Geotech_Report_-_Putnam_County_Lift_Station.pdf

Geotechnical Exploration and Evaluation Report

For Lift Station

East Palatka Septic to Sewer Phase IV

Putnam County, Florida

CSI Geo Project No.: 71-24-268-56 MSA No.: LEGL0300923L0104

Contract No.: #23L0104.00.9007 TWO No.: 8

Prepared by:

CSI Geo, Inc.

2394 St. Johns Bluff Road S., Suite 200

Jacksonville, FL 32246 Tel: (904) 641-1993

Prepared for:

Hanson Professional Services, Inc.

January 24, 2025

CSI Geo, Inc. • 2394 St. Johns Bluff Road S, #200 • Jacksonville, FL 32246 • (904) 641-1993 • www.csi-geo.com

2394 St. Johns Bluff Road South, Suite 200

Jacksonville, FL 32246

January 24, 2025

Mr. Daryl Myers, P.E.

Hanson Professional Services, Inc.

8075 Gate Parkway West, Suite 204 Jacksonville, Florida 32216

RE: East Palatka Septic to Sewer Phase IV

Putnam County, Florida

Subject: Geotechnical Exploration and Evaluation Report for Lift Station CSI Geo Project No.: 71-24-268-56

MSA No.: LEGL0300923L0104 Contract No.: #23L0104.00.9007 TWO No.: 8

Dear Mr. Myers:

CSI Geo, Inc. has performed the authorized geotechnical exploration and laboratory testing program for the proposed East Palatka Septic to Sewer Phase IV in Putnam

County, Florida. This report presents our understanding of the subsurface conditions and discusses the geotechnical investigation program, geotechnical-related findings, and engineering evaluation and recommendations for the lift station.

We have enjoyed working with you on this project and look forward to continued association with you on future projects. If you have any questions concerning this report, please do not hesitate to contact us.

Sincerely, Nader Amer, Ph.D. John A. Iya, P.E.

Geotechnical Engineer Senior Geotechnical Engineer Registered, Florida No. 77294 johniya Pen

East Palatka Septic to Sewer Phase IV – Lift Station

TABLE OF CONTENTS

1.0 Project Information

1.1 General Project Information

1.2 Existing Conditions and Project Description

2.0 Geotechnical Exploration

2.1 Field Exploration

2.2 Laboratory Testing

3.0 Geotechnical Subsurface Conditions

3.1 General

3.2 Subsurface Conditions

3.3 Groundwater Conditions

4.0 Geotechnical Engineering Evaluation and Recommendations

4.1 Basis of Evaluation and Recommendations

4.2 Foundation Evaluation

4.3 Sheetpile Design Soil Parameters

5.0 SITE PREPARATION & CONSTRUCTION RECOMMENDATIONS

5.1 Excavation Protection

5.2 Site and Fill Compaction

6.0 REPORT LIMITATIONS

LIST OF APPENDICES

Site Location Map

Field Exploration Plan

Report of SPT Borings

Summary of Laboratory Test Results

Key to Soil Classification

Field and Laboratory Test Procedures

East Palatka Septic to Sewer Phase IV – Lift Station Page 1 of 7

1.0 Project Information

1.1 General Project Information

This Geotechnical Exploration and Evaluation Report has been prepared for the East

Palatka Septic to Sewer Phase IV project in Putnam County, Florida. The project includes the construction of a new lift station. This report presents our understanding of the subsurface conditions, and discusses the geotechnical investigation program, geotechnical-related findings, and engineering evaluation and recommendations for the new lift station.

Our study required the collection of subsurface data and the performance of geotechnical engineering analysis and evaluation. This report briefly describes the field and laboratory testing activities and presents our findings and recommendations.

Project information for this geotechnical exploration and evaluation was provided to us by

Mr. Daryl Myers, P.E. of Hanson Professional Services, Inc (Hanson).

1.2 Existing Conditions and Project Description

The site is located at the southwest quadrant of US 17 and Gail Drive. A Site Location

Map of the project area is included in the Appendix. At the time of our field activities, the proposed location of the lift station was obstructed by concrete rubble and debris.

Therefore, our test location for the lift station was offset to the south where it was accessible.

Based on the information provided to us, the new lift station will be 7 or 8 feet in diameter with a 10-foot diameter base/foundation. The foundation for the lift station will be placed

14-feet below the existing grade.

East Palatka Septic to Sewer Phase IV – Lift Station Page 2 of 7

2.0 Geotechnical Exploration

2.1 Field Exploration

The area of the proposed lift station was explored by means of one Standard Penetration

Test (SPT) boring (B-1) drilled to a depth of 50 feet below the existing grade. However, the SPT boring was extended to a depth of 70 feet to penetrate very loose soil conditions encountered between the depths of 25 and 50 feet below the existing grade.

The boring location was selected and located in the field by personnel from CSI Geo. Soil samples collected were visually classified in the field and then transported to our laboratory for reclassification and testing. The approximate location of the soil boring is shown on the Field Exploration Plan sheet included in the Appendix.

2.2 Laboratory Testing

Laboratory testing was performed on representative soil samples recovered from the field exploration. These tests were performed to better define the physical properties of the soils encountered. The laboratory tests were performed to determine percent fines (-200 sieve), organic content, Atterberg limits, and natural moisture content of the selected samples. Results of the laboratory tests performed are presented in the Summary of

Laboratory Test Results included in the Appendix. The laboratory testing procedures used are described in the Field and Laboratory Test Procedures sheet also included in the Appendix.

East Palatka Septic to Sewer Phase IV – Lift Station Page 3 of 7

3.0 Geotechnical Subsurface Conditions

3.1 General

An illustrated representation of the subsurface conditions encountered in the area of the proposed lift station is shown on the Report of SPT Borings sheet presented in the

Appendix. The soil conditions outlined below highlight the major subsurface stratification.

The Report of SPT Borings in the Appendix should be consulted for a detailed description of the subsurface conditions encountered at the boring location. When reviewing the subsurface profiles, it should be understood that soil conditions may vary outside of the explored area. The soil was classified using the Unified Soil Classification System

(USCS).

3.2 Subsurface Conditions

Review of SPT boring B-1 indicates that the lift station area is generally underlain by loose to medium dense sands (SP, USCS) and silty sands (SM) in the upper 22 feet of depth below the existing grade. A layer of highly organic silty sands (PT) was encountered between the depths of 4 and 6 feet below the existing grades. Beneath these soils, very loose silty sands (SM) and clayey sands (SC) with weight of hammer values were encountered from a depth of 22 to 52 feet, followed by loose to medium dense slightly silty sands (SP-SM) until the boring termination depth of 70 feet below the existing grade.

3.3 Groundwater Conditions

The groundwater level was measured and recorded at the time of drilling at 6 feet below the existing grade. Fluctuations of the groundwater level should be anticipated as a result of fluctuations of the nearby water bodies, ponds, seasonal climatic variations, surface water runoff patterns, construction activities, and other related factors. During seasonal high precipitation periods, groundwater levels can be expected to vary from the levels recorded during this exploration. Therefore, design drawings and specifications should account for the possibility of groundwater level variations, and construction planning should be based on the assumption that such variations will occur.

East Palatka Septic to Sewer Phase IV – Lift Station Page 4 of 7

4.0 Geotechnical Engineering Evaluation and Recommendations

4.1 Basis of Evaluation and Recommendations

Our geotechnical evaluation of the site and the subsurface conditions are based on our understanding of the proposed project, our observations, and results of field and laboratory testing. If the project location is changed or if field conditions encountered during construction are different from those presented in this report, the information should be provided to CSI Geo for evaluation.

The recommendations provided in this report present construction methods and techniques that are appropriate for the proposed construction. We recommend that CSI

Geo be given the opportunity to review the design plans and specifications to ensure that our recommendations have been properly included and implemented.

4.2 Foundation Evaluation

It is our opinion that the soil conditions can provide adequate support for the proposed lift station founded on a concrete pad for a maximum allowable soil bearing capacity of 1,500 pounds per square foot (psf). Using a 1,500 psf bearing pressure, we estimate that total settlements of the lift station will be on the order of less than 1 inch. Following site work and construction techniques in general accordance with our subsequent recommendations, we anticipate that differential settlements of the structure should be within tolerable magnitudes.

Any concentrated root zones, if encountered at the bearing levels, should be completely removed and replaced with acceptable compacted structural fill material. If clayey soils classified as SC (USCS) or A-2-6, A-6 or A-7 (AASHTO) are encountered at the bottom of the excavations, they should be regarded as unsuitable soils and should be removed to a depth of at least 2 feet below the bearing levels and replaced with structural fill placed in maximum 12-inch loose lifts and compacted to densities equivalent to at least 95 percent of the theoretical dry density as determined by ASTM D1557. If #57 stone is used as backfill in the excavation, we recommend the use of filter fabric to wrap the granular backfill to reduce soil migration.

East Palatka Septic to Sewer Phase IV – Lift Station Page 5 of 7

4.3 Sheetpile Design Soil Parameters

We understand that sheet pile walls may be used to facilitate excavations and construction of the lift station. If deemed necessary, the temporary casing or sheet pile walls should extend below the depth of the very loose soils and/or organic soils. We recommend that soil parameters and assumptions to be used for the project should include the following:

Soil Parameter

Loose to

Medium Dense

Sands

Very Loose Silty

& Clayey Sands

Loose to medium

Dense Sands

Depth (ft) 0.0 – 22.0 22.0 – 57.0 57.0 – 70.0

Saturated unit weight (pcf) 115 95 105

Effective unit weight (pcf) 53 33 43

Estimated friction angle φ (degrees) 31 24 30

Estimated cohesion (psf) --- --- ---

At Rest Pressure Coefficient (Ko) 0.48 0.59 0.50

Active Pressure Coefficient (Ka) 0.32 0.42 0.33

Passive Pressure Coefficient (Kp) 3.12 2.37 3.00

East Palatka Septic to Sewer Phase IV – Lift Station Page 6 of 7

5.0 SITE PREPARATION & CONSTRUCTION RECOMMENDATIONS

5.1 Excavation Protection

All excavations should meet OSHA Excavation Standard Subpart P regulations for Type

C soils. A braced sheet pile structure may be required to support the open excavations.

The soil support system should be designed by a Florida registered Professional

Engineer.

5.2 Site and Fill Compaction

The backfill material should be granular SP, SP-SM, or A-3 fill with less than 10 percent material passing the no. 200 mesh sieve and containing less than 3 percent organic matter. Onsite excavated and suitable soils may be used in backfilling of the excavation.

The backfill material should be compacted to a minimum density of 95% of maximum dry density obtained from the Modified Proctor compaction test (ASTM D1557). The moisture content during compaction should be maintained within + 3 percent of the optimum moisture content as obtained from the Modified Proctor compaction test.

East Palatka Septic to Sewer Phase IV – Lift Station Page 7 of 7

6.0 REPORT LIMITATIONS

The subsurface exploration program including our evaluation and recommendations was performed in general accordance with accepted geotechnical engineering principles and standard practices. CSI Geo is not responsible for any independent conclusions, opinions, or interpretations made by others based on the data presented in this report.

This report does not reflect any variations that may occur adjacent or between soil borings. The discovery of any site or subsurface condition during construction that deviates from the findings and data as presented in this report should be reported to CSI

Geo for evaluation. If the locations of the proposed project features are changed, our office should be contacted so our recommendations can be re-evaluated. We recommend that CSI Geo be given the opportunity to review the final design drawings and specifications to ensure that our recommendations are properly included and implemented.

APPENDIX

Report of SPT Borings

Summary of Laboratory Test Results

B-1

JACKSONVILLE, FLORIDA 32246

2394 ST. JOHNS BLUFF ROAD S., SUITE 200

CSI GEO, INC. SITE LOCATION MAP

APPROXIMATE SITE LOCATION

PUTNAM COUNTY, FLORIDA

EAST PALATKA SEPTIC TO SEWER PHASE IV PROJECT

B-1

JACKSONVILLE, FLORIDA 32246

2394 ST. JOHNS BLUFF ROAD S., SUITE 200

CSI GEO, INC. FIELD EXPLORATION PLAN

LEGEND

N

Feet

100200

PUTNAM COUNTY, FLORIDA

EAST PALATKA SEPTIC TO SEWER PHASE IV PROJECT

(SPT) BORING LOCATION

STANDARD PENETRATION TEST

Report of SPT Borings

Summary of Laboratory Test Results

#4 #10 #40 #60 #100 #200 LL Pl

B-1 3 4.0 - 6.0 102 27.0 27 SM/PT

B-1 5 8.0 - 10.0 23 5 SP

B-1 9 28.5 - 30.0 29 13 NP NP SM

SUMMARY OF LABORATORY TEST RESULTS

E Palatka Septic to Sewer Lift Station

Percent Passing Sieve Size (%) Atterberg Limits Boring No.

Putnam County, Florida

Sample

No.

Approximate Depth (ft)

Natural

Moisture

Content

Organic

Content

Soil

Classification

Symbol

KEY TO SOIL CLASSIFICATION

Correlation of Penetration Resistance with Relative Density and Consistency

Granular Materials

Silts and Clays

Relative Density Auto Hammer SPT N-Value (Blows/foot)

Consistency Auto Hammer SPT N-Value (Blows/foot)

Very Loose Less than 3 Very Soft Less than 1

Loose 3 – 8 Soft 1 – 3

Medium Dense 8 - 24 Firm 3 - 6

Dense 24 - 40 Stiff 6 - 12

Very Dense Greater than 40 Very Stiff 12 - 24

- Hard Greater than 24

Particle Size Identification (Unified Soil Classification System)

Boulders: Diameter exceeds 12 inches

Cobbles: 3 to 12 inches in diameter

Gravel:

Coarse – ¾ to 3 inches in diameter

Fine – 4.76 mm to ¾ inch in diameter

Sand:

Coarse 2.00 mm to 4.76 mm in diameter

Medium 0.42 mm to 2.0 mm in diameter

Fine 0.074 mm to 0.42 mm in diameter

Modifiers

Approximate Fines Content Modifiers

5% Fines to 12% Slightly Silty or Slightly Clayey

12% Fines to 30% Silty or Clayey

30% Fines to 50% Very Silty or Very Clayey

(These modifiers provide our estimate of the amount of fines (silt or clay size particles) in soil samples)

Approximate Content By Weight Modifiers

< 5% Trace

5% to 10% Few

15% to 25% Little

30% to 45% Some

50% to 100% Mostly

(These modifiers provide our estimate of shell, rock fragments, or roots in the soil sample)

Organic Content Modifiers

1% to 3% Trace

3% to 5% Slightly Organic

5% to 20% Organic

20% to 75% Highly Organic (Muck)

> 75% Peat

(These modifiers provide our estimate of organic content in the soil sample)

FIELD TEST PROCEDURES

Standard Penetration Test (SPT) Borings – The soil penetration test borings were made in general accordance with ASTM D-1586/D-1586M-18, "Penetration Test and Split-Barrel Sampling of Soils". The borings were advanced by continuous driving the split spoon sampler to a depth of 10 feet below the existing ground surface. Below 10 feet and until boring termination depths, split spoon sampling was performed at a spacing of 5 feet. Bentonite drilling fluid was used below the ground water level to stabilize the sides and to flush the cuttings. At the sampling intervals, the drilling tools were removed and 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. Representative portions of the soil samples, obtained from the sampler, were placed in glass jars and transported to our laboratory. The samples were then examined by a geotechnical engineer to confirm the field classifications.

LABORATORY TEST PROCEDURES

Percent Fine Content – To determine the percentage of soils finer than No. 200 sieve, the dried samples were washed over a 200 mesh sieve. The material retained on the sieve was oven dried and then weighed and compared with the unwashed dry weight in order to determine the weight of the fines. The percentage of fines in the soil sample was then determined as the percentage of weight of fines in the sample to the weight of the unwashed sample. This test was conducted in accordance with ASTM D 1140.

Natural Moisture Content – The water 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 test was conducted in the general accordance with AASHTO T 265.

Percent Organic Content – This test is based on the percent of organics by weight of the total sample. This test was conducted in accordance with FM I - T 267.

Plasticity (Atterberg Limits) – The soil's Plastic Index (PI) is bracketed by the Liquid Limit (LL) and Plastic Limit (PL). The LL is the moisture content at which the soil flows as a heavy viscous fluid and is determined in general accordance with FM 1-T 089. The PL is the moisture content at which the soil begins to crumble when rolled into a small thread and is also determined in general accordance with FM 1-T 090. The water-plasticity ratio is computed from the above test data. This ratio is an expression comparing the relative natural state of soil with its liquid and plastic consolidation characteristics.