B08__A9_Geotechnical_Data_Report.pdf

Wapato Irrigation Project – Drop 1 Pumping Plant Structure

Geotechnical Data Report

Final

October 13, 2023

United States Department of the Interior, Bureau of Indian Affairs

Contract No. 140A1218D0020/140A1622F0179

Task 12 – Foundation Assessment

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BIA Wapato Drop 1 Pumping Plant Geotechnical Data Report ii

Project No.: D3673800

Document Title: BIA Wapato Drop 1 Pumping Plant Geotechnical Data Report

Document Status: Final

Date: October 13, 2023

Client Name: United States Department of the Interior, Bureau of Indian Affairs

Project Manager: Ron Fehringer

Author: Yvonne Wangare, Aynaz Biniyaz

Checked: Mohsen Kargar

Reviewed: Mark Kacmarcik

File Name: BIA Wapato Drop 1 Geotechnical Data Report

CH2M HILL Inc., a Jacobs Engineering Group Inc. Company

999 W. Main St., Suite 1200 Boise, ID 83702 United States T +1.208.345.5310 www.jacobs.com

© Copyright 2023 Jacobs Engineering Group Inc. The concepts and information contained in this document are the property of Jacobs. Use or copying of this document in whole or in part without the written permission of Jacobs constitutes an infringement of copyright.

Limitation: This document has been prepared on behalf of, and for the exclusive use of Jacobs’ client, the United States Department of the Interior, Bureau of Indian Affairs, and is subject to, and issued in accordance with, the provisions of the contract between Jacobs and the client. Jacobs accepts no liability or responsibility whatsoever for, or in respect of, any use of, or reliance upon, this document by any third party.

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Contents

1. Introduction .................................................................................................................................................................. 1-1

1.1 Project Description ....................................................................................................................................................................... 1-1

1.2 Objective and Scope of Work ................................................................................................................................................... 1-1

2. Field Investigation and Laboratory Testing .......................................................................................................... 2-1

2.1 Subsurface Investigation ............................................................................................................................................................ 2-1

2.1.1 Geotechnical Borings .................................................................................................................................................................. 2-1

2.1.2 Piezometer Installations ............................................................................................................................................................ 2-2

2.2 Laboratory Testing ....................................................................................................................................................................... 2-3

3. Subsurface Conditions................................................................................................................................................ 3-1

3.1 Geology ............................................................................................................................................................................................. 3-1

3.1.1 Regional Geology ......................................................................................................................................................................... 3-1

3.1.2 Project Area Geology ................................................................................................................................................................... 3-1

3.2 Soil Profile ....................................................................................................................................................................................... 3-2

3.2.1 Concrete Slab ................................................................................................................................................................................. 3-2

3.2.2 Fill ....................................................................................................................................................................................................... 3-2

3.2.3 Fine-grained Alluvial Deposit – Dominantly Lean Clay ................................................................................................. 3-2

3.2.4 Coarse-grained Alluvial Deposit – Dominantly Silty Sand ........................................................................................... 3-2

3.3 Groundwater ................................................................................................................................................................................... 3-3

4. Limitations .................................................................................................................................................................... 4-1

5. References ..................................................................................................................................................................... 5-1

Appendices

Appendix A Borehole Logs Appendix B Concrete Slab Corehole Repair Plan Appendix C Piezometer Completion Diagrams Appendix D General Site Photographs Appendix E Laboratory Test Results Appendix F Groundwater Monitoring Data (Ongoing) Appendix G Sonic Core Sample Photographs iii

Tables

2-1 Summary of Geotechnical Investigation Performed by Jacobs .................................................................................. 2-4 2-2 Piezometer Installations ............................................................................................................................................................ 2-5 2-3 Summary of Laboratory Test Results .................................................................................................................................... 2-6 2-4 Summary of the Soil Samples Selected for Advanced Laboratory Testing ........................................................... 2-9 3-1 Summary of the Measured Groundwater Data from Piezometers from April to September 2023 ............. 3-3

Figures

1-1 Vicinity and Location Map 2-1 Geotechnical Field Exploration Locations 3-1 Project Site Geology Map 3-2 Subsurface Soil Profiles iv

Executive Summary

This Geotechnical Data Report (GDR) documents the findings of the geotechnical subsurface investigation program performed between March 6 and March 21, 2023, in support of the Wapato Irrigation Project – Drop 1 Pumping Plant (the Project) located in Wapato, Washington.

The geotechnical subsurface investigation program consisted of 11 soil borings, 4 of which were converted to open standpipe piezometers. Two stilling wells were installed, one in the forebay and one in the tailrace, for monitoring water surfaces upstream and downstream of the drop structure and pumping plant. Boreholes were advanced from the top of east and west canal banks, the canal floor in the forebay, and tailrace areas with depths ranging from 26.3 to 61.0 feet below ground surface (bgs). The drilling was conducted using rotosonic drilling techniques, which recover near-continuous, disturbed, soil samples. Standard penetration testing (SPT) was conducted at approximately 5-foot intervals.

Continuous field observation and soil logging were conducted under the direct supervision of Jacobs geotechnical engineering staff. Sample descriptions, results of field tests, and observations made during drilling were recorded on soil boring logs. Soil samples from SPT testing and rotosonic cores were examined and visually classified on site. Representative portions of disturbed samples were retained in sealed plastic bags for laboratory testing.

Geotechnical index and advanced laboratory testing have been conducted on representative soil samples obtained during the investigation to provide soil classification and engineering properties of soil samples. The index tests comprise moisture content, particle size analysis (sieve, hydrometer, fine content), Atterberg Limits, compaction, and specific gravity. The advanced tests consist of consolidated-undrained and unconsolidated undrained triaxial tests, direct shear test, and hydraulic conductivity.

The subsurface conditions consist of a loose to medium dense fill layer, with depths ranging from 0.5 foot to 15 feet bgs overlying native alluvial deposits. The fill material has a dominant soil type of silty sand with varying amount of gravel and occasional organic inclusions. The fill layer was underlain by a 0.5 foot to 20 feet thick layer of unconsolidated fine-grained clayey soil with low to medium plasticity and typically soft to firm consistency for the boreholes drilled from the canal banks. The clay layer was underlain by a dense to very dense silty sand with varying amounts of gravel extending to the termination depths. This layer was encountered immediately below the concrete floors for the boreholes drilled within the bottom of the tailrace.

Upon completion of boreholes, four borings were converted to open standpipe piezometers for future groundwater monitoring, particularly to observe canal water level fluctuations during the irrigation season. The remainder of the borings were abandoned by filling with cement-bentonite grout placed using tremie methods.

The open standpipe piezometers consist of a 2-inch-diameter polyvinyl chloride (PVC) casing and a 10-foot-long machine-slotted screen. Additionally, two vertical PVC pipe stilling wells were installed to measure water levels in the forebay (upstream of the pumping plant facility) and tailrace (downstream of the facility). Data loggers were also installed at the location of piezometers and stilling wells to continuously record the water level data.

Dataloggers connected to vibrating wire pressure transducers installed in four borings and two stilling wells collect near-continuous data at these locations. The groundwater levels are expected to fluctuate with time, depending on canal operations, precipitation, seasonal variation, and other factors. Data is stored within the dataloggers, downloaded approximately monthly, and verified with manual field measurements. At the time of this report submission (October 2023), groundwater data collection is ongoing.

This report summarizes the piezometer, forebay, and tailrace water surface elevation data collected from April to September 2023. This information will be updated in the future at the conclusion of monitoring in April 2024.

Preliminary data indicates the groundwater elevation ranges from 897 to 918 feet above sea level. Also, surface v water elevation in the canal increased from 928.9 to 934.5 feet above sea level in the forebay and from 905.0 to

912.6 feet above sea level in the tailrace during the current monitoring period.

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1. Introduction

This Geotechnical Data Report (GDR) has been prepared for the United States Department of the Interior, Bureau of Indian Affairs (BIA) for the Wapato Irrigation Project (WIP) – Drop 1 Pumping Plant (Project) located in Wapato, Washington. It documents the results of the Project-specific geotechnical field investigations and laboratory soil tests and as regional and local geological summaries. Jacobs planned, coordinated, and led the geotechnical subsurface investigations and prepared this GDR for the BIA in accordance with Task 12 – Foundation Assessment, under Contract No. 140A1218D0020 Task Order No.

140A1622F0179.

1.1 Project Description

The WIP provides irrigation water to approximately 140,000 acres of farmland within the Project boundaries. The Drop 1 Pumping Plant is an integral component of the WIP Main Canal System that lifts up to 165 cubic foot per second (cfs) of water to serve approximately 7,000 acres of upper land along the northwest perimeter of the Project. The Drop 1 Pumping Plant structure is also a distribution junction for the Main Canal, with water being divided into the East and West Highline Canals (up to 165 cfs), the Main Extension Canal (up to 225 cfs) and dropped downstream into the continued Main Canal (up to 1500 cfs) at this location.

The Drop 1 Pumping Plant was completed in 1929 and consists of the following facilities:

A pumping plant structure and discharge pipeline serving the Unit 1 (East and West Highline) Canals

An attached gated drop structure and spillway (to pass Main Canal flows downstream when there is excess to hydraulic turbine pump needs or when the pumps are off)

An attached gated headworks structure serving the Main Extension Canal

Suspended electrical pumps that supplement flows to the discharge pipeline serving the Unit 1 canals

The Project is in Yakima County, approximately 8.2 miles south of the City of Yakima in Township 12N, Range 18E, Section 36, as referenced from the Willamette Principal Meridian. It is on the WIP Main Canal at canal station 230+49, which is approximately 4.4 miles downstream from the diversion headworks.

Project site coordinates are approximately 46° 29.055’ North latitude, 120° 31.420’ West longitude

(WGS84).

The site is 0.5 mile north of Lateral 1 Road, which crosses the WIP canal on a bridge approximately

3.7 miles east of U.S. Highway 97. Where Lateral 1 Road crosses the canal, the site can be accessed via Adams Lane, which parallels the canal on the west side and leads to the BIA office and drop structure. A gravel road on the eastern canal bank can be used to access the pumping plant. Figure 1-1 shows the location and vicinity map of the Project.

1.2 Objective and Scope of Work

The scope of the geotechnical assessment for the Project consists of the following objectives:

Review the available geological documents associated with the area.

Perform soil borings and conduct laboratory tests to characterize subsurface conditions.

Install groundwater monitoring piezometers in selected borings to monitor groundwater levels.

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Install stilling wells within the forebay and tailrace to measure surface water levels upstream and downstream of the pumping plant facility.

Evaluate site conditions and summarize general site data.

Prepare this GDR.

The information gathered and summarized in this GDR are intended to support the selection of engineering properties to be used in development of geotechnical design and construction recommendations.

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2. Field Investigation and Laboratory Testing

The Project-specific field investigation program was conducted by Jacobs, and it included geotechnical borings used to obtain samples for laboratory soil testing, observe subsurface conditions, and install open-standpipe piezometers for groundwater monitoring. A laboratory testing program was performed to confirm field soil classifications and estimate engineering properties of the representative soil samples obtained from the borings.

2.1 Subsurface Investigation

Eleven soil borings, identified as borings B01-23 through B11-23, were completed at the Project site between March 6 and March 21, 2023. Four of the borings were converted to open-standpipe piezometers.

Additionally, two vertical polyvinyl chloride (PVC) pipe stilling wells, S01-23 and S02-23, were installed to measure water levels in the canal forebay and tailrace, respectively. The geotechnical boring and stilling well locations were surveyed after the completion of the field investigations by Anderson Perry & Associates, Inc., of Walla Walla, Washington, and documented in BIA-WIP, Drop1, Pumping Plant, Forebay, Phase 3, Task 11 Drawings dated May 4, 2023 (Anderson Perry & Associates 2023). All elevations are reported in feet and refer to the North American Vertical Datum of 1988 (NAVD88), and the horizontal datum is the Universal Transverse Mercator (UTM) Zone 10 North. Figure 2-1 identifies the locations of the geotechnical investigations advanced for the Project. Tables 2-1 and 2-2 summarize the geotechnical investigation locations and details.

2.1.1 Geotechnical Borings

The geotechnical borings and open standpipe piezometers were completed by Western States Soil Conservation, Inc. (Western States), of Hubbard, Oregon, under contract to GN Northern, Inc. (GN Northern), of Yakima, Washington. GN Northern was subcontracted to Jacobs.

Prior to drilling, the borehole locations were marked and reported to Washington One-Call services for utility locating. Geophysical Survey LLC of Kennewick, Washington, provided private utility locating services. BIA provided cultural resources clearances prior to the start of the work.

Western States advanced the borings using a GeoProbe model 8150 track-mounted drill rig and 4 inch by 6 inch rotosonic drilling technique with continuous solid casing. That is, the drilling method advanced a 4-inch-diameter core barrel, which was advanced in maximum 5-foot intervals and cased with a 6-inch-diameter continuous casing. All drilling was performed at vertical orientation. The borings were drilled to depths ranging from 26.3 to 61.0 feet below ground surface (bgs). Representative disturbed soil samples were collected from the rotosonic cores and supplemented with Standard Penetration Test (SPT) samples. SPT samples were collected using a 2-inch outside-diameter split spoon sampler at approximately 5-foot intervals. The split spoon sampler was driven 18 inches using a 140-pound automatic hammer falling 30 inches in accordance with the ASTM D1586, Standard Test Method for Standard Penetration Test (SPT) and Split-Barrel Sampling of Soils. The total number of blows required to advance the sampler 12 inches beyond the first 6-inch increment was recorded in the boring log as the STP blow count, or N-value. When the sampler required more than 50 blows to penetrate 6 inches, the test was stopped at 50 blows, and the measured penetration was recorded as “refusal.” The rotosonic core barrel was used to collect continuous discrete samples every 5 feet.

Continuous field observations and soil logging were conducted under the direct supervision of Jacobs geotechnical engineering staff. Sample descriptions, results of field tests, and observations made during

2-2 drilling were recorded on soil boring logs. Soil samples from SPT testing and rotosonic cores were examined and visually classified in accordance with ASTM D2488, Standard Practice for Description and Identification of Soils (Visual-Manual Procedure) in accordance with the Unified Soil Classification System (USCS). Representative portions of disturbed samples of rotosonic core and SPT samples were placed in sealed plastic bags for laboratory testing.

Boring B04-23 was originally on the east canal bank. During drilling, the majority of the rotosonic core sample obtained between 0 and 5 feet bgs was observed to be concrete fragments. Drilling operations were halted when, upon further investigation, a slight depression and surface cracking were observed in the immediate vicinity of the original boring location. Western States safely demobilized from the location and backfilled the abandoned borehole with bentonite chips. The boring was later relocated east of the dry stacked concrete retaining wall.

Upon completion, borings B01-23, B04-23, B05-23, and B09-23 were converted to open standpipe piezometers for future groundwater monitoring, as described in Section 2.1.2. The boring names include “(P)” to designate conversion to piezometers. The remainder of the borings were backfilled with cement-bentonite grout using tremie placement methods in accordance with State of Washington requirements and to prevent caving or collapse of the boreholes. Hydrated bentonite chips and coated bentonite pellets were placed to “top off” backfill above the water table. Borings B02-23, B03-23, B07-23, and B08-23 were advanced through existing concrete slabs in the forebay and tailrace areas. The concrete slabs were cored by GN Northern using an 8-inch-diameter coring machine. At the completion of drilling, the coreholes were repaired by GN Northern in accordance with the approved concrete slab corehole repair plan provided by Jacobs. The soil cuttings generated from all the drilling were collected in clean 55-gallon steel drums and scattered onsite on the eastern canal bank as directed by BIA.

Of note, the concrete slab at borehole B02-23 was cored before drilling. During drill rig setup, an overhead utility was found to be too close to the drilling location to safely complete the work. The borehole was offset approximately 7 feet to the west and cored through the slab. Both coring locations at B02-23 were repaired per the concrete slab corehole repair plan.

Appendix A provides boring logs . Photographs of the site and drilling setup taken during the field investigation period and photographs of the rotosonic core samples are presented in Appendices B and C respectively. Appendix B provides the concrete slab corehole repair plan for the existing concrete slabs in the forebay and tailrace areas.

2.1.2 Piezometer Installations

Open-standpipe piezometers were installed with the screened interval in the zones of interest as determined by the onsite geotechnical engineer.

Western States Drilling installed four 2-inch-diameter piezometers at borings B01-23, B04-23, B05-23, and B09-23 to facilitate future observations of the depth to groundwater. The construction was done according to the State of Washington Department of Ecology guidelines. The standpipe piezometers consist of a 2-inch-diameter flush threaded Schedule 40 PVC casing and a 10-foot section of No. 10 (0.010 inch) machine-slotted screen. A #20 industrial sandpack was placed in the annular space around the screen from 1 foot below the bottom of the screen to a minimum of 2 feet above the top of the screen.

A bentonite seal was placed above the sand and up to the surface completion. Surface completions for all piezometers consisted of a 12-inch-diameter flush-mounted manhole set in concrete. Well-completion diagrams showing the details of the open-standpipe piezometer construction are presented in Appendix C.

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Additionally, two vertical PVC pipe stilling wells, S01-23 and S02-23, were installed to measure water levels in the forebay (upstream of the pumping plant facility) and tailrace (downstream of the pumping plant facility), respectively. Each stilling well consisted of a 10-foot-long well screen and threaded end cap with a 2-inch-diameter PVC well casing. The stilling wells were mounted to the east concrete wall upstream and downstream of the pumphouse building, respectively. Both PVC stilling wells were affixed to the existing structures with metal 2-hole pipe straps and nails.

Vibrating wire piezometer pressure transducers and dataloggers were also installed in open standpipe piezometers B01-23, B04-23, B05-23, B09-23 and in stilling wells S01-23 and S02-23 to record the data in the desired intervals (hourly). The data has been collected monthly by Jacobs staff, and data collection is ongoing until April 2024. Table 2-2 provides a summary of the installed piezometers.

2.2 Laboratory Testing

GN Northern conducted index testing on selected samples using the following methods:

ASTM D2216, Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass (2016)

ASTM D6913, Standard Test Methods for Particle-Size Distribution (Gradation) of Soils Using Sieve Analysis (2017)

ASTM D7928, Standard Test Method for Particle-Size Distribution (Gradation) of Fine-Grained Soils Using the Sedimentation (Hydrometer) Analysis (2021)

ASTM D1140, Standard Test Methods for Amount of Material in Soils Finer than the No. 200 (75 micrometer) Sieve (2017)

ASTM D4318, Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils (2018)

ASTM D7263, Standard Test Methods for Specific Gravity of Soil Solids by Water Pycnometer (2021)

ASTM D698-12, Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft3 (600 kN-m/m3)) (2021)

Geo-Logic Associates of California, under subcontract to GN Northern conducted strength and permeability testing (advanced testing) based using the following methods:

ASTM D4767-11, Standard Test Method for Consolidated Undrained Triaxial Compression Test for Cohesive Soils (2020)

ASTM D2850-03, Standard Test Method for Unconsolidated-Undrained Triaxial Compression Test on Cohesive Soils (2023)

ASTM D3080-04, Standard Test Method for Direct Shear Test of Soils Under Consolidated Drained Conditions (2012)

ASTM D5084-16a, Standard Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter (2016)

Table 2-3 summarizes laboratory test results, which are also presented on the field boring logs in Appendix D. The laboratory test results are included in Appendix E. Additionally, Table 2-4 summarizes the advanced laboratory tests conducted on the soil samples.

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Table 2-1. Summary of Geotechnical Investigation Performed by Jacobs

Boring No.

Date Completed Investigation Type

Northing[a] (feet)

Easting[a] (feet) Location Description

Ground Surface Elevation[a,b] (feet)

Completion Depth[c] (feet)

B01-23 (P)[d] 3/17/23 Rotosonic Soil Boring 16,899,057.5 2,263,971.3 West Canal Bank 937.8 61.0

B02-23 3/7/23 Rotosonic Soil Boring 16,899,031.3 2,264,043.8 Forebay 925.2 40.8

B03-23 3/7/23 Rotosonic Soil Boring 16,899,042.7 2,264,109.8 Forebay 925.5 41.0

B04-23 (P) 3/15/23 Rotosonic Soil Boring 16,899,017.3 2,264,182.1 East Canal Bank 927.1 51.0

B05-23 (P) 3/10/23 Rotosonic Soil Boring 16,899,091.9 2,264,167.1 East Canal Bank 936.6 51.8

B06-23 3/20/23 Rotosonic Soil Boring 16,898,967.5 2,263,971.8 West Canal Bank 935.5 51.4

B07-23 3/8/23 Rotosonic Soil Boring 16,898,969.6 2,264,045.5 Tailrace 903.8 26.5

B08-23 3/8/23 Rotosonic Soil Boring 16,898,966.6 2,264,106.8 Tailrace 904.0 26.3

B09-23 (P) 3/14/23 Rotosonic Soil Boring 16,898,970.0 2,264,173.2 East Canal Bank 923.7 51.5

B10-23 3/10/23 Rotosonic Soil Boring 16,899,113.7 2,264,015.9 West Canal Bank 938.2 51.0

B11-23 3/13/23 Rotosonic Soil Boring 16,899,153.9 2,264,193.1 East Canal Bank 936.9 51.5

S01-23 3/21/23 2-inch-diameter Stilling Well 16,899,051.9 2,264,137.2 Forebay – East Wall N/A N/A

S02-23 3/21/23 2-inch-diameter Stilling Well 16,898,972.8 2,264,140.0 Tailrace – East Wall N/A N/A

[a] Northing, Easting, and Surface Elevation data based on survey performed by Anderson Perry & Associates, Inc. and documented by "BIA-WIP, Drop 1, Pumping Plant, Phase 3, Task 11" dated May 4, 2023.

[b] Vertical Datum: North American Vertical Datum Of 1988 (NAVD88). Elevations in United States survey feet.

[c] Horizontal Datum: Universal Transverse Mercator (UTM) Zone 10 North. Distances are in United States survey feet at grid.

[d]“(P)” denotes conversion of boring to a 2-inch-diameter open-standpipe piezometer with flush mounted surface completion.

Note:

Refer to Table 2-2 for piezometer and stilling well installation details.

N/A = not applicable

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Table 2-2. Piezometer Installations

Piezometer/ Stilling Well No. Date Installed

Ground Surface Elevation[a] (feet)

Top of Casing Elevation (feet)

Screen Depth Range (feet) Screen Elevation Range (feet)

B01-23 (P)[b] 3/24/23 937.8 937.5 30.0-40.0 907.8-897.8

B04-23 (P) 3/24/23 927.1 926.8 30.0-40.0 897.1-887.1

B05-23 (P) 3/24/23 936.6 936.2 30.0-40.0 906.6-896.6

B09-23 (P) 3/24/23 923.7 923.4 30.0-40.0 893.7-883.7

S01-23 3/24/23 N/A 938.2 N/A N/A

S02-23 3/24/23 N/A 924.2 N/A N/A [a] Surface Elevation data based on survey performed by Anderson Perry & Associates, Inc., and documented by "BIA-WIP, Drop 1, Pumping Plant, Phase 3, Task 11" dated May 4, 2023.

[b]“(P)” denotes conversion of boring to a 2-inch-diameter open-standpipe piezometer with flush mounted surface completion.

N/A = not applicable

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Table 2-3. Summary of Laboratory Test Results

Borehole Sample

Average Depth (feet)

Average Elevation (feet)

Moisture Content

Atterberg Limits P200 Sieve Analysis Hydrometer Analysis

Liquid Limit

Plastic Limit

Fines Content

Gravel

Sand

Fines

Silt

Clay

B01-23 (P)[a] Bulk-2 2.5 935.3 9.1 -- -- -- -- -- -- -- --

B01-23 (P) SS-3 5.8 932.1 -- -- -- 57.9 -- -- -- -- --

B01-23 (P) SS-5 10.8 927.1 -- -- -- 67.7 -- -- -- -- --

B01-23 (P) SS-9 20.8 917.1 7.4 -- -- -- -- -- -- --

B01-23 (P) Bulk-10 22.5 915.3 -- -- -- 75.6 -- -- -- -- --

B01-23 (P) SS-11 25.8 912.1 10.9 -- -- -- -- -- -- -- --

B01-23 (P) Bulk-12a & b 27.5 910.3 19.0 -- -- -- 0.0 85.0 15.0 -- --

B01-23 (P) Bulk-14b 34.5 903.3 19.5 -- -- -- -- -- -- -- --

B01-23 (P) Bulk-18b 43.5 894.3 16.7 -- -- -- -- -- -- -- --

B02-23 Bulk-2 3.0 922.2 20.4 -- -- -- -- -- -- -- --

B02-23 Bulk-4a 7.0 918.2 -- -- -- 53.4 -- -- -- -- --

B02-23 Bulk-6 12.5 912.7 25.7 -- -- -- 0.0 27.3 72.7 -- --

B02-23 Bulk-8b 17.2 908.1 -- -- -- 35.9 -- -- -- -- --

B02-23 Bulk-10a 20.4 904.9 11.8 -- -- -- -- -- -- -- --

B02-23 Bulk-10d 23.6 901.7 8.3 -- -- -- -- -- -- -- --

B02-23 Bulk-13 32.5 892.7 20.4 -- -- -- -- -- -- -- --

B03-23 Bulk-2a 1.9 923.7 12.6 -- -- -- -- -- -- -- --

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Borehole Sample

Average Depth (feet)

Average Elevation (feet)

Moisture Content

Atterberg Limits P200 Sieve Analysis Hydrometer Analysis

Liquid Limit

Plastic Limit

Fines Content

Gravel

Sand

Fines

Silt

Clay

B03-23 Bulk-4a 5.4 920.2 -- -- -- 39.6 -- -- -- -- --

B03-23 SS-5 10.8 914.8 26.4 -- -- -- -- -- -- -- --

B03-23 Bulk-8 17.5 908.0 -- -- -- 55.1 -- -- -- -- --

B03-23 Bulk-12b 29.0 896.5 34.2 -- -- -- -- -- -- -- --

B03-23 Bulk-14 32.5 893.0 23.4 -- -- -- 13.3 61.0 25.7 -- --

B03-23 Bulk-16 37.5 888.0 23.4 -- -- -- 13.3 61.0 25.7 -- --

B04-23 (P) SS-5 10.8 916.4 49.4 -- -- -- -- -- -- -- --

B04-23 (P) Bulk-6 12.5 914.6 26.8 25.0 17.5 -- 2.0 28.2 69.8 -- --

B04-23 (P) Bulk-8 17.5 909.6 31.3 -- -- -- -- -- -- -- --

B04-23 (P) Bulk-14 32.5 894.6 23.3 -- -- -- -- -- -- -- --

B04-23 (P) Bulk-16 37.5 889.6 -- -- -- -- 15.1 59.9 25.0 -- --

B04-23 (P) Bulk-20b 49.6 877.5 9.3 -- -- -- 2.1 31.6 66.3 -- --

B05-23 (P) SS-5 13.8 922.9 18.1 26.2 14.6 -- -- -- -- -- --

B05-23 (P) Bulk-8 17.5 919.1 -- -- -- -- 0.0 23.7 76.3 -- --

B05-23 (P) Bulk-10 22.5 914.1 21.7 -- -- -- -- -- -- -- --

B05-23 (P) Bulk-12a 26.5 910.1 23.0 -- -- -- -- -- -- -- --

B05-23 (P) Bulk-16 37.5 899.1 23.3 -- -- -- -- -- -- -- --

B06-23 Bulk-4a 5.4 930.2 12.3 -- -- -- -- -- -- -- --

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Borehole Sample

Average Depth (feet)

Average Elevation (feet)

Moisture Content

Atterberg Limits P200 Sieve Analysis Hydrometer Analysis

Liquid Limit

Plastic Limit

Fines Content

Gravel

Sand

Fines

Silt

Clay

B06-23 Bulk-4b 6.1 929.4 -- -- -- 59.2 -- -- -- -- --

B06-23 Bulk-6a 11.0 924.5 19.3 -- -- -- -- -- -- -- --

B06-23 Bulk-6b 12.6 922.9 -- -- -- -- 0.0 23.6 76.4 37.2 39.2

B06-23 Bulk-8b 17.7 917.9 -- -- -- 50.5 -- -- -- -- --

B06-23 Bulk-10 23.3 912.3 16.5 26.3 16.1 -- 0.0 83.7 16.3 -- --

B06-23 SS-11b 26.1 909.4 13.1 -- -- -- -- -- -- -- --

B06-23 Bulk-12 27.5 908.0 7.4 -- -- -- 3.0 83.5 13.5 -- --

B06-23 Bulk-16 37.5 898.0 12.4 -- -- -- -- -- -- -- --

B07-23 SS-3 5.8 898.1 9.5 -- -- -- -- -- -- -- --

B07-23 Bulk-4b 8.6 895.2 31.4 24.9 15.4 -- 10.3 76.6 13.1 -- --

B07-23 Bulk-6 12.5 891.3 31.4 24.9 15.4 -- 10.3 76.6 13.1 -- --

B07-23 SS-7 15.8 888.1 24.3 -- -- -- -- --

B07-23 Bulk-10a 22.0 881.8 -- -- -- -- 1.0 85.3 13.7 -- -- [a]“(P)” denotes conversion of boring to a 2-inch-diameter open-standpipe piezometer with flush mounted surface completion.

-- = sample not tested SS = split spoon

2-9

Table 2-4. Summary of the Soil Samples Selected for Advanced Laboratory Testing

Borehole Sample Depth Top (feet)

Depth Bottom (feet) Conducted Advanced Tests

B02-23 Bulk-6 12.5 912.7 Hydraulic Conductivity

B03-23 Bulk-8 17.5 908.0 Hydraulic Conductivity, CU Triaxial

B05-23 (P)[a] SS-5 13.8 922.9 Specific Gravity

B06-23 Bulk-6b 12.6 922.9 CU Triaxial

B06-23 Bulk-10 23.3 912.3 Direct Shear

B08-23 Bulk-8 17.5 886.5 Hydraulic Conductivity

B09-23 (P) Bulk-12 27.5 896.2 Hydraulic Conductivity, Direct Shear

B10-23 Bulk-4b 6.9 931.4 Hydraulic Conductivity, UU Triaxial, CU Triaxial

B11-23 Bulk-4 7.5 929.4 Hydraulic Conductivity, UU Triaxial, CU Triaxial [a]“(P)” denotes conversion of boring to a 2-inch-diameter open-standpipe piezometer with flush mounted surface completion.

CU = consolidated undrained UU = unconsolidated undrained

3-1

3. Subsurface Conditions

This section presents the subsurface conditions within and in the vicinity of the Project area.

3.1 Geology

This section summarizes the regional geology and provides the soil profile for the Project area.

3.1.1 Regional Geology

The Project area is within the Yakima River Basin in the highly folded and faulted Yakima Fold Belt subprovince of the Columbia Plateau. The central, eastern, and southwestern parts of the basin are composed of basalt lava flows of the Columbia River Basalt Group (CRBG) with some intercalated sediments that are discontinuous and weakly consolidated. The lowlands are underlain by unconsolidated and weakly consolidated valley-fill composed of glacial, glacio-fluvial, lacustrine, and alluvium deposits that in places exceed 1,000 feet in thickness (Drost et al. 1990). Wind-blown deposits, called loess, occur locally along the lower valley.

The basalt lava flows consist of a series of flows that erupted during various stages of the Miocene Age, ranging from 6 million to 17 million years ago. Basalt erupted from fissures from the eastern part of the Columbia Plateau, and individual flows range in thickness from a few feet to more than 100 feet. The total thickness in the central part of the plateau is estimated to be greater than 10,000 feet (Drost et al. 1990).

Unlike most of the Columbia Plateau, the CRBG in the Yakima Fold Belt is underlain by sedimentary rocks.

The valley-fill deposits were eroded from the Cascade Range and from the east-west-trending anticlinal ridges formed from the buckling of the basalt sequence during mid- to late-Miocene time. Much of these deposits are part of the Ellensburg Formation. This formation composes most of the thickness of the unconsolidated deposits (informally called the overburden) (Drost et al. 1990) in the basinal areas. The basins are narrow to large open synclinal valleys intervening between the numerous anticlinal ridges.

The subsurface geology of the Wapato area is characterized by unconsolidated alluvial and colluvial deposits generally underlain by the basalt flows. The alluvial deposits are composed of gravel, sand, silt, and clay deposited by stream and river channels. The colluvial deposits are composed of soil, rock debris, and other materials transported downslope by gravity. The unconsolidated materials range from Miocene to Holocene in age.

3.1.2 Project Area Geology

Multiple surficial geologic units are mapped in the vicinity of the Project site by Bentley et al. (1993). The mapped geologic units within and in the immediate vicinity of the Project area are Terrace deposits (Qt) and Catastrophic flood slackwater deposits (Qfs). Figure 3-1 shows the mapped surficial geology within the vicinity of the Project site.

The Pleistocene surficial deposits are as follows:

Terrace deposits (Qt) consist of mainstream alluvial deposits of silt, sand, and gravel of diverse clast compositions. They locally include lacustrine, paludal, and eolian deposits that are poorly indurated and consist of slightly to moderately weathered clasts. This unit was deposited by the Yakima River and largely confined to its valley. It is divided into younger, lower-level terraces and older, middle-level terraces. The middle terrace deposits are mapped within the Project site and are typically restricted to the Yakima River

3-2 valley between Selah and Prosser at elevations approximately 10 meters above the modern Yakima River flood plain.

Catastrophic flood slackwater deposits (Qfs) consist of rhythmically bedded and graded silt and minor sand and gravel. They locally contain elastic dikes and ice-rafted clasts. This unit was deposited by Missoula (Spokane) floods and includes a thin layer of Mount St. Helens ash near the top near the west edge of the Granger quadrangle. It also includes the Touchet Beds (Flint 1938). The unit is mapped west of the Project site.

3.2 Soil Profile

The materials at the site encountered in the geotechnical investigation program are described below.

Descriptions are organized by depth, with shallower units described first. The stratigraphy at the Project site may vary between borings, particularly regarding fill materials and other site disturbance. Figure 3-2 presents the stratigraphic profiles interpreted from boreholes advanced at the Project site.

3.2.1 Concrete Slab

Borings B02-23, B03-23, B07-23, and B08-23 were advanced through the forebay and tailrace concrete slabs in the canal bottom. The concrete thickness varied from 7.75 to 12 inches.

3.2.2 Fill

Fill material was encountered in all borings except borings B02-23, B07-23, and B08-23. The fill layer consisted of brown to dark gray silty sand with varying amount of gravel (classified as SM). The fill occasionally contained traces of organic material. The fill layer was found from ground surface to variable depths ranging from 0.5 to 15 feet bgs. The fill layer was observed in loose to medium dense condition with SPT N-values reported ranging from 2 to 22.

3.2.3 Fine-grained Alluvial Deposit – Dominantly Lean Clay

At the Project site, the fine-grained alluvial deposits were observed underneath the fill layer in the borings B01-23, B03-23, B04-23, B05-23, B06-23, B09-23, B10-23 and B11-23 and underneath concrete in B02-23. The fine-grained alluvial deposits consist predominantly of brown to dark gray plastic clay soils with silt and varying amount of sand (classified as CL). Fine-grained alluvial deposits were observed in the borings with thickness ranging from 0.5 foot to 20 feet.

The fine-grained alluvial soils were observed in soft to very stiff condition. SPT N-values ranged from 2 to 17 blows per foot. The plasticity index for the soil layer ranged from 7.5 to 11.6, indicating low to medium plasticity.

3.2.4 Coarse-grained Alluvial Deposit – Dominantly Silty Sand

The coarse-grained alluvial deposits were encountered below the concrete slab in borings B07-23 and B08-23 and underlying the fine-grained alluvial deposits in all other borings. Coarse-grained alluvial deposits predominantly consisted of dense to very dense silty sand with varying amounts of gravel (classified as SM) and extended to the termination depths. SPT N-values in this layer varied from 36 blows per foot to refusal.

3-3

3.3 Groundwater

Four standpipe piezometers were installed at borings B01-23, B04-23, B05-23, and B09-23 as described in Section 2.

Groundwater and surface water data collected prior to the submission of this report are presented as plots of water depths and elevation head versus time in Appendix F. Table 3-1 provides the summary of the measured groundwater data from April 2023 to September 2023.

The groundwater levels are expected to fluctuate with time, depending on canal operations, precipitation, Yakima River flows, and other factors. The piezometers and the stilling wells installed at the forebay and tailrace locations, are instrumented. These instruments are being monitored approximately monthly under a separate scope of work. Additional data and interpretation of groundwater levels will be provided as a future addendum to this GDR following the completion of the groundwater monitoring in April 2024.

Based on the water level plots provided in Appendix F, surface water elevations in the canal increase from

928.89 to 934.49 feet above sea level in the forebay and from 905.00 to 912.59 feet above sea level in the tailrace during the current monitoring period (that is, before and during the irrigation season).

Table 3-1. Summary of the Measured Groundwater Data from Piezometers from April to September

Boring Location

Groundwater Elevation Range (feet)

Groundwater Depth Range (feet)

B01-23 (P)[a] West canal bank, upstream of drop structure 904.48 to 918.31 19.44 to 33.27

B04-23 (P) East canal bank, upstream of pumping plant 897.19 to 911.09 16.02 to 29.92

B05-23 (P) East canal bank, near pumping plant 898.15 to 913.32 23.23 to 38.40

B09-23 (P) East canal bank, downstream of pumping plant 898.35 to 912.23 11.5 to 25.38

[a]“(P)” denotes conversion of boring to a 2-inch-diameter open-standpipe piezometer with flush mounted surface completion.

Note:

Groundwater monitoring is ongoing.

4-1

4. Limitations

Jacobs prepared this GDR for the exclusive use of BIA for specific application to the Project. The report has been prepared following generally accepted geotechnical engineering practices. No other warranty, expressed or implied, is made. Jacobs is not responsible for any claims, damages, or liability associated with the interpretations of subsurface data or reuse of the subsurface data by others without the express written authorization of Jacobs.

The description and interpretation of subsurface conditions contained in this GDR are based on the data obtained from a limited number of field investigations, conducted by Jacobs, that indicate subsurface conditions only at specific locations and times, and only to the depths penetrated. They do not reflect the variations of strata between boring locations. Subsurface conditions and water levels at other locations throughout the Project may differ from those at presented investigation locations.

5-1

5. References

ASTM International (ASTM). Annual Book of ASTM Standards: Section 4, Construction: Volume 04.08: Soil and Rock (I): D421-D5876. West Conshohocken, Pennsylvania : ASTM International.

Anderson Perry & Associates, Inc. 2023. BIA-WIP, Drop1, Pumping Plant, Forebay, Phase 3, Task 11. May 4.

Bentley, R. D., N. P. Campbell. and J. E. Powell. 1993. Geologic Maps of Part of the Yakima Fold Belt, Northeastern Yakima County, Washington. Washington State Department of Natural Resources Open File Report 93-3.

Drost, B.W., Whiteman, K.J., and Gonthier, J.B., 1990, Geologic framework of the Columbia Plateau Aquifer System, Washington, Oregon, and Idaho: U.S. Geological Survey Water-Resources Investigations Report 87-4238, 10 p., 10 sheets.

Flint, R. F. 1938. Origin of the Cheney-Palouse scab-land tract. Washington: Geological Society of America Bulletin, v. 49, No. 3, p. 461-5231938.

Figures

SAN

JUAN

JEFFERSON

KITSAP

GRAYS

HARBOR

PACIFIC

COWLITZ

CLARK KLICKITAT

SKAMANIA

WAHKIAKUM

LEWIS

YAKIMA

BENTON

WALLA

WALLA

Waitsburg COLUMBIA ASOTIN

FRANKLIN

THURSTON

GARFIELD

PIERCE

MASON

KITTITAS

ADAMS WHITMAN

KING

CLALLAM

ISLAND

GRANT

DOUGLAS LINCOLN

CHELAN

SPOKANE

SNOHOMISH

SKAGIT

WHATCOM

OKANOGAN

FERRY

STEVENS

PEND

OREILLE

VANCOUVER

WALLA WALLA

YAKIMA

ELLENSBURG

TACOMA

SEATTLE

WENATCHEE

SPOKANE

OKANOGAN

BELLNGHAM

FIGURE 1-1

VICINITY AND LOCATION MAP

BIA WAPATO DROP 1 PUMPING PLANT

WAPATO, WA

PROJECT

LOCATION

N

NOT TO SCALE

TO YAKIMA, WA

±5 MILES

UNION GAP

WAPATO DIVERSION DAM

WIP CANAL

AD

AM

S

LN

PROJECT SITE

LATERAL 1 RD

US HWY 97

WAPATO, WA

INTERSTATE 82

YAKIMA RIVER

B10-23

B01-23 (P)

B02-23

B05-23 (P)

S01-23

B11-23

B04-23 (P)

B09-23 (P)S02-23B08-23 B07-23B06-23

B03-23

BXX-23 BORINGS (11)

(P) DENOTES PIEZOMETER INSTALLATION (4)

SXX-23 WATER LEVEL STILLING WELLS (2)

AD

AM

S LAN

E

C

AN

AL

R

O

AD

FL

OW

FL

O

W

FLOW

N

0 30 60

SCALE IN FEET

FIGURE 2-1A

GEOTECHNICAL FIELD EXPLORATION LOCATIONS

WAPATO DROP 1 PUMPING PLANT

WAPATO, WA

BXX-23 BORINGS (11)

(P) DENOTES PIEZOMETER INSTALLATION (4)

SXX-23 WATER LEVEL STILLING WELLS (2)

B10-23

B01-23 (P)

B02-23

B05-23 (P)

S01-23

B11-23

B04-23 (P)

B09-23 (P)S02-23B08-23 B07-23B06-23

B03-23

AD

AM

S LAN

E

C

AN

AL

R

O

AD

FL

OW

FL

O

W

FLOW

N

0 30 60

SCALE IN FEET

FIGURE 2-1B

GEOTECHNICAL FIELD EXPLORATION LOCATIONS

WAPATO DROP 1 PUMPING PLANT

WAPATO, WA

TOPOGRAPHICL CONTOUR LINES

FIGURE 3-1

Project Site Geology Map

BIA WAPATO DROP 1 PUMPING PLANT PROJECT

Legend Project Site

B10-23

B01-23 (P)

B02-23

B05-23 (P)

S01-23

B11-23

B04-23 (P)

B09-23 (P) S02-23B08-23

B07-23B06-23

B03-23

WAPATO, WA

BXX-23 BORINGS (11)

(P) DENOTES PIEZOMETER INSTALLATION (4)

SXX-23 WATER LEVEL STILLING WELLS (2)

A D

A M

S

LA

N E

C A

N A

L R

O A

D

FL

O

W

F L

O W

FLOW

N

0 30 60

SCALE IN FEET

A

B B'

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Depth = 51 ft Elevation = 876.11 ft

Depth = 50.8 ft Elevation = 885.75 ft

Depth = 51.5 ft Elevation = 872.23 ft

Depth = 51.5 ft Elevation = 885.37 ft

Depth = 59 ft Elevation = 113.5 ft

8/23/2007 10:45:00 AM

E le va tio n (f t)

Project Number:

VERTICAL SCALE: 1" = 10.0'

HORIZONTAL SCALE: 1" = 15.0'

LITHOLOGY GRAPHICS

Distance (ft)

BOREHOLE LEGEND

BIA Wapato Drop Structure #1

Silty Sand

Lean Clay

Poorly Graded Sand with Silt

Silt

Clayey Sand

Poorly Graded Gravel with Silt

X

S T

IC

K

L O

G W

IT

H

L E

G E

N D

W

A P

A T

O I

R R

IG

A

T

IO

N P

R O

JE

C

T -J

S N

.G P

J C

H

M G

E O

T E

C H

-R E

V

IS

E D

.G

T

/1 0/

50/5"

50/5"

50/6"

50/6"

SM

CL

CL

CL

SM

SP-

SM

SM

SM

SM

SM

ML

SM

GSE = 927.11 ft B04-23 (P)

50/3"

50/4"

50/5"

SM

CL

CL

CL

CL

CL

CL

SC

CL

SM

SM

SM

GSE = 936.55 ft B05-23 (P)

98/12"

50/5"

92/11"

90/12"

72/10"

SM

SM

SM

SM

CL

SM

GP-

GM

SM

SP-

SM

SM

SM

SM

SM

GSE = 923.73 ft B09-23 (P)

50/4"

75/12"

SM

CL

CL

SC

CL

SM

ML

SM

GSE = 936.87 ft B11-23

DEPTH AND ELEVATION OF

BOTTOM OF HOLE, AND DATE

AND TIME BORING COMPLETED

B-1

LITHOLOGY GRAPHIC COLUMN

GSE = 172.5 ft

GROUND SURFACE ELEVATION

ML

USCS CLASSIFICATION

50/2"

SPT N-VALUE (blows per foot)

100/66

RECOVERY (%)

RQD (%)

GROUNDWATER LEVEL

BOREHOLE NUMBER

B04-23 (P)

B05-23 (P)

B09-23 (P)

B11-23

Figure 3-2 (b) Subsurface Soil Profile

(Section A-A') East Canal Bank

BIA Wapato Drop Structure #1 Project Number: D3673800

0 20 40 60 80 100 120 140 160 180 200 220 240

0 20 40 60 80 100 120 140 160 180 200 220 240

Depth = 51.4 ft Elevation = 884.13 ft

Depth = 26.5 ft Elevation = 877.25 ft

Depth = 26.3 ft Elevation = 877.65 ft

Depth = 51.5 ft Elevation = 872.23 ft

Depth = 59 ft Elevation = 113.5 ft

8/23/2007 10:45:00 AM

E le va tio n (f t)

Project Number:

VERTICAL SCALE: 1" = 10.0'

HORIZONTAL SCALE: 1" = 20.0'

LITHOLOGY GRAPHICS

Distance (ft)

BOREHOLE LEGEND

BIA Wapato Drop Structure #1

Silty Sand

Lean Clay

Clayey Sand

Concrete

Poorly Graded Gravel with Silt

Poorly Graded Sand with Silt

X

S T

IC

K

L O

G W

IT

H

L E

G E

P

A T

O I

R R

IG

A

T

IO

N P

R O

JE

C

T -J

S N

.G P

J C

H

M G

E O

T E

C H

-R E

V

IS

E D

.G

/1 0/

50/6"

50/6"

84/11"

82/12"

82/11"

SM

CL

CL

CL

SC

SM

SM

SM

SM

GSE = 935.53 ft B06-23

SM

SC

SC

SM

SM

SM

SM

SM

GSE = 903.75 ft B07-23

82/10"

77/11"

86/10"

SM

SM

GSE = 903.95 ft B08-23

98/12"

50/5"

92/11"

90/12"

72/10"

SM

SM

SM

SM

CL

SM

GP-

GM

SM

SP-

SM

SM

SM

SM

SM

GSE = 923.73 ft B09-23 (P)

DEPTH AND ELEVATION OF

BOTTOM OF HOLE, AND DATE

AND TIME BORING COMPLETED

B-1

LITHOLOGY GRAPHIC COLUMN

GSE = 172.5 ft

GROUND SURFACE ELEVATION

ML

USCS CLASSIFICATION

50/2"

SPT N-VALUE (blows per foot)

100/66

RECOVERY (%)

RQD (%)

GROUNDWATER LEVEL

BOREHOLE NUMBER

B06-23 B07-23 B08-23

B09-23 (P)

Figure 3-2 (c) Subsurface Soil Profile

(Section B-B') Section Through Tailrace

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190

Depth = 61 ft Elevation = 876.75 ft

Depth = 51.4 ft Elevation = 884.13 ft

Depth = 51 ft Elevation = 887.21 ft

Depth = 59 ft Elevation = 113.5 ft

8/23/2007 10:45:00 AM

E le va tio n (f t)

Project Number:

VERTICAL SCALE: 1" = 10.0'

HORIZONTAL SCALE: 1" = 15.0'

LITHOLOGY GRAPHICS

Distance (ft)

BOREHOLE LEGEND

BIA Wapato Drop Structure #1

Silty Sand

Lean Clay

Clayey Sand

Silt

X

S T

IC

K

L O

G W

IT

H

L E

G E

P

A T

O I

R R

IG

A

T

IO

N P

R O

JE

C

T -J

S N

.G P

J C

H

M G

E O

T E

C H

-R E

V

IS

E D

.G

/1 0/

50/6"

50/5"

50/6"

SM

CL

CL

CL

CL

CL

SM

SM

SM

GSE = 937.75 ft B01-23 (P)

50/6"

50/6"

84/11"

82/12"

82/11"

SM

CL

CL

CL

SC

SM

SM

SM

SM

GSE = 935.53 ft B06-2311

50/5"

50/4"

90/10"

50/6"

SM

CL

CL

CL

SM

ML

SM

GSE = 938.21 ft B10-23

DEPTH AND ELEVATION OF

BOTTOM OF HOLE, AND DATE

AND TIME BORING COMPLETED

B-1

LITHOLOGY GRAPHIC COLUMN

GSE = 172.5 ft

GROUND SURFACE ELEVATION

ML

USCS CLASSIFICATION

50/2"

SPT N-VALUE (blows per foot)

100/66

RECOVERY (%)

RQD (%)

GROUNDWATER LEVEL

BOREHOLE NUMBER

B01-23 (P)

B06-23

B10-23

Figure 3-2 (d) Subsurface Soil Profile

(Section C-C') West Canal Bank

0 20 40 60 80 100 120 140 160 180 200 220 240

0 20 40 60 80 100 120 140 160 180 200 220 240

Depth = 61 ft Elevation = 876.75 ft

Depth = 40.75 ft Elevation = 884.4 ft

Depth = 41 ft Elevation = 884.46 ft

Depth = 51 ft Elevation = 876.11 ft

Depth = 59 ft Elevation = 113.5 ft

8/23/2007 10:45:00 AM

E le va tio n (f t)

Project Number:

VERTICAL SCALE: 1" = 10.0'

HORIZONTAL SCALE: 1" = 20.0'

LITHOLOGY GRAPHICS

Distance (ft)

BOREHOLE LEGEND

BIA Wapato Drop Structure #1

Silty Sand

Lean Clay

Concrete

Silt

Poorly Graded Gravel with Silt

Clayey Sand

Poorly Graded Sand with Silt

X

S T

IC

K

L O

G W

IT

H

L E

G E

P

A T

O I

R R

IG

A

T

IO

N P

R O

JE

C

T -J

S N

.G P

J C

H

M G

E O

T E

C H

-R E

V

IS

E D

.G

/1 0/

50/6"

50/5"

50/6"

SM

CL

CL

CL

CL

CL

SM

SM

SM

GSE = 937.75 ft B01-23 (P)

63/10"

50/6"

50/3"

CL

SM

SM

ML

SM

SM

GP-

GM

SM

SM

ML

SM

SM

SM

SM

SM

SM

GSE = 925.15 ft B02-23

50/5"

50/3"

50/6"

50/6"

SM

CL

SM

CL

CL

CL

CL

SC

CL

SM

ML

SM

SM

SM

GSE = 925.46 ft B03-23

50/5"

50/5"

50/6"

50/6"

SM

CL

CL

CL

SM

SP-

SM

SM

SM

SM

SM

ML

SM

GSE = 927.11 ft B04-23 (P)

DEPTH AND ELEVATION OF

BOTTOM OF HOLE, AND DATE

AND TIME BORING COMPLETED

B-1

LITHOLOGY GRAPHIC COLUMN

GSE = 172.5 ft

GROUND SURFACE ELEVATION

ML

USCS CLASSIFICATION

50/2"

SPT N-VALUE (blows per foot)

100/66

RECOVERY (%)

RQD (%)

GROUNDWATER LEVEL

BOREHOLE NUMBER

B01-23 (P)

B02-23

B03-23

B04-23 (P)

Figure 3-2 (e) Subsurface Soil Profile

(Section D-D') Section Through Forebay

Appendix A Borehole Logs

SOIL BORING LOG LEGEND

SAMPLES:

SS: SPLIT SPOON SAMPLE

MC: MODIFIED CALIFORNIA SPLIT SPOON SAMPLE

BU: BULK SAMPLE

ST: SHELBY TUBE SAMPLE

OT: THIN-WALL SHELBY (OSTERBERG) SAMPLE

BKT: BUCKET SAMPLE

DRILLING AND SAMPLING ABBREVIATIONS

TIME BETWEEN SAMPLES (DRILL RATE), DEPTH AND SIZE OF CASING, HOLE CAVING WITH DEPTH, CHANGES IN DRILLING AND MATERIAL, CUTTINGS, DRILLING COMMENTS, ROD CHATTER, DRILLING FLUID LOSS (DEPTH AND AMOUNT),COBBLES/ BOULDERS, PIEZOMETER AND OTHER INSTALLATION INFORMATION, IN SITU TESTING RESULTS, SAMPLES SLECTED FOR

LAB TESTING, BACKFILL, SURFACE FINISH, OTHER COMMENTS.

DRILLING COMMENTS

SOIL NAME, USCS GROUP SYMBOL, COLOR AND MOTTLING/STAINING, MOISTURE, RELATIVE DENSITY (SAND OR GRAVEL) OR CONSISTENCY (SILT OR CLAY), SOIL PARTICLE PERCENTAGE AND SIZES (SIZE THEN SHAPE), PLASTICITY AND DILATENCY, SOIL STRUCTURE, MINERALOGY, CEMENTATION, ORGANICS, HCL REACTION, ODOR, COBBLES AND/OR BOULDERS, FILL DETAILS (BRICK, CONCRETE, ETC.), OTHER DESCRIPTORS, NAME OF UNIT (FILL, ALLUVIUM, COLLUVIUM, RESIDUAL SOIL, NAME OF FORMATION, ETC.)

SOIL LOG ORDER

SPT N-VALUE (BLOWCOUNTS): THE NUMBER OF BLOWS REQUIRED TO…