Equalizer_Geotech_Data_Report_2015.pdf

EQUALIZER DAM AND DIKE

GEOTECHNICAL DATA REPORT

Prepared for

BUREAU OF INDIAN AFFAIRS

OFFICE OF TRUST SERVICES

13922 DENVER WEST PARKWAY

BUILDING 54, SUITE 300

LAKEWOOD, CO 80401

Prepared by

222 NORTH 32ND

STREET

P.O. BOX 31318

BILLINGS, MT 59107-1318

FEBRUARY 20, 2015

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2/20/2015

EQUALIZER DAM AND DIKE

GEOTECHNICAL DATA REPORT

Prepared For:

Bureau of Indian Affairs

Office of Trust Services

Division of Water and Power

13922 Denver West Parkway

Building 54, Suite 300

Lakewood, CO 80401

Prepared By:

DOWL HKM

PO Box 31318

Billings, MT 59107

Principal Author: Steven Weisenberger, PE

Reviewed By: Joshua Carter, PE and Jason Thom, PE

February 2015

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TABLE OF CONTENTS

Page

1.0 SUMMARY

2.0 PROJECT DESCRIPTION

2.1 General

2.2 Description

3.0 INVESTIGATION

3.1 General

3.2 SITE Geology

3.3 Field Investigation

3.4 Site Survey

4.0 LABORATORY TESTING

5.0 SITE CONDITIONS

5.1 Topography

5.2 Vegetation

5.3 Water

6.0 SUBSURFACE CONDITIONS

6.1 General

6.2 Soil & Bedrock

6.3 Groundwater

6.4 Soil Chemical Properties

7.0 CONCLUSIONS

8.0 LIMITATIONS

9.0 REFERENCES

LIST OF TABLES

Page

Table 4-1 Equalizer Geotechnical Laboratory Test Descriptions

Table 6-1 Sulfate Exposure Criteria

LIST OF FIGURES

Figure GT-1 Dam Locations Plan and Profile

Figure GT-2 Dam Geologic Cross Sections

Figure GT-3 Dike Exploration Hole Locations

U.S. Bureau of Reclamation 1998 Geologic Sections

Equalizer Dam 1936 Profile and Relative Data Drawings

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LIST OF APPENDICES

Appendix A Boring and Test Pit Logs

Appendix B Photo Log

Appendix C Laboratory Test Results

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1.0 SUMMARY

This report presents the results of the geotechnical study performed by DOWL HKM for the rehabilitation of Equalizer Dam and Dike located approximately two miles southeast of Blackfoot, Idaho. The rehabilitation project will generally consist of modifications at the existing dike, constructing a new principal spillway and outlet works at the dam, and modifying the existing auxiliary spillway structure.

This study included a field investigation (soil borings and test pits) and laboratory testing of soil samples collected from the dam and dike sites. The field investigation was performed during the week of

November 3 rd

, 2014. Site conditions, subsurface conditions, and geology are discussed further in the following sections of this report.

Representative soil samples were selected for laboratory testing after visual examination of the soil and consideration of the project requirements. Classification and engineering property tests were performed at the DOWL HKM and Tetra Tech Materials Laboratories in Billings, Montana.

Boring and test pit logs are included in Appendix A, photographs are in Appendix B, and laboratory test results are included in Appendix C.

2.0 PROJECT DESCRIPTION

2.1 GENERAL

Equalizer Dam and Dike are located on the Blackfoot River. These structures were originally constructed in 1937 to provide equalizing storage for the Fort Hall Reservation Irrigation Project and also flood detention. Equalizer Dam and Dike have both been classified as significant hazard structures in previous studies.

Equalizer Dam is a homogeneous earthfill embankment with a crest length of approximately 1,700 feet, a maximum height of approximately 23 feet and a crest elevation that varies between approximately 4529 feet and 4530 feet. The dam is reported to have wooden sheet piling near the core that extends through sand and silt to alluvial gravels in the dam foundation. The upstream dam face varies from approximately

1.5H:1V to 3H:1V and the downstream face varies from 1.5H:1V to 2H:1V.

Equalizer Dam has three existing outlets. The river outlet works is located on the Blackfoot River channel and includes a concrete intake structure with trashrack, double-barrel 5-ft by 6-ft box conduits, gate tower near the center of the dam, and an outlet terminal structure. The Fort Hall Main Canal Headworks is located near the left abutment and includes a steel trashrack and two radial gates that discharge to the canal. The privately owned Little Butte Canal headgate is located left of the spillway at the right abutment and consists of 2-foot slide gate with a 2-foot diameter concrete outlet pipe.

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The existing spillway was constructed in 1972 and is located at the right dam abutment. The spillway control structure is constructed of concrete and consists of seven, 4-foot wide stoplog bays with a walkway over the width of the stoplog bays. The spillway discharge channel is approximately 3,000 ft long with the first 500 ft downstream of the spillway crest cut through bedrock.

Equalizer Dike is a homogeneous earthfill structure located along the west and north sides of the reservoir, approximately 3,000 feet northeast of the Dam. The dike is just over 1-mile long with a maximum height of approximately 10 feet.

2.2 DESCRIPTION

DOWL HKM was contracted by the BIA to perform a geotechnical investigation at the site. The field investigation was performed during the week of November 3 rd

, 2014. Test pits were excavated and soil borings were drilled to study surface and subsurface conditions. Eight of the soil borings were completed as monitor wells to observe groundwater levels. A topographic survey was also performed by a DOWL

HKM survey crew to define the dimensions and features of the dam and dike and also locate the borings and test pits.

The purpose of this investigation was to gather subsurface information for use during final design of rehabilitation of the dam and dike. Locations of the borings and test pits were based on the conceptual design rehabilitation alternatives previously developed by DOWL HKM. Alternatives for rehabilitating the dike range from reconstruction to constructing chimney or toe drains in limited sections. Conceptual design for the dam rehabilitation included a new principal spillway and outlet works and modifications to the auxiliary spillway crest structure. Details of the conceptual design are included in DOWL HKM’s

July 2014 Equalizer Dam and Dike Conceptual Design Report.

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3.0 INVESTIGATION

3.1 GENERAL

The field investigation was performed during the week of November 3, 2014 and consisted of test pit excavations using a Caterpillar 430E backhoe operated by the BIA, and soil boring/monitor well installation using a CME-75 truck mounted drill rig equipped with 8-¼ inch hollow-stem augers and HQ diamond core drilling equipment. The rig was operated by Haztech Drilling of Meridian, Idaho.

Laboratory testing was conducted on selected samples from the dam and dike foundation, embankment material, and also potential borrow material. Results of the investigation are discussed herein.

3.2 SITE GEOLOGY

The dam is located on alluvial deposits placed by flooding from both glacial and non-glacial deposition along the Blackfoot River. Geologic field mapping was not performed as part of this investigation.

However, readily available geologic information and the previous “Geologic Report for Proposed

Replacement Headworks Structure”, dated May 1998, were reviewed.

To the south of the dam, silt and sand deposits were observed overlying basalt bedrock near the historic borrow pit. To the north of the dam, rhyolite and basalt outcrops were observed near the existing spillway and right abutment. To the east and west, silt and sand soils were observed to overly the bedrock

(bedrock was not encountered in the deeper borings located near the existing outlet). The bedrock formation depth potentially becomes very deep when proceeding south from the observed outcrops near the right abutment.

3.3 FIELD INVESTIGATION

Historic Borrow Site – One test pit (TP-3) was excavated to examine the historic borrow areas for possible use as a future borrow area. This location was outside of the survey limits for the project, but is located at latitude/longitude coordinates of 43° 9'50.20"N/112°17'39.01"W and is approximately 1,300 feet southeast of MW-7. Test pit logs are included in Appendix A and test pit locations are shown on

Figure GT-1 and GT-2.

Dam Site – Six soil borings (BH-1 and MW-4 through MW-8) were drilled at select locations at the dam.

Five of these borings were completed as monitor wells to obtain future groundwater level readings. The wells were constructed of solid and screened 2-inch diameter PVC pipe extending from near the bottom of the boring to the existing ground surface. Monitor well and boring locations are shown on Figure GT-

1. Boring logs with monitor well construction details are included in Appendix A.

Two test pits (TP-1 and TP-2) were also excavated along the dam crest as part of the investigation. Test pit logs are included in Appendix A with the locations shown on Figure GT-1.

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Dike Site – Three soil borings (MW-1 through MW-3) were drilled at select locations at the dike. All three of these borings were completed as monitor wells so groundwater levels can be monitored. The wells were constructed of solid and screened 2-inch diameter PVC pipe extending from near the bottom of the boring to the ground surface. Monitor well and boring locations at the dike are shown on Figure

GT-2. Boring logs with monitor well construction details are included in Appendix A.

All Sites - Soil type, sample depths, thickness, consistency, relative moisture content and groundwater occurrence were observed and documented by a DOWL HKM geotechnical engineer (see boring and test pit logs in Appendix A). Soil samples were collected while advancing the soil borings using a 2-inch outside-diameter split-spoon sampler driven into the soil layers using a 140 pound hammer falling 30-inches. Relatively undisturbed Shelby tube samples were hydraulically pushed into the soils at locations selected by the field engineer. Bulk soil samples were also obtained from the boring and test pit excavations. These samples were then transported to the DOWL HKM and Tetra Tech soils laboratory where engineering property and strength tests were conducted.

Soils were field-classified in general accordance with ASTM D2488 Visual-Manual Method. The stratigraphy contacts shown on the individual boring and test pit logs represent the approximate boundaries between soil types. The actual transitions may be more gradual or abrupt. The soil and groundwater conditions depicted are only for the specific dates and locations reported, and therefore, are not necessarily representative of other locations and times. Photographs of the borings, test pits and the project site are presented in Appendix B.

3.4 SITE SURVEY

A topographic land survey was conducted by a DOWL HKM survey crew after the geotechnical investigation. Boring and test pit excavations were surveyed to obtain ground surface elevations and horizontal coordinates.

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4.0 LABORATORY TESTING

Representative soil samples were selected for laboratory testing following visual examination of the soil and consideration of project reconstruction requirements. Classification and engineering property tests were performed by DOWL HKM and Tetra Tech material laboratories in Billings, Montana. Chemical analysis of soil samples was performed by Energy Laboratories in Billings, Montana. Laboratory tests performed are summarized in Table 4-1.

Table 4-1

Equalizer Geotechnical Laboratory Test Descriptions

Test Purpose of Test

Natural Moisture Content

(ASTM D2216)

Provides measure of natural (in situ) moisture content.

Atterberg Limits

(ASTM D4318)

Provides a measure of liquid limit and plastic limit relative to varying water content in silts and clays.

Particle-Size Distribution

(ASTM D422)

Provides a measure of the grain sizes of the soils for classification and identification of physical characteristics.

Consolidation/Swell

(ASTM D2435)

Provides a measure of the magnitude at which a soil will compress when loaded and rebound when unloaded.

Consolidated Undrained Shear

(ASTM

Provides a measure of both total and effective shear stress of soil

Direct Shear

(ASTM D3080-4)

Provides a measure of the shear strength of soil.

Resistivity, pH, and SO4 Provides a measure of deleterious effects of the soils on buried metals and concrete.

Moisture-Density Relationship

(ASTM D698)

Provides measure of the relationship of water content to the density of soil during compaction.

Laboratory tests were performed in general accordance with the most recent ASTM or other procedures standard to the industry. A summary of laboratory test results is presented in Appendix C along with individual test reports

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5.0 SITE CONDITIONS

5.1 TOPOGRAPHY

The general topography at the project site was noted to be gently sloping and with abrupt elevation gain when proceeding away from the dam to the north and south toward the adjacent hills (see Photos 1 and 2).

The main access road enters the dam site from the west and follows the dam crest to the river outlet and canal. Another road accesses the dike from the north, near the middle of the dike, and parallels the reservoir along the dike crest.

Photo 1 – Looking northeast toward existing spillway.

5.2 VEGETATION

Vegetation in the study area consists primarily of dry land grasses, small brush and trees, with various aquatic species in shallow areas of the reservoir. Land use near Equalizer Reservoir is generally open pasture south of the dam (see Photo 2 below) with irrigated cropland in all other directions. The reservoir is currently not being used for public recreation.

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Photo 2 - Looking south toward dam crest and borrow site.

5.3 WATER

Equalizer Dam and Dike are located in the Blackfoot River floodplain. The reservoir is filled for irrigation each year in April with the water level remaining fairly constant into October. The reservoir is drained by the end of October, after irrigation season ends. In the irrigation off-season the only water that remains is in the deepest areas, along the east side of the reservoir, with flowing water through the dam outlet works in the Blackfoot River channel.

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6.0 SUBSURFACE CONDITIONS

6.1 GENERAL

Surficial deposits at the Equalizer Dam and Dike site generally consist of alluvial and eolian soil deposits overlying rhyolite and basalt bedrock. The soils observed at the site generally consist of sand, gravel and silt. These deposits overlay the observed bedrock outcrops near the right abutment which were comprised of rhyolite and basalt.

6.2 SOIL & BEDROCK

Dam and Dike - Embankment and foundation materials generally consists of sand, silt, and gravel deposits that overlie bedrock. Laboratory testing results for the soil types noted below can be found in

Appendix C.

Silt – The silt encountered at the dam and dike sites classified as silt and silt with sand. Liquid and plastic limit tests performed on the silt indicates the material is non-plastic. Natural moisture contents obtained above the water table from the silt layer ranged from approximately 6 to 19 percent. Blow counts in the silt ranged from 2 to 32 blows per foot which indicates a soil stratum that varies from very soft to hard. A moisture-density determination performed on a sample of the silt indicated a maximum dry density of approximately 107 pounds per cubic foot (pcf) with an optimum moisture content of 14.9 percent. A consolidated drained triaxial shear test performed on the silt indicates a friction angle of 36.7 degrees with cohesion of approximately 300 pounds per square foot (psf). A dry density performed in conjunction with the triaxial test was measured at approximately 114 pcf.

Clay – A clay layer was encountered within the foundation of the dike in boring MW-1 at a depth of approximately 12.5 to 16.5 feet below ground surface. This clay had a liquid limit of 36 percent and a plasticity index of 13 percent. A direct shear performed on a sample of the clay indicates an internal friction angle of 25.7 degrees and cohesion of 970 psf. Blow counts in the layer were measured at 2 blows per foot which is indicative of a very soft soil stratum. A dry density performed in conjunction with the Shelby tube sampling and direct shear test was measured at approximately 83 pcf.

Sand – The sand encountered at the dam and dike classified as silty sand, poorly graded sand and poorly graded sand with silt. Liquid and plastic limit tests performed on the sand indicate the material is non-plastic. Natural moisture contents in the sand above the groundwater ranged from approximately 3 to 18 percent. Blow counts in the sand ranged from 2 to greater than 50 blows per foot which indicates a soil stratum that varies from very loose to very dense. One dimensional consolidation tests performed on the sand indicates the material has low to moderate compressibility potential under conditions of wetting and relatively light loading. A direct shear performed on a sample of the sand indicates an internal friction angle of 36 degrees and a cohesion of 106 psf. A consolidated drained triaxial shear test performed on the sand indicates a

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Gravel – The gravel encountered at the site visually classified as poorly graded gravel with silt and sand. Liquid and plastic limit tests performed on the gravel indicate the material is non-plastic. Blow counts in the gravel ranged from 13 to greater than 50 blows per foot which indicates a medium dense to very dense soil stratum.

Bedrock – The bedrock encountered when coring at the right dam abutment consisted of basalt.

The quality of rock was generally poor and was highly fractured or broken in many areas. Voids which were infilled with fine to coarse sand were encountered from 15 to 35 feet below ground.

The rock was generally hard as it took several strong hammer blows to break in the field.

Historic Borrow Site – The borrow site materials generally consisted of silt overlying basalt. Laboratory testing results for the soil types noted below can be found in Appendix C.

Silt – The silt encountered at the borrow site classified as silt. A natural moisture content taken in the silt was measured at approximately 7 percent. A liquid and plastic limit test performed on the silt indicates a liquid limit of 30 percent and a plasticity index of 5 percent.

Bedrock – The bedrock encountered at the borrow area below the silt consisted of basalt. The rock was generally hard as it took several strong hammer blows to break in the field.

6.3 GROUNDWATER

When considering groundwater levels near Equalizer Reservoir, soil moisture conditions will primarily fluctuate in response to seasonal precipitation, irrigation, and reservoir levels.

Dam Site – Groundwater was observed in borings BH-1 and MW-4 through MW-8 at depths ranging from 13.5 to 24 feet.

Dike Site – Groundwater was observed in borings MW-1 through MW-3 at depths ranging from

11.5 to 12 feet.

Historic Borrow Site – Groundwater was not observed in the test pit explored at the borrow site.

6.4 SOIL CHEMICAL PROPERTIES

The USDA Natural Resources Conservation Service (NRCS) criteria for anticipated corrosion activity to buried metal range from Very Severe (Under 1,000 ohm-cm) to Non-corrosive (over 10,000 ohm-cm).

Laboratory resistivity measurements from soil samples collected at the dam and dike sites indicated moderate to high corrosion potential (1,854 to 2,865 ohm-cm) for buried metals at the site.

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The Portland Cement Association criteria for sulfate exposure to buried concrete are as follows:

Table 6-1 Sulfate Exposure Criteria

Percent Water Soluble Sulfates Attack on Buried Concrete

0.00 – 0.10% Negligible

0.10% – 0.20% Moderate

0.20% – 2.0% Severe

Over 2.0% Very Severe

Laboratory sulfate measurements from soil samples collected at the dam and dike sites (pH=7.8 to 7.9;

SO4= Not detected) indicated negligible corrosion potential for buried concrete at the site.

7.0 CONCLUSIONS

The Equalizer Dam and Dike are constructed of, as well as underlain, by fine-grained silt and sand soils, which erode easily and exhibit moderate shear strength properties. Several zones within the silt and sand layers are soft or loose and may be prone to settlement. The following items should be addressed during final design of the dam:

Subgrade stabilization with the possible need for over-excavation and replacement with engineered fill for construction of the new outlet and spillway at the dam, Slope stability and seepage analyses of both the dam and dike using the soil information obtained from the field exploration and subsequent groundwater readings obtained from the monitor wells, Placement of drains and filters in the dam or dike embankment to reduce the potential for piping erosion of fine grained embankment materials, and

Construction dewatering, Test pit excavations performed near the historic borrow pit show good quantities of silt which will provide a more impervious zone when compared to the sand encountered on-site. We recommend using material near this location for constructing any areas of new embankment. Also, relatively clean, poorly graded sand was encountered at numerous locations at the site. This material may be used as filter drain material provided it meets the proper gradation specification and is filter compatible with the soils at the site. Coarse-grained riprap and gravel bedding will need to be imported from offsite sources.

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8.0 LIMITATIONS

The conclusions and recommendations presented in this report assume that site conditions are not substantially different than those exposed by the explorations. If during construction, subsurface conditions appear different from those encountered in the explorations, DOWL HKM should be advised at once to review those conditions and reconsider recommendations where necessary.

If there is a substantial lapse of time between submission of this report and the start of work at the site, and if conditions have changed due to natural causes or construction operations at or near the site, this report should be reviewed to determine the applicability of the conclusions and recommendations considering the changed conditions.

This report was prepared for the use of the Bureau of Indian Affairs and their Consultants for this project.

It should be made available to prospective contractors for information on factual data only and not as a warranty of subsurface conditions.

Any conclusions by a construction contractor or bidder relating to construction means, methods, techniques, sequences or costs based upon the information provided in this report are not the responsibility of the Bureau of Indian Affairs or DOWL HKM.

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9.0 REFERENCES

Gennett, Douglas J., Bureau of Reclamation. 1998. Geologic Report For Proposed Replacement

Headworks Structure Equalizer Dam.

U.S. Bureau of Reclamation. 1974. Earth Manual, 2 nd

Edition. U.S. Government Printing Office, Washington.

U.S. Bureau of Reclamation. 1977. Design of Small Dams. U.S. Government Printing Office, Washington.

FIGURES

PRELIMINARY

NOT FOR

CONSTRUCTION

D

AM

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LEGEND

A SECTION

PROFILE ALONG EMBANKMENT AXIS

CONSTRUCTION

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EMBANKMENT

ORIGINAL EMBANKMENT MATERIALS

CONSTRUCTION

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Appendix A

Boring and Test Pit Logs

SS

BS

SS

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RC

4524.4

4522.4

4517.9

4515.4

(27)

3-5-9 (14)

3-10-10 (20)

4-5-7 (12)

50/3"

MC = 7%

MC = 6%

MC = 8%

MC = 7%

6.0

8.0

12.5

15.0

SILT with Sand - brown, medium stiff to stiff, dry to moist, fine sand.

Poorly Graded GRAVEL with Silt and Sand - brown, medium dense, dry to moist, fine to coarse sand, fine to coarse subrounded gravel, cobbles present.

Poorly Graded SAND with Silt - brown, medium dense, dry to moist, fine sand, scattered fine to coarse gravel noted.

Poorly Graded GRAVEL with SIlt and Sand - brown, dry to moist, fine to coarse sand, fine to coarse subrounded to subangular gravel, cobbles present.

BASALT - black to dark gray, highly fractured, infilled sand zones noted throughout the layer, maintained circulation while drilling.

AFTER DRILLING ---

AT END OF DRILLING ---

AT TIME OF DRILLING --- Dry

GROUND WATER LEVELS:

SURFACE ELEVATION 4530.4 ft

HAMMER AUTO

DRILL RIG CME-75

CHECKED BY J. Carter

DRILLER D. Gonzales

LOGGED BY S. Weisenberger

STARTED 11/4/14

CONTRACTOR Haz-Tech Drilling

FINISHED 11/4/14

BORING LOCATION N43.1704 / W112.2982

S A

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(Continued Next Page)

LOG OF BORING BH-1

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

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222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

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RC

RC

RC

4490.4

(13)

(8)

(60)

40.0

BASALT - black to dark gray, highly fractured, infilled sand zones noted throughout the layer, maintained circulation while drilling. (continued)

Bottom of borehole at 40.0 feet.

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LOG OF BORING BH-1

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

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222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

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4525.4

4515.9

4511.9

4507.0

4-9-16 (25)

3-3-2-2 (5)

2-3-2-2 (5)

2-1-1-1 (2)

0-0-0-1 (0)

1-2-3-6 (5)

0-1-3 (4)

MC = 6%

MC = 4%

MC = 8%

MC = 18%

MC = 38%

DD = 83 pcf

LL = 36

PL = 23

Fines = 69%

3.0

12.5

16.5

21.4

SILT - light brown, very stiff, dry to moist.

Poorly Graded SAND - brown, very loose, moist, fine sand.

Sandy Lean CLAY - brown to light brown, soft, wet.

Poorly Graded SAND - brown, very loose to loose, wet, fine sand.

Bottom of borehole at 21.5 feet.

Cement

Bentonite

2-Inch Solid PVC

Silica Sand

2-Inch Slotted PVC

AFTER DRILLING ---

AT END OF DRILLING ---

AT TIME OF DRILLING 12.00 ft / Elev 4516.40 ft

GROUND WATER LEVELS:

SURFACE ELEVATION 4528.4 ft

HAMMER AUTO

DRILL RIG CME-75

CHECKED BY J. Carter

DRILLER D. Gonzales

LOGGED BY S. Weisenberger

STARTED 11/6/14

CONTRACTOR Haz-Tech Drilling

FINISHED 11/6/14

BORING LOCATION N43.1850 / W112.2817

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WELL MW-1

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

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222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

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MATERIAL DESCRIPTION WELL DIAGRAM

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SS

SS

SS

4512.7

4507.2

2-3-5 (8)

2-2-2-3 (4)

3-4-3-4 (7)

2-2-3-6 (5)

4-6-7-5 (13)

1-1-1-3 (2)

4-16-28 (44)

5-11-17 (28)

MC = 5%

MC = 5%

MC = 6%

LL = NP

PL = NP

Fines = 1%

MC = 18%

14.0

19.5

Poorly Graded SAND - brown, very loose to medium dense, dry to wet, fine sand.

SILT - light brown, very soft to soft, wet.

Poorly Graded GRAVEL with Silt and Sand -brown, medium dense to very dense, wet, fine to coarse sand, fine to coarse subrounded gravel, scattered cobbles noted.

Cement

Bentonite

2-Inch Solid PVC

Silica Sand

2-Inch Slotted PVC

AFTER DRILLING ---

AT END OF DRILLING ---

AT TIME OF DRILLING 11.50 ft / Elev 4515.20 ft

GROUND WATER LEVELS:

SURFACE ELEVATION 4526.7 ft

HAMMER AUTO

DRILL RIG CME-75

CHECKED BY J. Carter

DRILLER D. Gonzales

LOGGED BY S. Weisenberger

STARTED 11/6/14

CONTRACTOR Haz-Tech Drilling

FINISHED 11/6/14

BORING LOCATION N43.1820 / W112.2870

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(Continued Next Page)

WELL MW-2

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

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T P

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D

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T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

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IE

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IN

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\B O

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IN

G L

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S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

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R Y

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S (N

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LU

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TESTS

G R

A P

H

IC

LO

SS 4496.250 50 30.5

Poorly Graded GRAVEL with Silt and Sand -brown, medium dense to very dense, wet, fine to coarse sand, fine to coarse subrounded gravel, scattered cobbles noted. (continued)

Bottom of borehole at 30.5 feet.

S A

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U M

B E

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D E

P T

H (f t)

WELL MW-2

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

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O R

IN

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L O

G S

\B O

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IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

B

LO

W C

O U

N T

S (N

V A

LU

E

TESTS

G R

A P

H

IC

LO

SS

SS

SS

SS

SS

SS

4518.1

4516.1

4508.6

4-5-9 (14)

3-4-3-3 (7)

1-1-2-2 (3)

1-3-3-5 (6)

3-1-1-2 (2)

3-5-6-7 (11)

1-3-8 (11)

MC = 7%

MC = 3%

LL = NP

PL = NP

Fines = 13%

MC = 3%

MC = 4%

MC = 4%

12.0

14.0

21.5

Silty SAND - brown, very loose to medium dense, dry to wet, fine sand.

SILT - brown, soft to medium stiff, wet.

Poorly Graded SAND - brown, loose to medium dense, wet, fine sand.

Bottom of borehole at 21.5 feet.

Cement

Bentonite

2-Inch Solid PVC

Silica Sand

2-Inch Slotted PVC

AFTER DRILLING ---

AT END OF DRILLING ---

AT TIME OF DRILLING 12.00 ft / Elev 4518.10 ft

GROUND WATER LEVELS:

SURFACE ELEVATION 4530.1 ft

HAMMER AUTO

DRILL RIG CME-75

CHECKED BY J. Carter

DRILLER D. Gonzales

LOGGED BY S. Weisenberger

STARTED 11/6/14

CONTRACTOR Haz-Tech Drilling

FINISHED 11/6/14

BORING LOCATION N43.1796 / W112.2888

S A

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B E

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P T

H (f t)

WELL MW-3

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

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IE

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O R

IN

G

L O

G S

\B O

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IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

B

LO

W C

O U

N T

S (N

V A

LU

E

TESTS

G R

A P

H

IC

LO

BS

SS

SS

SH

SS

SS

4526.1

4524.1

4512.1

3-6-9 (15)

22-12-9 (21)

5-9-7 (16)

3-2-2 (4)

5-6-8 (14)

4-4-8 (12)

MC = 6%

MC = 14%

MC = 18%

MC = 19%

MC = 17%

MC = 18%

4.0

6.0

18.0

Sandy SILT - brown, stiff, moist, fine sand.

Poorly Graded GRAVEL with Silt and Sand -brown, dense, dry to moist, fine to coarse sand, fine to coarse subrounded to subangular gravel, some cobbles and boulders noted.

SILT - brown, soft to very stiff, moist, some fine sand noted in the layer, organics and roots noted from 14 to 15 feet.

Poorly Graded SAND with Silt - brown, very loose to medium dense, moist to wet, fine to medium sand.

Cement

Bentonite

2-Inch Solid PVC

AFTER DRILLING ---

AT END OF DRILLING ---

AT TIME OF DRILLING 24.00 ft / Elev 4506.10 ft

GROUND WATER LEVELS:

SURFACE ELEVATION 4530.1 ft

HAMMER AUTO

DRILL RIG CME-75

CHECKED BY J. Carter

DRILLER D. Gonzales

LOGGED BY S. Weisenberger

STARTED 11/5/14

CONTRACTOR Haz-Tech Drilling

FINISHED 11/5/14

BORING LOCATION N43.1697 / W112.2983

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(Continued Next Page)

WELL MW-4

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

B

LO

W C

O U

N T

S (N

V A

LU

E

TESTS

G R

A P

H

IC

LO

SS

4496.1

4492.6

4488.6

1-2-2 (4)

14-32-50 (82)

11-17-50 (67)

34.0

37.5

41.5

Poorly Graded SAND with Silt - brown, very loose to medium dense, moist to wet, fine to medium sand. (continued)

Poorly Graded GRAVEL with Silt and Sand -brown, very dense, wet, fine to coarse sand, fine to coarse subangular gravel.

Poorly Graded SAND with Silt - brown, very dense, wet, fine to medium sand.

Bottom of borehole at 41.5 feet.

Silica Sand

2-Inch Slotted PVC

S A

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H (f t)

WELL MW-4

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

B

LO

W C

O U

N T

S (N

V A

LU

E

TESTS

G R

A P

H

IC

LO

SH

SS

SS

SH

SS

SS

4506.6

4496.1

3-5-9 (14)

2-3-4 (7)

2-2-3 (5)

1-1-5 (6)

2-3-4 (7)

1-8-19 (27)

MC = 3%

MC = 4%

MC = 21%

DD = 102 pcf

LL = 21

PL = 20

Fines = 39%

MC = 20%

MC = 24%

MC = 17%

DD = 118 pcf

LL = NP

PL = NP

Fines = 12%

15.0

25.5

Poorly Graded SAND with Silt - brown, loose to medium dense, dry to wet, fine to medium sand, some thin silt and silty sand layers interbedded throughout the layer.

Sandy SILT - brown, very soft to medium stiff, wet, fine sand, some poorly graded sand layers interbedded throughout the layer.

Cement

Bentonite

2-Inch Solid PVC

AFTER DRILLING ---

AT END OF DRILLING ---

AT TIME OF DRILLING 13.50 ft / Elev 4508.10 ft

GROUND WATER LEVELS:

SURFACE ELEVATION 4521.6 ft

HAMMER AUTO

DRILL RIG CME-75

CHECKED BY J. Carter

DRILLER D. Gonzales

LOGGED BY S. Weisenberger

STARTED 11/4/14

CONTRACTOR Haz-Tech Drilling

FINISHED 11/4/14

BORING LOCATION N43.1667 / W112.2982

S A

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U M

B E

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H (f t)

(Continued Next Page)

WELL MW-5

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

B

LO

W C

O U

N T

S (N

V A

LU

E

TESTS

G R

A P

H

IC

LO

SS

SS

4487.6

4475.1

14-34- 50/3"

23-36- 50/4"

50/3"

9-10-13

(23) MC = 26%

34.0

46.5

Poorly Graded GRAVEL with Silt and Sand -brown, medium dense to very dense, wet, fine to coarse sand, fine to coarse subrounded gravel, cobbles present. (continued)

CALICHE - Cemented SILT - light to orange brown, very stiff to hard, wet, some fine sand noted, very silty.

Bottom of borehole at 46.5 feet.

Silica Sand

2-Inch Slotted PVC

S A

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U M

B E

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P T

H (f t)

WELL MW-5

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

B

LO

W C

O U

N T

S (N

V A

LU

E

TESTS

G R

A P

H

IC

LO

SH

SS

SS

SS

SH

SS

SS

4528.8

4510.8

4503.8

8-14-12 (26)

6-8-10 (18)

5-8-9 (17)

1-2-1 (3)

2-2-4 (6)

2-2-2 (4)

MC = 4%

MC = 17%

MC = 14%

DD = 114 pcf

LL = NP

PL = NP

Fines = 74%

MC = 18%

MC = 17%

MC = 21%

MC = 23%

DD = 100 pcf

LL = NP

PL = NP

Fines = 28%

MC = 23%

1.0

19.0

26.0

Poorly Graded GRAVEL with Silt and Sand -brown, medium dense, dry, fine to coarse sand, fine to coarse subrounded gravel.

SILT with Sand - brown, very stiff, moist, fine sand.

Silty SAND - brown to gray, loose, moist to wet, fine sand.

SILT with Sand - brown to gray, medium stiff, wet, fine sand.

Cement

Bentonite

2-Inch Solid PVC

AFTER DRILLING ---

AT END OF DRILLING ---

AT TIME OF DRILLING 23.00 ft / Elev 4506.80 ft

GROUND WATER LEVELS:

SURFACE ELEVATION 4529.8 ft

HAMMER AUTO

DRILL RIG CME-75

CHECKED BY J. Carter

DRILLER D. Gonzales

LOGGED BY S. Weisenberger

STARTED 11/3/14

CONTRACTOR Haz-Tech Drilling

FINISHED 11/3/14

BORING LOCATION N43.1666 / W112.2978

S A

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B E

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H (f t)

(Continued Next Page)

WELL MW-6

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

B

LO

W C

O U

N T

S (N

V A

LU

E

TESTS

G R

A P

H

IC

LO

SS

4497.3

4488.3

4-4-6 (10)

4-8-22 (30)

17-28-48 (76)

32.5

41.5

SILT with Sand - brown to gray, medium stiff, wet, fine sand. (continued)

Poorly Graded GRAVEL with Silt and Sand -brown to gray, medium dense to very dense, wet, fine to coarse sand, fine to coarse subrounded to subangular gravel.

Bottom of borehole at 41.5 feet.

Silica Sand

2-Inch Slotted PVC

S A

M P

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E N

U M

B E

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D E

P T

H (f t)

WELL MW-6

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

B

LO

W C

O U

N T

S (N

V A

LU

E

TESTS

G R

A P

H

IC

LO

SH

SS

SS

SS

SS

4526.3

4517.3

4509.3

2-2-2 (4)

6-9-8 (17)

5-6-6 (12)

0-1-3 (4)

2-3-2 (5)

MC = 18%

MC = 17%

MC = 14%

MC = 11%

MC = 25%

3.0

12.0

20.0

Poorly Graded GRAVEL with Silt and Sand -brown, dry, fine to coarse sand, fine to coarse subrounded to subangular gravel.

SILT with Sand - brown, soft to stiff, moist, fine sand.

Silty SAND - brown, very loose to medium dense, moist to wet, fine sand.

SILT with Sand - brown to gray, soft to medium stiff, wet, fine sand.

Cement

Bentonite

2-Inch Solid PVC

AFTER DRILLING ---

AT END OF DRILLING ---

AT TIME OF DRILLING 20.50 ft / Elev 4508.80 ft

GROUND WATER LEVELS:

SURFACE ELEVATION 4529.3 ft

HAMMER AUTO

DRILL RIG CME-75

CHECKED BY J. Carter

DRILLER D. Gonzales

LOGGED BY S. Weisenberger

STARTED 11/4/14

CONTRACTOR Haz-Tech Drilling

FINISHED 11/4/14

BORING LOCATION N43.1664 / W112.2976

S A

M P

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T

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U M

B E

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D E

P T

H (f t)

(Continued Next Page)

WELL MW-7

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

B

LO

W C

O U

N T

S (N

V A

LU

E

TESTS

G R

A P

H

IC

LO

SS

4499.3

4488.9

8-15-21 (36)

19-26-33 (59)

16-41- 50/5"

30.0

40.4

SILT with Sand - brown to gray, soft to medium stiff, wet, fine sand. (continued)

Poorly Graded GRAVEL with Silt and Sand -brown, very dense, wet, fine to coarse sand, fine to coarse subrounded gravel.

Bottom of borehole at 40.4 feet.

Silica Sand

2-Inch Slotted PVC

S A

M P

LE

T

Y P

E N

U M

B E

R

D E

P T

H (f t)

WELL MW-7

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

B

LO

W C

O U

N T

S (N

V A

LU

E

TESTS

G R

A P

H

IC

LO

SH

SS

SS

SS

4523.8

4518.3

4512.8

4509.3

2-12-20 (32)

2-3-3 (6)

3-4-3 (7)

5-4-9 (13)

0-2-3 (5)

MC = 6%

MC = 17%

MC = 16%

MC = 14%

MC = 7%

MC = 21%

7.0

12.5

18.0

21.5

SILT - brown, medium stiff to hard, dry.

Poorly Graded SAND with Silt - brown, loose, dry, fine sand, scattered cobbles noted.

Poorly Graded GRAVEL with Silt and Sand -brown, medium dense, dry to moist, fine to coarse sand, fine to coarse subrounded to subangular gravel.

SILT with Sand - brown to gray, very soft to medium stiff, moist, fine sand.

Bottom of borehole at 21.5 feet.

Cement

Bentonite

2-Inch Solid PVC

Silica Sand

2-Inch Slotted PVC

AFTER DRILLING ---

AT END OF DRILLING ---

AT TIME OF DRILLING --- Dry

GROUND WATER LEVELS:

SURFACE ELEVATION 4530.8 ft

HAMMER AUTO

DRILL RIG CME-75

CHECKED BY J. Carter

DRILLER D. Gonzales

LOGGED BY S. Weisenberger

STARTED 11/5/14

CONTRACTOR Haz-Tech Drilling

FINISHED 11/5/14

BORING LOCATION N43.1697 / W112.2985

S A

M P

LE

T

Y P

E N

U M

B E

R

D E

P T

H (f t)

WELL MW-8

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

B

LO

W C

O U

N T

S (N

V A

LU

E

TESTS

G R

A P

H

IC

LO

4528.4

4524.4

100 MC = 5%

3.0

7.0

SILT - brown, dry, some fine sand noted.

Poorly Graded SAND with Silt - brown, dry to moist, fine sand.

Bottom of test pit at 7.0 feet.

AFTER EXCAVATION ---

AT END OF EXCAVATION ---

AT TIME OF EXCAVATION --- Dry

GROUND WATER LEVELS:

SURFACE ELEVATION 4531.4 ft

HAMMER

DRILL RIG CAT 430E

CHECKED BY S. Weisenberger

DRILLER

LOGGED BY J. Carter

STARTED 11/5/14

CONTRACTOR BIA

FINISHED 11/5/14

BORING LOCATION N43.1693 / W112.2985

S A

M P

LE

T

Y P

E N

U M

B E

R

D E

P T

H (f t)

TEST PIT TP-1

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

TESTS

G R

A P

H

IC

LO

4526.0 4525.5

4523.0

100 MC = 16%

4.0 4.5

7.0

SILT - brown, dry, some fine sand noted.

Poorly Graded GRAVEL with Silt and Sand - brown, dry, fine to coarse sand, fine to coarse angular gravel, cobbles and boulders observed.

Poorly Graded SAND with Silt - brown, dry to moist, fine sand.

Bottom of test pit at 7.0 feet.

AFTER EXCAVATION ---

AT END OF EXCAVATION ---

AT TIME OF EXCAVATION --- Dry

GROUND WATER LEVELS:

SURFACE ELEVATION 4530 ft

HAMMER

DRILL RIG CAT 430E

CHECKED BY S. Weisenberger

DRILLER

LOGGED BY J. Carter

STARTED 11/5/14

CONTRACTOR BIA

FINISHED 11/5/14

BORING LOCATION N43.1692 / W112.2983

S A

M P

LE

T

Y P

E N

U M

B E

R

D E

P T

H (f t)

TEST PIT TP-2

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

TESTS

G R

A P

H

IC

LO

BS 100

MC = 7%

LL = 30

PL = 25

Fines = 86% 6.5 7.0

SILT - brown, dry to moist, some fine sand noted.

BASALT - black, massive, very difficult excavating, refusal encountered.

Bottom of test pit at 7.0 feet.

AFTER EXCAVATION ---

AT END OF EXCAVATION ---

AT TIME OF EXCAVATION --- Dry

GROUND WATER LEVELS:

SURFACE ELEVATION

HAMMER

DRILL RIG CAT 430E

CHECKED BY S. Weisenberger

DRILLER

LOGGED BY J. Carter

STARTED 11/5/14

CONTRACTOR BIA

FINISHED 11/5/14

BORING LOCATION N43.1639 / W112.2942

S A

M P

LE

T

Y P

E N

U M

B E

R

D E

P T

H (f t)

TEST PIT TP-3

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

TESTS

G R

A P

H

IC

LO

4525.0

4515.5

MC = 3%

LL = NP

PL = NP

Fines = 7%

MC = 7%

2.5

12.0

Poorly Graded SAND with Silt and Gravel - brown, moist, fine sand, fine to coarse subangular gravel.

Poorly Graded SAND - brown, dry to moist with more moisture noted at 10 feet, fine sand.

Bottom of test pit at 12.0 feet.

AFTER EXCAVATION ---

AT END OF EXCAVATION ---

AT TIME OF EXCAVATION --- Dry

GROUND WATER LEVELS:

SURFACE ELEVATION 4527.5 ft

HAMMER

DRILL RIG CAT 430E

CHECKED BY J. Carter

DRILLER

LOGGED BY S. Weisenberger

STARTED 11/5/14

CONTRACTOR BIA

FINISHED 11/5/14

BORING LOCATION N43.1811 / W112.2877

S A

M P

LE

T

Y P

E N

U M

B E

R

D E

P T

H (f t)

TEST PIT TP-4

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

TESTS

G R

A P

H

IC

LO

4522.4

MC = 4%

LL = NP

PL = NP

Fines = 3% 5.0

Poorly Graded SAND - brown, dry to moist, fine sand.

Bottom of test pit at 5.0 feet.

AFTER EXCAVATION ---

AT END OF EXCAVATION ---

AT TIME OF EXCAVATION --- Dry

GROUND WATER LEVELS:

SURFACE ELEVATION 4527.4 ft

HAMMER

DRILL RIG CAT 430E

CHECKED BY J. Carter

DRILLER

LOGGED BY S. Weisenberger

STARTED 11/5/14

CONTRACTOR BIA

FINISHED 11/5/14

BORING LOCATION N43.1765 / W112.2905

S A

M P

LE

T

Y P

E N

U M

B E

R

D E

P T

H (f t)

TEST PIT TP-5

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

TESTS

G R

A P

H

IC

LO

4522.2

100 MC = 12%

6.0

Poorly Graded SAND - brown, dry to moist, fine sand.

Bottom of test pit at 6.0 feet.

AFTER EXCAVATION ---

AT END OF EXCAVATION ---

AT TIME OF EXCAVATION --- Dry

GROUND WATER LEVELS:

SURFACE ELEVATION 4528.2 ft

HAMMER

DRILL RIG CAT 430E

CHECKED BY J. Carter

DRILLER

LOGGED BY S. Weisenberger

STARTED 11/5/14

CONTRACTOR BIA

FINISHED 11/5/14

BORING LOCATION N43.1861 / W112.2781

S A

M P

LE

T

Y P

E N

U M

B E

R

D E

P T

H (f t)

TEST PIT TP-6

PROJECT NO.: 4026.20690.01

CLIENT BIA

PROJECT Equalizer Dam

SITE Near Blackfoot, ID

G E

N E

R A

L B

H

T P

W

E

LL

D

O W

LT

E

M P

LA

T

E .G

D T

/2

/1

9:

H :\2

\2

0\

G E

O S

C

IE

N C

E \B

O R

IN

G

L O

G S

\B O

R

IN

G L

O G

S .G

P J

222 N 32nd St, Suite 700 Billings, Montana 59101 Telephone: (406) 656-6399 Fax: (406) 656-6398

R E

C O

V E

R Y

TESTS

G R

A P

H

IC

LO

Appendix B

Photo Log

Equalizer Dam and Dike Field Photos

Boring MW-1

Boring MW-2

Boring MW-3

Boring MW-4

Boring MW-5

Boring MW-6

Boring MW-7

Test Pit TP-1

Test Pit TP-1

Test Pit TP-2

Test Pit TP-2

Test Pit TP-3

Test Pit TP-3

Test Pit TP-4

Test Pit TP-4

Test Pit TP-5

Test Pit TP-5

Test Pit TP-6

Test Pit TP-6

Boring BH-1

Boring BH-1 - 20 to 25 foot Core Run

Boring BH-1 - 25 to 30 foot Core Run

Boring BH-1 - 30 to 35 foot Core Run

Boring BH-1 - 35 to 40 foot Core Run

Appendix C

Laboratory Test Results

EQUALIZER DAM SUMMARY OF PHYSICAL PROPERTIES TEST RESULTS GEOTECHNICAL INVESTIGATION

LA

B

N U

M B

E R

LO

C

A

TI

O N

D E

P

TH

R A

N G

E

C

LA

S S

IF

IC

A

TI

O N

S Y

M B

O L

S M

A

LL

E R

TH

A

N 0.

m m

0.

to

0.

m m

S A

N D

N O

.2

(0 .0 m m

TO

N

O .4

(4 .7 m m

G R

A V

E L

N O

.4 (4

.7 m m

TO

IN

.(7 6.

m m

LI

Q

U

ID

LI

M

IT

P

LA

S

TI

C

IT

Y

IN

D E

X

C O

N S

O

LI

D A

TI

O

N -P c

C O

N S

O

LI

D A

TI

O

N -C c

C O

N S

O

LI

D A

TI

O

N -C s

D

IR

E C

T S

H E

A R

A N

G

LE

-d eg

M A

X

IM

U M

D R

Y U

N

IT

W E

IG

H

T( D

8)

-p cf

O P

TI

M

U M

M O

IS

TU

R E

C O

N

TE

N T

U N

IT

W

T.

(C

O N

S O

L.

D R

Y P

C F

U N

IT

W

T.

A

V G

S

H E

A R

D

R Y

P C

F

U N

IT

W

T.

(U

N C

O N

F.

D R

Y P

C F

U N

IT

W

T.

(T

U B

E

D R

Y P

C F

N A

TU

R

A L

M O

IS

TU

R E

R es is tiv ity (O hm -C m

N at ur al

M oi st ur e

R es is tiv ity (O hm -C m

S at ur at ed pH

W A

TE

R

S O

LU

B

LE

S

O

C U

TR

IA

X

IA

L A

N G

LE

-d eg

29831 MW-1 0-1.5' 5.5

29832 MW-1 5.0-7.0' 4.1

29833 MW-1 7.0-9.0' 7.9

29834 MW-1 9.0-11.0' 18.4

29835 MW-1 13.0-15.0' CL 69.1 30.8 0.1 36 13 25.7 37.6

29836 MW-2 0-1.5' 5.0

29837 MW-2 5.0-7.0' 5.3

29838 MW-2 7.0-9.0' SP 1.0 99.0 NV NP 6.1

29839 MW-2 9.5-11.5' 18.3

29840 MW-3 0-1.5' 6.6

29841 MW-3 3.0-6.0' SM 5.8 7.3 86.4 0.5 NV NP 110.9 13.7 2.6 3112 2865 7.8 ND

29842 MW-3 5.0-7.0' 2.9

29843 MW-3 7.0-9.0' 3.7

29844 MW-3 9.0-11.0' 4.1

29845 MW-4 0-1.5' 5.9

29846 MW-4 5.0-6.5' 14.3

29847 MW-4 10.0-11.5' 18.0

29848 MW-4 15.0-16.5' 18.9

29849 MW-4 18.0-20.0' 17.0

29850 MW-4 20.0-21.5' 18.0

29851 MW-5 0-1.5' 3.0

29852 MW-5 5.0-6.5' 3.6

29853 MW-5 10.0-12.0' SM 38.5 61.5 21 1 36.0 20.7

29854 MW-5 12.0-13.5' 19.6

29855 MW-5 15.0-16.5' 24.3

29856 MW-5 20.0-22.0' SP-SM 11.7 88.0 0.3 NV NP 2.4 16.7 43.9

29857 MW-5 45.0-46.5' 25.6

4026.20690.01 1 12/31/2014

EQUALIZER DAM SUMMARY OF PHYSICAL PROPERTIES TEST RESULTS GEOTECHNICAL INVESTIGATION

LA

B

N U

M B

E R

LO

C

A

TI

O N

D E

P

TH

R A

N G

E

C

LA

S S

IF

IC

A

TI

O N

S Y

M B

O L

S M

A

LL

E R

TH

A

N 0.

m m

0.

to

0.

m m

S A

N D

N O

.2

(0 .0 m m

TO

N

O .4

(4 .7 m m

G R

A V

E L

N O

.4 (4

.7 m m

TO

IN

.(7 6.

m m

LI

Q

U

ID

LI

M

IT

P

LA

S

TI

C

IT

Y

IN

D E

X

C O

N S

O

LI

D A

TI

O

N -P c

C O

N S

O

LI

D A

TI

O

N -C c

C O

N S

O

LI

D A

TI

O

N -C s

D

IR

E C

T S

H E

A R

A N

G

LE

-d eg

M A

X

IM

U M

D R

Y U

N

IT

W E

IG

H

T( D

8)

-p cf

O P

TI

M

U M

M O

IS

TU

R E

C O

N

TE

N T

U N

IT

W

T.

(C

O N

S O

L.

D R

Y P

C F

U N

IT

W

T.

A

V G

S

H E

A R

D

R Y

P C

F

U N

IT

W

T.

(U

N C

O N

F.

D R

Y P

C F

U N

IT

W

T.

(T

U B

E

D R

Y P

C F

N A

TU

R

A L

M O

IS

TU

R E

R es is tiv ity (O hm -C m

N at ur al

M oi st ur e

R es is tiv ity (O hm -C m

S at ur at ed pH

W A

TE

R

S O

LU

B

LE

S

O

C U

TR

IA

X

IA

L A

N G

LE

-d eg

29858 MW-6 0-1.5' 3.7

29859 MW-6 3.0-6.0' 113.8 14.5 16.5 2350 1854 7.9 ND

29860 MW-6 5.0-7.0' ML 13.3 60.9 25.8 NV NP 14.0 36.7

29861 MW-6 7.0-8.5' 17.8

29862 MW-6 10.0-11.5' 17.2

29863 MW-6 15.0-16.5' 20.5

29864 MW-6 20.0-22.0' SM 28.3 71.7 4.11 0.04 22.6

29865 MW-6 22.0-23.5' 22.6

29866 MW-7 4.0-5.5' 17.7

29867 MW-7 9.0-11.0' 16.9

29868 MW-7 11.0-12.5' 13.6

29869 MW-7 14.0-15.5' 10.6

29870 MW-7 19.0-20.5' 25.4

29871 MW-8 0-1.5' 6.0

29872 MW-8 5.0-6.5' 16.9

29873 MW-8 8.0-10.0' 15.5

29874 MW-8 10.0-11.5' 13.5

29875 MW-8 15.0-16.5' 7.0

29876 MW-8 20.0-21.5' 21.2

29877 TP-1 1.0-7.0' 4.5

29878 TP-2 4.5-5.5' 16.3

29879 TP-3 4.0-6.0' ML 86.2 13.8 30 5 107.2 14.9 7.3

29880 TP-4 2.0-4.0' SP-SM 4.2 3 92.8 NV NP 109.6 12.6 3.1

29881 TP-4 10 6.8

29882 TP-5 3 SP 3.1 96.6 0.3 NV NP 3.9

29883 TP-6 4 11.9

29884 BH-1 0-1.5' 7.4

29885 BH-1 4.0-7.0' 6.2

29886 BH-1 5.0-6.5' 7.9

29887 BH-1 10.0-11.5' 7.4

4026.20690.01 2 12/31/2014

Tetra Tech

Billings, MT

12-8-14

(no specification provided)

PL= LL= PI=

D90= D85= D60= D50= D30= D15= D10= Cu= Cc=

USCS= AASHTO=

Sandy Lean CLAY 3/8 #4 #10 #20 #40 #80

#200

100.0 99.9 98.5 95.4 90.7 80.0 69.1

23 36 13

0.3951 0.2617

CL A-6(8)

DOWL HKM

Equalizer Dam

4026.20690.01

Material Description

Atterberg Limits

Coefficients

Classification

Remarks

Source of Sample: MW-1 Depth: 13'-15' Date:

Client:

Project:

Project No: Figure

SIEVE PERCENT SPEC.* PASS?

SIZE FINER PERCENT (X=NO)

P E

R C

E N

T F

IN

E

R

GRAIN SIZE - mm.

0.0010.010.1110100

% +3" Coarse

% Gravel

Fine Coarse Medium

% Sand

Fine Silt

% Fines

Clay

0.0 0.0 0.1 1.4 7.8 21.6 69.1 in in in

½ in in

¾ in

½ in

/8 in

Particle Size Distribution Report

Tested By: BB Checked By: MC

(no specification provided)

PL= LL= PI=

D90= D85= D60= D50= D30= D15= D10= Cu= Cc=

USCS= AASHTO=

Poorly Graded SAND #4 #10 #20 #40 #80

#100 #200

100.0 100.0

99.2 73.9 11.9

8.5 1.0

NP NV NP

0.5781 0.5144 0.3544

0.3150 0.2476 0.1951

0.1664 2.13 1.04

SP A-3

Sampled By:DOWL HKM

BIA

Equalizer Dam

4026.20690.01

Soil Description

Atterberg Limits

Coefficients

Classification

Remarks

Location: MW-2 Sample Number: 29838 Depth: 7.0-9.0' Date:

Client:

Project:

Project No: Figure

SIEVE PERCENT SPEC.* PASS?

SIZE FINER PERCENT (X=NO)

P E

R C

E N

T F

IN

E

R

GRAIN SIZE - mm.

0.0010.010.1110100

% +3" Coarse

% Gravel

Fine Coarse Medium

% Sand

Fine Silt

% Fines

Clay

0.0 0.0 0.0 0.0 26.1 72.9 1.0 i n i n i n

½ i n i n

¾ i n

½ i n

/8 i n

PL= LL= PI=

D90= D85= D60= D50= D30= D15= D10= Cu= Cc=

USCS= AASHTO=

Silty SAND .5

.375 #4 #10 #20 #40 #80

#100 #200

0.0356 mm.

0.0226 mm.

0.0131 mm.

0.0094 mm.

0.0067 mm.

0.0033 mm.

0.0014 mm.

100.0 99.7 99.5 99.4 98.8 85.7 29.1 24.6 13.1 12.8 11.6

9.3 7.0 5.8 5.8 4.0

NP NV NP

0.4679 0.4197 0.2928

0.2570…