western margin of the North American Plate. The ongoing subduction has

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2-2 ES030613113935PDX

created accretionary wedges, fore-arc sediment basins, uplift of the Oregon Coast Range, and a seismically active area with numerous faults, volcanoes, mountains, and valleys (Orr et al., 1992).

Like much of the rest of the west coast of North America, the geologic history of the Project area is defined primarily by near-shore ocean basins and their sedimentary record. Surficial geology within the vicinity of the Project area generally consists of Quaternary aged alluvial deposits and sedimentary rock and igneous rock (primarily basalt) units from the Quaternary and Tertiary periods. Periods of uplift also occurred, leading to precursors of the current Coast Range. These episodes typically are characterized by unconformities in the geologic and paleogeographic record. The Tertiary sediments in the area represent two series: the first is a lower, Eocene-age section separated by an unconformity from the second series, which consists of an upper Oligocene to Miocene-age sequence of sediments. In both series, there are initial deeper-water sediments grading upward to shallow-water and terrestrial sediments, including coal beds. The intervening unconformity represents a period of uplift thought to have been controlled by the relative motion of the Juan de Fuca and North American plates.

Volcanic rocks are also an important part of the geologic record in this area. They include the remnants of volcanism associated with subduction on an active continental margin, as well as basalts attributable to the cataclysmic Miocene basalt floods that originated in the Columbia Basin area. Tuffaceous sedimentary units, as well as sandstones derived primarily from volcanic rocks, are therefore common in many of the sedimentary units discussed in this section.

2.2.1 Project Geology Overview The proposed Terminal will be located near the mouth of the Columbia River, where it enters the Pacific Ocean. This site consists of hundreds of feet of alluvial sediments deposited by the river over thousands of years. The proposed Pipeline loops through the Coast range, dips down into the Columbia River Valley between MP 80 and 81, then begins to climb the Cascade foothills at approximately MP 85.5. The proposed Pipeline will cross many different types of soils, bedrock, and geologic formations along its 87-mile route inland.

Geologic maps prepared by the Oregon Department of Geology and Mineral Industries (DOGAMI) available from the Oregon Geologic Data Compilation Release 5 (DOGAMI, 2009) and Washington DNR Surface Geology (DNR, 2010), in cooperation with the United States Geological Survey (USGS), were used to determine the geologic units mapped at each of the proposed HDD locations.

The major surficial geologic units that are mapped at proposed HDD locations are discussed in additional detail in Section 6.1 of Oregon LNG Bidirectional Project Resource Report 6Geological Resources (filed with FERC by Oregon LNG under docket numbers CP13-__ and CP13-___-000) (Oregon LNG, 2013b).

2.2.2 Quaternary Deposits The Quaternary period refers to the Pleistocene and the more recent Holocene epochs, or from about 1.7 mya to the present. Quaternary period sediments are often unconsolidated to semiconsolidated and are frequently not given formation names as is the case with older rocks. They generally consist of a heterogeneous mixture of clay, silt, sand, and gravel. The Quaternary sediment deposits (identified as Quaternary Alluvium, Young Alluvium, Recent Alluvium, and Alluvial Deposits) located along the Pipeline alignment are generally present from the Terminal site to approximately MP 6 along the Pipeline and from the eastern edge of the Coast Range physiographic province through the Portland Basin physiographic province (approximately MP 80 to 85). These deposits are also locally present along streams and drainages throughout the Coast Range, such as the Adairs Slough and Lewis and Clark River. Quaternary terrace deposits (identified as Quaternary Terraces and Terrace Gravel) are generally the most coarsely grained of these Quaternary deposits and are present where major Coast Range rivers enter the coastal lowlands. They can also be traced farther upstream as much thinner valley trains of coarse gravel.

2.2.3 Sedimentary Rock Units 2.2.3.1 Tertiary Sedimentary Rocks As with much of North Americas Pacific Coast from San Diego County northward, the geology of the study area is typified to a large extent by Tertiary marine sediments. These represent former, offshore basins that were

2 1BPROJECT SETTING

ES030613113935PDX 2-3

subsequently accreted to the western edge of the North American plate during its collision with the Pacific plate in the Cenozoic epoch (the last 65 million years). As may be expected from accretionary processes that have been occurring for tens of millions of years, marine sedimentary units tend to decrease in age as the current shoreline is approached. Near the top of the marine sediment section, which in most areas is Miocene in age, the marine sedimentary units are intercalated with flood basalts that originated in the Columbia Basin and flowed all the way to what was then the coast.

Generally, marine sedimentary rock formations are spatially variable, sometimes over short distances. The specific sedimentary units are discussed below, listed generally in order of their first occurrence, from the Terminal and MP 0 of the Pipeline corridor to the eastern terminus of the Project at approximately MP 86.8.

2.2.3.2 Yamhill Formation The Yamhill Formation consists of bedded shale and siltstone, with occasional interbeds of arkosic as well as basaltic sandstone. One prominent sandstone member is mentioned by Myer et al. (2005). Locally interbedded basaltic lava flows and lapili tuffs are found, as well as infrequent limestone concretion zones interbedded with the finer-grained rocks. Limestone beds increase in thickness to the south and toward the base of the formation (Bostrom and Komar, 1997).

2.2.3.3 Hamlet Formations, Including the Sunset Highway, Roy Creek, and Sweet Home Creek Members

The Hamlet Formation is a generally massive mudstone, carbonaceous and biotite rich, with thinner beds of fine to coarse sandstone. The Hamlet Formation has three members the Sunset Highway, Roy Creek, and Sweet Home Creek. The Sunset Highway member is an interbedded basaltic sandstone with arkosic strata, with coarser interbeds and debris flow deposits that occurs at MP 52.

The Roy Creek member is a generally unstratified basalt conglomerate that is commonly overlain by well-bedded, pebbly, very coarse to fine-grained fossiliferous basaltic sandstone. The conglomerate consists of very poorly sorted, frame-supported subangular to rounded cobbles and boulders of basalt and basaltic andesite to rare dacite in a volcaniclastic sandstone matrix. The overlying sandstone ranges from approximately 10 to 100 feet in thickness, and is brown to green, poorly to moderately sorted, massive to commonly thinly bedded, and contains common molluscan fossils. The Roy Creek member commonly overlies the Tillamook Volcanics and its molluscan fauna is similar to the type found in the upper Eocene Cowlitz formation in southwestern Washington (DOGAMI, 1985). It occurs along the Pipeline route from approximately MP 34 to 46.

The Sweet Home Creek member is typically interbedded carbonaceous mudstone and rhythmically bedded arkosic turbidite sandstones. It is found intermittently between MP 46.5 and 53.

2.2.3.4 Cowlitz Formation, Including the Clark and Wilson Sandstone Member The Cowlitz Formation is well-known throughout the Puget Lowland and lower Columbia River area as a fossiliferous geologic formation that is host to fossil fuel deposits (coal and gas). It can be found along the Pipeline route from approximately MP 48.3 to 48.5, 50.4 to 51.5, and 53.0 to 53.6. The lithology of the Cowlitz Formation is complex; it consists of interbedded shallow marine and nonmarine sediments, as well as volcanic and pyroclastic rocks. In general, it is frequently manifested as a micaceous, arkosic-basaltic marine sandstone, siltstone, or mudstone. Collectively, these sediments represent a deltaic environment on the margin of a fore-arc basin that occupied southwestern Washington and northwestern Oregon.

2.2.3.5 Keasey Formation Outcrops of the Keasey Formation appear along the Pipeline route between MP 31.6 to 33.4, 49.0 to 50.4, and 53.6 to 61.2. The Keasey Formation is a thinly bedded to laminated, glacionitic to tuffaceous siltstone with arkosic lenses. It contains tuffaceous strata, as well as beds containing calcareous concretions.

2.2.3.6 Middle and Upper Eocene Tuffaceous Siltstone and Sandstone This unnamed geologic unit was mapped by Walker and MacLeod (1991) and includes (among others) the Spencer, Keasey, and Sager Creek formations, and the Pittsburg Bluff, Smuggler Cove, and Northrup Creek formations. The Tuffaceous Siltstone and Sandstone consists of bedded marine mudstones and sandstones that

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contain calcareous concretions and are carbonaceous in places. The mapping shows Tuffaceous Siltstone and Sandstone outcropping along the Pipeline route between MP 61.1 and 64.8 and 79.2 to 79.9.

2.2.4 Igneous Rock Units Igneous rock units mapped in proposed HDD locations include the Tillamook Volcanics unit, the Columbia River Basalt Group, and the Cole Mountain Basalt unit. This unit was mapped by DOGAMI (1985) and consists of subaerial aphyric to abundantly plagioclase- and pyroxene-phyric, dark-gray to greenish-gray, high-titanium basalt and basaltic andesite flows with red oxidized to deeply weathered vesicular top and bottom flow breccias. Lavas have platy to blocky columnar-jointed interiors. The upper part of this unit also contains some volcanic mudflow breccias, basalt conglomerate, lapilli tuffs, basaltic sandstone, and minor medium-dark-gray to reddish oxidized siltstone interbeds. Locally, flows and breccias are hydrothermally altered. This unit is believed to have been deposited during the upper to middle Eocene epoch. The Tillamook Volcanics Unit is mapped intermittently along the Pipeline route from approximately MP 41 to 53. The Columbia River Basalt Group is mapped between MP 11.3 to 11.5, 12.0 to 12.5, 30.4 to 30.5, 65.4 to 70.5, 70.8 to 71.0, 71.2 to 74.0, and 74.9 to 78.1. The Cole Mountain Basalt unit is mapped from MP 40.1 to 40.4.

2.2.5 Volcanic Rock Units Flows of the Columbia River Basalt Group erupted from fissures in eastern Washington and Oregon, traversed the Cascade Range via and ancestral Columbia River valley, and spread out to cover large areas of the coast range province. In the Deer Island area near the crossing of the Columbia just north of Columbia City, these flows are believed to be the Grande Ronde Basalts and the Volcanic Breccia of Troutdale Formation (Evarts, 2002).

Source: Orr, Elizabeth et al. Geology of Oregon. 1992. Fourth Edition. Dubuque, Iowa: Kendall/Hunt Publishing Company.

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Figure 2-2Physiographic Provinces

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Range

PUBLIC

Source: Washington State Department of Natural Resources (DNR). 2012. Geology of Washington. Obtained from website http://www.dnr.wa.gov/ResearchScience/Topics/GeologyofWashington/Pages/geolofwa.aspx. Last accessed March 16, 2012. Website contained modified text from the following article: Lasmanis, Raymond. 1991. The Geology of Washington: Rocks and Minerals. v. 66. no. 4. p. 262-277. Copyright Heldref Publications.

COLUMBIA

BASIN

BLUE

MOUNTAINS

CASCADE

RANGEOLYMPIC

MOUNTAINS

WILLAPA

HILLS

PORTLAND

BASIN

PUGET

LOWLAND

OKANOGAN HIGHLANDS

YAKIMA

FOLD BELT

PALOUSE

SLOPE

NORTH EASTWEST

SOUTH

SECTION 3

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Preliminary Geotechnical Exploration 3.1 Field Exploration Program The preliminary geotechnical field exploration program for the proposed Project was conducted between October 2008 and March 2009 and February and April 2012. The explorations consisted of advancing a total of 21 borings in the vicinity of proposed HDD locations. Geotechnical borings were advanced where access to private land was granted by property owners or where borings could be advanced from public highways or roads. At least one boring was advanced in the vicinity of 11 of the proposed HDD locations. Borings were not advanced in the vicinity of one proposed HDD location because of the inability to gain access to privately held property on which the locations are situated. Additional borings will be needed to support final design of the HDDs.

3.1.1 Geotechnical Borings Nineteen of the 21 geotechnical borings were advanced by Western States Soil Conservation, Inc., of Hubbard, Oregon. Twelve of the borings were drilled during the original exploration between October 2008 and March 2009. An additional eight borings were drilled between February and April, 2012, for the Columbia County reroute portion of the pipeline. These borings were advanced using a track-mounted CME 55 high torque (HT) drill rig, a truck-mounted CME 75 HT drill rig, and a truck-mounted CME 55 HT drill rig. The drilling was performed using mud rotary drilling techniques. Borings were advanced to depths ranging from 61.5 feet to 200 feet. In two of the borings, H2641BH-A and NR51BH-A, rock coring techniques using NQ-size core, were used when rock was encountered. Rock coring using HQ Triple-Tube techniques was used after competent rock was encountered in Borings NR-1, NR-2, and NR-4, and was attempted without much success in Borings RC-1, RC-2, and CR-1. Loss of circulation from shallower depths and hole squeezing were generally the cause of coring difficulties. The approximate locations of borings are shown in Figures 3-1 through 3-10.

One boring, Boring BH-36, was advanced by Boart Longyear, of Tualatin, Oregon from August 10 to August 13, 2007. This boring was advanced in the vicinity of the proposed HDD crossing of the Skipanon River to provide utility service to the Terminal using a truck-mounted CME 850 drill rig and mud rotary techniques. The boring was advanced to a depth of 101.5 feet below ground surface (bgs). The approximate location of the boring is shown in Figure 3-11.

The one remaining boring was advanced by Hardcore Drilling, Inc., of Dundee, Oregon, from January 8 to January 9, 2009. This boring was advanced in the vicinity of the proposed HDD crossing at Lewis and Clark River at Pipeline MP 11 using a truck-mounted CME 75 drill rig and mud rotary techniques. The boring was advanced to a depth of 70 feet bgs in the vicinity of the location where Western States Soil Conservation, Inc., had previously advanced a boring to 36.5 feet and abandoned the hole because of difficult drilling conditions and slow advancement rate. The boring advanced by Western States Soil Conservation, Inc., is LCR11BH-A1. The boring advanced by Hardcore Drilling, Inc., is LCR11BH-A2. The approximate location of the Hardcore Drilling boring is shown in Figure 3-4.

Borings were abandoned in accordance with Oregon Administrative Rule 690-240.

CH2M HILL provided continuous observation and logging of the boreholes. Unless otherwise noted, the locations of the borings were identified and recorded using a handheld global positioning system (GPS) receiver (Garmin GPSmap 60CSx) that has a horizontal accuracy of approximately 15 feet. Surface elevations were estimated based primarily on USGS Digital Elevation Models, which are based on the North American Vertical Datum of 1988 (NAVD88). At some locations this information was supplemented with elevation data from the Google Earth computer program. A summary of the borings is presented in Table 3-1. The approximate locations of the borings are shown in relation to the proposed HDD alignments in Figures 3-1 through 3-11.

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TABLE 3-1 Geotechnical Boring Summary

HDD Location Boring

Advanced

Boring Location Approximate Ground

Surface Elevation (feet) Completion Depth

(feet, bgs) Northing Easting

Pipeline Alignment

Highway 101 and Adairs Slough ASBH-B 928469 7341047 10 86.5

ASBH-C 926603 7343038 10 86.5

Lewis and Clark River at MP 3 LCR3BH-A 921944 7348599 6 81.5

Lewis and Clark River at MP 5.0 No borings advanced

Lewis and Clark River at MP 5.5 LCR55BH-B 907732 7348758 37 100.3

Lewis and Clark River at MP 11 LCR11BH-A1 885627 7350926 43 36.5

LCR11BH-A2 885627 7350926 43 70.0

Nehalem River at MP 33.5 NRBH-A 819182 7420144 440 66.0

NRBH-C 819320 7420708 425 71.0

Highway 26 at MP 41 H2641BH-A 793075 7444274 1445 120.1

H2641BH-B 791774a 7443809a 1420 75.2

Highway 26 at MP 43 H2643BH-A 785663 7451371 1560 65.1

H2643BH-B 785195 7453073 1610 72.6

Rock Creek at MP 57 RC-1 818289 7501947 742 100.5

RC-2 819703 7504012 782 114.0

Nehalem River at MP 64 NR-1 828417 7527138 736 100.0

NR-2 828302 7527869 592 150.0

NR-3 827891 7529829 585 200.9

NR-4 827822 7530829 773 100.0

Columbia River at MP 82 CR-1 829825 7612613 22 120.1

CR-4 829766 761664 23 120.3

Skipanon River for Terminal Utilities BH-36b 932233.25 b 7338313.24 b 14.3 101.5

Notes: a Unless noted otherwise, coordinates were estimated using the Google Earth computer program. b Horizontal and vertical controls were surveyed using a Leica GPS base and rover. Northing and easting coordinates were collected using a handheld Garmin GPSmap 60CSx GPS receiver. Coordinates are based on Oregon North State Plane, NAD83, International feet. Elevations are referenced to the North American Vertical Datum of 1988 (NAVD88).

3.1.2 Soil Sampling Soil samples were collected from the boreholes using primarily a standard 2-inch-outside-diameter split-spoon sampler in accordance with standard procedures outlined in American Society for Testing and Materials (ASTM) D 1586, Standard Test Method for Standard Penetration Test (SPT) and Split-Barrel Sampling of Soils. This test is used to characterize the consistency of fine-grained soil or the relative density of coarse-grained soil by measuring penetration resistance expressed as blow counts, or N-value. The blow count is the number of blows required to advance the standard split-spoon sampler 6 inches with a 140-pound hammer falling 30 inches. The sampler is driven 18 inches and the blow count is recorded for each 6-inch increment. The sum of the blow counts for the second and third increments is referred to as the N-value in blows per foot (bpf). Low N-values indicate soft or

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loose soil; high N-values are evidence of hard or dense materials. After the sampler is driven and the blow counts are recorded, the sampler is withdrawn from the borehole to recover a disturbed soil sample. Soil samples were occasionally collected using a 3-inch-outside diameter split spoon sampler, commonly referred to as a Modified California Sampler, in accordance with ASTM D 3550, Standard Practice for Ring-Lined Barrel Sampling of Soils. This larger-diameter sampler is used to obtain larger-sized recovery material or to obtain soil samples in brass rings so that compression and shear testing can be performed. Unless specifically called out differently on the logs, the standard diameter sampler was used.

In select locations, relatively undisturbed samples of fine-grained soils were collected in accordance with standard procedures outlined in ASTM D1587, Standard Practice for Thin-Walled Tube Sampling of Soils for Geotechnical Purposes. A soil sample in this test is recovered by pushing a 36-inch-long steel Shelby tube having a 3-inch OD and 0.065-inch wall thickness into the bottom of the borehole. The tube, together with the encased soil, is then removed from the borehole and sealed before transporting. The sealed sample can be extruded from the tube and logged or used for other laboratory tests.

The visual classification of soil allows convenient and consistent soil comparison using a standard method for describing the soil. Soil classification systems attempt to group soil having similar engineering behavior (based on index tests). Several classification systems have been developed, usually for a specific application. The system most generally accepted for a wide range of engineering applications is the Unified Soil Classification System (USCS). The use of this method of classification provides a basis for comparison of soil from widespread geographic areas. Soil samples from the soil borings were examined and visually classified in accordance with ASTM D 2488, Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), which uses the USCS guidelines.

Disturbed samples were placed in sealable plastic bags. Sampling intervals and field classifications of soil samples are recorded on the soil boring logs presented in Appendix A.

3.1.3 Rock Core Drilling and Sampling In a number of boring locations rock core drilling procedures were initiated when relatively intact rock was encountered. Coring was performed in accordance with ASTM D 2113, Standard Practice for Rock Core Drilling and Sampling of Rock for Site Investigation. The rock cores were advanced using either an HQ or NQ-sized diamond core drill bit and recovered using a triple-barrel rock core sampler and wireline. The drill bit and core barrel were rotated at high speeds. The cuttings were brought to the surface by circulating water. Rock core samples of the material penetrated were protected and retained in the inner sampler barrel. Upon completion of the core run, the core barrel was brought to the surface for logging and the recovered rock core was labeled and placed in core boxes. The rock recovery and rock quality designation (RQD) were determined and recorded for each core run.

The recovery is the ratio of the rock core length obtained to the depth interval drilled, expressed as a percent. The RQD is the percentage of the length of rock core recovered that is 4 or more inches long compared to the total length of the run. The percent recovery and RQD are related to rock soundness and continuity. The RQD values serve as relative indicators of rock quality. Rock hardness terminology from the Oregon Department of Transportation (ODOT) Soil and Rock Classification Manual (ODOT, 1987) was used to describe the relative hardness of the rock. A table showing the relative rock hardness categories is included at the front of Appendix A. Generalized rock descriptions, percent recovery, RQD values, hardness, discontinuities, lithology, and the bit size used are presented on the rock coring logs in Appendix A. Photographs of the recovered rock core are presented in Append