Kellogg_Park_Nature_Center_-_Geotech_Report.pdf

GEOTECHNICAL

ENGINEERING

REPORT

Kellogg Bayside Park Improvements Santa Rosa Beach, Walton County, Florida

PREPARED FOR:

Kimley-Horn & Associates, Inc.

2615 Centennial Boulevard, Suite 102

Tallahassee, Florida 32308

NOVA Project Number: 10111-2022024

November 11, 2022

P R O F E S S I O N A L | P R A C T I C A L | P R O V E N

1 7 6 1 2 A s h l e y D r i v e , P a n a m a C i t y B e a c h , F l o r i d a 3 2 4 1 3 t . 8 5 0 . 2 4 9 . 6 6 8 2 / f . 8 5 0 . 2 4 9 . 6 6 8 3 / u s a n o v a . c o m

November 11, 2022

Ms. Kelsey Lewis, P.E.

Kimley-Horn & Associates, Inc.

2615 Centennial Boulevard, Suite 102

Tallahassee, Florida 32308

Subject: Geotechnical Engineering Report

NOVA Project Number 10111-2022024

Dear Ms. Lewis, NOVA Engineering and Environmental LLC (NOVA) has completed the authorized subsurface exploration and geotechnical engineering evaluation for the proposed park improvements to be constructed in Santa Rosa Beach, Walton County, Florida. The work was performed in general accordance with NOVA Proposal 011-20215856, dated September 9, 2021. This report briefly discusses our understanding of the project at the time of the subsurface exploration, describes the geotechnical consulting services provided by NOVA, and presents our findings, conclusions, and recommendations.

We appreciate your selection of NOVA and the opportunity to be of service on this project. If you have any questions, or if we may be of further assistance, please do not hesitate to contact us.

Sincerely, NOVA Engineering and Environmental LLC

Oliver D. Rosen, E.I.

Staff Engineer

Florida Registration No. 1100022655

Copies Submitted: Addressee (electronic)

TABLE OF CONTENTS

1.0 SUMMARY

1.1 GENERAL

1.2 SITE PREPARATION

1.3 GROUNDWATER CONTROL

1.4 FOUNDATION RECOMMENDATIONS

1.5 PARKING/DRIVE AREA RECOMMENDATIONS

1.6 STORMWATER MANAGEMENT SYSTEM RECOMMENDATIONS

2.0 INTRODUCTION

2.1 PROJECT INFORMATION

2.2 SCOPE OF WORK

3.0 SITE DESCRIPTION

3.1 LOCATION AND LEGAL DESCRIPTION

3.2 SUBJECT PROPERTY VICINITY GENERAL CHARACTERISTICS

4.0 FIELD AND LABORATORY PROCEDURES

4.1 FIELD EXPLORATION

4.2 LABORATORY TESTING

5.0 SUBSURFACE CONDITIONS

5.1 GEOLOGY

5.2 SOIL CONDITIONS

5.3 GROUNDWATER CONDITIONS

6.0 CONCLUSIONS AND RECOMMENDATIONS

6.1 SITE PREPARATION

6.2 FILL PLACEMENT

6.3 GROUNDWATER CONTROL

6.4 FOUNDATION RECOMMENDATIONS

6.5 SLAB-ON-GRADE

6.6 STORMWATER MANAGEMENT SYSTEM RECOMMENDATIONS

6.7 PAVEMENT RECOMMENDATIONS

7.0 CONSTRUCTION OBSERVATIONS

7.1 SHALLOW FOUNDATIONS

7.2 PAVEMENTS

7.3 SUBGRADE

APPENDIX

APPENDIX A – FIGURES & MAPS

APPENDIX B – SUBSURFACE DATA

APPENDIX C – LABORATORY DATA

APPENDIX D – SUPPORT DOCUMENTS

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

1.0 SUMMARY

A brief summary of pertinent findings, conclusions and recommendations is presented below.

This information should not be utilized in design or construction without reading all of the recommendations presented in the text and Appendix of this report.

1.1 GENERAL

Our field exploration at the subject site included performing two (2) Standard Penetration

Test (SPT) borings within the proposed structure footprint, two (2) SPT borings and one

(1) Double Ring Infiltrometer (DRI) test within the proposed stormwater management system (SMS) basin and two (2) auger borings within the proposed pavement areas.

Drilling, testing, and sampling operations were performed in general accordance with

ASTM designations and other industry standards.

The test borings generally encountered mixed strata of loose to medium dense silty to slightly silty fine-grained sands (USCS classifications of SM and SP-SM) from the existing ground surface elevation to the maximum depth explored of about 25 feet below existing grade (BEG). We note that unimproved (gravel) parking and access drive areas were also present within the park facility and were encountered in the two pavement borings.

1.2 SITE PREPARATION

We recommend removing all topsoil and surficial vegetation, trees and associated root systems, and any other deleterious non-soil materials that are found to be present from within the proposed construction limits. The exposed subgrade soils at the undercut elevations, subsequent lifts of backfill and fill soils, and all footing excavations should be compacted to a minimum soil density of at least 98 percent of the maximum dry density as determined by the Modified Proctor test (ASTM D-1557).

A geotechnical engineer should carefully evaluate all subgrades prior to foundation, slab-on-grade, and pavement section construction to confirm compliance with this report;

evaluate geotechnical sections of the plans and specifications for the overall project;

and provide additional recommendations that may be required.

1.3 GROUNDWATER CONTROL

Groundwater was encountered in the test borings at depths ranging between approximately 1½ feet to 3½ feet BEG at the time of our subsurface exploration, which occurred during a period of relatively normal seasonal rainfall.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

Groundwater should therefore be expected to impact the planned near surface construction, most especially during shallow foundation and subsurface utility installations in lower-lying areas of the site. Contractors should be prepared to utilize a significant dewatering system during construction to maintain separation between the groundwater levels and the desired working platforms for below-grade work.

1.4 FOUNDATION RECOMMENDATIONS

After the recommended site/subgrade preparation and fill placement, we recommend that the proposed structure be supported on a conventional shallow foundation system bearing upon compacted native soils and/or compacted structural fill. The building foundation may be designed utilizing a maximum soil bearing pressure of 1,500 pounds per square foot (psf).

1.5 PARKING/DRIVE AREA RECOMMENDATIONS

We understand that the proposed park improvements will include the addition of flexible

(asphalt) pavements for the entrance drives and parking areas. Based on the results of our test borings, the subsurface conditions encountered appear to be adaptable for supporting this pavement section.

1.6 STORMWATER MANAGEMENT SYSTEM RECOMMENDATIONS

NOVA understands that the stormwater management system (SMS) to treat and dispose of stormwater runoff is desired to consist of shallow dry retention basin. Based on the results of our field exploration, the subsurface conditions encountered in the SMS appear to be only marginally adaptable for employing a dry retention basin due to the presence of a relatively shallow groundwater table. We recommend that the soil parameters presented in Table 1 of Section 6.6 of this report be considered for the design of the SMS for this project.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

2.0 INTRODUCTION

2.1 PROJECT INFORMATION

Our understanding of the proposed development is based on recent conversations and email exchanges with the Client, review of the provided site plan and aerial photography of the site via internet-based GIS software; our site reconnaissance activities; and our recent experience providing previous geotechnical consulting services for other similar projects in the general locale.

2.1.1 SITE PLANS AND DOCUMENTS

Architectural or structural plans were not provided to us.

2.1.2 PROPOSED CONSTRUCTION

NOVA understands the project will include the construction of a new park facility including a new structure with restrooms, kitchenette, and an assembly area, paved entrance drives and parking areas, associated subsurface utilities, and the re-design of an existing SMS. The proposed building is anticipated to be of wood frame or Concrete Masonry Unit (CMU) construction supported by a shallow foundation system.

Final structural loadings were not available from the design team at the time of the issuance of this report; we have therefore assumed that isolated interior column and continuous load bearing wall loads will not exceed 30 kips per column and 3 kips per linear foot, respectively, for the planned structure.

2.1.3 SITE GRADING

Final site grading details were not available from the design team at the time of the issuance of this report; we have therefore assumed that finish site grades will not change greater than +/- 3 feet from existing grades within the proposed structure footprint and pavement areas. The dry detention basin has been assumed to be on the order of 3 feet to 5 feet in depth.

If these assumptions are not accurate, please advise us so that we may adjust our scope of work and costs as appropriate.

2.2 SCOPE OF WORK

Kimley-Horn & Associates, Inc., engaged NOVA to provide geotechnical engineering consulting services for the proposed Kellogg Bayside Park Improvements project. This report briefly discusses our understanding of the project, describes our exploratory

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024 procedures, and presents our findings, conclusions, and recommendations. The primary objectives of this study were to perform a geotechnical exploration within the proposed construction areas and to assess these findings as they relate to geotechnical aspects of the planned site improvements.

The authorized geotechnical engineering services included a soil test boring and sampling program, laboratory testing, engineering evaluation of the field and laboratory data, and the preparation of this report. The services were performed substantially as outlined in our proposal number NOVA Proposal 011-20215856, dated September 9, 2021, and in general accordance with industry standards. As authorized per the above referenced proposal, this completed geotechnical report includes:

• A description of the site, fieldwork, laboratory testing and general soil conditions encountered, together with a Boring Location Plan and individual Test Boring

Records.

• Site preparation considerations that include geotechnical discussions regarding site stripping and subgrade preparation, and engineered fill/backfill placement.

• Recommendations for controlling groundwater and/or run-off during construction, and the potential need for permanent dewatering systems based on the anticipated post construction groundwater levels.

• Foundation system recommendations for the proposed structure, as appropriate based on the boring results.

• Slab-on-grade construction considerations based on the geotechnical findings, including the need for a sub-slab vapor barrier or a capillary barrier.

• Recommended pavement sections based on assumed traffic loading and subgrade strengths estimated from correlations with test borings, laboratory data, and soil types collected from the test borings.

• The measured apparent and estimated seasonal high groundwater levels at the boring locations.

• Recommended soil related design parameters for the SMS area.

• Suitability of on-site soils for re-use as structural fill and backfill. Additionally, the criteria for suitable fill materials will be provided.

• Recommended quality control measures (i.e., sampling, testing, and inspection requirements) for site grading and pavement section installation operations.

The assessment of site environmental conditions, including the presence of wetlands or detection of pollutants in the soil, rock or groundwater, laboratory testing of samples, or a site-specific seismic study was beyond the scope of this geotechnical study. If requested, NOVA can provide these services.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

3.0 SITE DESCRIPTION

3.1 LOCATION AND LEGAL DESCRIPTION

Kellogg Bayside Park (Walton County Parcel I.D. Number 14-2S-20-33000-006-0020) is located at the northeast corner of the intersection of Nursery Road East and Garden

Lane Drive in Santa Rosa Beach, Walton County, Florida.

3.2 SUBJECT PROPERTY VICINITY GENERAL CHARACTERISTICS

At the time of our field exploration, the vicinity of the Subject Property was observed to generally consist of vacant undeveloped land and single-family residences.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

4.0 FIELD AND LABORATORY PROCEDURES

4.1 FIELD EXPLORATION

The test and boring locations were established in the field by NOVA personnel using a hand-held GPS unit. Consequently, referenced test and boring locations should be considered approximate. If the Client desires increased accuracy, NOVA recommends that the test and boring locations and elevations be surveyed. Our field exploration included performing:

• Two (2), 25-foot deep SPT borings within the proposed building footprint.

• Two (2), 15-foot SPT borings boring within an existing SMS area that will be re-designed. Additionally, one (1) DRI was performed within this area.

• Two (2) auger borings within the proposed pavement areas.

SPT Borings: The Standard Penetration Test borings were performed using the guidelines of ASTM Designation D-1586, "Penetration Test and Split-Barrel Sampling of Soils". A mud rotary drilling process was used to advance the borings. At regular intervals, soil samples were obtained with a standard 1.4-inch I.D., 2.0-inch O.D., split-tube sampler.

The sampler was first seated six inches and then driven an additional foot with blows of a 140-pound hammer falling 30 inches. The number of hammer blows required to drive the sampler the final foot is designated the "Penetration Resistance". The penetration resistance, when properly interpreted, is an index to the soil strength and density.

Auger Borings: The auger borings were performed using a hand operated soil sampler.

Soil samples were obtained from the auger bucket, approximately at each stratum transition.

Test Boring Records in Appendix B present the soil conditions encountered in the borings. These records represent our interpretation of the subsurface conditions based on the field exploration data, visual examination of the recovered samples, laboratory test data, and generally accepted geotechnical engineering practices. The stratification lines and depth designations represent approximate boundaries between various subsurface strata. Actual transitions between materials may be gradual.

Groundwater Levels: The groundwater levels reported on the Test Boring Records represent measurements made at the completion of each test boring. The test borings were subsequently backfilled with the soil cuttings from the drilling process for safety concerns.

Double Ring Infiltrometer Testing: The Double Ring Infiltrometer (DRI) testing was performed in general accordance with ASTM D-3385. The DRI is used for determining water infiltration rates of soil within the retention area footprint. The rings are partially

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024 inserted into the soil and filled with water, after which the speed of infiltration is measured. Infiltration is the process of water penetrating the ground surface. The intensity of this process is called the infiltration rate and is expressed in terms of the volume of water per ground surface and per unit of time (inches/hour).

4.2 LABORATORY TESTING

A laboratory testing program was conducted to characterize materials existing at the site using split spoon and bulk/grab soil samples recovered from the borings. The laboratory test data are presented in the Appendix. Select test data are also presented on the Test

Boring Records attached in the Appendix, and the specific tests are briefly described below. Further laboratory testing was beyond the scope of this exploration.

All soil samples will be properly disposed of 30 days following the submittal of this NOVA subsurface exploration report unless you request otherwise.

4.2.1 SOIL CLASSIFICATION

Soil classification provides a general guide to the engineering properties of various soil types and enable the engineer to apply past experience to current problems. In our explorations, samples obtained during drilling operations are observed in our laboratory and visually classified by an engineer. The soils are classified according to relative density (based on SPT N-values), color and texture. These classification descriptions are included on our Test Boring

Records. The classification system discussed above is primarily qualitative;

laboratory testing is generally required for detailed soil classification. Using the test results, the soils were visually/manually classified according to the Unified

Soil Classification System. This classification system and the in-place physical soil properties provide an index for estimating the soil's behavior. The soil classification and physical properties obtained are presented in this report.

4.2.2 MOISTURE CONTENT

The moisture content is the ratio expressed as a percentage of the weight of water in a given mass of soil to the weight of the solid particles. This testing was conducted in general accordance with ASTM Designation D-2216. Three

(3) moisture content tests were performed in this study.

4.2.3 FINES CONTENT

The percentage of fines passing through the No. 200 sieve is generally considered to represent the amount of silt and clay of the tested soil sample. The sieve analysis testing was conducted in general accordance with ASTM Designations D-

6913 and D-1140. Three (3) fines content tests were performed in this study.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

5.0 SUBSURFACE CONDITIONS

5.1 GEOLOGY

According to the United States Geological Survey (USGS), the subject site is located in

Walton County within the Gulf Coastal Plain, separated from the Florida Platform by geologic structures known as the Gulf Trough and Apalachicola Embayment. These structures formed a bathymetric and environmental barrier from the earliest Eocene or earliest Oligocene periods into the Miocene.

According to the “Text to Accompany the Geologic Map of Florida” by Scott, 2001, the site is generally underlain by undifferentiated sediments deposited during the

Quaternary period. These sediments typically consist of siliciclastics (sand), organics and freshwater carbonates. These soils are highly permeable and form the Sand and

Gravel Aquifer of the surficial aquifer system.

Surficial soils in the region are primarily siliciclastic sediments deposited in response to the renewed uplift and erosion in the Appalachian highlands to the north and sea-level fluctuations. The extent and type of deposit is influenced by numerous factors, including mineral composition of the parent rock and meteorological events.

5.2 SOIL CONDITIONS

The following paragraph provides a generalized description of the subsurface profile and soil conditions encountered by the borings. The Test Boring Records provided in the

Appendix should be reviewed to provide more detailed descriptions of the subsurface conditions encountered at the boring locations. Conditions may vary at other locations and times.

The test borings generally encountered mixed strata of loose to medium dense silty to slightly silty fine-grained sands (USCS classifications of SM and SP-SM) from the existing ground surface elevation to the maximum depth explored of about 25 feet below existing grade (BEG). We note that unimproved (gravel) parking and access drive areas were also present within the park facility and were encountered in the two pavement borings.

5.3 GROUNDWATER CONDITIONS

5.3.1 GENERAL

Groundwater in the Gulf Coastal Plain typically occurs as an unconfined aquifer condition. Recharge is provided by the infiltration of rainfall and surface water through the soil overburden. More permeable zones in the soil matrix can affect groundwater conditions. The groundwater table is expected to be a subdued replica of the original surface topography.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

5.3.2 SOIL TEST BORING GROUNDWATER CONDITIONS

approximately 1½ feet to 3½ feet BEG at the time of our subsurface exploration, which occurred during a period of relatively normal seasonal rainfall.

We estimate that the normal permanent seasonal high groundwater (SHGW) tables for this property will occur within 1 foot above the groundwater levels measured at each boring location during our field exploration.

Groundwater levels vary with changes in season and rainfall, construction activity, surface water runoff and other site-specific factors. Groundwater levels in the south Walton County area are typically lowest in the late spring and the late fall and highest in the summer with annual groundwater fluctuations by seasonal rainfall; consequently, the water table may vary at times.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

6.0 CONCLUSIONS AND RECOMMENDATIONS

The following conclusions and recommendations are based on our understanding of the proposed construction, our site observations, our evaluation and interpretation of the field and laboratory data obtained during this exploration, our experience with similar subsurface conditions, and generally accepted geotechnical engineering principles and practices.

Subsurface conditions in unexplored locations or at other times may vary from those encountered at specific boring locations. If such variations are noted during construction, or if project development plans are changed, we request the opportunity to review the changes and amend our recommendations, if necessary.

As previously noted, the test and boring locations were established in the field using a hand-held GPS unit. If increased accuracy is desired by the Client, we recommend that the boring locations and elevations be surveyed.

6.1 SITE PREPARATION

We recommend removing all topsoil and surficial vegetation, trees and associated root systems, and any other deleterious non-soil materials that are found to be present from within the proposed structure footprint and pavement areas. Exposed subgrade soils at the undercut elevation(s), as well as subsequent lifts of fill soils, should be compacted via non-vibratory methods to a minimum soil density of at least 98 percent of the maximum dry density as determined by the Modified Proctor test (ASTM D-

1557). We note that vibratory compaction operations should not be performed within a clear distance of 50 feet from any adjacent structures.

A geotechnical engineer should carefully evaluate all subgrades prior to foundation construction to confirm compliance with this report; evaluate geotechnical sections of the plans and specifications for the overall project; and provide additional recommendations that may be required.

6.2 FILL PLACEMENT

6.2.1 FILL SUITABILITY

Fill materials should be relatively clean sands with less than 12 percent fines

(material passing the No. 200 sieve), and free of non-soil materials and rock fragments larger than 3 inches in diameter. On-site near surface soils that are categorized as fine-grained slightly silty sands (SP-SM) based on the Unified Soil

Classification System (USCS) are considered suitable for reuse as structural fill in proposed building and pavement areas, provided that the materials are free of rubble, clay, rock, roots, and organics.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

All materials to be used for backfill or compacted fill construction should be evaluated and, if necessary, tested by NOVA prior to placement to determine if they are suitable for their intended use. Any off-site materials used as fill should be approved by NOVA prior to acquisition. Organic and/or debris-laden material is not suitable for re-use as structural fill.

6.2.2 SOIL COMPACTION

Fill should be placed in thin, horizontal loose lifts (maximum 12-inch depth) and compacted to a minimum soil density of at least 98 percent of the Modified

Proctor maximum dry density (ASTM D-1557). In confined areas, such as utility trenches, portable compaction equipment and thinner fill lifts (3 to 4 inches) may be necessary. Fill materials used in structural areas should have a target maximum dry density of at least 100 pounds per cubic foot (pcf). If lighter weight fill materials are used, the NOVA geotechnical engineer should be consulted to assess the impact on design recommendations.

Soil moisture content should be maintained within 2 percent of the optimum moisture content. We recommend that the grading contractor have equipment on site during earthwork for both drying and wetting fill soils. Moisture control may be difficult during rainy weather.

Filling operations should be observed by a NOVA soils technician, who can confirm suitability of material used and uniformity and appropriateness of compaction efforts. He/she can also document compliance with the specifications by performing field density tests using thin-walled tube, nuclear, or sand cone testing methods (ASTM D-2937, D-6938, or D-1556, respectively).

One test per 2,000 square feet in the structure footprint and every 5,000 square feet in pavement areas should be performed in each lift of fill, with test locations well distributed throughout the fill mass. When filling in small areas, at least one test per day per area should be performed. One (1) test at conventional spread foundations, one (1) test per lift at each planned column footing area, and one (1) test per 75 linear feet at continuous strip foundations are also recommended.

6.3 GROUNDWATER CONTROL

approximately 1½ feet to 3½ feet BEG at the time of our subsurface exploration, which occurred during a period of relatively normal seasonal rainfall.

Groundwater should therefore be expected to impact the planned near surface construction, most especially during shallow foundation and subsurface utility installations in lower-lying areas of each property.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

Contractors should be prepared to utilize a significant dewatering system during construction to maintain separation between the groundwater levels and the desired working platforms for below-grade work.

6.4 FOUNDATION RECOMMENDATIONS

6.4.1 GENERAL

NOVA understands the project will include the construction of new park facility building with restrooms, kitchenette and an assembly area. Final structural loadings were not available from the design team at the time of issuance of this report. We have therefore assumed that isolated interior column and continuous load bearing wall loads will not exceed 30 kips per column and 3 kips per linear foot, respectively, for the planned structure.

6.4.2 SHALLOW FOUNDATION SYSTEMS

Design: After the recommended site/subgrade preparation and fill placement, we recommend that the proposed structure be supported on a conventional shallow foundation system bearing upon compacted native soils and/or compacted structural fill. The building foundation may be designed utilizing a maximum soil bearing pressure of 1,500 pounds per square foot (psf).

Settlement: Settlements for spread foundations bearing on compacted native or approved fill materials were assessed using SPT values to estimate elastic modulus, based on published correlations and previous NOVA experience. We note that the settlements presented are based on the results of the SPT borings.

Conditions may be better or worse in other areas, however, we believe the estimated settlements are reasonably conservative.

Based on the soil bearing capacity and the presumed foundation elevations discussed above, we expect primary total settlement beneath individual foundations to be on the order of 1 inch or less. The amount of differential settlement is difficult to predict because the subsurface and foundation loading conditions can vary considerably across the site. However, we anticipate differential settlement between adjacent foundations will be on the order of ½ inch or less. The final deflected shape of the structure will be dependent on actual foundation locations and loading.

Foundation support conditions are highly erratic and may vary dramatically in short horizontal distances. It is anticipated that the geotechnical engineer may recommend a different bearing capacity upon examination of the actual foundation subgrade at numerous locations.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

To reduce the differential settlement if lower consistency materials are encountered, a lower bearing capacity should be used, or the foundations should be extended to more competent materials. We anticipate that timely communication between the geotechnical engineer and the structural engineer, as well as other design and construction team members, will be required.

Construction: Foundation excavations should be evaluated by the NOVA geotechnical engineer prior to reinforcing steel placement to observe foundation subgrade preparation and confirm bearing pressure capacity. Foundation excavations should be level and free of debris, ponded water, mud, and loose, frozen, or water-softened soils. Concrete should be placed as soon as is practical after the foundation is excavated, and the subgrade evaluated. Foundation concrete should not be placed on frozen or saturated soil. If a foundation excavation remains open overnight, or if rain or snow is imminent, a 3 to 4-inch thick "mud mat" of lean concrete should be placed in the bottom of the excavation to protect the bearing soils until reinforcing steel and concrete can be placed.

6.5 SLAB-ON-GRADE

The conditions exposed at subgrade levels will vary across the site and may include structural fill or densified in-situ soils. The slab-on-grade may be adequately supported on these subgrade conditions subject to the recommendations in this report. The slab-on-grade should be jointed around columns and along walls to reduce cracking due to differential movement. An impermeable vapor barrier is recommended beneath finished spaces to reduce dampness. Once grading is completed, the subgrade can be exposed to adverse construction activities and weather conditions during the period of sub-slab utility installation. The subgrade should be well drained to prevent the accumulation of water. If the exposed subgrade becomes unstable, excessively wet or exhibits excessive rutting or pumping, the geotechnical engineer should be consulted.

6.6 STORMWATER MANAGEMENT SYSTEM RECOMMENDATIONS

NOVA understands that the stormwater management system (SMS) to treat and dispose of stormwater runoff associated with the planned improvements to this park facility is desired to consist of a re-design of an existing dry retention basin. Based on the results of our field exploration, the subsurface conditions encountered in the SMS area appear to be only marginally adaptable for employing a dry retention basin due to the presence of a relatively shallow groundwater table.

Provided the design team elects to proceed with the proposed SMS design, we recommend that the soil parameters presented on the next page in Table 1 be considered for the design of the SMS for this project.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

Should the design parameters provided in Table 1 below prove insufficient for providing an adequate SMS design for a conventional dry retention basin, we recommend that consideration be given to designing this basin for wet detention, or possibly employing a wet-dry hybrid SMS design.

TABLE 1: SMS SOIL DESIGN PARAMETERS

Corresponding Soil Boring Test Location S-1, S-2, DRI-1

Approximate Depth to Confining Stratum, BEG 8 feet

Measured/Estimated Vertical Infiltration Rate (DRI)* Per the ERP Applicant’s Handbook, this value is limited to 25 inches per hour for the SMS designs 8 inches/hour

Estimated Lateral Saturated Hydraulic Conductivity (kh)* 1 foot/day

Estimated Fillable Porosity of Soil 25%

Depth to Stabilized Groundwater Table, BEG 1½ feet

Estimated Normal Permanent SHGW Table, BEG 1 foot

Estimated Normal Permanent SLGW Table, BEG 3 feet

* Factors of Safety have not been applied to the noted hydraulic conductivity and infiltration values.

6.7 PAVEMENT RECOMMENDATIONS

6.7.1 PAVEMENT DESIGN CRITERIA

A recommended flexible pavement section has been developed for this project based on our understanding of the existing subsurface conditions, review of applicable FDOT specifications, and the assumed requirements of a 20-year pavement design life with moderate traffic loadings.

6.7.2 FLEXIBLE PAVEMENT

We recommend a minimum compaction requirement of 98 percent of the maximum dry density be specified for the base and stabilized subgrade courses as determined by the Modified Proctor test method (ASTM D-1557). We recommend employing the following parameters presented on the next page in

Table 2 (Standard Duty) and Table 3 (Heavy Duty) for the flexible pavement section designs for this project.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

Table 2 – Recommended Standard Duty Flexible Pavement Section

Asphaltic Concrete Surface Course

(such as a 9.5 mm SuperPave approved FDOT mix) 1 inch

Asphaltic Concrete Structural Course

(such as a 12.5 mm SuperPave approved FDOT mix) 1½ inch

FDOT Approved Crushed Limerock, Crushed Concrete, or

Graded Aggregate Base (GAB) Material 6 inches

Stabilized Subgrade Course (minimum LBR of 40) 12 inches

Table 3 – Recommended Heavy Duty Flexible Pavement Section

(Primary Entrance, and areas where static wheel turning is required)

Asphaltic Concrete Surface Course

(such as a 9.5 mm SuperPave approved FDOT mix) 1½ inches

Asphaltic Concrete Structural Course

(such as a 12.5 mm SuperPave approved FDOT mix) 2 inches

FDOT Approved Crushed Limerock, Crushed Concrete, or

Graded Aggregate Base (GAB) Material 8 inches

Stabilized Subgrade Course (minimum LBR of 40) 12 inches

Based on visual classification of the near-surface materials encountered in the pavement auger borings, the native sand (SP) soils will not likely not meet the minimum LBR requirement of 40 for the Stabilized Subgrade Course (SSC, which is the upper 12 inches of subgrade beneath flexible pavement sections) and will require stabilization with soil fines or additional base course material.

An imported material having a minimum LBR value of 40 should be specified for the final (12-inch) lift of fill for pavement areas being installed over fill.

All asphalt material and paving operations should meet applicable specifications of the Asphalt Institute and Florida Department of Transportation. A NOVA technician should observe placement and perform density testing of the stabilized subgrade course, base course material and asphalt.

Geotechnical Engineering Report November 11, 2022 Kellogg Bayside Park Improvements NOVA Project Number 10111-2022024

7.0 CONSTRUCTION OBSERVATIONS

7.1 SHALLOW FOUNDATIONS

Foundation excavations should be level and free of debris, ponded water, mud, and loose, frozen, or water-softened soils. All foundation excavations should be evaluated by a NOVA geotechnical engineer prior to reinforcing steel placement to observe foundation subgrade preparation and assess bearing pressure capacity. Due to variable site subsurface and construction conditions, some adjustments in isolated foundation bearing pressures, depth of foundations or undercutting and replacement with controlled structural fill may be necessary.

7.2 PAVEMENTS

The recommended pavement section should utilize materials and be constructed in accordance with applicable FDOT specifications and specific project requirements. Also, NOVA should be retained during construction to confirm subgrade conditions are as anticipated and that the construction process is as required by the contract documents.

7.3 SUBGRADE

Once site grading is completed, the subgrade may be exposed to adverse construction activities and weather conditions. The subgrade should be well-drained to prevent the accumulation of water. If the exposed subgrade becomes saturated or frozen, the

NOVA geotechnical engineer should be consulted.

APPENDIX A

Figures and Maps

Scale: Not To Scale PROJECT LOCATION MAP

Date Drawn: March 14, 2022 Kellogg Bayside Park Improvements

Drawn By: O. Rosen Santa Rosa Beach, Walton County, Florida

Checked By: W. Lawrence NOVA Project Number 10111-2022024

17612 Ashley Drive

Panama City Beach, Florida 32413

850.249.6682 ♦ 850.249.6683

Base map provided by Google Earth orosen PolyLine orosen Callout Site Location

Soil Map—Walton County, Florida (Kellogg Bayside Park Improvements)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

3/14/2022

575400 575440 575480 575520 575560 575600 575640 575680 575720 575760

575400 575440 575480 575520 575560 575600 575640 575680 575720 575760

30° 24' 17'' N

2'

4' ' W

30° 24' 17'' N

2'

0' ' W

30° 24' 9'' N

2'

4' ' W

30° 24' 9'' N

2'

0' ' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 16N WGS84 0 50 100 200 300

Feet 0 25 50 100 150

Meters Map Scale: 1:1,800 if printed on A landscape (11" x 8.5") sheet.

Soil Map may not be valid at this scale.

MAP LEGEND MAP INFORMATION

Area of Interest (AOI) Area of Interest (AOI)

Soils Soil Map Unit Polygons

Soil Map Unit Lines

Soil Map Unit Points

Special Point Features Blowout

Borrow Pit

Clay Spot

Closed Depression

Gravel Pit

Gravelly Spot

Landfill

Lava Flow

Marsh or swamp

Mine or Quarry

Miscellaneous Water

Perennial Water

Rock Outcrop

Saline Spot

Sandy Spot

Severely Eroded Spot

Sinkhole

Slide or Slip

Sodic Spot

Spoil Area

Stony Spot

Very Stony Spot

Wet Spot

Other

Special Line Features

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:20,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: Walton County, Florida Survey Area Data: Version 21, Sep 8, 2021

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Dec 31, 2009—Dec 10, 2017

The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Soil Map—Walton County, Florida (Kellogg Bayside Park Improvements)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

3/14/2022

Map Unit Legend

Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI

27 Rutlege fine sand, 0 to 2 percent slopes

4.5 42.6%

57 Hurricane sand, 0 to 5 percent slopes

6.1 57.4%

Totals for Area of Interest 10.6 100.0%

Soil Map—Walton County, Florida Kellogg Bayside Park Improvements

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

3/14/2022

APPENDIX B

Subsurface Data

Scale: Not To Scale BORING LOCATION PLAN

Date Drawn: March 14, 2022 Kellogg Bayside Park Improvements

Drawn By: O. Rosen Santa Rosa Beach, Walton County, Florida

Checked By: W. Lawrence NOVA Project Number 10111-2022024

17612 Ashley Drive

Panama City Beach, Florida 32413

850.249.NOVA(6682) ♦ 850.249.6683

LEGEND

25’ SPT Boring Locations (B-1 & B-2)

15’ SPT Boring Locations (S-1 & S-2)

5’ Hand Auger Boring Locations (P-1 & P-2)

Double Ring Infiltrometer Location (DRI-1)

Base map provided by Google Earth orosen Text Box P-1 orosen Text Box S-2 orosen Text Box

DRI-1

orosen Text Box S-1 orosen Text Box P-2 orosen Text Box B-2 orosen Text Box B-1

KEY TO BORING LOGS

Medium Stiff

FI

N E -G R A

IN

E D S O

IL

S or m or e pa ss es th e N o.

si ev e*

C O A R S E -G R A

IN

E D S O

IL

S

M or e th an re ta in ed on th e th e N o.

si ev e* jbrooks Polygon

Loose to medium dense brown to grey slightly silty fine-grained SAND (SP-SM)

Boring Terminated at 25 feet

PROJECT NO.: 2022024 CLIENT: Kimley-Horn & Associates, Inc.

PROJECT NAME: Kellogg Bayside Park Improvments DATE: 2/18/2022

G ra ph ic

10 20 30 40 50 60 70 80 90

PL LLG

ro un dw at er

Moisture Content (%)

S am pl e

Ty pe

DRILLED BY: L. Griffin LOCATION: See Boring Location Plan ELEVATION: Existing Grade

Material Description Fines Content (%)

PROJECT LOCATION: Santa Rosa Beach, Walton County, Florida

DRILLING METHOD: Mud Rotary LOGGED BY: K. Selle

Th is in fo rm at io n pe rt ai ns o nl y to th is b or in g an d sh ou ld n ot b e in te rp re te d as b ei ng in di ca tiv e of th e si te

Organic Content (%)

N-Value (Blows per Foot)

D ep th (f ee t)

El ev at io n

HAMMER: Manual

Note:

APPARENT GW DEPTH: 3.5 feet

N -V al ue

SHGW DEPTH: 2.5 feet

TEST BORING

RECORD

B-1

Loose to medium dense brown to light grey slightly silty fine-grained SAND (SP-SM)

Loose to very lose grey silty fine-grained SAND (SM)

Boring Terminated at 25 feet

PROJECT NO.: 2022024 CLIENT: Kimley-Horn & Associates, Inc.

PROJECT NAME: Kellogg Bayside Park Improvments DATE: 2/18/2022

G ra ph ic

10 20 30 40 50 60 70 80 90

PL LLG

ro un dw at er

Moisture Content (%)

S am pl e

Ty pe

DRILLED BY: L. Griffin LOCATION: See Boring Location Plan ELEVATION: Existing Grade

Material Description Fines Content (%)

PROJECT LOCATION: Santa Rosa Beach, Walton County, Florida

DRILLING METHOD: Mud Rotary LOGGED BY: K. Selle

Th is in fo rm at io n pe rt ai ns o nl y to th is b or in g an d sh ou ld n ot b e in te rp re te d as b ei ng in di ca tiv e of th e si te

Organic Content (%)

N-Value (Blows per Foot)

D ep th (f ee t)

El ev at io n

HAMMER: Manual

Note:

APPARENT GW DEPTH: 3.5 feet

N -V al ue

SHGW DEPTH: 2.5 feet

TEST BORING

B-2

Loose to medium dense brown to grey/dark grey slightly silty fine-grained SAND (SP-SM)

Boring Terminated at 15 feet

PROJECT NO.: 2022024 CLIENT: Kimley-Horn & Associates, Inc.

PROJECT NAME: Kellogg Bayside Park Improvments DATE: 2/18/2022

G ra ph ic

10 20 30 40 50 60 70 80 90

PL LLG

ro un dw at er

Moisture Content (%)

S am pl e

Ty pe

DRILLED BY: L. Griffin LOCATION: See Boring Location Plan ELEVATION: Existing Grade

Material Description Fines Content (%)

PROJECT LOCATION: Santa Rosa Beach, Walton County, Florida

DRILLING METHOD: Mud Rotary LOGGED BY: K. Selle

Th is in fo rm at io n pe rt ai ns o nl y to th is b or in g an d sh ou ld n ot b e in te rp re te d as b ei ng in di ca tiv e of th e si te

Organic Content (%)

N-Value (Blows per Foot)

D ep th (f ee t)

El ev at io n

HAMMER: Manual

Note:

APPARENT GW DEPTH: 1.4 feet

N -V al ue

SHGW DEPTH: 0.4 feet

TEST BORING

S-1

Very loose to medium dense brownn to grey slightly silty fine-grained SAND (SP-SM)

Buried wood encountered

Loose grey/brown slightly silty fine-grained SAND

(SP-SM)

Boring Terminated at 15 feet

PROJECT NO.: 2022024 CLIENT: Kimley-Horn & Associates, Inc.

PROJECT NAME: Kellogg Bayside Park Improvments DATE: 2/18/2022

G ra ph ic

10 20 30 40 50 60 70 80 90

PL LLG

ro un dw at er

Moisture Content (%)

S am pl e

Ty pe

DRILLED BY: L. Griffin LOCATION: See Boring Location Plan ELEVATION: Existing Grade

Material Description Fines Content (%)

PROJECT LOCATION: Santa Rosa Beach, Walton County, Florida

DRILLING METHOD: Mud Rotary LOGGED BY: K. Selle

Th is in fo rm at io n pe rt ai ns o nl y to th is b or in g an d sh ou ld n ot b e in te rp re te d as b ei ng in di ca tiv e of th e si te

Organic Content (%)

N-Value (Blows per Foot)

D ep th (f ee t)

El ev at io n

HAMMER: Manual

Note:

APPARENT GW DEPTH: 2.0 feet

N -V al ue

SHGW DEPTH: 1.0 foot

TEST BORING

S-2

Light brown GRAVEL (GP)

Boring Terminated at 1.5 feet

PROJECT NO.: 2022024 CLIENT: Kimley-Horn & Associates, Inc.

PROJECT NAME: Kellogg Bayside Park Improvments DATE: 2/10/2022

G ra ph ic

10 20 30 40 50 60 70 80 90

PL LLG

ro un dw at er

Moisture Content (%)

S am pl e

Ty pe

DRILLED BY: N. Hubert LOCATION: See Boring Location Plan ELEVATION: Existing Grade

Material Description Fines Content (%)

PROJECT LOCATION: Santa Rosa Beach, Walton County, Florida

DRILLING METHOD: Mud Rotary LOGGED BY: K. Selle

Th is in fo rm at io n pe rt ai ns o nl y to th is b or in g an d sh ou ld n ot b e in te rp re te d as b ei ng in di ca tiv e of th e si te

Organic Content (%)

N-Value (Blows per Foot)

D ep th (f ee t)

El ev at io n

HAMMER:

Note:

APPARENT GW DEPTH: GNE

N -V al ue

SHGW DEPTH:

TEST BORING

P-1

Light brown GRAVEL (GP)

Brown/dark brown to light brown/light grey fine-grained SAND (SP-SM)

Boring Terminated at 5 feet

PROJECT NO.: 2022024 CLIENT: Kimley-Horn & Associates, Inc.

PROJECT NAME: Kellogg Bayside Park Improvments DATE: 2/10/2022

G ra ph ic

10 20 30 40 50 60 70 80 90

PL LLG

ro un dw at er

Moisture Content (%)

S am pl e

Ty pe

DRILLED BY: N. Hubert LOCATION: See Boring Location Plan ELEVATION: Existing Grade

Material Description Fines Content (%)

PROJECT LOCATION: Santa Rosa Beach, Walton County, Florida

DRILLING METHOD: Mud Rotary LOGGED BY: K. Selle

Th is in fo rm at io n pe rt ai ns o nl y to th is b or in g an d sh ou ld n ot b e in te rp re te d as b ei ng in di ca tiv e of th e si te

Organic Content (%)

N-Value (Blows per Foot)

D ep th (f ee t)

El ev at io n

HAMMER:

Note:

APPARENT GW DEPTH: 2.0 feet

N -V al ue

SHGW DEPTH: 1.0 foot

TEST BORING

P-2

Project:

Project Location:

Project Number:

Date(s) of Test October 11, 2022 Tested by N. Patel Weather Clear

Test Method ASTM D 3385 Logged by N. Patel Type of liquid tap water

Area Inner Ring 110.75 sq. in. Checked by W. Lawrence Liquid Temperature 80 ⁰F

Area Outer Ring 447.69 sq. in. See Auger Boring Record for Soil Profile Soil Temperature 83 ⁰F

Area Annular Space 334.59 sq. in. Approx. Elevation 9 in. below grade Location Per Boring Location Plan

Time Elapsed Volume Infiltration Volume Infiltration Comments

Time Rate Rate

(minutes) (gal) (In/hr) (gal) (In/hr)

12:40 10 0.6 7.4 2.7 8.3

12:50 10 0.7 8.7 3.0 9.2

13:00 10 0.6 7.4 2.9 8.9

13:10 10 0.6 7.4 3.0 9.2

13:20 10 0.7 8.7 3.0 9.2

13:30 10 0.7 8.7 2.9 8.9

13:40 10 0.7 8.7 3.0 9.2

13:50 10 0.6 7.4 2.7 8.2

14:00 10 0.6 7.9 2.6 8.1

INCREMENTAL INFILTRATION RATE vs. TOTAL ELAPSED TIME

Report of DRI - 1

Figure DRI-1

Inner Ring Outer Ring

Kellogg Bayside Park Improvements

Santa Rosa Beach, Walton County, Florida

10111-202204

INFILTRATION RATE = 8 in/hr

Test began after a 30-minute saturation period.

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

12:28 12:43 12:57 13:12 13:26 13:40 13:55 14:09

In fi lt ra ti o n R a te in

/h r)

Time

Infiltration Rate

Inner Ring

Outer Ring

APPENDIX C

Laboratory Data

SUMMARY OF CLASSIFICATION & INDEX TESTING

NOVA Project Number 10111-2022024

Lab Summary – Page 1 of 1

Boring

Number

Sample

Depth

(ft)

Natural Moisture

Percent (%)

Passing

Sieve #200

USCS

Soil

Classification

B-1 2.0 – 4.0 15 11 SP-SM

B-2 4.0 – 6.0 18 10 SP-SM

S-1 0.0 – 2.0 18 10 SP-SM

APPENDIX D

Support Documents

QUALIFICATIONS OF RECOMMENDATIONS

The findings, conclusions and recommendations presented in this report represent our professional opinions concerning subsurface conditions at the site. The opinions presented are relative to the dates of our site work and should not be relied on to represent conditions at later dates or at locations not explored. The opinions included herein are based on information provided to us, the data obtained at specific locations during the study, and our previous experience. If additional information becomes available which might impact our geotechnical opinions, it will be necessary for NOVA to review the information, re-assess the potential concerns, and re-evaluate our conclusions and recommendations.

Regardless of the thoroughness of a geotechnical exploration, there is the possibility that conditions between borings may differ from those encountered at specific boring locations, that conditions are not as anticipated by the designers and/or the contractors, or that either natural events or the construction process has altered the subsurface conditions. These variations are an inherent risk associated with subsurface conditions in this region and the approximate methods used to obtain the data. These variations may not be apparent until construction.

The professional opinions presented in this report are not final. Field observations and foundation installation monitoring by the geotechnical engineer, as well as soil density testing and other quality assurance functions associated with site earthwork and foundation construction, are an extension of this report. Therefore, NOVA should be retained by the owner to observe all earthwork and foundation construction to confirm that the conditions anticipated in this study actually exist, and to finalize or amend our conclusions and recommendations.

NOVA is not responsible or liable for the conclusions and recommendations presented in this report if NOVA does not perform these observation and testing services.

This report is intended for the sole use of Kimley-Horn & Associates, Inc. only. The scope of work performed during this study was developed for purposes specifically intended by Kimley-

Horn & Associates, Inc. only and may not satisfy other users’ requirements. Use of this report or the findings, conclusions or recommendations by others will be at the sole risk of the user.

NOVA is not responsible or liable for the interpretation by others of the data in this report, nor their conclusions, recommendations, or opinions.

Our professional services have been performed, our findings…