B01_RFP_Attachment_J02.3_Crow_Creek_WM_Geotechnical_Reports.pdf

Geotechnical Engineering • Environmental Services • Materials Testing

115 West Beebe Avenue

Chamberlain, South Dakota 57325 ph: (605) 234-2673 fx: (605) 234-2674

1603 Locust Street

Yankton, South Dakota 57078 ph: (605) 260-4908 fx: (605) 260-4908

December 9, 2016

Crow Creek Tribal Utilities 100 Drifting Goose Drive Fort Thompson, SD 57339

Attn: Mr. Don Big Eagle

Re: Proposal for Geotechnical Services Proposed Bad Nation to Crow Creek Water Main Buffalo County, South Dakota Hunkpati Dakota Nation CEC Job #01-16-005-02

Dear Mr. Big Eagle, This report presents the results of a subsurface exploration program for the proposed water main project to be constructed between the Bad Nation and Crow Creek communities in rural Buffalo County, South Dakota on the Hunkpati Dakota Nation. This work was conducted in accordance with the contract between you and Core Engineering & Consulting, Inc. (CEC) dated January 9th, 2016 and authorized January 11th, 2016. We are submitting three (3) copies of the report to you.

The soil samples remaining after the laboratory testing is completed will be retained for a period of 1 month from the date of this report unless written request is made to retain them for a longer period of time.

CEC appreciates the opportunity to provide these services to you. As your project proceeds, we would be interested in providing additional geotechnical and construction materials engineering services. If you have any questions about this report, or if you require additional information, feel free to contact us.

Sincerely, Core Engineering & Consulting, Inc.

Victoria D. Job, EIT Staff Engineer victoria@coresd.com

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REPORT OF GEOTECHNICAL EXPLORATION

AND ENGINEERING REVIEW

Proposed Bad Nation to Crow Creek Water Main

Buffalo County, South Dakota

CEC Job No.: 01-16-005-02

Report Date: Friday December 9, 2016

Prepared For: Crow Creek Tribal Utilities

Fort Thompson, South Dakota

CEC Job No. 01-16-005-02

PROJECT SUMMARY

Core Engineering & Consulting, Inc. (CEC), under contract with the Crow Creek Tribal Utilities, mobilized to the sites in rural Buffalo County on June 27th & 29th and July 12th, 2016 to perform a subsurface exploration program and subsequent engineering review. The purpose of the work performed at this site is to provide the Crow Creek Tribal Utilities and their project team the necessary subsurface soil information to adequately plan, design and construct the project.

The proposed project consists of constructing a new potable water main between the Bad Nation and Crow Creek communities to connect the Crow Creek community to the Tribal water system. Based on past experience with similar structures we estimate the water main to be buried at levels ranging from 6’ to 20’ below grade. Site grading is expected to be minimal.

The field exploration consisted of five Standard Penetration Test (SPT) borings drilled and sampled to depths of 21’ to 26’ below existing surface grade. Based on our interpretation of the soil boring results, it is our judgment the generalized soil profile for the borings in the proposed pipeline consists of the following:

Table 1: Summary of Soil Boring Results

Boring Number Generalized Soil Profile

B1 ~5’ of Fill overlying ~2’ of Alluvium overlying Pierre Formation Shale Bedrock

B2 ~1½’ of Loess over ~2½’ of Glacial Till over ~13½’ of Alluvium over

Niobrara Formation Chalkstone Bedrock

B3 ~15½’ of Mixed Alluvium overlying Niobrara Formation Chalkstone Bedrock

B4 ~11’ of Fine Alluvium overlying Coarse Alluvium

B5 Mixed Fine and Coarse Alluvium

Groundwater measurements taken immediately following drilling revealed measurable groundwater surface within four of the five boring locations, ranging from 8.9’ to 15.0’ below surface grade. The fifth location (Boring #1) eventually showed groundwater following approximately 3 weeks of monitoring.

The soils encountered at the anticipated pipeline elevation were found to consist primarily of fat clay comprising the Pierre Formation & high-plasticity silt comprising the Niobrara Formation. The soils encountered were found to be moderately to highly corrosive to buried metals, while the pH was found to be neutral to slightly acidic. Based on these findings, we make the following recommendations.

• Utility installations should be properly bedded in a clean bedding material, extending from below pipes to above pipe haunches

• If a steel casing is used, the buried casing should either be cathodically protected from corrosion or be designed with sacrificial metals.

• Utility trench backfill placed above the sand bedding material should be placed in thin, horizontal lifts and compacted to a minimum of 98% below pavements and 92% in green space

• Leak testing should be performed prior to the water main becoming operational

These recommendations are summarized, please read the entire report for additional details.

TABLE OF CONTENTS

INTRODUCTION

BACKGROUND INFORMATION

PROPOSED CONSTRUCTION

AUTHORIZED SCOPE OF SERVICES

METHODOLOGIES

FIELD TESTING & OBSERVATIONS

Drilling

Sampling

Split-Spoon Samples (SS)

Thin-Walled Tube Samples (TW)

Sampling Limitations

Soil Classification

Water Level Measurements

LABORATORY TESTING

Natural Moisture Content (ASTM:D2216)

Atterberg Limits (ASTM:D4318)

Particle Size Analyses (ASTM:D422)

Soil pH (ASTM:D4972)

Soil Electric Resistivity (ASTM:G187)

FINDINGS

SURFACE OBSERVATIONS

SUBSURFACE CONDITIONS

Site Geology

Glacial Till

Pierre Formation

Niobrara Formation

Subsurface Soils

Fill

Fine-Grained Alluvium

Coarse-Grained Alluvium

Niobrara Chalkstone

Soil Resistivity & pH

Groundwater

RECOMMENDATIONS

EXCAVATION SIDE-SLOPING/RETENTION

DIRECTIONAL BORE

CORROSION RESISTANCE

SOIL MOISTURE CONTROL

SOIL DENSITY TESTING

FINAL TESTING

LIMITATIONS

SIGNATURES

APPENDIX A

FIGURE 1 – SITE LOCATION MAP

FIGURE 2 – BORING LAYOUT MAP

SUBSURFACE BORING LOG (5)

ATTERBERG LIMITS TEST RESULTS (ASTM:D4318)

PARTICLE SIZE ANALYSIS (ASTM:D422)

BORING LOG NOTES

UNIFIED SOIL CLASSIFICATION SYSTEM

PROPOSED BAD NATION TO CROW CREEK WATER MAIN

BUFFALO COUNTY, SOUTH DAKOTA

HUNKPATI DAKOTA NATION

CEC #01-16-005-02

INTRODUCTION

This report presents the results of a subsurface exploration program for the proposed construction of a water main from the Bad Nation Community to the Crow Creek Community in rural Buffalo

County, South Dakota on the Hunkpati Dakota Nation. To protect you, Core Engineering &

Consulting, Inc. (CEC), and the public, we authorize use of the data contained in this report only by you and your project team for this specific project. Contact us if other uses are intended.

BACKGROUND INFORMATION

Proposed Construction

Based on the information provided, we understand that the anticipated construction will include construction of a new potable water main between the two communities with a new standpipe elevated water storage reservoir (ESR) near the intersection of SD Highway 34 and Lee Road

(Lee’s Corner), approximately 6 miles east of Fort Thompson.

Authorized Scope of Services

CEC’s services for this project were performed in accordance with our Proposal for Geotechnical

Services dated March 24th, 2015. The authorized scope of services for this project consists of the following:

• Drill five (5) Standard Penetration Test (SPT) borings along the proposed pipeline route to depths of 21’ to 26’ below surface grade

• Perform laboratory testing to determine the physical properties of the site soils encountered

• Provide a summary report of our findings and a discussion of the subsurface conditions

The contracted scope of services is intended for geotechnical purposes only and is not intended to explore for the presence or extent of environmental contamination at the site or provide opinions regarding the status of the site relative to “wetland” definitions.

Proposed Bad Nation to Crow Creek Water Main Page 2 of 12

METHODOLOGIES

Field Testing & Observations

The subsurface exploration program consisted of five (5) Standard Penetration Test borings. The field exploration was performed on June 27th & 29th and July 12th, 2016

The approximate soil boring locations are shown on attached Figure 2. Borings were located in the field by a handheld GPS unit.

Drilling

The standard penetration test borings were drilled using 3¼” I.D. hollow-stem augers. The boreholes were backfilled in compliance with Tribal and/or Federal regulations.

Sampling

Split-Spoon Samples (SS)

Soil sampling was performed according to the procedures described by ASTM:D1586. Using this procedure, a two-inch O.D., split-barrel sampler is driven into the soil by a 140-pound weight falling 30 inches. After an initial set of six inches, the number of blows required to drive the sampler an additional 12 inches is known as the penetration resistance, or N-value. The N-value is an index of the relative density of cohesionless soils and the consistency of cohesive soils.

Thin-Walled Tube Samples (TW)

The thin-walled tube samplers used by CEC consist of 3” O.D., 2.8” I.D. solid-barrel steel samplers

30” in length. The sampler is hydraulically advanced into the undisturbed subsurface soils. Thin-walled tube samples are considered relatively undisturbed samples and, unlike split spoon or

California spoon samples, can be used for laboratory determination of in-place dry density, swell/consolidation and various soil strength parameters.

Sampling Limitations

Unless actually observed in a sample, contacts between soil layers are estimated based on the spacing of samples and the action of drilling tools. Cobbles, boulders and other large objects generally cannot be recovered from test borings. They may still be present in the ground even if they are not noted on the boring logs.

Soil Classification

Included are the Subsurface Boring Logs, indicating the depth and identification of the various strata, the laboratory test data, water level information and pertinent information regarding the

Proposed Bad Nation to Crow Creek Water Main Page 3 of 12 method of maintaining and advancing the boreholes. Soil classifications shown on the boring logs are based on the Unified Soil Classification (USC) system. The USC system is described in

ASTM:D2487 and D2488. Where laboratory classification tests (i.e. particle size analyses and

Atterberg Limits) have been performed, classifications per ASTM:D2487 are possible. We have attached charts illustrating the USC system, the descriptive terminology and the symbols used on the boring logs.

As the borings were advanced in the field, recovered soils were visually and manually classified by a geotechnical engineer in accordance with ASTM:D2488. The boring logs also include judgments of the geological depositional origin. This judgment is primarily based on observation of the soil samples, which can be limited. Observations of the surrounding topography, vegetation and development can sometimes aid this judgment.

Water Level Measurements

The ground water measurements are shown at the bottom of the boring logs. The following information appears under “Water Level Measurements” on the logs:

• Date and Time of measurement

• Sampled Depth: lowest depth of soil sampling at the time of measurement

• Casing Depth: depth to bottom of casing or hollow-stem auger at time of measurement

• Cave-in Depth: depth at which measuring tape stops in the borehole

• Water Level: depth in the borehole where free water is encountered

• Drilling Fluid Level: same as Water Level, except the liquid in the borehole is drilling fluid, if used

The true location of the water table at the boring locations may be different than the water levels measured in the boreholes. This is possible because there are several factors that can affect the water level measurements in the borehole. Some of these factors include: permeability of each soil layer in the profile, presence of perched water, amount of time between water level readings, presence of drilling fluid, weather conditions and the use of borehole casing.

Laboratory Testing

Representative samples of the soils encountered were selected for laboratory testing to determine index properties. The test consisted exclusively of the determination of the natural moisture content, Atterberg Limit determinations, particle size distribution, soil pH and soil electric resistivity. The test results can be found noted on the Subsurface Boring Logs opposite the samples upon which they were performed, with the exception of the pH/resistivity tests which are presented in table form below. The individual test reports can also be found in the Appendix.

Proposed Bad Nation to Crow Creek Water Main Page 4 of 12

Natural Moisture Content (ASTM:D2216)

The natural moisture content was determined for each soil type recovered from each boring location at various depths below surface grade. The natural moisture content is determined by drying a representative sample of the soil to a constant weight in an oven at approximately 230°F.

By weighing the soil before and after drying the total moisture loss can be compared against the total weight of soil solids to determine the percent moisture content. The natural moisture content can be used as an index value to qualify SPT N-values and to evaluate relative stability and potential constructability issues, amongst other things.

Atterberg Limits (ASTM:D4318)

The Atterberg Limits were determined for samples taken from each boring location at approximate pipe bedding depth. The Atterberg Limits are those moisture contents at which a soil changes phases from a solid material to a plastic material (plastic limit) and from a plastic material to a liquid material (liquid limit). The plastic limit is determined by rolling a moist soil sample into a thread until it will no longer hold together at a diameter less than ⅛”. The liquid limit is determined by adjusting the moisture content of a soil sample until dropping a brass cup against a solid surface a distance of ½” 25 times causes a standard groove cut through the soil sample to close upon itself. The Atterberg Limits can be used to evaluate the shrink/swell potential of soils and their relative stability under varying moisture conditions.

Particle Size Analyses (ASTM:D422)

The particle size distribution was determined for samples taken from each of the boring location at approximate pipe bedding depth. The particle size distribution for the coarse fraction

(gravel/sand) is determined by mechanical sieve analysis where the soil particles are agitated over a series of sieves and the weight retained on each recorded as a percent of the total. The particle size distribution for the fine fraction (silt/clay) is determined by colloidal analysis where the soil particles are forced into suspension and the rate of sedimentation is monitored by measuring the change in specific gravity of the solution through the use of a calibrated hydrometer. The particle size distribution is plotted on a logarithmic scale as a function of “percent finer by weight” and “effective particle size”.

Soil pH (ASTM:D4972)

The soil pH was determined for samples taken from each boring location, at approximate casing depth. The soil pH is determined by mixing a soil sample with distilled water to its approximate liquid limit. The saturated sample is then probed with a calibrated pH meter and the result noted by direct readout.

Proposed Bad Nation to Crow Creek Water Main Page 5 of 12

Soil Electric Resistivity (ASTM:G187)

The electric resistivity was determined for samples taken from each boring location, at approximate casing depth. The resistivity is found by compacting a sample of soil passing the

#8 sieve into the test box at increasing increments of moisture content. After addition of moisture and compaction, the resistivity levels are read. The lowest resistivity reading obtained is used to calculate the resistivity value.

FINDINGS

Surface Observations

The pipeline route is primarily adjacent to or within the road right-of-way for SD Highways 34 &

50 and BIA Route 2. Three of the five borings were adjacent to creek crossings with the remaining two borings in low-lying, flood-prone areas.

Subsurface Conditions

Logs of the test borings are included in Appendix A. The logs contain information concerning soil layering, soil classification, geologic description and moisture. Please note the boring logs only indicate the subsurface conditions at the sampled locations. Variations often occur between and beyond borings.

Site Geology

The primary geologic origin of the soils encountered at this site consists of alluvial soils, referring soils transported and deposited to water flow, glacial till, Pierre Formation shale bedrock and

Niobrara Formation chalkstone bedrock.

Glacial Till

The glacial till soils in Buffalo County are primarily comprised of Upper Wisconsin age glacial deposits. The following description of the geologic depositions in the area comes from the SD

Geologic Survey website (http://www.sdgs.usd.edu/geology/pleistocene.html):

Beginning about 2 million years ago, continental glaciers moved generally southward across North America, covering eastern South Dakota several times. As each ice sheet advanced, it transported large volumes of rock debris frozen into the lower layers of ice. If the ice sheet was very thick and heavy, the glaciers scoured and smoothed off the terrain. In contrast, where the ice was thin, the glaciers overrode obstacles rather than planing them. As the ice melted, sediment called glacial drift was left behind.

Upper Wisconsin age glacial till consists primarily of a compact, silty, clay-rich matrix with sand-to boulder-sized clasts of glacial origin. The total thickness of the Upper Wisconsin age glacial

Proposed Bad Nation to Crow Creek Water Main Page 6 of 12 deposits is as much as 300 ft; however, the thickness of the deposit varies greatly from site to site.

Pierre Formation

The Pierre Formation in its undisturbed state consists primarily of waxy, dark gray to olive colored shale deposited in a marine environment during the Cretaceous period. The exception to this is the Crow Creek member which is primarily light brown to buff in color. The Crow Creek Member is one of several marl units recognized within the Upper Cretaceous Pierre Shale Formation of eastern South Dakota and northeastern Nebraska. The formation contains interbedded layers of bentonite, which can vary from less than 1” to several feet in thickness. Laminations and lenses of silty claystone concretions up to several inches thick can be predominant in the formation.

When weathered, the Pierre Formation reverts back to the constituent clays that form the shale structure. The shale-derived clays resulting from weathering of the Pierre Formation typically classify as fat clay, silty fat clay or high-plasticity silt. The shale-derived clays are known to be problematic with regards to structural support due to their high swell potential. Slope instability is common in the Pierre Formation as the shale is weak, poorly-drained bedrock prone to shear failure under load.

Niobrara Formation

The Niobrara Formation is a cretaceous-age deposit consisting of white to dark gray argillaceous chalk, marl and shale. When weathered the formation turns yellow to orange. The Niobrara

Formation contains thin, laterally continuous bentonite beds, chalky carbonaceous shale, minor amounts of sand and small concretions. The total thickness of the formation ranges from 160 to

225 feet.

Subsurface Soils

Based on our interpretation of the soil boring results, it is our judgment the generalized soil profile for the borings in the proposed pipeline consists of the following:

Table 1: Summary of Soil Boring Results

Boring Number Generalized Soil Profile

B1 ~5’ of Fill overlying ~2’ of Alluvium overlying Pierre Formation Shale Bedrock

B2 ~1½’ of Loess over ~2½’ of Glacial Till over ~13½’ of Alluvium over

Niobrara Formation Chalkstone Bedrock

B3 ~15½’ of Mixed Alluvium overlying Niobrara Formation Chalkstone Bedrock

B4 ~11’ of Fine Alluvium overlying Coarse Alluvium

B5 Mixed Fine and Coarse Alluvium

Proposed Bad Nation to Crow Creek Water Main Page 7 of 12

The following are detailed descriptions of the different soil layers encountered.

Fill

The fill soils encountered at the site consist primarily of silty lean clay. The fill soils placed as unclassified fill soils encountered in the areas are considered potentially compressible, primarily due to the uncertainty surrounding the condition in which they were placed. The fill soils encountered are considered very slow draining and are judged to be at least moderately frost susceptible though not significantly expansive.

Laboratory testing performed for the fill soils includes solely the determination of the natural moisture content. The test results indicate these soils occur naturally at approximately 28%, slightly above the Standard Proctor optimum moisture contents for these soils.

Fine-Grained Alluvium

The alluvial soils encountered consist primarily of sandy fat clay, silty lean clay, clayey silt, silt with clay, high-plasticity silt, sandy silt and silt. The SPT N-values indicate the alluvial soils range from soft to very stiff or loose.

Laboratory tests performed on the recovered samples of the fine-grained alluvium consists of the determination of the natural moisture content, Atterberg Limits and particle size analyses.

The natural moisture content determinations indicate the fine-grained alluvium at this site has moisture contents ranging from 9% to 51%, likely well below to well above the Standard Proctor optimum moisture content for these soils.

The Atterberg Limits determinations indicate the fine-grained alluvium at this site have Liquid

Limits ranging from 35% to 72%, Plastic Limits ranging from 17% to 23% and resultant Plasticity

Indices ranging from 18% to 49%. These values indicate the soils have a USCS classification of

Lean Clay (CL) and Fat Clay (CH).

The particle size analyses performed indicate the fine-grained alluvium encountered indicates the chalkstone has a constituent particle size makeup of 0.0% to 23.8% gravel, 19.5% to 65.6% sand, 3.5% to 32.1% silt and 7.1% to 48.4% clay. When combined with the Atterberg limit test results, these values indicate the constituent soils have USCS classification of Silty Fat Clay with

Sand (CH).

Proposed Bad Nation to Crow Creek Water Main Page 8 of 12

Coarse-Grained Alluvium

The alluvial soils encountered consist primarily of clayey sand, sand and clayey sand with gravel.

The SPT N-values indicate the alluvial soils range from loose to medium dense.

Laboratory tests performed on the recovered samples of the coarse-grained alluvium consists of the determination of the natural moisture content, Atterberg Limits and particle size analyses.

The natural moisture content determinations indicate the coarse-grained alluvium at this site has moisture contents ranging from 11% to 44%. These values are likely slightly below to well above the Standard Proctor optimum moisture content for the constituent soil types.

The Atterberg Limits determination indicates the coarse-grained alluvium at this site have a Liquid

Limit of approximately 47%, a Plastic Limit of approximately 17% and a resultant Plasticity Index of approximately 30%. These values indicate the soils have a USCS classification of Lean Clay

(CL).

The particle size analysis performed indicates the coarse-grained alluvium encountered have a constituent particle size makeup of approximately 5.1% gravel, 46.5% sand, 21.3% silt and

27.0% clay. When combined with the Atterberg limit test results, these values indicate the constituent soils have USCS classification of Clayey Sand with Silt (SC).

Glacial Till

The glacial till soils encountered consist primarily of lean clay. These soils are very slow and are judged to be highly frost susceptible though not significantly expansive. The glacial till soils are not considered significantly compressible.

Laboratory testing performed for the glacial till soils includes solely the determination of the natural moisture content. The test results indicate these soils occur naturally at approximately

10% moisture, likely well below the Standard Proctor optimum moisture contents for these soils.

The Pierre Formation shale encountered has a constituent soil makeup consisting primarily of sandy fat clay and silty fat clay. The Pierre Formation shale encountered is very slow draining and is judged to be highly frost susceptible and potentially expansive under varying moisture conditions.

Proposed Bad Nation to Crow Creek Water Main Page 9 of 12

Laboratory tests performed on the recovered samples of the shale consists of the determination of the natural moisture content, Atterberg Limits and particle size analyses.

The natural moisture content determinations indicate the shale at this site has moisture contents ranging from 24% to 26%. These values are likely very near the Standard Proctor optimum moisture content for the constituent soil types.

The Atterberg Limits determination indicates the shale at this site have a Liquid Limit of approximately 67%, a Plastic Limit of approximately 22% and a resultant Plasticity Index of approximately 46%. These values indicate the soils have a USCS classification of Fat Clay (CH).

The particle size analysis performed indicates the shale encountered indicates these soils have a constituent particle size makeup of 0.9% gravel, 5.3% sand, 30.2% silt and 63.6% clay. When combined with the Atterberg limit test results, these values indicate the constituent soils have a

USCS classification of Silty Fat Clay (CH).

Niobrara Chalkstone

The Niobrara Formation chalkstone encountered at this site was found to be primarily non-weathered. The chalkstone is considered a weak bedrock material however is not considered significantly compressible. The chalkstone is considered relatively impermeable, highly frost susceptible and not significantly expansive.

Laboratory tests performed on the recovered samples of the chalkstone consist of the determination of the natural moisture content, Atterberg Limits and particle size analyses.

The natural moisture content determinations indicate the chalkstone at this site has moisture contents ranging from 21% to 38%, likely slightly below to well above the Standard Proctor optimum moisture content for the constituent soil types.

The Atterberg Limits determination indicates the chalkstone at this site have a Liquid Limit of approximately 56%, a Plastic Limit of approximately 32% and a resultant Plasticity Index of approximately 24%. These values indicate the soils have a USCS classification of High-Plasticity

Silt (MH).

The particle size analysis performed indicate the chalkstone encountered indicates the chalkstone has a constituent particle size makeup of approximately 0% gravel, 4.7% sand, 30.6% silt and

64.7% clay. When combined with the Atterberg limit test results, these values indicate the constituent soils have a USCS classification of Clayey High-Plasticity Silt (MH).

Proposed Bad Nation to Crow Creek Water Main Page 10 of 12

Soil Resistivity & pH

The soil resistivity and pH tests were completed for the Pierre Formation, Niobrara Formation, fine-grained alluvium and coarse-grained alluvium. The test results are summarized in the table below.

Table 2: Summary of Soil Resistivity & pH Tests

Boring Number Soil Origin Resistivity (OHM-cm) pH

B1 S7&S8 Pierre Formation 1270 7.0

B2 S8&S9 Niobrara Formation 1390 7.0

B3 S4b&S5 Coarse to Fine-Grained Alluvium 4130 7.0

B4 S4&S5 Fine-Grained Alluvium 1720 7.0

B5 S8&S9 Fine to Coarse-Grained Alluvium 8180 6.7

The results of the soil resistivity test performed indicate the various site soils encountered consist of a highly corrosive to moderately corrosive soil, while the soil pH tests performed indicate the varying site soils are slightly acidic to neutral.

Groundwater

The boreholes were probed for the presence of ground water and water level measurements were taken. The measurements are recorded on the boring logs.

Groundwater was encountered within each of the five boreholes following eleven to fifteen days after drilling, at depths ranging from 8.9’ to 24.0’. Note that the boreholes were allowed to stand open for a moderate period of time prior to backfilling, possibly adequate for the available groundwater to fully infiltrate the borehole through the relatively slow draining site soils encountered.

Based on the appearance of the soils samples and experience in similar geologic deposits, however, it is our opinion the static groundwater table is likely at the water surface elevation on the adjacent stream and therefore will very likely be encountered during construction.

Contractors should be prepared to dewater excavations to facilitate pipe placement and backfilling.

Note that ground water levels usually fluctuate. Fluctuations occur due to varying seasonal and yearly rainfall and snow melt, as well as other factors.

Proposed Bad Nation to Crow Creek Water Main Page 11 of 12

RECOMMENDATIONS

Pipes should be properly bedded in a sand material to provide consistent support and limit point loads on the pipes. Trench backfill should be moisture-conditioned to near optimum moisture content, placed in thin lifts and compacted to a minimum of 96% of the Standard Proctor maximum dry density in fill sections less than 8’ deep, 98% for fill sections 8’ to 16’ in depth and

100% for fill sections greater than 16’ in depth. Maintaining minimum compaction standards will help limit excessive settlements in trenches, particularly beneath roadways, driveways and other structures where settlements can be detrimental to the functionality of the respective structures.

Excavation Side-Sloping/Retention

If un-retained, excavations should maintain side slopes in accordance with OSHA Regulations

(Standards - 29 CFR) Part 1926, Subpart P, “Excavations.” Even with the required OSHA sloping, ground water seepage and/or surface water runoff can induce side slope raveling or running which would require maintenance.

Directional Bore

We would like to caution that the directional bore could cross the interface between relatively sound shale/chalkstone bedrock and alluvial deposits. It is common, however, for the upper, weathered portions of the shale/chalkstone deposits to become hardened and brittle in contrast to the stiff and plastic lower regions of the deposit. Special care will need to be taken to maintain alignment of the bore through this interface.

Corrosion Resistance

The soils encountered were found to be moderately to highly corrosive to buried metals. If a steel casing is used, the buried casing should either be cathodically protected from corrosion or be designed with sacrificial metals.

Soil Moisture Control

Most of the site soils will be quite sensitive to changes in moisture content due to the high clay/silt content. If the site soils are re-used as fill or backfill they will likely need to be moisture-conditioned to within 3% of optimum to facilitate compaction. Thorough and consistent incorporation of moisture into the soils is imperative to successful compaction control.

Soil Density Testing

Soil density testing should be performed on new fill placed in order to document that project specifications for compaction have been satisfied. Settlement of utility trench fill can cause

Proposed Bad Nation to Crow Creek Water Main Page 12 of 12 depressions which allow water to pond and subsequently infiltrate the subsurface soils resulting in softening and potential settlements. Maintaining minimum compaction standards during backfilling will help to limit this.

Final Testing

Prior to operation of the newly constructed pipeline, a leak test should be performed to ensure the pipeline will operate at working pressures without any major leaks.

LIMITATIONS

The data derived through this sampling and observation program has been used to develop our opinions about the subsurface conditions at your site. However, because no exploration program can reveal totally what is in the subsurface, conditions between borings and between samples and at other times, may differ from conditions described in this report. The exploration we conducted identified subsurface conditions only at those points where we took samples or observed groundwater conditions. Depending on the sampling methods and sampling frequency, every soil layer may not be observed, and some materials or layers which are present in the ground may not be noted on the boring logs.

The extent and detail of information about the subsurface condition is directly related to the scope of the exploration. It should be understood, therefore, that additional information can be obtained by means of additional exploration.

Our services for your project have been conducted to those standards considered normal for services of this type at this time and location. Other than this, no warranty, express or implied, is intended.

SIGNATURES

Report Prepared by: Report Reviewed by:

Core Engineering & Consulting, Inc. Core Engineering & Consulting, Inc.

Victoria D. Job, EIT Patrick J. Engels, PE Staff Engineer Geotechnical Engineer victoria@coresd.com patrick@coresd.com

APPENDIX A

FIGURE 1 – SITE LOCATION MAP

FIGURE 2 – BORING LAYOUT MAP

SUBSURFACE BORING LOG (5)

ATTERBERG LIMITS TEST RESULTS (ASTM:D4318)

PARTICLE SIZE ANALYSIS (ASTM:D422)

Project Site

115 West Beebe Avenue PO Box 456 Chamberlain, SD 57325-1223 www.coresd.com

Job No.: 16-005-02 Drawn By: JLH Checked By:

Date: August 2, 2016

Site Location Map

Project: Proposed Bad Nation to Crow Creek Water Main Buffalo County, South Dakota; Hunkpati Dakota Nation

Figure 1

PO Box 456 Chamberlain, SD 57325-1223 www.coresd.com

Job No.: 16-005-2 Drawn By: JLH Checked By:

Date: August 2, 2016

Boring Layout Map

Project: Proposed Bad Nation to Crow Creek Water Main Buffalo County, South Dakota; Hunkpati Dakota Nation

Figure 2

CEC JOB NO: LOG OF BORING NO.

PROJECT:

WC DEN LL PL -#200

2 M SS 10

28%

5 M SS 7

9 M SS 15 24%

10 M SS 16 24%

19 M SS 21

23 M SS 21

25 M SS 22 26%

67% 22% 94%

61 M SS 26

32 M SS 27

CC: PE CA: MV Rig: 3

DEPTH

IN FEET

DEPTH DRILLING METHOD

SAMPLE

TYPE

REC.

IN.

24.0'

WATER LEVELDATE

3¼" I.D. HSA

6/27/16

BORING COMPLETED: "

24.5'

DRILLING

FLUID LEVEL

SUBSURFACE BORING LOG

Visual-Manual Classification Unless Verified by Laboratory Testing n/a

MATERIAL DESCRIPTION

FIELD & LABORATORY TESTS

16-005-02

Proposed Bad Nation to Crow Creek Water Main; Buffalo County, South Dakota; Hunkpati Dakota Nation

SURFACE ELEVATION: GEOLOGY GWN

7/12/16

6/29/16

26.0'

END OF BORING

6/27/2016

0' - 24½'

"" 24.0'

" 24.5'

11:45

09:25

12:45

CASING DEPTH

WATER LEVEL MEASUREMENTS

TIME

SAMPLED

DEPTH

NoneN/AN/A

CAVE-IN

DEPTH

FILL, mostly Silty Lean Clay, trace roots, brown, moist, soft (CL)

Lense of Gravely Lean Clay at 4½'

SILTY LEAN CLAY, trace roots, brown, moist, stiff

(CL)

SHALE, severly weathered, gray and brown, (Pierre Formation) [Textural Classification: Sandy Fat Clay, pieces of shale, gray with brown mottled, moist, stiff (CH)]

SHALE, moderatly to slightly weathered, gray, (Pierre Formation)

[Textural Classificaiton: Silty Fat Clay, a little sand, trace gravel, gray, moist, very stiff to hard

(CH)]

Lense of Sand Concretion at 20'

Fill

Fine Alluvium

Pierre Formation

1 -

2 -

3 -

4 -

5 -

6 -

7 -

8 -

9 -

10 -

11 -

12 -

13 -

14 -

15 -

16 -

17 -

18 -

19 -

20 -

21 -

22 -

23 -

24 -

25 -

26 -

WC DEN LL PL -#200

10%

7 D SS 8

10 D SS 8 10%

10 D SS 14 21%

19 D SS 19

18 M SS 21 29%

12 M SS 19

8 M SS 21 41%

102 M SS 27 25% 56% 32% 95%

CC: PE CA: ME Rig: 3

N/A 21.8' N/A 14.0'

BORING COMPLETED: 7/1/2016

7/12/16 13:15 26.0'

END OF BORING

DEPTH DRILLING METHOD WATER LEVEL MEASUREMENTS

0' - 24½' 3¼" I.D. HSA

DATE TIME

SAMPLED

DEPTH

CASING DEPTH

CAVE-IN

DEPTH

DRILLING

FLUID LEVEL

WATER LEVEL

CLAYEY SILT, trace roots, brown, dry, loose (ML) Loess

Fine Alluvium

Niobrara Formation

GW

SAMPLE

TYPE

REC.

IN.

FIELD & LABORATORY TESTS

MATERIAL DESCRIPTION

DEPTH

IN FEET

SURFACE ELEVATION: n/a GEOLOGY N

SUBSURFACE BORING LOG

Visual-Manual Classification Unless Verified by Laboratory Testing

16-005-02 2

Proposed Bad Nation to Crow Creek Water Main; Buffalo County, South Dakota; Hunkpati Dakota Nation

LEAN CLAY, a little sand, gray, dry, stiff (CL) Glacial Till

CLAYEY SILT, brown to gray and yellow mottled, dry to moist, stiff to very stiff (ML)

HIGH-PLASTICITY SILT, brown to gray and yellow mottled with white laminations, moist, stiff

(MH)

CHALKSTONE, slighty to non-weathered, gray with white mottled (Niobrara Formation)

[Textural Classification: Clayey Silt, a little sand, gray with white mottled, moist, hard (MH)]

1 -

2 -

3 -

4 -

5 -

6 -

7 -

8 -

9 -

10 -

11 -

12 -

13 -

14 -

15 -

16 -

17 -

18 -

19 -

20 -

21 -

22 -

23 -

24 -

WC DEN LL PL -#200

10%

11 D SS 9 9%

9 D SS 13 18%

8 M SS 14 14%

15%

33% 47% 17% 48%

8 M SS 18 22%

5 M 15

7 M SS 20

21%

111 M SS 26 38%

CC: PE CA: MV Rig: 3

REC.

IN.

FIELD & LABORATORY TESTS

END OF BORING

SS 20M8

Fine Alluvium

Coarse Alluvium

SUBSURFACE BORING LOG

Visual-Manual Classification Unless Verified by Laboratory Testing

16-005-02 3

Proposed Bad Nation to Crow Creek Water Main; Buffalo County, South Dakota; Hunkpati Dakota Nation

DEPTH

IN FEET

SURFACE ELEVATION: n/a GEOLOGY N GW

MATERIAL DESCRIPTION

CLAYEY SILT, trace roots, dark brown, dry, soft (ML) SANDY SILT, a little clay, trace roots, brown, dry, medium dense (ML)

SAMPLE

TYPE

SILT, a little sand & clay, gray with brown mottled, dry ,loose (ML)

SILT WITH CLAY, trace sand, brown, moist, loose

(ML)

SILTY LEAN CLAY, dark brown, moist, firm (CL)

CLAYEY SAND WITH SILT, a little gravel, dark brown, moist, loose (SC)

DEPTH DRILLING METHOD WATER LEVEL MEASUREMENTS

Niobrara Formation

SANDY FAT CLAY, gray and brown mottled, moist, firm (CH)

CHALKSTONE, slightly to non-weathered, gray with white mottled (Niobrara Formation)

[Textural Classification: Clayey Silt, gray with white mottled, moist, hard (ML)]

Fine Alluvium

CAVE-IN

DEPTH

DRILLING

FLUID LEVEL

WATER LEVEL

0' - 19½' 3¼" I.D. HSA

DATE TIME

SAMPLED

DEPTH

CASING DEPTH

N/A 19.5' N/A 15.0'

BORING COMPLETED: 7/1/2016 7/12/16 13:35 " "

7/1/16 10:05 21'

18.0' " 14.0'

1 -

2 -

3 -

4 -

5 -

6 -

7 -

8 -

9 -

10 -

11 -

12 -

13 -

14 -

15 -

16 -

17 -

18 -

19 -

20 -

21 -

WC DEN LL PL -#200

8 M SS 11

11 M SS 20

17 M SS 21 25%

51% 72% 23% 81%

7 M SS 22

6 M SS 22

5 W SS 10 44%

16 W SS 24 14%

5 W SS 17 28%

CC: PE CA: MV Rig: 3

DEPTH

IN FEET

SURFACE ELEVATION: n/a GEOLOGY N

SILTY FAT CLAY, trace roots, dark brown, firm

(CH)

Fine Alluvium

SUBSURFACE BORING LOG

Visual-Manual Classification Unless Verified by Laboratory Testing

16-005-02 4

Proposed Bad Nation to Crow Creek Water Main; Buffalo County, South Dakota; Hunkpati Dakota Nation

GW

SAMPLE

TYPE

REC.

IN.

FIELD & LABORATORY TESTS

MATERIAL DESCRIPTION

DRILLING

FLUID LEVEL

WATER LEVEL

CAVE-IN

DEPTH

3¼" I.D. HSA

DATE TIME

SAMPLED

DEPTH

CASING DEPTH

DRILLING METHOD WATER LEVEL MEASUREMENTS

Coarse Alluvium

END OF BORING

DEPTH

8.9'

9.0'

N/A

BORING COMPLETED: 6/29/2016 7/12/16 13:35 " "

6/29/16 16:15 21.0'

9.0' "

N/A 12.8'

FAT CLAY WITH SILT, brown with gray mottled, moist, stiff (CH)

SILTY FAT CLAY WITH SAND, brown with gray mottled, moist, firm (CH)

CLAYEY SAND, mostly fine-grained, brown, wet, loose (SC)

Sand, well-graded, little gravel, brown, wet, medium dense (SC)

0' - 19½'

1 -

2 -

3 -

4 -

5 -

6 -

7 -

8 -

9 -

10 -

11 -

12 -

13 -

14 -

15 -

16 -

17 -

18 -

19 -

20 -

21 -

WC DEN LL PL -#200

24 D SS 14

11%

12 D SS 14 22%

9 M SS 16

7 M SS 15 39%

32%

9 M SS 21

29%

7 M SS 16

7 M SS 16

18%

8 W SS 13 23% 35% 17% 11%

27%

CC: PE CA: MV Rig: 3

Fine Alluvium

Coarse Alluvium

Fine Alluvium

Coarse Alluvium

Fine Alluvium

FAT CLAY WITH SILT, pieces of shale, gray with brown mottled, moist, firm (CH)

CLAYEY SAND WITH GRAVEL, mostly fine-grained, gray and brown, wet, loose (SC)

SANDY LEAN CLAY WITH SAND, a little gravel, dark gray, moist, firm (CL)

CLAYEY SAND, well-graded, brown, wet, loose to medium dense (SC)

CLAYEY SAND WITH GRAVEL, dark brown, dry, medium dense (SC)

SANDY FAT CLAY, a little gravel, dark brown, moist, stiff (CH)

FAT CLAY WITH SILT, trace sand, dark brown, moist, stiff (CH)

SANDY FAT CLAY, brown and gray, moist, stiff

(CH)

CLAYEY SAND, mostly fine-grained, brown, moist to wet, loose (SC)

Lenses of Clayey Sand at 13'

DEPTH

IN FEET

SURFACE ELEVATION: n/a GEOLOGY N

SUBSURFACE BORING LOG

Visual-Manual Classification Unless Verified by Laboratory Testing

16-005-02 5

Proposed Bad Nation to Crow Creek Water Main; Buffalo County, South Dakota; Hunkpati Dakota Nation

MATERIAL DESCRIPTION

SILTY FAT CLAY, trace roots, brown, dry firm (CH)

Fine Alluvium

Coarse Alluvium

GW

SAMPLE

TYPE

REC.

IN.

FIELD & LABORATORY TESTS

END OF BORING

DEPTH DRILLING METHOD WATER LEVEL MEASUREMENTS

Coarse Alluvium

CAVE-IN

DEPTH

DRILLING

FLUID LEVEL

WATER LEVEL

0' - 24½' 3¼" I.D. HSA

DATE TIME

SAMPLED

DEPTH

CASING DEPTH

N/A 15.4' N/A 12.0'

BORING COMPLETED: 6/29/2016 7/12/16 14:00 " "

6/29/16 13:10 26.0'

14.3' " "

1 -

2 -

3 -

4 -

5 -

6 -

7 -

8 -

9 -

10 -

11 -

12 -

13 -

14 -

15 -

16 -

17 -

18 -

19 -

20 -

21 -

22 -

23 -

24 -

Boring Sample Depth LL (%) PL (%) PI (%) Classification

B1 S7 & S8 15' - 20½' 67 22 46 CH

B2 S9 25' - 25½' 56 32 24 MH

B3 S4b 8' - 8½' 47 17 30 CL

B4 S4 7½' - 8' 72 23 49 CH

B5 S8 20' - 20½' 35 17 18 CL

Project: Job Number: 16-005-02 Location: Date: 8/30/2016

Test Results

Buffalo County, South Dakota; Hunkpati Dakota Nation

Project Information Proposed Bad Nation to Crow Creek Water Main

ATTERBERG LIMITS TEST RESULTS

(ASTM:D4318)

0 10 20 30 40 50 60 70 80

P la st ic it y

In d ex

Liquid Limit (%)

Soil Classification Chart Unified Soil Classification System

B1 S7 & S8 B2 S9 B3 S4b B4 S4 B5 S8

MH or OH

ML or OL

CH or OH

CL or OL

CL-ML

Equation of "A" Line:

Horizontal at PI=4 to LL=25.5 then PI=0.73(LL-20)

Equation of "U" Line:

Vertical at LL=16 to PI=7 then

PI=0.9(LL-8)

Boring Sample Depth Gravel (%) Sand (%) Silt (%) Clay (%) Cu Cc Classification

B1 S7 & S8 15' - 20½' 0.9% 5.3% 30.2% 63.6% N/A N/A CH

B2 S9 25' - 25½' 0.0% 4.7% 30.6% 64.7% N/A N/A MH

B3 S4b 8' - 8½' 5.1% 46.5% 21.3% 27.0% N/A N/A SC

B4 S4 7½' - 8' 0.0% 19.5% 32.1% 48.4% N/A N/A CH

B5 S8 20' - 20½' 23.8% 65.6% 3.5% 7.1% 211.9 31.3 SP-SC

Project: Job No.: 16-005-02 Location: Date: 8/16/2016

Test Results

Project Information

Buffalo County, South Dakota; Hankpati Dakota Nation

PARTICLE SIZE ANALYSIS

(ASTM:D422)

Proposed Bad Nation to Crow Creek Water Main

Gravel Sand Silt Clay

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.00010.0010.010.1110100

P er ce n t Fi n er b y

W ei g h t

Effective Diameter (mm)

Grain Size Distribution Curves

B1 S7 & S8 B2 S9 B3 S4b B4 S4 B5 S8

Geotechnical Engineering

Environmental Services Materials Testing

BORING LOG NOTES

Core Engineering & Consulting, Inc.

DRILLING AND SAMPLING SYMBOLS

Symbol Definition

B,H,N: Size of flush-joint casing

CA: Crew Assistant (initials) CAS: Pipe casing, number indicates nominal diameter in inches

CC: Crew Chief (initials) COT: Clean-out tube

DC: Drive casing; number indicates diameter in inches DM: Drilling mud or bentonite slurry

DS: Disturbed sample from auger flights

FA: Solid-stem flight auger; number indicates outside diameter in inches

HA: Hand auger; number indicates outside diameter HSA: Hollow stem auger; number indicates inside diameter in inches MC: Column used to describe moisture condition of samples and for the ground water level symbols

N (BPF): Standard penetration resistance (N-value) in blows per foot (see notes)

NQ: NQ wireline core barrel PQ: PQ wireline core barrel

RD: Rotary drilling with fluid and roller or drag bit

94mm: 94 millimeter wireline core barrel thin-walled tube sampling, the recovered length (in inches) of sample. In rock coring, the length of core recovered (expressed as percent of the total core run). Zero indicates no sample recovered.

REV: Revert drilling fluid

2L: California-spoon sampler (steel; 2” inside diameter with 4” long brass liners; 3” outside diameter) SS: Standard split-spoon sampler (steel; 1⅜” inside diameter; 2” outside diameter); unless indicated otherwise

SU: Spin-up sample from hollow stem auger

TW: Thin-walled tube; number indicates inside diameter in inches

WC: Core sample of pavement materials cut using a diamond-tipped wet saw

WASH: Sample of material obtained by screening returning rotary drilling fluid or by which has collected inside the borehole after “falling” through drilling fluid WH: Sampler advanced by static weight of drill rod and

140 lb hammer WR: Sampler advanced by static weight of drill rod

Water level directly measured in boring

Estimated water level based solely on sample appearance

TEST SYMBOLS

Symbol Definition

CONS: One-dimensional consolidation test

DEN: Dry density, pcf DST: Direct shear test

E: Pressuremeter Modulus, tsf

HYD: Hydrometer analysis LL: Liquid Limit, %

LP: Pressuremeter Limit Pressure, tsf OC: Organic Content, %

PERM: Coefficient of permeability (K) test; F – Field;

L-Laboratory PL: Plastic Limit, % qp: Pocket Penetrometer strength, tsf (approximate) qc: Static cone bearing pressure, tsf qu: Unconfined compressive strength, psf R: Electrical Resistivity, ohm-cms

RQD: Rock Quality Designation of Rock Core, in percent

(aggregate length of core pieces 4” or more in length as a percent of total core run)

SA: Sieve analysis TRX: Triaxial compression test

VSR: Vane shear strength, remolded (field), psf

VSU: Vane shear strength, undisturbed (field), psf WC: Water content, as percent of dry weight

%-200: Percent of material finer than #200 sieve

STANDARD PENETRATION TEST NOTES

The standard penetration test consists of driving the sampler with a 140 pound hammer and counting the number of blows applied in each of three 6” increments of penetration. If the sampler is driven less than 18” (usually in highly resistant material), permitted in ASTM:D1586, the blows for each complete 6” increment and for each partial increment is on the boring log. For partial increments, the number of blows is shown to the nearest 0.1’ below the slash. An “R” in the N-value column indicates refusal of the sampler prior to completing the initial 6” set.

The length of sample recovered, as shown on the “REC” column, may be greater than the distance indicated in the

N column. The disparity is because the N-value is recorded below the initial 6” set (unless partial penetration defined in

ASTM:D1586 is encountered) whereas the length of sample recovered is for the entire sampler drive (which may even extend more than 18”).

PO Box 456 Chamberlain, SD 57325

Geotechnical Engineering • Environmental Services • Materials Testing

Chamberlain, South Dakota 57325 ph: (605) 234-2673 fx: (605) 234-2674

1603 Locust Street

Yankton, South Dakota 57078 ph: (605) 260-4908 fx: (605) 260-4908

November 30, 2016

Crow Creek Tribal Utilities

Fort Thompson, SD 57339

Attn: Mr. Don Big Eagle

RE: Geotechnical Exploration and Review Proposed Standpipe Elevated Water Storage Reservoir

Northeast of the Intersection of SD Highways 50 & 34; Buffalo County, SD Hunkpati Dakota Nation

CEC #01-16-005-01

Dear Mr. Big Eagle, This report presents the results of a subsurface exploration program and geotechnical engineering review for the proposed standpipe water storage reservoir to be constructed northeast of the intersection of SD Highways 50 and 34 in rural Buffalo County, South Dakota on the Hunkpati Dakota Nation. This work was conducted in accordance with the contract between you and Core Engineering & Consulting, Inc. (CEC) dated January 9th, 2016 and authorized January 11th, 2016.

We are submitting three (3) copies of the report to you.

The opinions expressed in this report are based on information provided by you and the data obtained from our subsurface exploration. Should there be any changes as the project develops, we request that we be notified so that these new conditions can be reviewed and, if necessary, we can modify our recommendations.

The soil samples remaining after the laboratory testing is completed will be retained for a period of one month, at which time they will be discarded. Please advise us in writing if you wish to have us retain them for a longer period of time.

CEC appreciates the opportunity to provide these services to you. As your project proceeds, we would be interested in providing additional geotechnical and construction materials engineering services. If you have any questions about this report, or if you require additional information, feel free to contact us.

Sincerely, Victoria D. Job, EIT Staff Engineer victoria@coresd.com

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Proposed Standpipe Elevated Water Storage Reservoir

Northeast of the Intersection of SD Highways 50 & 34 Buffalo County, South Dakota

CEC Job No.: 01-16-005-01

Report Date: Wednesday, November 30, 2016

Prepared For: Crow Creek Tribal Utilities

Fort Thompson, South Dakota

CEC Job No. 01-16-005-01

PROJECT SUMMARY

Core Engineering & Consulting, Inc. (CEC), under contract with the Crow Creek Tribal Utilities, mobilized to the site near the intersection of SD Highways 50 & 34 on April 13th and May 12th, 2016 to perform a subsurface exploration program and subsequent engineering review. The purpose of the work performed at this site is to provide the Crow Creek Tribal Utilities and their project team the necessary subsurface soil information to adequately plan, design and construct the project.

The proposed project consists of constructing a standpipe elevated water storage reservoir with accompanying booster station. No information is available regarding the tank diameter or the total estimated capacity, however based on past experience with similar structures we estimate the total foundation loading from the structure will be less than 1,000 kips when filled to capacity.

Site grading is expected to be minimal.

The field exploration consisted of three Standard Penetration Test (SPT) borings drilled and sampled to depths of 31’ to 51’ below existing surface grade. The borings encountered ¼’ to 1’ of topsoil overlying 3’ to 3¾’ of fine alluvium soils, which in turn overlies Pierre Formation shale bedrock, extending to the full depth of exploration at each of the three boring locations.

Groundwater measurements taken immediately following drilling revealed no measurable groundwater surface at any of the boring locations however after approximately 1 month of monitoring, a measurable groundwater surface was encountered in the Boring #2 location, at a depth of 28.3’ below existing surface grade.

The soils encountered at the anticipated…