Geotechnical_Report.pdf

GEOTECHNICAL

REPORT

REPORT COVER PAGE

Geotechnical Engineering Report

Potable Water Looping Project Sarasota County, Florida

August 25, 2021 Terracon Project No. HC205099

Prepared for:

McKim & Creed

Sarasota, FL

Prepared by:

Terracon Consultants, Inc.

Sarasota, Florida

Terracon Consul tants, Inc. 8260 Vico Court , Uni t B Sarasota, F lor ida 34240 P (941) 379 0621 F (941) 379 5061 terracon.com

REPORT COVER LETTER TO SIGN

August 25, 2021

McKim & Creed 551 North Cattlemen Road, Suite 106 Sarasota, FL 34232

Attn: Mr. Blake Peters, P.E.

P: (941) 379-3404 E: bpeters@mckimcreed.com

Re: Geotechnical Engineering Report Potable Water Looping Project South Tamiami Trail & South Jackson Road Sarasota County, Florida Terracon Project No. HC205099

Dear Mr. Peters:

We have completed the Geotechnical Engineering services for the above referenced project. This study was performed in general accordance with Terracon Proposal No. PHC205099 dated December 22, 2020 and authorized on July 27, 2021. This report presents the findings of the subsurface exploration and provides geotechnical recommendations concerning the planned pipeline construction.

We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this report or if we may be of further service, please contact us.

Sincerely, Terracon Consultants, Inc.

James M. Jackson, P.E. Douglas S. Dunkelberger, P.E.

Department Manager Principal FL License No. 77733 FL License No. 33317

This item has been digitally signed and sealed by James M. Jackson, P.E. on the date adjacent to the seal.

Printed copies of this document are not considered signed and sealed and the signature must be verified on any electronic copies.

Responsive ■ Resourceful ■ Reliable 1

REPORT TOPICS

INTRODUCTION

SITE CONDITIONS

PROJECT DESCRIPTION

GEOTECHNICAL CHARACTERIZATION

GEOTECHNICAL OVERVIEW

LATERAL EARTH PRESSURES

TRENCH BACKFILL RECOMMENDATIONS

GENERAL COMMENTS

FIGURES

Note: This report was originally delivered in a web-based format. Orange Bold text in the report indicates a referenced section heading. The PDF version also includes hyperlinks which direct the reader to that section and clicking on the GeoReport logo will bring you back to this page. For more interactive features, please view your project online at client.terracon.com.

ATTACHMENTS

EXPLORATION AND TESTING PROCEDURES

SITE LOCATION AND EXPLORATION PLANS

EXPLORATION RESULTS

SUPPORTING INFORMATION

Note: Refer to each individual Attachment for a listing of contents.

http://client.terracon.com/

Responsive ■ Resourceful ■ Reliable 1

INTRODUC TION

Geotechnical Engineering Report Potable Water Looping Project

South Tamiami Trail & South Jackson Road Sarasota County, Florida Terracon Project No. HC205099

August 25, 2021

INTRODUCTION

This report presents the results of our subsurface exploration and geotechnical engineering services performed for the proposed new potable water pipe to be located at various locations along South Tamiami Trail & South Jackson Road in Sarasota County, Florida. The purpose of these services is to provide information and geotechnical engineering recommendations relative to:

■ Subsurface soil and rock conditions ■ Soil parameters for HDD design

■ Groundwater conditions ■ Site preparation and earthwork

■ Dewatering considerations

The geotechnical engineering Scope of Services for this project called for the advancement of four test borings to depths of approximately 20 feet below existing site grades.

Maps showing the site and boring locations are shown in the Site Location and Exploration Plan sections, respectively. The results of the laboratory testing performed on soil samples obtained from the site during the field exploration are included on the boring logs in the Exploration Results section.

SITE CONDITIONS

The following description of site conditions is derived from our site visit in association with the field exploration and our review of publicly available geologic and topographic maps.

Item Description

Parcel Information

The project is located in Sarasota County, Florida at the following locations:

■ South Tamiami Trail at Reynolds Street

■ South Tamiami Trail at Buccaneer Drive

■ South Tamiami Trail at Cass Street

■ South Jackson Road

See Site Location

Potable Water Looping Project ■ Sarasota County, Florida August 25, 2021 ■ Terracon Project No. HC205099

Responsive ■ Resourceful ■ Reliable 2

Item Description

Existing Improvements

Existing roadways with grass shoulders. We understand there is an active petroleum cleanup site at the intersection of South Tamiami Trail and Reynolds Street. However, we have not completed an environmental assessment of this area and recommendations for addressing potentially contaminated groundwater during construction dewatering have not been included.

Current Ground Cover Short grasses

Surficial Soil Conditions

Review of the Web Soil Survey indicates the site is mapped with Soil Unit 55, EauGallie-Myakka fine sands-Urban land complex and Unit 70, Pomello fine sand-Urban land complex. Urban land generally consists of areas that have been disturbed by earthmoving activities. The typical native soil profile of the EauGallie-Myakka fine sands consists of fine sand to a depth of about 48 inches followed by either sandy loam or fine sand to a depth of 80 inches or more. The Pomello soils typically consist of fine sand to a depth of 80 inches or more. Under natural (pre-development) conditions, the seasonal high groundwater levels (SHGWLs) for these soil units is reported to be between 6 and 40 inches below the ground surface (bgs).

Additionally, our experience near the vicinity of the proposed site indicates that subsurface conditions will likely consist of sands with varying amounts of silt and clay from the surface to a depth of about 10 to 20 feet followed by soft to hard limestone to a depth of about 30 feet. Groundwater is expected to be within 5 feet of the ground surface.

PROJECT DESCRIPTION

Our final understanding of the project conditions is as follows:

Item Description

Information Provided The following information was provided by you via e-mail on December 14, 2020.

Project Description The project includes the design of new potable water main piping.

Grading/Slopes Existing site grades to be maintained.

Below-Grade Structures

Approximately 3,500 linear feet of 6, 8, and 12-inch diameter new potable water main pipe is planned. We understand the pipe is to either be shallow (i.e. less than 5 feet below the ground surface) and installed by cut-and-cover construction or deeper (between 10 to 15 feet bgs) and installed by horizontal directional drilling (HDD).

August 25, 2021 ■ Terracon Project No. HC205099

Responsive ■ Resourceful ■ Reliable 3

GEOTECHNICAL CHARACTERIZATION

We have developed a general characterization of the subsurface conditions based upon our review of the subsurface exploration, laboratory data, geologic setting and our understanding of the project. This characterization, termed GeoModel, forms the basis of our geotechnical calculations and evaluation of site preparation and foundation options. Conditions encountered at each exploration point are indicated on the individual logs. The individual logs can be found in the Exploration Results section and the GeoModel can be found in the Figures section of this report.

As part of our analyses, we identified the following model layers within the subsurface profile. For a more detailed view of the model layer depths at each boring location, refer to the GeoModel.

Model Layer Layer Name General Description 1 Sand Poorly graded sand with silt (SP-SM), very loose to medium dense 2 Clayey Sand Clayey sand (SC), loose to medium dense

3 Limestone Formation

Limestone, soft to hard1, recovered in the split spoon sampler as calcareous silt or silty sand with limestone gravel

1. Soft limestone refers to material containing limestone or limerock fragments with SPT N-values less than or equal to 50 blows per foot (ref. Florida Department of Transportation Soils and Foundations Handbook, 2020). Hard limestone corresponds to N-values > 50 blows per foot.

The description of “relative hardness” should not be applied to constructability items such as excavating, pile driving and/or pile augering.

It should be noted that the “soft Limestone” designation does not necessarily mean that the limestone will be easy to excavate and/or drill as part of the construction activities. Difficult excavation/drilling should be anticipated throughout the limestone layer.

Additionally, boring B-4 had 100 percent loss of drilling fluid circulation from about 16 to 18 feet bgs. Drilling fluid loss is indicative of fissures or voids in cemented soils or rock formations and is a usual occurrence near the top and within the natural limestone formation. Our experience indicates that such voids/fissures are localized, small, and not detrimental to the global structure (strength) of the formation.

Groundwater

Groundwater was found at depths ranging from about 4 to 6 feet bgs while sampling. Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff and other factors not evident at the time the borings were performed. Therefore, groundwater levels during construction or at other times in the life of the structure may be higher or lower than the levels indicated on the boring logs. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project.

August 25, 2021 ■ Terracon Project No. HC205099

Responsive ■ Resourceful ■ Reliable 4

If more accurate groundwater data is desired, we recommend the installation of piezometers that could be monitored over a period of time.

GEOTECHNICAL OVERVIEW

In general, the borings found very loose to medium dense poorly graded fine sand with silt and clayey sand from the surface followed by soft to hard limestone beginning at a depth of 14 feet and extending to the maximum borehole termination depth of 20 feet bgs. Based on the planned maximum HDD depth of about 15 feet, typical HDD construction procedures should generally be sufficient for the installation of the new force main piping although encountering a limestone formation is likely at the deeper depths. The top of the limestone could vary somewhat from the depth shown in the borings which were relatively few and widely spaced and therefore the HDD contractor should be prepared to drill through hard limestone. Drilling fluid circulation losses should also be anticipated and adequately planned for if drilling near and/or through the limestone.

The Lateral Earth Pressures section provides soil parameters for design of below-grade structures.

The Trench Backfill Recommendations section addresses recommendations for backfilling trenches associated with the planned construction.

The General Comments section provides an understanding of the report limitations.

August 25, 2021 ■ Terracon Project No. HC205099

Responsive ■ Resourceful ■ Reliable 5

LATERAL EARTH PRESSURES

Design Parameters

The soil parameters shown in the following tables are based on empirical correlations with SPT blow counts (N-values) and should be utilized for the design of HDD construction.

In estimating shear modulus values, an empirical formula (Coduto, 2001) was used to relate the elastic modulus to both N-value and soil type. For the granular and limestone soils, we assumed drained conditions and assigned Poisson’s ratios of 0.1 for loose soils, 0.2 for medium dense soils, and 0.3 for dense soils (Rowe, 2000).

Boring B-1

GeoModel Layer USCS

Depth (ft, bgs)

SPT

N-Values

Total Weight

(pcf)

Submerged Weight

(pcf)

Friction Angle (phi)1

Cohesion (psf)2

Coefficients

Active (Ka)

Passive (Kp)

At-Rest (K0)

1 SP-SM 0 to 4 N/A 105 43 30 0 0.333 3.00 0.500

1 SP-SM 4 to 8 2 to 3 100 38 28 0 0.361 2.77 0.531

1 SP-SM 8 to 10 5 105 43 30 0 0.333 3.00 0.500

1, 2 SP-SM 10 to 12 12 110 48 31 0 0.320 3.12 0.485 2 SC 12 to 17 18 to 20 110 48 30 0 0.333 3.00 0.500 3 LS 17 to 20 50+ 135 73 0 12,000 1.00 1.00 1.00

1. Based on Florida Department of Transportation Soils and Foundations Handbook (2020)

2. Based on Essentials of Soil Mechanics and Foundations, 7th Edition by David F. McCarthy

Estimated shear modulus values based on depth are also provided in the following table.

Depth (feet) U.S.C.S. Relative Density Average Shear Modulus, G (psf) Range Average

0 to 4 SP-SM Not Measured 100,000 100,000 100,000 4 to 8 SP-SM Very Loose 67,000 78,000 72,500

8 to 10 SP-SM Loose 100,000 100,000 100,000 10 to 12 SP-SM Medium Dense 162,000 162,000 162,000

12 to 17 SC Medium Dense 111,000 121,000 116,000 17 to 20 LS Hard 962,000 962,000 962,000

August 25, 2021 ■ Terracon Project No. HC205099

Responsive ■ Resourceful ■ Reliable 6

Boring B-2

GeoModel Layer USCS

Depth (ft, bgs)

SPT

N-Values

Total Weight

(pcf)

Submerged Weight

(pcf)

Friction Angle (phi)1

Cohesion (psf)2

Coefficients

Active (Ka)

Passive (Kp)

At-Rest (K0)

1 SP-SM 0 to 4 N/A 105 43 30 0 0.333 3.00 0.500

2 SP-SM 4 to 12 9 to 11 110 48 31 0 0.320 3.12 0.485

2 SC 12 to 14 18 110 48 30 0 0.333 3.00 0.500

2 SP-SM 14 to 16 7 105 43 30 0 0.333 3.00 0.500

3 LS 16 to 20 50+ 135 73 0 12,000 1.00 1.00 1.00

1. Based on Florida Department of Transportation Soils and Foundations Handbook (2020)

2. Based on Essentials of Soil Mechanics and Foundations, 7th Edition by David F. McCarthy

Estimated shear modulus values based on depth are also provided in the following table.

Depth (feet) U.S.C.S. Relative Density Average Shear Modulus, G (psf) Range Average

0 to 4 SP-SM Loose 100,000 100,000 100,000

4 to 12 SC Loose to Medium Dense 142,000 152,000 145,500

12 to 14 SC Medium Dense 111,000 111,000 111,000 14 to 16 SC Very Loose 122,000 122,000 122,000 16 to 20 LS Hard 962,000 962,000 962,000

August 25, 2021 ■ Terracon Project No. HC205099

Responsive ■ Resourceful ■ Reliable 7

Boring B-3

GeoModel Layer USCS

Depth (ft, bgs)

SPT

N-Values

Total Weight

(pcf)

Submerged Weight

(pcf)

Friction Angle (phi)1

Cohesion (psf)2

Coefficients

Active (Ka)

Passive (Kp)

At-Rest (K0)

1 SP-SM 0 to 6 N/A to 5 105 43 30 0 0.333 3.00 0.500

2 SC 6 to 8 10 110 48 28 0 0.361 2.77 0.531

2 SC 8 to 10 24 110 48 30 0 0.333 3.00 0.500

2 SC 10 to 14 3 to 4 100 38 26 0 0.390 2.56 0.562

3 LS 14 to 16 10 135 73 0 4,000 1.00 1.00 1.00

3 LS 16 to 18 50+ 135 73 0 12,000 1.00 1.00 1.00 3 LS 18 to 20 33 135 73 0 8,000 1.00 1.00 1.00

3. Based on Florida Department of Transportation Soils and Foundations Handbook (2020)

4. Based on Essentials of Soil Mechanics and Foundations, 7th Edition by David F. McCarthy

Estimated shear modulus values based on depth are also provided in the following table.

Depth (feet) U.S.C.S. Relative Density Average Shear Modulus, G (psf) Range Average

0 to 6 SP-SM Loose 100,000 100,000 100,000 6 to 8 SC Medium Dense 71,000 71,000 71,000

8 to 10 SC Medium Dense 141,000 141,000 141,000 10 to 14 SC Very Loose 39,000 45,000 42,000 14 to 16 LS Soft 142,000 142,000 142,000 16 to 18 LS Hard 962,000 962,000 962,000 18 to 20 LS Soft 372,000 372,000 372,000

August 25, 2021 ■ Terracon Project No. HC205099

Responsive ■ Resourceful ■ Reliable 8

Boring B-4

GeoModel Layer USCS

Depth (ft, bgs)

SPT

N-Values

Total Weight

(pcf)

Submerged Weight

(pcf)

Friction Angle (phi)1

Cohesion (psf)2

Coefficients

Active (Ka)

Passive (Kp)

At-Rest (K0)

1 SP-SM 0 to 4 N/A to 6 105 43 30 0 0.333 3.00 0.500

1 SP-SM 4 to 6 14 110 48 31 0 0.320 3.12 0.485

1 SP-SM 6 to 12 5 to 11 105 43 30 0 0.333 3.00 0.500

1 SP-SM 12 to 16 3 to 4 100 38 28 0 0.361 2.77 0.531

3 LS 16 to 20 50+ 135 73 0 12,000 1.00 1.00 1.00

1. Based on Florida Department of Transportation Soils and Foundations Handbook (2020)

2. Based on Essentials of Soil Mechanics and Foundations, 7th Edition by David F. McCarthy

Estimated shear modulus values based on depth are also provided in the following table.

Depth (feet) U.S.C.S. Relative Density Average Shear Modulus, G (psf) Range Average

0 to 4 SP-SM Loose 100,000 111,000 105,500 4 to 6 SP-SM Medium Dense 182,000 182,000 182,000 6 to 12 SP-SM Very Loose 100,000 152,000 124,500

12 to 16 SP-SM Very Loose 78,000 89,000 83,500 16 to 20 LS Hard 962,000 962,000 962,000

TRENCH BACKFILL RECOMMENDATIONS

n Any open trench (excavation) areas should be accomplished in the dry (i.e. not in saturated or submerged conditions). Dewatering to a depth of 2 feet below the bottom of all excavations should be performed prior to placement of backfill materials.

n Should the excavation bottom become unstable due to persistent moisture or hydrostatic pressure, the bottom should be “over-excavated” a minimum of 12 inches (deep) and replaced with clean gravel (FDOT No. 57 Stone) that is wrapped on all sides with a filter fabric.

n Backfill below the existing water level at the time of construction should consist of relatively clean sands or gravels, with a maximum of 15% passing the U.S. No. 200 sieve and no particle size larger than 1 inch in any dimension. Backfill above the existing water level at the time of construction should consist of sands or gravels with particle sizes of less than 1 inch in any dimension, no more than 35 percent fines, and of low plasticity (i.e. Liquid Limit less than 40 and Plasticity Index less than 10). The fill should be placed in the dry

August 25, 2021 ■ Terracon Project No. HC205099

Responsive ■ Resourceful ■ Reliable 9 in lifts that do not exceed 12 inches in vertical measure. Each lift should be compacted to at least 95% of the Modified Proctor maximum dry density (ASTM D-1557). Backfill in pavement areas should be compacted to at least 98% density (ASTM D-1557).

n The GeoModel Layer 1 soils should generally meet the backfill gradation requirements of a maximum of 15% passing the U.S. No. 200 sieve. The GeoModel Layer 2 soils generally do not meet the plasticity requirements for re-use as backfill and would need to be replaced with a low-plasticity fill if encountered.

n As a minimum, all temporary excavations should be sloped or braced as required by Occupational Health and Safety Administration (OSHA) regulations to provide stability and safe working conditions. Temporary excavations will probably be required during pipe installation operations. The utility contractor, by contract, is usually responsible for designing and constructing stable, temporary excavations and should shore, slope, or bench the sides of the excavations, as required, to maintain stability of both the excavation sides and bottom. All excavations should comply with applicable local, state, and federal safety regulations including the current OSHA Excavation and Trench Safety Standards.

Temporary Dewatering

Dewatering will be needed to facilitate earthwork and underground construction operations for this project. The necessity for dewatering will be dependent on the depth of excavation below existing grade and the groundwater levels at the time of construction. Actual dewatering “means and methods” should be left up to a contractor experienced in installation and operation of dewatering systems. The contractor should provide a dewatering plan for review and approval by the engineer prior to the installation of the dewatering systems.

Also, the dewatering plan should consider the potential impact of lowered groundwater (i.e.

increased vertical stress on subsoils which could trigger settlement) on nearby, existing construction. Furthermore, the dewatering plan may need to address areas of known (i.e.

documented) groundwater contamination within the project limits.

GENERAL COMMENTS

Our analysis and opinions are based upon our understanding of the project, the geotechnical conditions in the area, and the data obtained from our site exploration. Natural variations will occur between exploration point locations or due to the modifying effects of construction or weather.

The nature and extent of such variations may not become evident until during or after construction.

Terracon should be retained as the Geotechnical Engineer, where noted in this report, to provide observation and testing services during pertinent construction phases. If variations appear, we can provide further evaluation and supplemental recommendations. If variations are noted in the absence of our observation and testing services on-site, we should be immediately notified so that we can provide evaluation and supplemental recommendations.

August 25, 2021 ■ Terracon Project No. HC205099

Responsive ■ Resourceful ■ Reliable 10

Our Scope of Services does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken.

Our services and any correspondence or collaboration through this system are intended for the sole benefit and exclusive use of our client for specific application to the project discussed and are accomplished in accordance with generally accepted geotechnical engineering practices with no third-party beneficiaries intended. Any third-party access to services or correspondence is solely for information purposes to support the services provided by Terracon to our client.

Reliance upon the services and any work product is limited to our client, and is not intended for third parties. Any use or reliance of the provided information by third parties is done solely at their own risk. No warranties, either express or implied, are intended or made.

Site characteristics as provided are for design purposes and not to estimate excavation cost. Any use of our report in that regard is done at the sole risk of the excavating cost estimator as there may be variations on the site that are not apparent in the data that could significantly impact excavation cost. Any parties charged with estimating excavation costs should seek their own site characterization for specific purposes to obtain the specific level of detail necessary for costing.

Site safety, and cost estimating including, excavation support, and dewatering requirements/design are the responsibility of others. If changes in the nature, design, or location of the project are planned, our conclusions and recommendations shall not be considered valid unless we review the changes and either verify or modify our conclusions in writing.

Responsive ■ Resourceful ■ Reliable

FIGURES

Contents:

GeoModel

D E

P T

H B

E L

O W

G R

A D

E

F ee

t) Sarasota Potable Water Looping Project Sarasota, FL Terracon Project No. HC205099

Layering shown on this figure has been developed by the geotechnical engineer for purposes of modeling the subsurface conditions as required for the subsequent geotechnical engineering for this project.

Numbers adjacent to soil column indicate depth below ground surface.

NOTES:

B-1 B-2 B-3 B-4

GEOMODEL

This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions.

Groundwater levels are temporal. The levels shown are representative of the date and time of our exploration. Significant changes are possible over time.

Water levels shown are as measured during and/or after drilling. In some cases, boring advancement methods mask the presence/absence of groundwater. See individual logs for details.

First Water Observation

Limestone, soft to hard, recovered in the split spoon sampler as calcareous silt or silty sand with limestone gravel3

LEGEND

Poorly-graded Sand with Silt

Clayey Sand

Weathered Limestone

Model Layer General DescriptionLayer Name

Poorly graded sand with silt (SP-SM), very loose to medium dense1

Clayey sand (SC), loose to medium dense2

Limestone Formation

Sand

Clayey Sand

18.3

18.2

18.1

ATTACHMENTS

August 25, 2021 ■ Terracon Project No. HC205099

Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 1 of 2

EXPLORATION AND TESTING PROCEDURES

Field Exploration

Number of Borings Boring Depth (feet) Location

4 20 See Exploration Plan

Boring Layout and Elevations: Unless otherwise noted, Terracon personnel provided the boring layout. Coordinates were obtained with a handheld GPS unit (estimated horizontal accuracy of about ±10 feet). If elevations and a more precise boring layout are desired, we recommend borings be surveyed following completion of fieldwork.

Subsurface Exploration Procedures: We advanced the borings with a track-mounted rotary drill rig using mud rotary procedures. Samples were obtained continuously at 2-foot intervals throughout the depth of the borings. In the split-barrel sampling procedure, a standard 2-inch outer diameter split-barrel sampling spoon was driven into the ground by a 140-pound rope and cathead operated safety hammer falling a distance of 30 inches. The number of blows required to advance the sampling spoon the last 12 inches of a normal 18-inch penetration or the middle 12 inches of a 24-inch penetration is recorded as the Standard Penetration Test (SPT) resistance value. The SPT resistance values, also referred to as N-values, are indicated on the boring logs at the test depths. A split-barrel sampling spoon was used for sampling. We observed and recorded groundwater levels during drilling. All borings were backfilled with cement grout at their completion.

The sampling depths, penetration distances, and other sampling information was recorded on the field boring logs. The samples were placed in appropriate containers and taken to our soil laboratory for testing and classification by a Geotechnical Engineer. Our exploration team prepared field boring logs as part of the drilling operations. These field logs included visual classifications of the materials encountered during drilling and our interpretation of the subsurface conditions between samples. Final boring logs were prepared from the field logs. The final boring logs represent the Geotechnical Engineer's interpretation of the field logs and include modifications based on observations and tests of the samples in our laboratory.

Laboratory Testing

The project engineer reviewed the field data and assigned laboratory tests to understand the engineering properties of the various soil strata, as necessary, for this project. Procedural standards noted below are for reference to methodology in general. In some cases, variations to methods were applied because of local practice or professional judgment. Standards noted below include reference to other, related standards. Such references are not necessarily applicable to describe the specific test performed.

August 25, 2021 ■ Terracon Project No. HC205099

Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 2 of 2

■ ASTM D2216 Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass

■ ASTM D1140-17 Standard Test Method for Amount of Material in Soils Finer than No. 200 (75-μm) Sieve)

Our laboratory testing program also includes examination of soil samples by an engineer. Based on observation and test data, the engineer classified the soil samples in accordance with the Unified Soil Classification System (ASTM D2487).

SITE LOCATION AND EXPLORATION PLANS

Contents:

Site Location Plans (2 pages) Exploration Plans (2 pages)

SITE LOCATION

August 25, 2021 ■ Terracon Project No. HC205099

SITE LOCA TION POR TRAI T

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS

SITE LOCATION

August 25, 2021 ■ Terracon Project No. HC205099

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS

EXPLORATION PLAN

August 25, 2021 ■ Terracon Project No. HC205099

EXPLORATION P LAN PORTRAI T

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS

Petroleum clean-up site

EXPLORATION PLAN

August 25, 2021 ■ Terracon Project No. HC205099

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS

S.Jackson R oad

EXPLORATION RESULTS

Boring Logs (B-1 through B-4)

1-1-1-1 N=2

2-2-1-2 N=3

2-2-3-4 N=5

2-4-8-7 N=12

7-8-10-11 N=18

13-10-10-10 N=20

14-21-50/3"

50/3"

1515.7

POORLY GRADED SAND WITH SILT (SP-SM), fine grained, brown to light brown to light gray, very loose to medium dense

CLAYEY SAND (SC), fine grained, gray, medium dense

- with sand-sized phosphate grains

LIMESTONE, with sand-sized phosphate grains, light brown, hard, recovered as calcareous silt

Boring Terminated at 18.3 Feet

12.0

17.0

18.3

Begin mud rotary at 10 feet

Hand augered to 4 feet due to close proximity of buried utilities.

Hammer Type: Rope and CatheadStratification lines are approximate. In-situ, the transition may be gradual.

T H

IS

B

O R

IN

G

L O

G

IS

N O

T V

A

LI

D

IF

S E

P A

R A

T E

D F

R O

M O

R

IG

IN

A

L R

E P

O R

T

G E

O S

M A

R T

L O

G -N

O W

E

LL

H C

S

A R

A S

O T

A P

O T

A B

LE

.G

P J

T E

R R

A C

O N

_D A

T A

T E

M P

LA

T

E .G

D T

/2

4/

W A

T E

R L

E V

E L

O B

S E

R V

A T

IO

N

S

D E

P T

H

F t.)

F

IE

LD

T E

S T

R E

S U

LT

S

P E

R C

E N

T F

IN

E

S

W A

T E

R C

O N

T E

N T

)LOCATION See Exploration Plan

Latitude: 27.2560° Longitude: -82.5181°

G R

A P

H

IC

L O

G

M O

D E

L

LA

Y E

R

DEPTH

Advancement Method:

Mud rotary Continuous sampling for entire depth

Abandonment Method:

Boring backfilled with cement grout upon completion

Notes:

Project No.: HC205099

Drill Rig: BR 2500

BORING LOG NO. B-1

McKim & CreedCLIENT:

Sarasota, FL

Driller: S.D.

Boring Completed: 08-05-2021

PROJECT: Sarasota Potable Water Looping Project

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

Vaires Sarasota, FL

SITE:

Boring Started: 08-05-2021

8260 Vico Ct, Unit B Sarasota, FL

At 4' while sampling

WATER LEVEL OBSERVATIONS

S A

M P

LE

T

Y P

E

2-4-5-6 N=9

5-5-5-7 N=10

2-4-7-7 N=11

1-4-5-7 N=9

7-9-9-10 N=18

3-3-4-5 N=7

35-50/2"

50/2"

POORLY GRADED SAND WITH SILT (SP-SM), fine grained, brown to gray, medium dense

CLAYEY SAND (SC), fine grained, gray, medium dense

POORLY GRADED SAND WITH SILT (SP-SM), with sand-sized phosphate grains, fine grained, gray, loose

LIMESTONE, light brown, hard, recovered as silty sand with limestone gravel

Boring Terminated at 18.2 Feet

12.0

14.0

16.0

18.2

Begin mud rotary at 10 feet

Hand augered to 4 feet due to close proximity of buried utilities.

Hammer Type: Rope and CatheadStratification lines are approximate. In-situ, the transition may be gradual.

T H

IS

B

O R

IN

G

L O

G

IS

N O

T V

A

LI

D

IF

S E

P A

R A

T E

D F

R O

M O

R

IG

IN

A

L R

E P

O R

T

G E

O S

M A

R T

L O

G -N

O W

E

LL

H C

S

A R

A S

O T

A P

O T

A B

LE

.G

P J

T E

R R

A C

O N

_D A

T A

T E

M P

LA

T

E .G

D T

/2

4/

W A

T E

R L

E V

E L

O B

S E

R V

A T

IO

N

S

D E

P T

H

F t.)

F

IE

LD

T E

S T

R E

S U

LT

S

P E

R C

E N

T F

IN

E

S

W A

T E

R C

O N

T E

N T

)LOCATION See Exploration Plan

Latitude: 27.2522° Longitude: -82.5147°

G R

A P

H

IC

L O

G

M O

D E

L

LA

Y E

R

DEPTH

Advancement Method:

Mud rotary Continuous sampling for entire depth

Abandonment Method:

Boring backfilled with cement grout upon completion

Notes:

Project No.: HC205099

Drill Rig: BR 2500

BORING LOG NO. B-2

McKim & CreedCLIENT:

Sarasota, FL

Driller: S.D.

Boring Completed: 08-20-2021

PROJECT: Sarasota Potable Water Looping Project

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

Vaires Sarasota, FL

SITE:

Boring Started: 08-20-2021

8260 Vico Ct, Unit B Sarasota, FL

At 8' while sampling

WATER LEVEL OBSERVATIONS

S A

M P

LE

T

Y

POORLY GRADED SAND WITH SILT (SP-SM), fine grained, brown, loose

CLAYEY SAND (SC), fine grained, light brown to gray, loose to medium dense

LIMESTONE, light brown to gray, soft to hard, recovered as calcareous silt with limestone gravel

- hard drilling from 18 to 18.5 feet

Boring Terminated at 20 Feet

6.0

14.0

20.0

2-2-3-5 N=5

4-3-7-16 N=10

9-14-10-6 N=24

3-2-2-1 N=4

1-1-2-2 N=3

14-7-3-2 N=10

50/2.5"

9-15-18-7 N=33

21.6

33.4

Begin mud rotary at 10 feet

Hand augered to 4 feet due to close proximity of buried utilities.

Hammer Type: Rope and CatheadStratification lines are approximate. In-situ, the transition may be gradual.

T H

IS

B

O R

IN

G

L O

G

IS

N O

T V

A

LI

D

IF

S E

P A

R A

T E

D F

R O

M O

R

IG

IN

A

L R

E P

O R

T

G E

O S

M A

R T

L O

G -N

O W

E

LL

H C

S

A R

A S

O T

A P

O T

A B

LE

.G

P J

T E

R R

A C

O N

_D A

T A

T E

M P

LA

T

E .G

D T

/2

4/

W A

T E

R L

E V

E L

O B

S E

R V

A T

IO

N

SSee Exploration Plan

Latitude: 27.2496° Longitude: -82.5131°

G R

A P

H

IC

L O

G

M O

D E

L

LA

Y E

R

DEPTH

Advancement Method:

Mud rotary Continuous sampling for entire depth

Abandonment Method:

Boring backfilled with cement grout upon completion

Notes:

Project No.: HC205099

Drill Rig: BR 2500

BORING LOG NO. B-3

McKim & CreedCLIENT:

Sarasota, FL

Driller: S.D.

Boring Completed: 08-05-2021

D E

P T

H

F t.)

F

IE

LD

T

E S

T R

E S

U

LT

S

P E

R C

E N

T F

IN

E

S

W A

T E

R C

O N

T E

N T

)LOCATION

PROJECT: Sarasota Potable Water Looping Project

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

Vaires Sarasota, FL

SITE:

Boring Started: 08-05-2021

8260 Vico Ct, Unit B Sarasota, FL

At 4' while sampling

WATER LEVEL OBSERVATIONS

S A

M P

LE

T

Y

2-3-3-4 N=6

9-8-6-5 N=14

3-3-2-2 N=5

4-4-3-2 N=7

4-5-6-6 N=11

3-2-2-2 N=4

3-2-1-2 N=3

20-50/1.5"

50/0.5"

POORLY GRADED SAND WITH SILT (SP-SM), fine grained, brown to gray, loose to medium dense

- with gravel-sized shell fragments

LIMESTONE, light brown to gray, hard, 100% loss of drilling fluid circulation from 16 to 18 feet, recovered as silty sand with limestone gravel, hard drilling from 17 to 18 feet

Boring Terminated at 18.1 Feet

16.0

18.1

Begin mud rotary at 10 feet

Hand augered to 2 feet due to close proximity of buried utilities.

Hammer Type: Rope and CatheadStratification lines are approximate. In-situ, the transition may be gradual.

T H

IS

B

O R

IN

G

L O

G

IS

N O

T V

A

LI

D

IF

S E

P A

R A

T E

D F

R O

M O

R

IG

IN

A

L R

E P

O R

T

G E

O S

M A

R T

L O

G -N

O W

E

LL

H C

S

A R

A S

O T

A P

O T

A B

LE

.G

P J

T E

R R

A C

O N

_D A

T A

T E

M P

LA

T

E .G

D T

/2

4/

W A

T E

R L

E V

E L

O B

S E

R V

A T

IO

N

S

D E

P T

H

F t.)

F

IE

LD

T E

S T

R E

S U

LT

S

P E

R C

E N

T F

IN

E

S

W A

T E

R C

O N

T E

N T

)LOCATION See Exploration Plan

Latitude: 27.0895° Longitude: -82.3601°

G R

A P

H

IC

L O

G

M O

D E

L

LA

Y E

R

DEPTH

Advancement Method:

Mud rotary Continuous sampling for entire depth

Abandonment Method:

Boring backfilled with cement grout upon completion

Notes:

Project No.: HC205099

Drill Rig: BR 2500

BORING LOG NO. B-4

McKim & CreedCLIENT:

Sarasota, FL

Driller: S.D.

Boring Completed: 08-05-2021

PROJECT: Sarasota Potable Water Looping Project

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

Vaires Sarasota, FL

SITE:

Boring Started: 08-05-2021

8260 Vico Ct, Unit B Sarasota, FL

At 6' while sampling

WATER LEVEL OBSERVATIONS

S A

M P

LE

T

Y

SUPPORTING INFORMATION

General Notes Unified Soil Classification System

Exhibit: C-1

Unconfined Compressive Strength Qu, (psf)

500 to 1,000

2,000 to 4,000

4,000 to 8,000

1,000 to 2,000 less than 500

> 8,000

Non-plastic Low Medium High

DESCRIPTION OF SYMBOLS AND ABBREVIATIONS

Hand Penetrometer

Torvane

Dynamic Cone Penetrometer

Photo-Ionization Detector

Organic Vapor AnalyzerS A

M P

L

IN

G

W A

T E

R L

E V

E L

F

IE

L D

T E

S T

S

(HP)

(T)

(DCP)

(PID)

(OVA)

GENERAL NOTES

Over 12 in. (300 mm) 12 in. to 3 in. (300mm to 75mm) 3 in. to #4 sieve (75mm to 4.75 mm) #4 to #200 sieve (4.75mm to 0.075mm Passing #200 sieve (0.075mm)

Particle Size

< 5 5 - 12 > 12

Percent of Dry Weight

Descriptive Term(s) of other constituents

RELATIVE PROPORTIONS OF FINES

1 - 10 11 - 30

> 30

Plasticity Index

Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency.

LOCATION AND ELEVATION NOTES

Percent of Dry Weight

Major Component of Sample

Trace With Modifier

RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY

Trace With Modifier

DESCRIPTIVE SOIL CLASSIFICATION

Boulders Cobbles Gravel Sand Silt or Clay

Descriptive Term(s) of other constituents

< 15 15 - 29 > 30

Term

PLASTICITY DESCRIPTION

Water levels indicated on the soil boring logs are the levels measured in the borehole at the times indicated.

Groundwater level variations will occur over time. In low permeability soils, accurate determination of groundwater levels is not possible with short term water level observations.

Water Level After a Specified Period of Time

Water Level After a Specified Period of Time

Water Initially Encountered

Auger Cuttings Rock Core

Grab Sample

No Recovery

Shelby Tube

Standard Penetration Test

Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The accuracy of such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographical survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the area.

S T

R E

N G

T H

T E

R M

S Standard Penetration or N-Value

Blows/Ft.

Descriptive Term (Consistency)

Descriptive Term (Density)

CONSISTENCY OF FINE-GRAINED SOILS

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

Consistency determined by laboratory shear strength testing, field visual-manual procedures or standard penetration resistance

Standard Penetration or N-Value

Blows/Ft.

(More than 50% retained on No. 200 sieve.)

Density determined by Standard Penetration Resistance

RELATIVE DENSITY OF COARSE-GRAINED SOILS

Hard > 30

> 50 15 - 30Very Stiff

Stiff

Medium Stiff

Very Soft 0 - 1

Medium Dense

SoftLoose

Very Dense

8 - 1530 - 50Dense

4 - 810 - 29

2 - 44 - 9

Very Loose 0 - 3 jmjackson2 Text Box

UNIFIED SOIL CLASSIFICATION SYSTEM

UNIFIED SOI L CLASSI FICATI ON SYSTEM

Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A Soil Classification

Group Symbol Group Name B

Coarse-Grained Soils:

More than 50% retained on No. 200 sieve

Gravels:

More than 50% of coarse fraction retained on No. 4 sieve

Clean Gravels:

Less than 5% fines C

Cu ³ 4 and 1 £ Cc £ 3 E GW Well-graded gravel F

Cu < 4 and/or [Cc<1 or Cc>3.0] E GP Poorly graded gravel F

Gravels with Fines:

More than 12% fines C

Fines classify as ML or MH GM Silty gravel F, G, H

Fines classify as CL or CH GC Clayey gravel F, G, H

Sands:

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

Clean Sands:

Less than 5% fines D

Cu ³ 6 and 1 £ Cc £ 3 E SW Well-graded sand I

Cu < 6 and/or [Cc<1 or Cc>3.0] E SP Poorly graded sand I

Sands with Fines:

More than 12% fines D

Fines classify as ML or MH SM Silty sand G, H, I

Fines classify as CL or CH SC Clayey sand G, H, I

Fine-Grained Soils:

50% or more passes the No. 200 sieve

Silts and Clays:

Liquid limit less than 50

Inorganic:

PI > 7 and plots on or above “A” line J

CL Lean clay K, L, M

PI < 4 or plots below “A” line J ML Silt K, L, M

Organic:

Liquid limit - oven dried

< 0.75 OL Organic clay K, L, M, N

Liquid limit - not dried Organic silt K, L, M, O

Silts and Clays:

Liquid limit 50 or more

Inorganic:

PI plots on or above “A” line CH Fat clay K, L, M

PI plots below “A” line MH Elastic Silt K, L, M

Organic:

Liquid limit - oven dried

< 0.75 OH Organic clay K, L, M, P

Liquid limit - not dried Organic silt K, L, M, Q

Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat A Based on the material passing the 3-inch (75-mm) sieve.

B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name.

C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay.

D Sands with 5 to 12% fines require dual symbols: SW-SM well-graded sand with silt, SW-SC well-graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay.

E Cu = D60/D10 Cc =

DxD

)(D

F If soil contains ³ 15% sand, add “with sand” to group name.

G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.

H If fines are organic, add “with organic fines” to group name.

I If soil contains ³ 15% gravel, add “with gravel” to group name.

J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.

K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,” whichever is predominant.

L If soil contains ³ 30% plus No. 200 predominantly sand, add

“sandy” to group name.

MIf soil contains ³ 30% plus No. 200, predominantly gravel, add

“gravelly” to group name.

NPI ³ 4 and plots on or above “A” line.

OPI < 4 or plots below “A” line.

P PI plots on or above “A” line.

QPI plots below “A” line.