Letcher County FEIS Appendix F - Additional Geotechnical Study Roxanna Site (2016).pdf

APPENDIX F

ADDITIONAL GEOTECHNICAL STUDY

ROXANA SITE (2016)

Additional Geotechnical Study

Proposed Federal Correctional Facility Roxana Site

Letcher County, Kentucky

October 2016

Prepared for:

United States Department of Justice Federal Bureau of Prisons 320 First Street NW Washington, DC 20534

Prepared by:

Cardno, Inc.

5480 Swanton Drive Lexington, Kentucky 40509 www.cardno.com

Additional Geotechnical Study • Proposed Federal Correctional Facility Roxana Site • Letcher County Kentucky

Prepared for: US Department of Justice, Federal Bureau of Prisions

October 2016 Cardno, Inc. i

Table of Contents 1 Introduction and Purpose of Investigation

2 Background Information

2.1 Existing Conditions

2.2 Review of Past Mining

2.3 Proposed Site Development

3 Subsurface Exploration

3.1 Subsurface Exploration (Drilling) and Drill Rig Supervision

4 Subsurface Conditions

4.1 Boring Hole RX-14

4.2 Boring Hole RX-15

4.3 Soils Laboratory Testing

5 Foundation and Site Grading Recommendations

5.1 General

5.2 Area Base Elevations

5.3 Foundation Design Recommendations

5.4 Slab-On-Grade Design Recommendations

5.5 Asphalt Pavement Recommendations

5.6 Earthwork and Excavations

5.7 Structural Fill and Backfill Criteria

5.8 Control of Groundwater and Surface Water

6 Earthwork Quantities and Costs

7 Engineers’ Statement

Résumés of Writers

Tables

Table 3-1 Depth and Elevation of Fill and Boring Termination Table 4-1 Laboratory Results – Soil Moisture Content Table 4-2 Laboratory Results – Atterburg Limits and Compaction Tests Table 4-3 Laboratory Results – Soil Strength Parameters Table 5-1 Typical Pavement Section Table 6-1 Roxana Site – Volumes by Area Table 6-2 Roxana Site • 2016 Revised Earthwork Quantities and Construction Costs

Exhibits

RX-7 - Facility Location Map RX-8 - Existing Topography and Boring Location Map RX-9 – Clearing and Grubbing Map RX-10 – Cut and Fill Limits Map

Appendices

Appendix A: Boring Logs Appendix B: Laboratory Test Results

October 2016 Cardno, Inc. 1

1 Introduction and Purpose of Investigation

The Roxana, Kentucky, site has been selected for proposed construction of a federal correctional facility by the United States Department of Justice (USDOJ), Federal Bureau of Prisons (BOP). Cardno has previously conducted studies and submitted reports relative to those studies for this site that include a “Geotechnical Feasibility Report” dated June 2012, and prepared by Marshall Miller & Associates, Inc. now doing business as Cardno, Inc. (Cardno); a “Revised Earthwork Quantities and Construction Costs Report” dated October 24, 2014, and issued by Cardno MM&A now doing business as Cardno; and a “Title Reports and ALTA Survey Results Report” dated May 2016, and prepared by Cardno. All previous reports are included by reference.

The proposed facility includes several structures as shown on the attached Exhibit RX-7 “Facility Location Map.”

The proposed primary footprint of the United States Penitentiary (USP) is approximately 20 hectares (50 acres). Several other facilities including a prison camp, staff training center and a utility plant are proposed for the site. The BOP has relocated the prison camp and the access road to avoid a certain property at the site.

Based upon these relocations and other studies, Cardno was requested to perform the following tasks:

Task 1 – Locate Access Road and Federal Prison Camp Cardno located the access road and Federal Prison Camp (FPC) such that they will fit the topography of the site near the location indicated by the BOP on June 3, 2016. These locations were determined from a plausible “cut and fill” perspective, and a preliminary location was submitted to the BOP for approval. The access road was designed at or less than a 10-percent grade.

Task 2 - Revise Earthwork Quantities and Construction Costs Cardno determined and balanced the quantities of cut and fill for the new access road and the FPC locations relative to the previously determined facility locations. The quantities are based on a subgrade pad elevation of 445 meters for the main building, a subgrade pad elevation of 421 meters for the FPC and finished pad elevation of 447 meters for the utility plant area and training facility. The cut and fill quantities were balanced and an estimate of current construction costs was computed based upon those quantities. Buildings are located in areas near bedrock, where possible.

Task 3 - Drilling and Sampling Borings at the New FPC Site and Select Areas Due to the relocating of the FPC and findings of the June 2012, Feasibility Study, four (4) borings were drilled at the site by Horn & Associates, Inc. (Horn & Associates) to determine engineering parameters relative to the site construction.

Cardno drilled and sampled two (2) borings at the locations shown on the proposed FPC site on a map provided by BOP on July 27, 2016. The borings were advanced to auger refusal and samples collected at 2.5-foot intervals for the first 10 feet and 5-foot intervals thereafter. The encountered refusal material was core drilled to determine if the refusal material is bedrock.

Cardno drilled and sampled two (2) additional borings on July 25, 2016, through July 28, 2016, at locations identified in the October 24, 2014, report as requiring further information. Those borings are located in hollow fills remaining from the surface mining activities that previously occurred on-site.

Based upon the information collected from the borings, Cardno was requested to relocate the USP area to avoid founding a building on mine spoil in hollow fill areas.

Task 4 - Laboratory Testing Cardno provided the soil samples to S&ME, Inc. laboratory to classify the soil and to determine the soil strength parameters.

October 2016 Cardno, Inc. 2

Task 5 - Reporting Cardno has summarized the subsurface conditions based upon the additional and prior drilling, sampling and testing. A summary of the earthwork cut and fill balancing and construction costs are provided. The report includes portions of the “Geotechnical Feasibility Report” issued for this site on June 1, 2012, by Cardno.

The above tasks comprised Cardno’s additional geotechnical study (i.e., “study”) for the selected site. Cardno did not perform environmental investigations or assessments.

The purpose of the study was to document additional baseline site conditions to provide a basis for developing feasible (albeit preliminary) geotechnical and earthwork plans for the site. Cardno’s investigation scope was limited to consideration of gross earthwork quantities to achieve rough subgrade elevations, and foundation types judged feasible for the observed site-specific conditions. An additional detailed study will be required to evaluate and recommend foundations for the final proposed structures, and their specific locations on the selected site and applicable loading conditions.

Cardno is pleased to present our additional geotechnical study for the proposed federal correctional facility at the Roxana Site (Roxana) near Roxana, Kentucky. Our report for the Roxana site follows, and presents:

1. background information, including a description of the existing site conditions, summary of past mining on, below, and/or proximate to the site, and Cardno’s assumptions and concept with regard to preparatory site development (i.e., gross earthwork and grading);

2. scope of geotechnical subsurface exploration;

3. inferred, generalized subsurface conditions, and laboratory soils testing results; and

4. preliminary foundation and site grading recommendations.

2 Background Information

2.1 Existing Conditions

Information pertaining to the Roxana site was provided by TEC, Inc., now doing business as Cardno Government Services Divisions (Cardno GS) and from persons (including property owners and personnel from the Letcher County Economic Development Authority) who were available on-site. Additional information was also obtained by Cardno during research of public information, and through site visits and drilling and sampling of the exploratory borings.

The proposed location for the correctional facilities are presented on Exhibit RX-7 “Existing Topography and Boring Location Map.” The Roxana site has been surface mined by the mountaintop removal (MTR) mining method. The site is characterized as a wide, gently sloping to flat ridge created by surface mine overburden removal and valley filling. Ridge side slopes are moderate to steep into the valleys. Surface cover consists of grasses with sparse shrubs and immature trees on the surface-mined area, with the remaining area being mature forest and roads. A natural gas compressor station is located on the surface-mined portion of the site.

Also, an agricultural structure and storage sheds are located on-site. The subject site is located in the 0.2 to 0.3g Peak Ground Acceleration (PGA) range presented on the 2014 National Seismic Hazard Map for Probabilistic Ground Motion (2-percent in 50-year return period event) as developed by the United States Geological Survey (USGS).1

The limited stormwater management structures currently in-place will not properly manage flow from the proposed development. Additional evaluation and design relative to stormwater management will be required after a final site plan is developed.

1 Geotechnical Feasibility Report” dated June 2012, and prepared by Marshall Miller & Associates, Inc. now doing business as Cardno, Inc.

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2.2 Review of Past Mining2

Cardno researched publicly available records related to surface and underground mining in the general vicinity of the site. Cardno also conducted a field reconnaissance for surficial evidence of past mining and mining impacts in the area. Additionally, we reviewed a report by Summit Engineering, Inc. (Summit) on previous mining in the vicinity of the site. Refer to Map RX-3 from the June 2012, report for known and documented mine workings.

Cardno’s efforts attempted to identify mine workings on, adjacent to, and underlying the site and, if underground workings were identified, to assess the potential impact of mine subsidence (if any) on the earthwork and foundation designs. Potential subsidence associated with underground mine workings can significantly impact site development costs to provide mine stabilization measures and/or special foundations over higher risk subsidence zones and for more sensitive (less movement-tolerant) structures. No documented underground mining has been conducted in the immediate vicinity of the Roxana site, based on Cardno’s review of publicly available documents.

Surface mining has been conducted in the Fireclay and Fireclay Rider coal seams at or above elevation 445 meters prior to 1995. During mining of the site, mine spoil (un-controlled/un-compacted fill material consisting primarily of shot rock) was placed over most of the site to the present existing grade. Surface mine spoil averages 21 meters (69 feet) in depth. In certain areas of the site, primarily where excess mine spoil was placed in valley fills, the mine spoil thickness is as much as 58.2 meters (191 feet).

2.3 Proposed Site Development

BOP provided Cardno with the proposed facilities to be built upon the property along with a generalized site development plan. The development will consist of an access road, FPC area, USP area, utility plant area and staff training center area including a firing range and a warehouse.

3 Subsurface Exploration

3.1 Subsurface Exploration (Drilling) and Drill Rig Supervision

Cardno retained the services of Horn & Associates, a geotechnical drilling contractor, to perform the subsurface exploration program. Cardno was responsible for supervision of the drilling activities, and logging the materials encountered. Cardno provided experienced field engineering personnel to monitor the drilling program, classify materials encountered in the borings, and prepare field boring logs. A summary of the borings drilled at the site is presented in Table 3-1, their respective locations are shown on Exhibit RX-8 “Existing Topography and Boring Location Map” and the logs of the borings are contained in Appendix A.

Standard hollow-stem augers with rock auger cutting bits were utilized to advance the borings through unconsolidated overburden, although earlier exploration stopped when encountering the practical limits of the tooling, this additional exploration extended the borings to refusal and into bedrock. Disturbed split-spoon sampling and Standard Penetration Tests (SPT) were performed to ASTM D1586 standards (ahead of augering) on 0.75-meter (2.5-feet) intervals in the upper 3 meters (10 feet) below the ground surface and at 1.5 meter (5 feet) intervals thereafter, until reaching SPT or auger refusal. Undisturbed sampling (e.g., Shelby-tube sampling) was not attempted due to the variable nature of the mine spoil and common difficulties obtaining viable samples in such material. Below the depth of refusal, rock coring was undertaken to confirm the presence and location of bedrock.

For each 46-centimeter (18-inch) sampling interval, SPT blow counts on the 5-centimeter (2-inch) diameter split-spoon sampler were recorded for every 15-centimeter (6-inch) increment and SPT “N-values” were recorded as the sum of the blow counts for the final two 15-centimeter (6-inch) increments. Samples were visually logged in

2 Geotechnical Feasibility Report” dated June 2012, and prepared by Marshall Miller & Associates, Inc. now doing business as Cardno, Inc.

October 2016 Cardno, Inc. 4 accordance with ASTM D2488 standards. Water levels in the boreholes were measured at the completion of drilling and, when practical, approximately 24 hours after drilling completion, and are noted on the boring logs.

Auger cuttings from the borings were collected, tested and remolded for additional testing purposes. The completed boreholes were filled and leveled with auger cuttings. The location and surface elevation at each boring was determined using survey-grade, global positioning system (GPS) techniques.

The four (4) borings summarized in Table 3-1 were advanced at the respective locations shown on Exhibit RX-8 “Existing Topography and Boring Location Map.” All borings were advanced into the bedrock.

Table 3-1 Depth and Elevation of Fill and Boring Termination

Boring No.

Surface Elevation meters (feet)

Approximate Depth of Fill meters (feet)

Approximate Elevation of Base of Fill meters (feet)

Total Boring Depth meters (feet)

Boring Bottom Elevation meters (feet)

RX-12 443.6 (1,455.5) 2.8 (9.2) 440.8 (1,446.3) 9.8 (32.0) 433.9 (1,423.5)

RX-13 445.9 (1,463.0) 4.5 (14.8) 441.4 (1,448.3) 11.4 (37.5) 434.5 (1,425.5)

RX-14 466.3 (1,530.0) 46.4 (152.2) 419.9 (1,377.7) 50.9 (167.0) 415.4 (1,363.0)

RX-15 466.2 (1,529.4) 58.2 (190.9) 408.0 (1,338.4) 63.9 (209.5) 402.3 (1,319.9)

4 Subsurface Conditions

The subsurface conditions discussed in this report were inferred from the test borings summarized in Table 3-1, and the borings drilled in an earlier study. These borings are the basis for our preliminary geotechnical evaluations. Subsurface conditions between test borings will vary. Accordingly, project designers and others utilizing this information should not rely solely upon the subsurface information in this report, but should perform their own research and site observations, and further augment the available subsurface information as they deem necessary for their independent evaluations and design purposes.

The subject site is overlain with mine spoil (unconsolidated overburden) from previous surface coal mining activities. The surface mining activities were completed in the early-1990s. The mine spoil appears to have been randomly placed with little to no compaction (i.e., “uncontrolled” fill), and is highly variable in gradation and consistency with depth among the borings.

All borings are located in previously surface mined areas within the USP proposed footprint and the proposed FPC area. The unconsolidated overburden is comprised of varying proportions of dry to moist, brown and gray clayey silt and gray sandstone and dark gray shale fragments. Trace organics were observed in some borings at random depths. Material consistency was estimated from SPT blow counts. The penetration resistance (N-value) is used to describe the relative density and consistency of the soil being tested. The N-value can also be used to correlate the in-situ strength and compressibility of the soil. SPT N-values ranged from 4 to 79+.

Higher N-values were observed in zones containing a substantial fraction of coarser particle sizes (i.e., rock fragments and boulders).

The zones where cohesive soil predominated ranged in consistency from soft to very stiff, with no consistent trend with depth. Those zones containing a substantial or predominant fraction of rock fragments exhibited a loose to dense consistency, with no apparent trend with depth. The cohesive soils exhibited varying degrees of plasticity from non-plastic to low plasticity. The bedrock encountered immediately below mine spoil consisted of gray sandstone of good to excellent quality based on Rock Quality Designation (RQD).

The proposed FPC will be located in a gap in the topography between the previous FPC location and the USP.

Borings RX-12 and RX-13 were drilled where the proposed FPC was to be located with surface elevations slightly below and above the 445 meter elevation thought to be the approximate coal mine bench level in holes drilled previously to the south. Mine spoil was encountered in both holes at elevations 448.0 and 441.4 meters

October 2016 Cardno, Inc. 5 respectively. The mine spoil consisted of moist to wet, clayey silts with many sandstone and shale fragments and layers. SPT N-Values ranged from 11 to 39 indicating a consistency from stiff to very stiff. The bedrock encountered was shaley sandstone with shale layers into sandstone conglomerate into massive sandstone. The auger cuttings were collected from each boring.

Borings RX-14 and RX-15 are located in areas identified as requiring additional investigation in the Cardno MM&A report dated October 24, 2014. Those borings are located in existing valley fills where the total depth to bedrock was previously undetermined.

4.1 Boring Hole RX-14

Soils encountered in RX-14 were generally dry to moist, stiff to hard, brown clayey silt containing some sandstone and shale fragments. SPT N-Values ranged from 9 to 68+ indicating a consistency from medium stiff to hard. A bag sample of the auger cuttings was collected. Rock was encountered in the borehole and rock coring was initiated at elevation 437.77 meters only to discover that the rock was a boulder. Several additional attempts to core in the unconsolidated material resulted in very poor recovery until competent bedrock was encountered at elevation 419.94 meters. The competent bedrock was gray sandstone with coal streaks present at elevation 417.99 meters and soft shale seams beginning at elevation 417.47 meters.

4.2 Boring Hole RX-15

Soils encountered in RX-15 were generally dry to moist, soft to hard, brown and grey, clayey silts with sandstone and shale fragments and layers. A bag sample of the auger cuttings was collected. The bedrock encountered at elevation 408.0 meters immediately below the unconsolidated overburden was massive gray sandstone.

4.3 Soils Laboratory Testing

Cardno delivered all soil samples to the subcontracted geotechnical testing laboratory, S&ME, Inc. and requisitioned desired testing. The natural moisture content (ASTM-2216) test was performed on several of the SPT samples. In addition, the following testing was performed on bulk samples obtained from the auger cuttings at the test boring locations:

> Atterberg Limits [ASTM D4318]

> Grain-size analyses [ASTM D422]

> Standard Proctor (ASTM D-698), > Unconfined compression, remolded (ASTM D-2166), and

> Consolidated undrained triaxial (ASTM D-4767) on remolded samples.

Split spoon samples were collected from each SPT and placed in a jar for identification and possible laboratory testing. A total of four bag samples were collected, one from each of the borings. The two smaller samples from borings RX-12 and Rx-13 were composited in the laboratory. A total of three bag samples were tested, designated as RX-12/RX-13, RX-14 and RX-15.

The moisture contents of several of the split spoon samples were determined and the results ranged from 5.5-percent to 19.9-percent. The test results from the bag samples indicated soil classifications of clayey sand with gravel, sandy lean clay and clayey sand with gravel, respectively. The maximum dry density (MDD) of the three samples was 120.7 pounds per cubic foot (pcf), 126.8 pcf and 132.6 pcf. The optimum moisture corresponding to the maximum dry densities was 9.3-percent, 9.8-percent and 6.5-percent, respectively. The maximum compressive strength for the remolded samples was 5.129 tons per square foot (tsf), 5.121 tsf and

4.68 tsf, respectively. The total stress parameters of the remolded samples were Ф = 12.6⁰ and c=3.3 pounds per square inch (psi); Ф = 18.4⁰ and c= 1.7 psi and Ф = 13.8⁰ and c= 3.2 psi. The effective stress parameters of the remolded samples were Ф = 21.6⁰ and c = 2.5 psi; Ф = 30.7⁰ and c = 0 psi and Ф = 28.6⁰ and c= 1.1 psi.

Soil testing results are presented in the following Tables 4-1, 4-2 and 4-3 and in Appendix B.

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Table 4-1 Laboratory Results – Soil Moisture Content

Sample Id # Material Description Moisture (%)

RX-12 • SS-1 n/a 10.8

RX-12 • SS-3 n/a 9.6

RX-13 • SS-2 n/a 5.5

RX-13 • SS-4 n/a 19.9

RX-12 & RX-13 • Bags Clayey sand with gravel 6.2

RX-14 • SS-6 n/a 8.7

RX-14 • SS-14 n/a 10.1

RX-14 • Bag Sandy lean clay 6.6

RX-15 • SS-7 n/a 11.6

RX-15 • SS-17 n/a 9.8

RX-15 • Bag Clayey sand with gravel 4.9

Table 4-2 Laboratory Results – Atterburg Limits and Compaction Tests

Lab Compaction Test Report

Liquid & Plastic Limits Test Report Rock Corrected Test

Results Uncorrected

Sample Id # Material

Description LL PL PI %<# 40

200 USCS

Maximum dry density (pcf)

Optimum moisture

Maximum dry density (pcf)

Optimum moisture

RX-12/RX-13

Clayey sand with gravel 29 20 9 50.8 40.8 SC 120.7 9.3% 118.7 9.8%

RX-14 Sandy lean clay 29 20 9 63.1 55.6 CL 126.8 9.8% 125.4 10.2%

RX-15

Clayey sand with gravel 28 18 10 42.3 33.8 SC 132.6 6.5% 128.8 7.3%

Table 4-3 Laboratory Results – Soil Strength Parameters

Sample Id # Material

Description Moisture

Wet Density

(pcf) Dry Density

(pcf)

Max Comp.

Strength

(tsf)

Strain @ Max Comp.

Strength (%)

Friction Angle

(Degrees), Effective Stress

Cohesion (psi), Effective Stress

RX-12/RX-13

Clayey sand with gravel 12 126.3 112.8 5.129 1.4 21.6 2.5

RX-14

Sandy lean clay 12 134.6 120.2 5.121 1.5 30.7 0

RX-15

Clayey sand with gravel 10.7 134.1 121.1 4.68 1.3 28.6 1.1

The soil moisture content test indicates the in-situ moisture of the soil for comparison to the optimum moisture content determined in the compaction test. The maximum density and the optimum moisture can be determined from the compaction test. These values are used when the soil is excavated, transported and placed in structural fill to determine the percent compaction.

A grain-size analysis and Atterberg Limits tests are used to determine the classification of the soil. The maximum compressive strength of the soil is generally twice the undrained shear strength of the soil. The total

October 2016 Cardno, Inc. 7 stress and effective stress parameters are used to determine the bearing capacity of the soil and can be used in slope stability analysis.

5 Foundation and Site Grading Recommendations

5.1 General

The data obtained from the subsurface exploration and laboratory testing programs were relied on for our preliminary geotechnical evaluations and formulation of foundation and site grading recommendations. The test borings indicate that the subsurface conditions within the primary facility footprint consist of surface mine spoil of highly variable consistency, roughly averaging 21 meters (69 feet) in thickness. Accordingly, Cardno has assumed that the primary facility footprint (approximately 50 acres) at the Roxana site would be graded to an approximate subgrade elevation of 445 meters (1,460 feet), which Cardno estimates would locate building foundations on or in rock.

Cardno considered the possibility that portions of the site may contain expansive shale, which could impact foundation behavior if such materials existed near foundation level or were incorporated within fills beneath structures or around piping. The U.S. Army Technical Manual (TM5-818-7) for Foundations in Expansive Soils indicates that Letcher County, Kentucky is located in a “non-expansive” region of the Appalachian Plateau physiographic province. Non-expansive is defined in the aforementioned-reference as the extremely limited occurrence of expansive materials. Cardno attempted to visually identify evidence of expansive materials, such as the existence of pyrite and gypsum materials within shale in the mine spoil and bedrock. Given the findings of our desktop research and lack of visual evidence of expansive shale during the exploration program, laboratory testing for expansive constituents (e.g., sulfur species) was not performed.

5.2 Area Base Elevations

Cardno determined base elevations relative to the site topography and the geotechnical studies for each area.

Based upon the amount of mine spoil present on the site, the buildings should be founded on bedrock or other competent material such as structural fill.

The USP area is proposed to be graded to a subgrade elevation of 445 meters (1,460 feet), which Cardno estimates will locate building foundations on or in rock across the majority of the area. Earthwork to reach the subgrade elevation is primarily excavation and relocation of mine spoil (unconsolidated overburden). Valley fills that extend deeper than the 445 elevation are located along the north and east sides. The building footprint has been rotated to avoid the valley fill areas. The roadway on the east side of the USP and the parking area on the north side of the USP will be located on as much as 38 meters (125 feet) of mine spoil fill in the original valleys.

The fenced perimeter of the USP area will also cross the deep mine spoil on the east side and structural fill on the south side.

The training center is proposed to be graded to an approximate subgrade elevation of 447 meters (1,467 feet).

The training center will be founded on structural fill that has been placed in a controlled manner from the excavated mine spoil.

The utility plant area will be graded to an approximate elevation of 447 meters (1,467 feet). The utility plant area will be founded on bedrock.

The FPC will be graded to approximate elevation of 421 meters (1,381 feet). The prison camp buildings will be founded on bedrock and the other facilities will be founded on structural fill.

5.3 Foundation Design Recommendations

As noted in the preceding section, structures could be reliably supported on shallow foundations on or in bedrock (sandstone) or structural fill. This would require that the USP area be graded to approximate elevation 445

October 2016 Cardno, Inc. 8 meters. The FPC should be graded to approximate elevation 421 meters and the utility plant and training center areas should be graded to elevation 447 meters. This foundation configuration would afford an allowable bearing capacity of 4,000 pounds per square foot (psf) in bedrock and 2,000 psf in structural fill. This will limit potential total and differential settlements to less than 1-inch, if all recommendations can be followed. All perimeter foundations should bear below the frost line for the area.

The mine spoil that will be removed from the USP building footprint has surcharged the fill remaining in the valleys below elevation 445 meters. Therefore, the fill in the valleys has likely consolidated since the mine spoil was placed in the 1990s. However, Cardno discourages building foundations bearing on or within untreated/unimproved mine spoil which could lead to at least six (6) inches of total settlement and 2.5 inches of differential settlement over a 50-foot distance per 100 feet thickness of mine spoil. The unknown of the presence of large boulders or deleterious materials in the fill could likely result in future settlement and could likely cause damage to any facilities bearing on this medium. Therefore, Cardno recommends geosynthetic reinforcement or grout compaction in critical areas which support the roadway, parking lot, perimeter fences and/or walls.

Control of surface water drainage in the valley fill areas is paramount to reduce the risk of settlement in these areas.

Mine spoil transported to the valleys to be compacted as structural fill will have a bearing capacity of 2,000 psf if placed according to the recommendations herein.

In all cases, Cardno recommends that the foundation subgrades be examined by a licensed Geotechnical Engineer prior to placement of concrete. Any subgrades that are found unsuitable should be over-excavated to suitable subgrade and the bottom level of the foundation lowered in elevation or brought up with properly compacted structural fill or flowable fill. All structural fill materials should be examined for potentially expansive constituents, and approved by the Geotechnical Engineer. As previously mentioned, a reinforced structural fill (incorporating geosynthetic reinforcement [i.e., geotextile or geogrid or grout compaction]) could be designed and installed beneath the roadway, the parking lot, the fence and/or walls, if necessary or desirable, to increase bearing capacity and help mitigate the impacts of potential total and differential settlements.

Depending on the final facility layout (horizontal and vertical configurations) on the site, additional subsurface exploration might be required to evaluate and design a ground improvement program, finalize recommendations for geotechnical aspects of the project, and complete detailed foundation designs.

5.4 Slab-On-Grade Design Recommendations3

Cardno recommends that the floor slabs be designed to be structurally independent of the foundations, and that all control and expansion joints be filled with appropriate joint filler materials. We further recommend that the floor slabs be designed and constructed in accordance with American Concrete Institute (ACI) 302.1R, ACI 330R, and ACI 360R standards.

5.5 Asphalt Pavement Recommendations4

A California Bearing Ratio (CBR) of 2 may be used for design of asphalt pavements that bear upon mine spoil.

A typical pavement section based on the 2007 Pavement Design Guide from the Division of Highway Design of the Kentucky Transportation Cabinet is presented in the following table along with the assumed design criteria.

3 Geotechnical Feasibility Report” dated June 2012, and prepared by Marshall Miller & Associates, Inc. now doing business as Cardno, Inc.

4 Ibid.

October 2016 Cardno, Inc. 9

Table 5-1 Typical Pavement Section

Parameter Value Comments

CBR 2

ESAL* 500,000

Structural Number

4.97 Based on 50% asphalt curves

* Equivalent Single Axle Load

Typical Asphalt Pavement Sections

Structural Layer

Coefficient Thickness (in.)

Surface Layer 0.44 2

Binder Layer 0.42 2

Base Layer 0.40 4

Aggregate Base 0.14 12

5.6 Earthwork and Excavations

Cardno anticipates that the preparatory mass earthwork can be performed using conventional heavy construction equipment and techniques. Vegetation and shallow soils containing roots and other unsuitable components should be removed (cleared) from structure (foundation and slab), pavement, other new construction areas, and areas of fill construction or material stockpiling/disposal. The “Clearing and Grubbing Map” as shown in Exhibit RX-9 depicts the limits of the areas to be cleared. Upon removal of these unsuitable materials, the exposed subgrades in areas requiring fill placement or near finished grade for foundation, slab or pavement construction should be examined by a licensed Geotechnical Engineer, while the areas are heavily compacted and thoroughly proof-rolled. For the heavy compaction process, Cardno recommends use of a sheepsfoot roller compactor with a minimum static weight of 10 tons, and having a leading blade for filling compaction indentations in advance of successive passes. For proof-rolling, we recommend use of a smooth drum roller with a minimum static weight of 10 tons. Cardno recommends a minimum of three overlapping passes in each of two orthogonal directions with the sheepsfoot compactor for heavy compaction, followed by two overlapping passes in each of two orthogonal directions with the smooth drum roller for proof-rolling purposes. The intent is to compact areas of relatively soft/loose shallow soils and re-compact areas disturbed during subgrade excavation or other activities, and identify unacceptable subgrade areas that require correction/restoration. Areas which remain unsuitable in the professional opinion of the Geotechnical Engineer or deviate from the contract specification requirements, after the heavy compaction and proof-rolling process, should be over-excavated to a suitable bearing stratum and replaced with compacted structural fill or acceptable on-site soils.

Excavations must be performed in accordance with the current Occupational Safety and Health Administration (OSHA) Standards for Excavations (29 CFR 1926, Subpart P). The majority of the silty clay materials encountered at the site is Type “B” or Type “C” soils, as classified in the above-referenced OSHA standard. The Contractor must evaluate soil and water conditions during excavations, since variations in the soil can occur across the site. The Contractor is ultimately responsible for all excavation safety.

5.7 Structural Fill and Backfill Criteria

All material placed as fill beneath foundations, slabs, and pavements, and as backfill against foundations and in utility trenches should be a well-graded, durable, chemically inert, granular fill, free of organic matter, debris, and other deleterious material.

All structural fill and backfill should be placed in horizontal lifts not to exceed 10 inches loose lift thickness (i.e., pre-compaction thickness) and shall be compacted to at least 95-percent of the MDD as determined by the Standard Proctor Test (ASTM D-698) using a minimum 10-ton static roller. In confined areas, such as over-

October 2016 Cardno, Inc. 10 excavated spread footing areas, the structural fill should be placed in horizontal lifts not to exceed 6 inches loose lift thickness and compacted to at least 95-percent of the MDD (per ASTM D-698) using a manually-operated compactor. For both of the compaction operations, the placement moisture content shall be controlled within ±3-percent of the optimum moisture content (per ASTM D-698), or within an alternate moisture range determined by the Geotechnical Engineer based on the makeup and moisture sensitivity of the specific fill material. Granular structural fill/backfill should be compacted with equipment operating in vibratory mode if the nature and moisture condition of the underlying subgrade and trench walls (if applicable) would not be deteriorated by the vibratory action.

Excavated/borrowed mine spoil might constitute acceptable structural fill in larger areas (not small or confined areas), if supported by an appropriate scope of prequalification index and moisture-density testing, and durability testing if predominantly comprised of rocky material. The mine spoil may require screening to comply with structural fill grain size and placement specifications, noting that the maximum predominant particle size within the fill material should not exceed 1/3 to 1/4 the recommended lift thickness, depending on the application and the durability of the larger particles.

The excavated rock used for structural fill should be isolated from the mine spoil structural fill. The excavated rock fill should be placed at the bottom of each of the hollow fills to promote free drainage of subsurface water.

The excavated rock fill should be separated from the mine spoil fill with a geosynthetic fabric to prevent piping of the spoil fines. The excavated rock should have a maximum size of 15 inches and should be well-graded.

Cardno recommends placing the excavated rock fill in lifts no greater than 24 inches and the rock fill should be bladed in with a dozer. The rock fill should be compacted with a 10- to 20-ton smooth vibratory roller.

5.8 Control of Groundwater and Surface Water

The Contractor should be required to conduct all excavation and backfill operations “in-the-dry”. Provisions should be made to remove infiltrating groundwater and perched water, divert surface runoff away from work areas, and seal working surfaces from water penetration throughout construction. Design, construction, and maintenance of water control methods should be the responsibility of the Contractor. We anticipate that proper grading of the prevailing ground surface to direct surface runoff away from active and completed work areas, and from excavations, combined with pumping from properly filtered sumps will be adequate to control groundwater and normal surface runoff. The mass excavation of existing mine spoil and construction of drainage controls through remaining spoil could alter surface and subsurface drainage patterns and interaction within the spoils.

Should the mine spoil include rocky zones with significant void space and/or rock that degrades rapidly, the introduction/reintroduction of water and additional oxygen into such spoil zones could prompt subsurface erosion and/or accelerated weathering/deterioration in otherwise inert zones. The institution of construction-period and permanent surface drainage controls, maintenance of well-sealed earthwork surfaces, and precautions to ensure that installed subsurface drains, rain gutter outlets, water lines, and other plumbing are absent leaks should largely mitigate these potential adverse consequences.

6 Earthwork Quantities and Costs

Preliminary earthwork quantities are presented in Table 6-1. Limits of cut and fill are presented on Exhibit RX-10. Additional (i.e., fine) grading to achieve site drainage and landscaping will be required.

Site drainage should be designed to avoid any mine spoil areas left in-place.5

The earthwork quantities have been estimated from the three-dimensional modeling of the site using Carlson® Software.6 The earthwork quantities for each area were determined and balanced such that the amount of material excavated was equal to the amount of material placed and compacted.

5 Geotechnical Feasibility Report” dated June 2012, and prepared by Marshall Miller & Associates, Inc. now doing business as Cardno, Inc.

6 www.carlsonsw.com

October 2016 Cardno, Inc. 11

Cardno estimated that the spoil material will be denser in the structural fill and shrink in volume by 10-percent;

Cardno further estimated that the rock excavated will be 25-percent greater in the structural fill. The soil or spoil fill are sloped at 2 horizontal to 1 vertical (2:1). The rock cuts are sloped 1/4:1. Some areas containing softer rock such as shale may have to be sloped flatter. The following Table 6-1 represents the amount of cut and fill for each area. The cut and fill balancing is shown on Exhibit RX-8.

Table 6-1 Roxana Site – Volumes by Area

Item (Cubic Meters) USP Area

Access Road Area

Training Center Area

Utility Plant Area

Prison Camp Area Total

Spoil Excavation 5,915,065 0 0 661,469 8,551 6,585,085

Rock Excavation 0 104,737 0 237,146 216,025 557,908

Structural Fill 47,382 1,216 3,956,737 6 2,678,634 6,683,976

Spoil Fill 0 0 0 0 0 0

Base Elevation 445 Varies 447 447 421

The unit costs for the construction quantities were based on “RSMeans Cost Data”7 and updated to reflect 2016 costs. The updated lower excavation costs reflect large excavations (more than 200,000 bank cubic yards) typical of surface mines in the area, and because of the depressed coal market, heavy equipment generally used in that industry is available. The estimated costs are presented in Table 6-2.

Table 6-2 Roxana Site • 2016 Revised Earthwork Quantities and Construction Costs

Unit Cost Unit Cost Units Units Cost

Item ($/Cubic Meters) ($/Cubic Yards) (Cubic Meters) (Cubic Yards) ($)

Spoil Excavation $4.88 $3.73 6,585,085 8,612,966 $32,135,215

Rock Excavation $22.54 $17.23 557,908 729,716 $12,575,246

Structural Fill $5.00 $3.82 6,683,976 8,742,310 $33,419,878

($/Hectare) ($/Acres) (Hectare) (Acres) $

Clear Mined Area $850 $342 24.1 60 $20,485

Clear Forest Area $21,930 $8,876 49.9 123 $1,094,307

Total $79,245,131

7 Engineers’ Statement

Cardno requests and recommends that we be provided the opportunity to review the details of development within the primary facility footprint, and the associated site development drawings, foundation designs and details, and contract specifications for consistency with our recommendations. Cardno’s recommendations are contingent upon continuous monitoring by the licensed Geotechnical Engineer or his representative of geotechnical aspects of the construction. At a minimum, Cardno recommends that the monitoring include observation of preparatory site earthwork, including structural fill placement and compaction; foundation, slab, and pavement subgrade preparation; and foundation construction.

Slope stability calculations were not included in this scope of services. Slope stability evaluations for existing mine spoil valley fills, and proposed cut and fill slopes are recommended. Slope stability evaluations should encompass, but not necessarily be limited to, slopes constructed of, or in, mine spoil and surface water and groundwater influences on stability. Also, subsidence prediction associated with previous coal mining or

7 Hale, Derrick, PE, Senior Editor, RSMeans Heavy Construction Cost Data 2016, 30th Annual Edition, From the Gordian Group®, Construction Publishers & Consultants, 2015.

October 2016 Cardno, Inc. 12 recommendations to mitigate subsidence were not included in this scope of services. Only identification of the potential for subsidence at the site was assessed, which is judged acceptable for this site selection process.

Additional geotechnical investigation should be performed if construction over mine spoil and ground improvement of the spoil will be pursued as a site development approach. Additionally, the feasibility-level earthwork quantities and estimates of select construction costs will require refinement as additional geotechnical information is obtained and details of the planned development are finalized for the selected site.

Cardno prepared this report in support of the proposed federal correctional facility to be located in Letcher County, Kentucky. Cardno’s conclusions and recommendations are based on information obtained from the subsurface investigation and Cardno’s understanding of the proposed development as expressed in this report.

As noted previously in this report, changes to our recommendations might be warranted if the actual subsurface conditions vary from those anticipated, or as details of the proposed development become known.

Generally-accepted geotechnical engineering practices were used to develop Cardno’s recommendations. The services provided for this project were performed with the care and skill ordinarily exercised by reputable members of the profession practicing under similar conditions at the same time and in the same or similar locality. No warranty, expressed or implied, is made or intended by rendition of these consulting services or by furnishing oral or written reports of the findings made. Cardno reserves the right to revise or amend our opinions in this report in the event new information, documentation or evidence becomes available.

Résumés of Writers

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Current Position Senior Forensic Engineer

Profession Civil Engineer

Years' Experience 35+

Joined Cardno

Education BS – Civil Engineering, University of Kentucky

AS – Civil Engineering Technology, Lexington Technical Institute

Professional Registrations

PE – KY, WV, VA, TN,

AR, OK, NY

LS – KY

PI – KY, WV, TN

Fire Investigator – CFI-

IAAI, CFEI-NAFI

MSHA 8 Hour Annual Refresher

Summary of Experience

Mr. Nicholson investigates and provides expert opinions as to the causation of property damage claims to residential and commercial structures, equipment, vehicles and land-related to construction errors, water, wind, hail, vibration, fire, explosion, mine subsidence, landslides, settlement, accidents and other causes. He investigates and provides expert opinions relative to regulations and codes for the above referenced cases as well as personal injuries or fatalities. He also performs environmental site assessments on commercial and mining properties. Mr. Nicholson provides professional land surveying services including boundary surveys, stockpile surveys and topographic surveys.

Significant Projects

> Various Insurance Adjusters: Analysed structural damage due to blasting, fire, and weather-related causes; investigated automobile accidents; analysed ground water infiltration and associated damage to residential and commercial properties;

conducted landslide investigations.

> Various Attorneys: Provided expert witness testimony regarding damages to residential and commercial property and relative to personal injury and fatalities.

> Commercial Real Estate: Performed Phase I Environmental Site Assessments.

> Surveying: Performed boundary surveys of commercial and personal properties;

conducted stockpile surveys to determine volume of materials including coal, limestone, lead concentrate, zinc concentrate, copper concentrate, soil contamination and vermiculite.

Specific Projects

> Investigated the causation of landslides on or near properties owned or leased by oil and gas companies and coal companies.

> Investigated the causation of structural damage to residential and commercial properties for insurance companies in Kentucky, West Virginia, Tennessee and Louisiana (Hurricane Katrina).

> Investigated the origin and cause of natural gas explosions for insurance companies in Kentucky.

> Investigated the origin and cause of fires for insurance companies in Kentucky, West Virginia and Tennessee.

> Performed Phase I Site Assessments of coal mining properties in Kentucky, West Virginia, Virginia and Pennsylvania.

> Performed Phase I Site Assessments at various motels in Kentucky.

> US Army Corps of Engineers: Coordinated development of proposal that included health and safety plan, and access plan for geotechnical drilling project;

managed drilling project.

W. Dale Nicholson

Current Position Senior Principal, Practice Leader - Engineering

Profession Mining Engineer

Years' Experience 44+

Joined Cardno

Education MS - Mining Engineering (Mineral Economics, Rock Mechanics), Columbia University, Henry Krumb School of Mines, New York, New York

Professional Registrations

PE - IL, KY, OH, PA,

UT, VA, WV

Land Surveyor - WV

SME - Founding Registered Member, Competent Person for Mineral Reporting

MSHA Certified Trainer

MSHA 8 Hour Annual Refresher

Summary of Experience

Mr. Feddock serves as the principal investigator in mineral economic and mining geotechnical projects to meet standards as developed by the U.S. Securities and Exchange Commission (SEC), the Canadian National Instrument (NI) 43-101, and the Australian Joint Ore Reserves Committee (JORC) code. Previously, he served as Vice President/Manager of Engineering for two major coal companies. In addition, he serves as an expert witness and manages all administrative aspects of the Lexington, KY, office.

Significant Projects

> Served as consultant for projects at surface and underground mines for the mineral industry including coal; stone metal and non-metal mining (underground mine projects included mine planning and entry layout, longwall applications, subsidence prediction and control, productivity analysis and prediction, continuous miner and longwall equipment applications, roof support analysis, and coal pillar sizing)

> Characterization of all types of mineral resources for effective layout and design for surface and underground mines

> Coordinated mineral economics projects that included discounted cash flow and rate of return analysis; equipment and facility investment requirements (Capex); the valuation of property, plant, equipment, and reserves; mine operating cost (Opex) forecasting and analysis; mine feasibility studies, and company valuations

> Provided expert witness testimony, attorney technical support, insurance claim analysis for cases that involved: longwall mining, blasting, subsidence, groundwater impacts, slope stability, lost coal claims, personal injury, production capability, sales contracting, and other mining and geotechnical engineering issues in both State and Federal courts

Specific Projects

> Overseas Assignments: Australia, Chile, China, Colombia, United Kingdom

> Valuation of Reserves, Mines and/or Facilities: Colorado, Indiana, Illinois, Kentucky, Utah, Virginia, and West Virginia in the U.S.A., and Chile and China

> Design of Plug-Type Mine Seals in compliance with 30CFR§75.335 (Federal regulation for mine seals)

> Evaluation of Business Interruption Claim at open pit copper mines

> Regional Search for Coal Seams containing specific trace elements

> Longwall Equipment Entrapment, damage, assessment and performance

> Reclamation Liability (Asset Retirement Obligation) Assessment

> Valuation of Companies, Assets, and Goodwill Impairment

John E. Feddock

Exhibits

Jewell

Lilly Cornett Branch

B ig

B ra nc h

T ol so n

C r

RT 1

B ig B ranch T olson C r

RT 160

RT 160

Main State

RT 588

R T

R ou te

UTILITY PLANT AREA

1+

2+

3+

4+

5+00

6+00

7+00

8+

9+00

10+00

11+00

12+00

13+

14+

0+

0+00 0+10 0+20 0+30

0+00 0+10 0+20 0+30

2:1 8%

C/L

C/L

Existing Grade

1.52 m.

(5 ft.) w/guardrail

2:1

0.25:1

3:1

3.35 m.

(11 ft.)

3.35 m.

(11 ft.)

0.914 m.

(3 ft.)

8% 2% 2% toward ditch where bermed grade

Proposed Road Ditch (To Be Sized)

Cross Section Sta. 3+00 (Typical Two-Lane Roadway)

Cross Section Sta. 4+00 (Typical Three-Lane Roadway)

1.52 m.

(5 ft.) w/guardrail

3.35 m.

(11 ft.)

3.35 m.

(11 ft.)

0.914 m.

(3 ft.)

2%

3.35 m.

(11 ft.)

toward ditch where bermed grade

2% 8%

P as si ng

L an e

S lo w L an e

Proposed Road Ditch (To Be Sized)

0.25:1

Existing Grade

3:1

Prepared For:

R…