G20013_Site_A_Preliminary_Geotechnical_Report_-_ESS_-_REVISED03-26-20.pdf

PRELIMINARY GEOTECHNICAL STUDY

Medical Examiner Facilities - Site A: VCME Daytona Beach, Volusia County, Florida

BET Project No. G20013 March 26, 2020

Prepared For:

Laura Laser, AIA Volusia County Engineering & Construction

123 West Indiana Avenue, Room 402 DeLand, Florida 32720

Prepared By:

Bechtol Engineering and Testing, Inc.

605 West New York Avenue

DeLand, Florida 32720

March 26, 2020 BET Project No.G20013

TO: Laura Laser, AIA Volusia County Engineering & Construction 123 West Indiana Avenue, Room 402 DeLand, Florida 32720

RE: Preliminary Geotechnical Study Medical Examiner Facilities - Site A: VCME Daytona Beach, Volusia County, Florida

Dear Ms. Laser:

As requested, Bechtol Engineering and Testing, Inc. (BET) has completed a Preliminary Geotechnical Study at the subject site relative to potential construction of a new Volusia County Medical Examiner Facility.

The purpose of BET’s study was to gain general insight as to the project site’s shallow soils and groundwater characteristics, and based on these characteristics, to evaluate the general suitability of the site for development. The following report summarizes BET’s findings and preliminary evaluations.

BET appreciates the opportunity to be of service, and trusts this report is sufficient for your immediate needs. However, if you should have any questions, or if BET may be of further service, please do not hesitate to call.

Respectfully, Bechtol Engineering and Testing, Inc.

Certificate of Authorization No. 00005492

Thomas Bechtol, P.E.

President / Principal Engineer Thom as Bechtol, P.E., State of Florida, Professional Engineer, License No. 38538 This item has been digitally signed and sealed by Thomas Bechtol, P.E. on the date indicated here. Printed copies of this document are not considered signed and sealed, and the signature must be verified on any electronic copies.

L. Patel Love B. Patel, MS, EI

Project Engineer

G20013 Site A Preliminary Geotechnical Report - REVISED 03-26-20.wpd

Preliminary Geotechnical Study - Medical Examiner Facilities - Site A: VCME, Daytona Beach, Volusia County, Florida BET Project No. G20013 G20013 Site A Preliminary Geotechnical Report - REVISED 03-26-20.wpd

TABLE OF CONTENTS

1.0 INTRODUCTION

1.1 Purpose Of Study

1.2 Intended Use/Limitations

2.0 SITE AND VICINITY CHARACTERISTICS

2.1 Site Location

2.2 Regional Geology

2.3 Site Physical Characteristics

3.0 GEOTECHNICAL FIELD STUDY

3.1 Soil Borings

4.0 ENCOUNTERED SUBSURFACE CONDITIONS

4.1 General Soil Conditions

4.2 Groundwater Conditions

4.3 Soil Permeability / Hydraulic Conductivity

5.0 PRELIMINARY GEOTECHNICAL EVALUATIONS

5.1 Soils Suitability and Stability

5.2 Site Grading

5.3 Foundations

5.4 Pavement Sections

5.5 Stormwater Retention

LIST OF APPENDICES

APPENDIX A - BORING LOCATION PLAN, SOIL PROFILES, SOILS LEGEND

Preliminary Geotechnical Study - Medical Examiner Facilities - Site A: VCME, Daytona Beach, Volusia County, Florida

G20013 Site A Preliminary Geotechnical Report - REVISED 03-26-20.wpd

1.0 INTRODUCTION

1.1 Purpose Of Study

Bechtol Engineering and Testing, Inc. (BET) has completed a Preliminary Geotechnical Study relative to relative to potential construction of a new Volusia County Medical Examiner Facility on a portion of a Volusia County-owned parcel of land in Daytona Beach, Volusia County, Florida. The purpose of BET’s study was to gain general insight as to the project site’s shallow soils and groundwater characteristics, and based on these characteristics, to evaluate the general suitability of the site for development. The following report summarizes BET’s findings and preliminary evaluations.

1.2 Intended Use/Limitations

This report is prepared solely for the use of BET’s client and their various design professionals as an aid in preliminarily evaluating the potential suitability of the project site for development.

Evaluations presented herein are based on very limited subsurface data derived from soil borings, and without the knowledge of any final developmental scheme. Subsurface conditions not disclosed by the borings performed may occur, and could influence the suitability of the site for future development. Varying developmental schemes may alter the applicability of BET’s preliminary evaluations.

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Preliminary Geotechnical Study - Medical Examiner Facilities - Site A: VCME, Daytona Beach, Volusia County, Florida

G20013 Site A Preliminary Geotechnical Report - REVISED 03-26-20.wpd

2.0 SITE AND VICINITY CHARACTERISTICS

2.1 Site Location

The potential development area, hereinafter referred to as “project site” or “site”, is located within the southeastern portion of a +/-480 acre parcel of land, generally situated north of International

Speedway Boulevard (US Highway 92), west of Indian Lake Road and south of Tiger Bay Road, in Daytona Beach, Volusia County, Florida. The parcel is located in Section 01, Township 16

South, Range 31 East, and is centered near Latitude 29° 08' 24", Longitude -81° 09' 06". The project site is centered near Latitude 29° 08' 15", Longitude -81° 08' 43"

2.2 Regional Geology

The project site lies in Central Volusia County along the Talbot Terrace, a broad (8± mile wide) plain paralleling the Atlantic Ocean. The area is characterized by broad pine/palmetto flatwoods, interspersed with swamps and shallow hardwood depressional areas. Elevations throughout the plain are on the order of 40' National Geodetic Vertical Datum of 1929 (NGVD). Groundwater levels are generally within a few feet of ground surface, and in many areas rise above ground surface during wet periods.

Sediments of Pleistocene and Recent Age, consisting mostly of unconsolidated beds of sand and shell, blanket the area. In the site vicinity, these deposits extend to elevations on the order of 10'

NGVD. Underlying deposits are of Miocene or Pliocene Age, consisting mostly of beds of clay and shell. These deposits extend to elevations on the order of -40' NGVD, and act as confining/restrictive layers atop the underlying Ocala Group Limestones associated with the

Floridan Aquifer. Potentiometric surface level of the Floridan Aquifer in the site vicinity is estimated to be on the order of 30' NGVD. No evidence of Karst Topography, faults, or seismic activity exist in the immediate site vicinity.

2.3 Site Physical Characteristics

The project site consists of +/-3.5 acres of land, bounded by the Volusia County Correctional

Facility to the north, Volusia Regional Juvenile Detention Center to the south, vacant wooded land and a lake (borrow pit) to the east and vacant wooded land to the west. At the time of BET’s field study in March, 2020, the northern portion of the site was developed with buildings and parking areas associated with the existing Volusia County Medical Examiner’s office. The remainder of the site was heavily wooded with pine and hardwood trees with understory of palmetto, scrub and native grasses. In reference to Volusia County LiDAR mapping, the existing site elevations generally range from a high of about 43' North American Vertical Datum of 1988 (NAVD) in the developed northeastern portion of the site to a low of about 37' NAVD in the southwestern portion of the site.

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Preliminary Geotechnical Study - Medical Examiner Facilities - Site A: VCME, Daytona Beach, Volusia County, Florida

G20013 Site A Preliminary Geotechnical Report - REVISED 03-26-20.wpd

3.0 GEOTECHNICAL FIELD STUDY

3.1 Soil Borings

BET’s field study consisted of advancing four (4) Standard Penetration Test (SPT) borings (ASTM

D1586) to depth of 25 feet, and four (4) auger borings, to depths ranging from 4 to 6 feet below the ground surface existing at the time of drilling. Approximate locations of the borings are shown on the Boring Location Plan presented on Sheet A1 in Appendix A. Encountered subsurface conditions are presented in the form of Soil Profiles, along with Soil & Symbol Legend, on Sheet

A2 in Appendix A.

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Preliminary Geotechnical Study - Medical Examiner Facilities - Site A: VCME, Daytona Beach, Volusia County, Florida

G20013 Site A Preliminary Geotechnical Report - REVISED 03-26-20.wpd

4.0 ENCOUNTERED SUBSURFACE CONDITIONS

4.1 General Soil Conditions

In general, the borings conducted in the developed northern portion of the site encountered surficial asphalt pavement section (Stratum 1) and/or fill deposits comprised of slightly silty fine sands, some with trace shell (Stratum 2) extending to depths ranging from 14 to 24 inches below grade.

Throughout the remainder of the site, the surficial soils consisted of very loose/soft organic sand and silt [muck/peat] (Stratum 3). The surficial muck/peat deposits ranged from 12 to 45 inches in thickness, and were underlaid by loose to dense slightly silty sands (Stratum 4) to depths ranging from 6 to 9 feet. Underlying soils consisted of medium dense to very dense slightly silty to silty sands and fine sand to slightly silty sands (Strata 5 and 6), extending the deeper boring termination depths of 25 feet. For a more in-depth soil stratification, please refer to the Soil Profiles on Sheet

A2 in Appendix A.

4.2 Groundwater Conditions

Groundwater levels, as measured at the boring locations, were encountered at depths ranging from

0.1 to 5.3 feet below ground surface. In reference to approximate ground surface elevations at the boring locations, the corresponding groundwater elevation appeared to be on the order of 37'

NAVD. BET notes that groundwater levels are subject to variation due to seasonal climate changes and man-induced influences. Average seasonal high groundwater levels are estimated to be about 12 inches above the encountered levels, or about elevation 38' NAVD.

4.3 Soil Permeability / Hydraulic Conductivity

Generally, the site’s soils are considered to be poorly drained to very poorly drained organic and sandy soils. BET’s experience with similar soils in the region suggests that the permeability / hydraulic conductivity rates are moderate in the upper 6 to 9 feet, and moderately low to low in the underlying subsoil.

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Preliminary Geotechnical Study - Medical Examiner Facilities - Site A: VCME, Daytona Beach, Volusia County, Florida

G20013 Site A Preliminary Geotechnical Report - REVISED 03-26-20.wpd

5.0 PRELIMINARY GEOTECHNICAL EVALUATIONS

5.1 Soils Suitability and Stability

Although not encountered by the borings performed, surficial topsoil materials containing appreciable quantities of roots and organic matter may exist in some areas within the developed northern portion of the site. If present, surficial topsoils should be stripped from all structural areas during standard clearing and grubbing operations. Results of the borings performed do indicate that surficial muck/peat deposits (Stratum 3), ranging from 12 to 45 inches in thickness, are present throughout much of the remainder of the site. Where present, structural areas, plus suitable margins beyond, should be demucked to depth sufficient to remove muck deposits in their entirety.

In general, the existing subgrade soils are granular in nature and should generally be suitable for use as foundation and pavement section subgrade and as structural fill, pending adequate degrees of compaction. BET cautions that existing surficial soils which become saturated, and materials excavated from below groundwater level may retain excess water and therefore be difficult to compact, unless allowed to sufficiently drain prior to placement and/or compaction. The subgrade soils should provide for stable embankments with slopes as steep as 2 horizontal to 1 vertical (2:1).

5.2 Site Grading

Encountered and estimated seasonal high groundwater levels suggest that most areas of the site may need to be raised 1 to 3 feet, or more, to allow for construction of structures and pavement sections. Fill materials used to raise the site to desired finish grades should consist of clean, granular soils with less than 15% passing No. 200 U.S. Standard Sieve. Generally, it appears that soils excavated from stormwater retention ponds or other areas of the site, except for surficial organic topsoils and muck, should be suitable for use as structural fill in building and pavement areas. BET cautions that materials excavated from below groundwater level may retain excess water and therefore be difficult to compact, unless allowed to sufficiently drain prior to placement.

5.3 Foundations

Based on the results of this preliminary study, BET envisions that suitable support of buildings should be attainable with conventional shallow foundations, proportioned for allowable soil bearing pressures in the range of 2,000 to 2,500 PSF. However, actual foundation recommendations would be dependant on several earthwork considerations including adequate clearing of vegetation and stripping of surface organics, demucking where applicable, and compaction of subgrade and structural fill soils.

Anticipated depth of stripping/demucking necessary to remove organic topsoils and muck/peat deposits is 1 to 4 feet. The required depth and degree of soils compaction would be dependent

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Preliminary Geotechnical Study - Medical Examiner Facilities - Site A: VCME, Daytona Beach, Volusia County, Florida

G20013 Site A Preliminary Geotechnical Report - REVISED 03-26-20.wpd on design grading and structural loading characteristics. BET envisions that the required depth of subgrade soils compaction would be on the order of one foot, while the required degree of compaction may be in the range of 95% to 98% of the materials Modified Proctor (ASTM D-1557) maximum dry density. Fill soils should be placed in loose lifts of about 8 to 16 inches and compacted to a similar degree.

The suitability of conventional shallow foundations would also be dependent on the potential degrees of foundation settlement which might be expected. Provided building areas are adequately stripped/demucked of organic topsoils and muck/peat deposits, and provided that adequate degrees of foundation subgrade soils compaction are achieved, BET envisions that total and differential foundation settlements can be kept well within typical tolerable limits of one-half inch and one-quarter inch, respectively.

5.4 Pavement Sections

BET envisions that suitable pavement sections should be attainable with either asphaltic concrete surface course over limerock or crushed concrete base and stabilized subgrade (LBR 40), or

Portland Cement concrete over stabilized subgrade (LBR 30). Required pavement section layer thicknesses would be dependent on anticipated vehicle frequencies and wheel loadings. For asphalt pavement sections, BET envisions minimum asphalt thickness of 1.5 inches, minimum base thickness of 6 inches, and minimum stabilized subgrade thickness of 6 inches. Minimum concrete thickness is envisioned to be 6 inches over minimum stabilized subgrade thickness of 8 inches.

The suitability of asphalt pavement sections constructed with limerock base course would be dependent on design finish pavement grades. If limerock base is desirable, it is recommended that finish pavement grades be set a minimum of 24 inches above seasonal high groundwater level.

If lower finish grades are anticipated, the use of soil-cement base or crushed concrete base in lieu of limerock should be considered.

5.5 Stormwater Retention

Considering the potential for seasonal high groundwater levels near existing ground surface, and the anticipated moderate to low permeability of subsurface soils, BET envisions that the most effective means of stormwater management would likely be through the use of wet retention / detention ponds. Depending upon finish grades and the characteristics of fill soils used, small isolated dry retention ponds may work in some areas of the site.

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APPENDIX A

BORING LOCATION PLAN

SOIL PROFILES

SOILS LEGEND