A.01.38_31_00_00_Appendix_-_YTC_Draft_Geotechnical_Report.pdf

Hydrogeologic Report Repair Sanitary Sewer System

MTEF Facility, Yakima Training Center Yakima, Washington

Contract No. W912DW–16–D–0001 Task Order 0014

Design Package CE0460, IJO STE000414J

CLIN 0001

June 15, 2017

Submitted To:

Mr. Greg Nespor

WJA Design Collaborative 119 South Main Street, Suite 400

Seattle, Washington 98104

By:

Shannon & Wilson, Inc.

400 N 34th Street, Suite 100 Seattle, Washington 98103

21-1-22302-001

21-1-22302-001-R1/wp/aya 21-1-22302-001 i

TABLE OF CONTENTS

Page

1.0 INTRODUCTION

2.0 FIELD EXPLORATIONS

3.0 SUBSURFACE CONDITIONS

3.1 Regional Geologic Setting

3.2 Mapped Area Geology

3.3 Subsurface Conditions

4.0 CONCLUSIONS

4.1 Infiltration Feasibility

5.0 CONSTRUCTION CONSIDERATIONS

5.1 Septic Tank Excavation

5.2 Temporary Excavations

5.3 Septic Tank and Sanitary Sewer Manhole Subgrade Preparation

5.4 Fill Placement, Use of On-Site Soils, and Compaction

6.0 LIMITATIONS

7.0 REFERENCES

TABLE

1 Summary of Exploratory Probe Depth to Bedrock

FIGURES

1 Vicinity Map 2 Site and Exploration Plan

APPENDICES

A Subsurface Exploration Logs B Important Information About Your Geotechnical/Environmental Report

HYDROGEOLOGIC REPORT

REPAIR SANITARY SEWER SYSTEM MTEF FACILITY

YAKIMA TRAINING CENTER

YAKIMA, WASHINGTON

CONTRACT NO. W912DW–16–D–0001

TASK ORDER 0014, DESIGN PACKAGE CE0460, IJO STE000414J

CLIN 0001

1.0 INTRODUCTION

This draft report presents results of our hydrogeologic study for a proposed sanitary sewer system repair near the existing Multipurpose Training and Exercise Facility (MTEF) at the Yakima Training Center (YTC) in Yakima, Washington. The project location is shown in the Vicinity Map, Figure 1. The purpose of our study was to determine subsurface conditions and the feasibility of infiltration for the design of a proposed septic drain field.

Our services were authorized through the subconsultant agreement dated November 2, 2016.

Our scope of services was described in our proposal dated September 2, 2016. This work was performed under the Indefinite Duration Indefinite Quantity contract number W912DW-16-D-0001 and corresponds to CLIN 0001.

Based on the results of our field work, the design team revised the design of the proposed sanitary sewer system repair and eliminated the construction of a drain field because of shallow depth to bedrock. This revised design will include septic tanks and piping that routes to the existing northwest lined pond that is located approximately 800 feet northeast of the septic tank location. The location of proposed septic tanks was also moved approximately 200 feet in the northeast direction as indicated on the Site and Exploration Plan, Figure 2.

2.0 FIELD EXPLORATIONS

Ken Leingang Excavating, Inc. (KLE), under subcontract to Shannon & Wilson, Inc. (Shannon & Wilson) excavated three test pits on April 21, 2017. Approximate locations of the test pits are shown in the Site and Exploration Plan.

KLE excavated the test pits using a John Deere 410L backhoe to depths of 1.5 to 2.5 feet below ground surface (bgs). All excavated test pits encountered basalt bedrock at shallow depths.

Once the test pits were completed, the excavations were backfilled and compacted in lifts using the excavator bucket. Logs of the test pits are included in Appendix A.

After attempting excavation of the test pits, we performed additional exploratory probes (EP-1 to EP-4) at the request of the civil designer using a T-bar and backhoe. We located the exploratory probes approximately 100 to 200 feet away from the proposed drain field location as shown in Figure 2.

3.0 SUBSURFACE CONDITIONS

3.1 Regional Geologic Setting

The project site is in the western part of the Columbia Plateau physiographic province, which encompasses most of Eastern Washington, and is bordered on the west by the Cascade Mountains. The Columbia Plateau is characterized by incised rivers, extensive plateaus, and anticlinal ridges to 4,000 feet above sea level. The region is underlain by Tertiary (Miocene age), Columbia River Basalt Group (CRBG) bedrock, and interbedded terrestrial sediments (Lasmanis, 1991).

The basalt that comprises most of the CRBG was extruded between about 17 and 6 million years ago. The basalt accumulated as successive eruptions filled the area, creating the Columbia Plateau and covering more than 77,000 square miles. The CRBG is divided into five formations

– the Saddle Mountains, Wanapum, Grande Ronde, Picture Gorge, and Imnaha Basalts (Reidel and others, 2003) and includes tuffs, sandstones, conglomerates, and other sediments deposited between eruptions (Lasmanis, 1991).

More recent Quaternary (Holocene and Pleistocene) sediments have been deposited on the older Tertiary sedimentary and CRBG rock. Numerous glacial outburst floods originating in northeastern Washington and northern Idaho/western Montana deposited gravel, sand, and silt during the Pleistocene Epoch throughout much of the Plateau area. Extensive areas of Late Pleistocene and Holocene wind-blown loess also accumulated. Locally, the present topography and Quaternary surface geology of the Yakima Valley have been affected by episodic erosion and deposition by the Yakima River. The valley has been flooded repeatedly by blockage of the river channel and by glacial runoff.

3.2 Mapped Area Geology

To understand site geology, the project team reviewed a YTC geology report and interactive geologic map prepared by the United States Department of Agriculture (USDA) and Natural Resources Conservation Service Web Soil Survey (NRCS, 2017). The map shows that the site predominantly consists of Benwy Silt Loam that has at least 60 inches of silt loam and calcareous gravelly loam. The preliminary location of the proposed drain field was selected based on the USDA map information. During our subsurface investigation, we did not observe Benwy Silt Loam in the explored test pits and exploratory probes.

We also reviewed Geologic Maps of the East Half of the Yakima 1:100,000 Quadrangle, Washington, and related Report (Schuster, 1994). The map indicates that the surficial geologic units within the project area consist of Miocene CRBG as part of the Saddle Mountains formation. Deposits of Quaternary age loess deposits are mapped approximately 50 feet southwest of the proposed septic drain field location.

3.3 Subsurface Conditions

In each of the three test pits (TP-1 to TP-3), we encountered a surficial layer of topsoil that is approximately 1 to 2 inches thick. We observed that the topsoil is underlain by a 1- to 2-foot-thick layer of very loose to loose sandy silt that is underlain by basaltic bedrock. We did not observe any of the mapped loess material (Benwy Silt Loam) overlying the bedrock within our explorations. We characterized the basaltic bedrock as being weathered within the upper 2 to 3 inches and having a low to moderate strength.

Similar subsurface conditions were encountered in each of the four exploratory probes (EP-1 to EP-4) as we observed in the test pits. Depths to the basaltic bedrock encountered in the exploratory probes are included in the following table:

TABLE 1

SUMMARY OF EXPLORATORY

PROBE DEPTH TO BEDROCK

Point ID Depth to Bedrock (feet)

EP-1 0.5

EP-2 1.0

EP-3 1.5

EP-4 2.5

4.0 CONCLUSIONS

4.1 Infiltration Feasibility

As part of our original scope, we were tasked with determining an infiltration rate using field testing corresponding to Washington State Department of Ecology guidance. However, we did not perform infiltration testing due to the shallow depth to the impermeable bedrock layer.

According to Site Suitability Criteria 5 of the 2014 Stormwater Management Manual for Western Washington (SMMWW) (Ecology, 2014), a separation greater than or equal to 5 feet is required below the base of the infiltration system and a low permeability layer. Due to the shallow depth to the impermeable bedrock, infiltration is not feasible at this location.

5.0 CONSTRUCTION CONSIDERATIONS

5.1 Septic Tank Excavation

The project will consist of construction of new septic tanks to depths at about 7 to 8 feet, and influent/effluent sanitary sewer lines with approximately 4- to 6-foot-deep manholes. We understand that three sanitary sewer tanks will be installed at the location shown in the Site and Exploration Plan, Figure 2.

As we summarized above, all exploration test pits and exploratory probes encountered low to moderate strength basalt bedrock at shallow depths. We did not perform laboratory strength testing to determine rippability of encountered basalt bedrock. However, we spoke with a local excavating contractor, KLE, regarding their experience performing utility excavations within the shallow basaltic bedrock in the Yakima area. KLE informed us that they have utilized a two-excavator approach. One excavator uses a hydraulic breaker bar (chisel) to break up the material and the other excavator follows behind with a rock bucket attachment to remove the material. It is our opinion that drilling and blasting would not be required for this type of installation.

5.2 Temporary Excavations

Under the current design, the maximum depth of excavation will range between 5 and 8 feet below the existing ground surface. An open cut excavation is recommended for the proposed sanitary sewer improvements construction.

In our opinion, open cut excavations could be accomplished with temporary side slopes in soil of 1 horizontal to 1 vertical (1H:1V); however, this slope may be too steep in areas if wet soil or sloughing is encountered. Temporary and permanent slopes in the basalt can be trimmed at 0.25H:1V. The temporary excavation slopes should be made the responsibility of the Contractor, who is continually present at the site to observe subsurface conditions.

There is always potential for earth movement and erosion into excavations. Therefore, we recommend that open-cut slopes be continuously monitored by the Contractor for possible movements. The safety of people working near excavation slopes should also be made the responsibility of the Contractor. Excavations should be accomplished in compliance with local, state, and federal safety codes and practices. Such codes would include, but not be limited to, the Occupational Safety and Health Act and the “Safety Standards for Construction Work” of the State of Washington, Department of Labor and Industries, Division of Safety.

5.3 Septic Tank and Sanitary Sewer Manhole Subgrade Preparation

We recommended that the septic tanks and sanitary sewer manholes be placed on a leveled surface prepared using compacted, clean, well-graded structural fill placed above the bedrock.

This material could consist of imported soils or processed on-site soil or rock. Structural fill should be free of organic matter or oversized material, such as cobles and boulders. The fill should contain no more than 2 percent of particles retained on U.S. No. 200 sieve.

5.4 Fill Placement, Use of On-Site Soils, and Compaction

In areas to be filled, such as around septic tanks, manholes, and along sanitary sewer trenches, the exposed soil and rock surface, prior to any fill placement or foundation construction, should be evaluated by a representative from our firm. Unsuitable soil that is loose, soft, wet, or contains organic material should be removed and replaced with densely compacted structural fill.

Native granular soil in dry conditions and granular on-site fill material without debris, wood, and free of topsoil (abundant organic material) would be suitable for use as structural fill provided the soil is within ±2 percent of its optimum moisture content for compaction. On-site fill soil could be reused as structural fill, provided it is evaluated by a geotechnical engineer and used following the recommendations in this section. During dry weather in semi-arid climate where control of soil moisture is difficult, the Contractor should be prepared to moisture condition onsite or imported structural fill that is not within 2 percent of its optimum moisture content for compaction.

Imported structural fill soil should consist of a well-graded mixture of sand and gravel; free of organics, debris, and rubbish; and should contain no more than 15 percent fines (material passing the No. 200 mesh sieve, based on the minus 3/4-inch fraction). The fines should be non-plastic, and the moisture content of the soil should also be within +/- 2 percent of its optimum. All structural fill should have a maximum particle size of 3 inches.

Structural fill should be placed in uniform lifts and compacted to a dense and unyielding condition, to at least 95 percent of the Modified Proctor maximum dry density (ASTM International [ASTM] D1557-12e1) (ASTM, 2012). The thickness of soil layers before compaction should not exceed 8 inches for heavy equipment compactors or 4 inches for hand-operated mechanical compactors.

7.0 REFERENCES

ASTM International (ASTM) D1557-12e1, 2012, Standard test methods for laboratory compaction characteristics of soil using modified effort (56,000 ft-lbf/ft(cubed) (2700 kN-m/m(cubed))

Lasmanis, Raymond, 1991, The geology of Washington: Rocks and Minerals, v. 66, no. 4,

p. 262-277.

Reidel, S.P.; Martin, B.S.; and Petcovic, H.L., 2003, The Columbia River flood basalts and the Yakima fold beltin Swanson, T.W., ed., Western Cordillera and adjacent areas: Boulder, Colorado, Geological Society of America Field Guide 4, p.87-105.

Schuster, J. E., 1994, Geologic map of the east half of the Yakima 1:100,000 quadrangle, Washington: Washington State Department of Natural Resources, Division of Geology and Earth Resources, Open File Report 94-12, 19 p., 1 plate, scale 1:100,000.

U. S. Natural Resources Conservation Service, 2017, Web soil survey: Available:

http://websoilsurvey.nrcs.usda.gov/app/, accessed June 2017.

Washington State Department of Ecology (Ecology), 2014, Stormwater management manual for Western Washington (Ecology, 2014): Olympia, Wash., Washington State Department of Ecology Publication no. 14-10-055, 5 v., available:

https://fortress.wa.gov/ecy/publications/SummaryPages/141005 5.html.

http://websoilsurvey.nrcs.usda.gov/app/

APPENDIX A

SUBSURFACE EXPLORATION LOGS

21-1-22302-001-R1-AA_AB 21-1-22302-001

A-i

APPENDIX A

SUBSURFACE EXPLORATION LOGS

TABLE OF CONTENTS

FIGURES

A-1 Soil Classification and Log Key (3 sheets) A-2 Log of Test Pit TP-1 A-3 Log of Test Pit TP-2 A-4 Log of Test Pit TP-3

Hydrogeologic Study Yakima Training Center

Yakima, Washington

1Gravel, sand, and fines estimated by mass. Other constituents, such as organics, cobbles, and boulders, estimated by volume.

2Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, www.astm.org.

140 pounds with a 30-inch free fall.

Rope on 6- to 10-inch-diam. cathead 2-1/4 rope turns, > 100 rpm

NOTE: If automatic hammers are used, blow counts shown on boring logs should be adjusted to account for efficiency of hammer.

10 to 30 inches long Shoe I.D. = 1.375 inches Barrel I.D. = 1.5 inches Barrel O.D. = 2 inches

Sum blow counts for second and third 6-inch increments.

Refusal: 50 blows for 6 inches or less; 10 blows for 0 inches.

RELATIVE

CONSISTENCY

N, SPT,

BLOWS/FT.

5% to 12% fine-grained:

with Silt or with Clay 3

15% or more of a second coarse-grained constituent:

with Sand or with Gravel 5

< 5%

5 to 10%

15 to 25%

30 to 45%

50 to 100%

Surface Cement Seal

Asphalt or Cap

Slough

Inclinometer or Non-perforated Casing

Vibrating Wire Piezometer

N, SPT,

BLOWS/FT.

< 4 4 - 10

10 - 30 30 - 50

> 50

DESCRIPTION

< #200 (0.075 mm = 0.003 in.)

#200 to #40 (0.075 to 0.4 mm; 0.003 to 0.02 in.)

#40 to #10 (0.4 to 2 mm; 0.02 to 0.08 in.)

#10 to #4 (2 to 4.75 mm; 0.08 to 0.187 in.)

SIEVE NUMBER AND/OR APPROXIMATE SIZE

#4 to 3/4 in. (4.75 to 19 mm; 0.187 to 0.75 in.)

3/4 to 3 in. (19 to 76 mm)

3 to 12 in. (76 to 305 mm)

> 12 in. (305 mm)

Fine Coarse

Fine Medium Coarse

BOULDERS

COBBLES

GRAVEL

FINES

SAND

Sheet 1 of 3

CONSTITUENT2

SOIL DESCRIPTION

AND LOG KEY

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

Absence of moisture, dusty, dry to the touch

Damp but no visible water

Visible free water, from below water table

FIG. A-1

Shannon & Wilson, Inc. (S&W), uses a soil identification system modified from the Unified Soil Classification System (USCS). Elements of the USCS and other definitions are provided on this and the following pages. Soil descriptions are based on visual-manual procedures (ASTM D2488) and laboratory testing procedures (ASTM D2487), if performed.

STANDARD PENETRATION TEST (SPT)

SPECIFICATIONS

Hammer:

Sampler:

N-Value:

Dry

Moist

Wet

MOISTURE CONTENT TERMS

Modifying (Secondary)

Precedes major constituent

Major

Minor Follows major constituent

1All percentages are by weight of total specimen passing a 3-inch sieve.

2The order of terms is: Modifying Major with Minor.

3Determined based on behavior.

4Determined based on which constituent comprises a larger percentage.

5Whichever is the lesser constituent.

COARSE-GRAINED

SOILS

(less than 50% fines)1

NOTE: Penetration resistances (N-values) shown on boring logs are as recorded in the field and have not been corrected for hammer efficiency, overburden, or other factors.

PARTICLE SIZE DEFINITIONS

RELATIVE DENSITY / CONSISTENCY

Sand or Gravel 4

30% or more coarse-grained:

Sandy or Gravelly 4

More than 12% fine-grained:

Silty or Clayey 3

15% to 30% coarse-grained:

with Sand or with Gravel 4

30% or more total coarse-grained and lesser coarse-grained constituent is 15% or more:

with Sand or with Gravel 5

Very soft Soft Medium stiff Stiff Very stiff Hard

Very loose Loose Medium dense Dense Very dense

RELATIVE

DENSITY

FINE-GRAINED SOILS

(50% or more fines)1

COHESIVE SOILS

< 2 2 - 4 4 - 8

8 - 15 15 - 30

> 30

COHESIONLESS SOILS

Silt, Lean Clay, Elastic Silt, or

Fat Clay 3

PERCENTAGES TERMS 1, 2

Trace

Few

Little

Some

Mostly

WELL AND BACKFILL SYMBOLS

Bentonite Cement Grout

Bentonite Grout

Bentonite Chips

Silica Sand

Perforated or Screened Casing

S&W INORGANIC SOIL CONSTITUENT DEFINITIONS

S O

IL

_C

LA

S

S _K

E Y

_P G

-2

.G P

J S

H A

N _W

IL

.G

D T

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Yakima Training Center

Yakima, Washington

GC

SC

Inorganic

Organic

(more than 50% of coarse fraction retained on No. 4 sieve)

MAJOR DIVISIONS GROUP/GRAPHIC

SYMBOL

CH

OH

ML

CL

TYPICAL IDENTIFICATIONS

Gravel

Sand

Silty Sand; Silty Sand with Gravel

Clayey Sand; Clayey Sand with Gravel

Clayey Gravel; Clayey Gravel with Sand

Sheet 2 of 3

Gravels

Primarily organic matter, dark in color, and organic odor

SW

(more than 12% fines)

Silts and Clays

Silts and Clays

(more than 50% retained on No.

200 sieve)

(50% or more of coarse fraction passes the No. 4 sieve)

(liquid limit less than 50)

(liquid limit 50 or more)

Organic

Inorganic

FINE-GRAINED

SOILS

SM

Sands

Silty or Clayey Gravel

Silt; Silt with Sand or Gravel; Sandy or Gravelly Silt

Organic Silt or Clay; Organic Silt or Clay with Sand or Gravel; Sandy or Gravelly Organic Silt or Clay

HIGHLY-

ORGANIC SOILS

COARSE-

GRAINED

SOILS

OL

(less than 5% fines)

GW

Geotechnical and Environmental Consultants

SHANNON & WILSON, INC.

(less than 5% fines)

PT

FIG. A-1

(more than 12% fines)

MH

SP

GP

GM

Silty or Clayey Sand

Silty Gravel; Silty Gravel with Sand

(50% or more passes the No. 200 sieve)

SOIL DESCRIPTION

AND LOG KEY

Elastic Silt; Elastic Silt with Sand or Gravel; Sandy or Gravelly Elastic Silt

Fat Clay; Fat Clay with Sand or Gravel;

Sandy or Gravelly Fat Clay

Organic Silt or Clay; Organic Silt or Clay with Sand or Gravel; Sandy or Gravelly Organic Silt or Clay

Poorly Graded Sand; Poorly Graded Sand with Gravel

Well-Graded Sand; Well-Graded Sand with Gravel

Well-Graded Gravel; Well-Graded Gravel with Sand

Poorly Graded Gravel; Poorly Graded Gravel with Sand

Lean Clay; Lean Clay with Sand or Gravel; Sandy or Gravelly Lean Clay

Peat or other highly organic soils (see

ASTM D4427)

NOTES

1. Dual symbols (symbols separated by a hyphen, i.e., SP-SM, Sand with Silt) are used for soils with between 5% and 12% fines or when the liquid limit and plasticity index values plot in the CL-ML area of the plasticity chart. Graphics shown on the logs for these soil types are a combination of the two graphic symbols (e.g., SP and SM).

2. Borderline symbols (symbols separated by a slash, i.e., CL/ML, Lean Clay to Silt; SP-SM/SM, Sand with Silt to Silty Sand) indicate that the soil properties are close to the defining boundary between two groups.

S O

IL

_C

LA

S

S _K

E Y

_P G

-2

.G P

J S

H A

N _W

IL

.G

D T

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NOTE: No. 4 size = 4.75 mm = 0.187 in.; No. 200 size = 0.075 mm = 0.003 in.

UNIFIED SOIL CLASSIFICATION SYSTEM (USCS)

(Modified From USACE Tech Memo 3-357, ASTM D2487, and ASTM D2488)

Yakima Training Center

Yakima, Washington

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

FIG. A-1

Sheet 3 of 3

SOIL DESCRIPTION

AND LOG KEY

1Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, www.astm.org.

2Adapted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, www.astm.org.

Interbedded

Laminated

Fissured

Slickensided

Blocky

Lensed

Homogeneous

ATD

Diam.

Elev.

ft.

FeO gal.

Horiz.

HSA

I.D.

in.

lbs.

MgO mm

MnO

NA

NP

O.D.

OW

pcf

PID

PMT

ppm psi

PVC

rpm

SPT

USCS

qu

VWP

Vert.

WOH

WOR

Wt.

Crumbles or breaks with handling or slight finger pressure.

Crumbles or breaks with considerable finger pressure.

Will not crumble or break with finger pressure.

PLASTICITY2

CEMENTATION TERMS1

GRADATION TERMS

STRUCTURE TERMS1

ACRONYMS AND ABBREVIATIONS

Alternating layers of varying material or color with layers at least 1/4-inch thick;

singular: bed.

Alternating layers of varying material or color with layers less than 1/4-inch thick;

singular: lamination.

Breaks along definite planes or fractures with little resistance.

Fracture planes appear polished or glossy;

sometimes striated.

Cohesive soil that can be broken down into small angular lumps that resist further breakdown.

Inclusion of small pockets of different soils, such as small lenses of sand scattered through a mass of clay.

Same color and appearance throughout.

Narrow range of grain sizes present or, within the range of grain sizes present, one or more sizes are missing (Gap Graded). Meets criteria in ASTM D2487, if tested.

Full range and even distribution of grain sizes present. Meets criteria in ASTM D2487, if tested.

Poorly Graded

Well-Graded

Weak

Moderate

Strong

Irregular patches of different colors.

Soil disturbance or mixing by plants or animals.

Nonsorted sediment; sand and gravel in silt and/or clay matrix.

Material brought to surface by drilling.

Material that caved from sides of borehole.

Disturbed texture, mix of strengths.

VISUAL-MANUAL CRITERIA

A 1/8-in. thread cannot be rolled at any water content.

A thread can barely be rolled and a lump cannot be formed when drier than the plastic limit.

A thread is easy to roll and not much time is required to reach the plastic limit. The thread cannot be rerolled after reaching the plastic limit. A lump crumbles when drier than the plastic limit.

It takes considerable time rolling and kneading to reach the plastic limit. A thread can be rerolled several times after reaching the plastic limit. A lump can be formed without crumbling when drier than the plastic limit.

Sharp edges and unpolished planar surfaces.

Similar to angular, but with rounded edges.

Nearly planar sides with well-rounded edges.

Smoothly curved sides with no edges.

Width/thickness ratio > 3.

Length/width ratio > 3.

PARTICLE ANGULARITY AND SHAPE TERMS1

ADDITIONAL TERMS

Angular

Subangular

Subrounded

Rounded

Flat

Elongated

DESCRIPTION

Nonplastic

Low

Medium

High

At Time of Drilling Diameter Elevation Feet Iron Oxide Gallons Horizontal Hollow Stem Auger Inside Diameter Inches Pounds Magnesium Oxide Millimeter Manganese Oxide Not Applicable or Not Available Nonplastic Outside Diameter Observation Well Pounds per Cubic Foot Photo-Ionization Detector Pressuremeter Test Parts per Million Pounds per Square Inch Polyvinyl Chloride Rotations per Minute Standard Penetration Test Unified Soil Classification System Unconfined Compressive Strength Vibrating Wire Piezometer Vertical Weight of Hammer Weight of Rods Weight

Mottled

Bioturbated

Diamict

Cuttings

Slough

Sheared

APPROX.

PLASITICITY

INDEX

RANGE

< 4

4 to 10

10 to 20

> 20

S O

IL

_C

LA

S

S _K

E Y

_P G

-2

.G P

J S

H A

N _W

IL

.G

D T

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APPENDIX B

IMPORTANT INFORMATION ABOUT YOUR

GEOTECHNICAL/ENVIRONMENTAL REPORT

Page 1 of 2 1/2017

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

Dated:

Attachment to and part of Report 21-1-22302-001

Date: June 15, 2017 To: Mr. Greg Nespor WJA Design Collaborative

IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL/ENVIRONMENTAL

REPORT

CONSULTING SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES AND FOR SPECIFIC CLIENTS.

Consultants prepare reports to meet the specific needs of specific individuals. A report prepared for a civil engineer may not be adequate for a construction contractor or even another civil engineer. Unless indicated otherwise, your consultant prepared your report expressly for you and expressly for the purposes you indicated. No one other than you should apply this report for its intended purpose without first conferring with the consultant. No party should apply this report for any purpose other than that originally contemplated without first conferring with the consultant.

THE CONSULTANT'S REPORT IS BASED ON PROJECT-SPECIFIC FACTORS.

A geotechnical/environmental report is based on a subsurface exploration plan designed to consider a unique set of project-specific factors. Depending on the project, these may include: the general nature of the structure and property involved; its size and configuration; its historical use and practice; the location of the structure on the site and its orientation; other improvements such as access roads, parking lots, and underground utilities; and the additional risk created by scope-of-service limitations imposed by the client. To help avoid costly problems, ask the consultant to evaluate how any factors that change subsequent to the date of the report may affect the recommendations. Unless your consultant indicates otherwise, your report should not be used: (1) when the nature of the proposed project is changed (for example, if an office building will be erected instead of a parking garage, or if a refrigerated warehouse will be built instead of an unrefrigerated one, or chemicals are discovered on or near the site); (2) when the size, elevation, or configuration of the proposed project is altered; (3) when the location or orientation of the proposed project is modified; (4) when there is a change of ownership; or (5) for application to an adjacent site. Consultants cannot accept responsibility for problems that may occur if they are not consulted after factors which were considered in the development of the report have changed.

SUBSURFACE CONDITIONS CAN CHANGE.

Subsurface conditions may be affected as a result of natural processes or human activity. Because a geotechnical/environmental report is based on conditions that existed at the time of subsurface exploration, construction decisions should not be based on a report whose adequacy may have been affected by time. Ask the consultant to advise if additional tests are desirable before construction starts; for example, groundwater conditions commonly vary seasonally.

Construction operations at or adjacent to the site and natural events such as floods, earthquakes, or groundwater fluctuations may also affect subsurface conditions and, thus, the continuing adequacy of a geotechnical/environmental report. The consultant should be kept apprised of any such events, and should be consulted to determine if additional tests are necessary.

MOST RECOMMENDATIONS ARE PROFESSIONAL JUDGMENTS.

Site exploration and testing identifies actual surface and subsurface conditions only at those points where samples are taken. The data were extrapolated by your consultant, who then applied judgment to render an opinion about overall subsurface conditions. The actual interface between materials may be far more gradual or abrupt than your report indicates. Actual conditions in areas not sampled may differ from those predicted in your report. While nothing can be done to prevent such situations, you and your consultant can work together to help reduce their impacts. Retaining your consultant to observe subsurface construction operations can be particularly beneficial in this respect.

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A REPORT'S CONCLUSIONS ARE PRELIMINARY.

The conclusions contained in your consultant's report are preliminary because they must be based on the assumption that conditions revealed through selective exploratory sampling are indicative of actual conditions throughout a site. Actual subsurface conditions can be discerned only during earthwork; therefore, you should retain your consultant to observe actual conditions and to provide conclusions.

Only the consultant who prepared the report is fully familiar with the background information needed to determine whether or not the report's recommendations based on those conclusions are valid and whether or not the contractor is abiding by applicable recommendations. The consultant who developed your report cannot assume responsibility or liability for the adequacy of the report's recommendations if another party is retained to observe construction.

THE CONSULTANT'S REPORT IS SUBJECT TO MISINTERPRETATION.

Costly problems can occur when other design professionals develop their plans based on misinterpretation of a geotechnical/environmental report. To help avoid these problems, the consultant should be retained to work with other project design professionals to explain relevant geotechnical, geological, hydrogeological, and environmental findings, and to review the adequacy of their plans and specifications relative to these issues.

BORING LOGS AND/OR MONITORING WELL DATA SHOULD NOT BE SEPARATED FROM THE REPORT.

Final boring logs developed by the consultant are based upon interpretation of field logs (assembled by site personnel), field test results, and laboratory and/or office evaluation of field samples and data. Only final boring logs and data are customarily included in geotechnical/environmental reports. These final logs should not, under any circumstances, be redrawn for inclusion in architectural or other design drawings, because drafters may commit errors or omissions in the transfer process.

To reduce the likelihood of boring log or monitoring well misinterpretation, contractors should be given ready access to the complete geotechnical engineering/environmental report prepared or authorized for their use. If access is provided only to the report prepared for you, you should advise contractors of the report's limitations, assuming that a contractor was not one of the specific persons for whom the report was prepared, and that developing construction cost estimates was not one of the specific purposes for which it was prepared.

While a contractor may gain important knowledge from a report prepared for another party, the contractor should discuss the report with your consultant and perform the additional or alternative work believed necessary to obtain the data specifically appropriate for construction cost estimating purposes. Some clients hold the mistaken impression that simply disclaiming responsibility for the accuracy of subsurface information always insulates them from attendant liability. Providing the best available information to contractors helps prevent costly construction problems and the adversarial attitudes that aggravate them to a disproportionate scale.

READ RESPONSIBILITY CLAUSES CLOSELY.

Because geotechnical/environmental engineering is based extensively on judgment and opinion, it is far less exact than other design disciplines. This situation has resulted in wholly unwarranted claims being lodged against consultants. To help prevent this problem, consultants have developed a number of clauses for use in their contracts, reports, and other documents. These responsibility clauses are not exculpatory clauses designed to transfer the consultant's liabilities to other parties; rather, they are definitive clauses that identify where the consultant's responsibilities begin and end. Their use helps all parties involved recognize their individual responsibilities and take appropriate action. Some of these definitive clauses are likely to appear in your report, and you are encouraged to read them closely.

Your consultant will be pleased to give full and frank answers to your questions.

The preceding paragraphs are based on information provided by the ASFE/Association of Engineering Firms Practicing in the Geosciences, Silver Spring, Maryland