Report of Geotechnical Exploration – Revision No. 1

Project:

Proposed New Bridge West 4th Street

Gulf Shores, Alabama

GeoCon Project No. DL 4207-23

Prepared For:

Mr. Trey Jinright, P.E.

JADE Consulting P.O. Box 1929

Fairhope, Alabama 36533

Date: January 31, 2024

Prepared By:

GeoCon Engineering & Materials Testing, Inc.

22830 McAuliffe Drive Robertsdale, Alabama 36567

22885 McAuliffe Drive Robertsdale, Alabama 36567

Phone (251) 947-1035

January 31, 2024

JADE Consulting P.O. Box 1929 Fairhope, Alabama 36533

Attn: Mr. Trey Jinright, P.E.

RE: Report of Geotechnical Exploration – Revision No. 1 Proposed New Bridge West 4th Street Gulf Shores, Alabama GeoCon Project No. DL 4207-23

Dear Mr. Jinright:

GeoCon Engineering & Materials Testing, Inc. is pleased to submit this report of geotechnical exploration for the above referenced project. Included in this report is a summary of our understanding of the project, results of the field exploration, and our recommendations for foundation design. This testing has been performed in general accordance with our earlier discussions with you.

Enclosed please find our report with evaluations and recommendations followed by an Appendix which includes a Site Location Map, Test Location Plan, graphical logs of the soundings, laboratory test data, a Unified Soil Classification Chart, important notes about your Geotechnical Report and the Terms and Conditions that govern our work for this project.

We appreciate the opportunity to have provided you with our geotechnical engineering services. If you have any questions concerning this report, or if we can be of any further assistance, please contact our office.

Sincerely, GeoCon, Inc.

David R. McKee, P.E. Hayden R. Mason, E.I.

Geotechnical Engineer Staff Engineer

Hayden Mason Pencil

Proposed New Bridge GeoCon, Inc.

West 4th Street Gulf Shores, Alabama January 31, 2024

TABLE OF CONTENTS

Page No.

1.0 Project Description

2.0 Area Geology

3.0 Geotechnical Exploration

4.0 Soil Conditions Encountered

5.0 Groundwater Conditions Encountered

6.0 Structural Fill

7.0 Corrosion Indicators

8.0 Closure

West 4th Street Gulf Shores, Alabama January 31, 2024

1.0 Project Description

The project subject to this report is the construction of a new bridge along West 4th Street, between West 2nd Avenue and West 3rd Avenue, in Gulf Shores, Alabama. At the time of our January 2024 field exploration, the existing bridge was still in place; however, the test locations were accessible to our equipment.

Based on the provided information, we understand that the proposed bridge will include a single-span, 20-foot-long timber bridge. We also understand that round timber piles are planned to support the proposed bridge. The purpose of this geotechnical exploration was to determine the soil conditions underlying the proposed new bridge and provide soil data for foundation design by others.

Note: If our understanding of the above project information differs from the actual project plans and specifications or if revisions to the project plans are made after this report, we should be contacted for analysis and comment as needed.

2.0 Area Geology

Published geologic information indicated that the subject site is located within the Coastal Plain Physiographic Province and is in an area underlain by alluvial, coastal and low river terrace sediments. These sediments typically consist of poorly-sorted, cross-bedded, gravelly medium to coarse sand containing zones of clayey sand and sandy clay.

3.0 Geotechnical Exploration

Soil conditions were investigated by performing two (2) Cone Penetration Test (CPT) soundings to depths of about 47 to 48 feet below the existing ground surface. GPS coordinates for the bridge layout were provided by JADE Consulting. The general test locations are shown on the attached Test Location Plan (Figure 2).

CPT testing was performed in accordance with ASTM D-5778 using a Vertek S4 electronic CPT rig. CPT testing includes pushing an electronic cone on a series of rods into the ground at a constant rate. The electronic cone collects continuous measurements of the resistance to penetration of the cone tip and side friction sleeve. Correlations between Cone Resistance values and Standard Penetration Test (SPT) “N” values were performed using methods developed by Robertson, Campanella and Wightman. The CPT logs attached in the appendix show the cone tip friction, sleeve friction, pore pressure, correlated “N” value and the soil behavior type (SBT).

West 4th Street Gulf Shores, Alabama January 31, 2024

4.0 Soil Conditions Encountered

Below about 4 inches of asphalt pavement, the soundings initially penetrated sand fill material to depths of about 5 feet below the pavement surface. Below the fill material, the soundings generally penetrated sand soils with thin varying strata of clay soils to depths of about 30 to 31 feet below the existing ground surface. Below depths of about 30 to 31 feet, the soundings generally penetrated clay soils to depths of about 39 to 42 feet followed by sand soils to sounding termination at depths of about 47 to 48 feet below the existing ground surface.

Based on the cone tip friction values and the correlated Standard Penetration Test values (N-values), the sand soils in the upper 30 to 31 feet were generally in a loose to dense condition.

The deeper sand soils were generally in a dense to very dense condition. The clay soils were generally in a soft condition. The soil conditions encountered are described in more detail on the Sounding Logs attached in the Appendix of this report.

5.0 Groundwater Conditions Encountered

Groundwater was encountered at depths of about 6 feet below the existing ground surface at the time of the field exploration. Groundwater conditions are subject to seasonal variations and are expected to fluctuate in response to local variations in precipitation and drainage conditions along the tributary. Considering the relatively short time frame of the field exploration, groundwater levels may not have had sufficient time to stabilize. Therefore, actual depths to groundwater may vary.

6.0 Structural Fill

Structural fill (if any) should meet the city and/or county color requirements and the following minimum requirements:

1) Exhibit A-3 classification according to the AASHTO Classification System

2) Exhibit SP or SP-SM classification according to the Unified Soil Classification System

3) Have a maximum of 10% soil fines passing the No. 200 sieve

4) Have a maximum Liquid Limit (LL) of 20

5) Have a Plasticity Index (PI) of 0 (Non-Plastic)

6) Have a minimum standard Proctor (ASTM D-698) maximum dry density of 105 pcf

Structural fill should be placed in 8-inch loose lifts and compacted to 98% ASTM D-698 standard density at moisture contents within +/- 3% of the material’s optimal moisture content.

Once the surface of each lift of structural fill is ready for the next lift, the exposed soil should be maintained at the placed moisture content until the next lift of fill is placed. The surface of the lifts should not be exposed to weather, especially drying, for an extended period of time.

West 4th Street Gulf Shores, Alabama January 31, 2024

7.0 Corrosion Indicators

Laboratory chemical analysis was performed on soil samples gathered from boring C-1 (4 to 6 feet below the existing ground surface). In addition, a chemical analysis was also performed on a water sample collected at the site. The results are shown below in Table 1 and the chemical analysis sheet is attached in the Appendix.

Table 1

Analyte Soil Sample

C-1 (4 - 6 feet) Water Sample pH 4.8 7.8

Resistivity 0.013 Mohm-cm 0.000033 Mohm-cm

Chloride <2.4 17,000 mg/L

Sulfate <7.6 1,900 mg/L

8.0 Closure

This report has been prepared for the exclusive use of JADE Consulting and their project design professionals for specific application to the above referenced project in accordance with generally accepted current standards of geotechnical engineering practice common to the local area.

The comments and recommendations of this report provide manageable and reasonable solutions to the advancement of the project based on the collected test data and the provided design information. Significant changes in site conditions or project design may result in alternative solutions to the design required or may permit more manageable and economical construction techniques. Should such significant changes occur, we will be available to offer supplemental comments.

The comments and recommendations of this report are based upon our interpretation of the information supplied by the client, the data collected at the two (2) CPT soundings and the site conditions observed at the time of testing. A significant amount of interpolation was necessary. Because it is not possible to know or predict detailed conditions hidden beneath the ground surface, our comments and recommendations are presented as opinions and judgements, as opposed to statements of fact.

Improper site preparation, extremes in climatic conditions, significant changes in grade, time, etc., can affect the groundwater, surface, and subsurface conditions. If conditions are encountered as the construction advances which vary significantly from those described by this report, we should be contacted for additional comment.

West 4th Street Gulf Shores, Alabama January 31, 2024

We have not intended to reflect specific volumes of subsurface conditions at the site.

Volumetric estimates often require a large number of borings placed on a close grid with the collected data associated with civil engineering cross-sections. If volume estimates are required of us for the design/development of this project to advance, please contact us for further comment. Again, we appreciate the opportunity to provide our geotechnical engineering services for this project. We recommend that the owner retain GeoCon, Inc. to provide construction observation and construction materials testing for the project.

APPENDIX

A-1 Site Location Map

A-2 Test Location Plan

A-3 Graphical Logs of the Soundings

A-4 Laboratory Test Data

A-5 Unified Soil Classification Chart

A-6 Important Notes About Your Geotechnical Report

A-7 Terms & Conditions Sheet

Figure 1

Date 1/8/2024

GEOCON, INC.

22830 McAuliffe Drive

Robertsdale, Alabama 36567

SITE LOCATION MAP

NOT TO SCALE

Proposed New Bridge West 4th Street Gulf Shores, AL

DL 4207-23

N

Site

Figure 2

Date 1/8/2024

GEOCON, INC.

22830 McAuliffe Drive Robertsdale, AL 36567

TEST LOCATION PLAN

NOT TO SCALE

Proposed New Bridge West 4th Street Gulf Shores, AL

DL 4207-23

N

C-1

C-2

C-1 CPT Testing Done By : GeoCon Proposed: New Bridge CUSTOMER: Jade Consulting LOCATION: Gulf Shores, AL

HOLE NUMBER: C-1

JOB NUMBER: DL 4207-23

TEST DATE: 1/4/2024

OPERATOR: Bryant Volovecky

GPS (LAT,LON,ALT): 3014.9630N,08741.8510W,-1.0

Depth (ft)

Tip Stress UNC (tsf) 0 7000

Sleeve Stress (tsf)

Pore Pressure (psi) 0 50

SPT

(blows/ft) 0 80

SBT FR

(RC 1983)

1 sensitive fine grained 2 organic material 3 clay

4 silty clay to clay 5 clayey silt to silty clay 6 sandy silt to clayey silt

7 silty sand to sandy silt 8 sand to silty sand 9 sand

10 gravelly sand to sand 11 very stiff fine grained (*) 12 sand to clayey sand (*)

*SBT/SPT CORRELATION: UBC-1983

0 12

GROUNDWATER AT 6 FT

4 INCHES ASPHALT PAVING

SANDY FILL

SAND WITH THIN

CLAY LAYERS

SAND

CLAY WITH THIN

CLAY LAYERS

COARSE SAND

FIRM/VERY FIRM

LOOSE/FIRM

FIRM/VERY FIRM

SOFT

DENSE/VERY DENSE

C-2 CPT Testing Done By : GeoCon Proposed: New Bridge CUSTOMER: Jade Consulting LOCATION: Gulf Shores, AL

HOLE NUMBER: C-2

JOB NUMBER: DL 4207-23

TEST DATE: 1/4/2024

OPERATOR: Bryant Volovecky

GPS (LAT,LON,ALT): 3014.9690N,08741.8520W,9.0

Depth (ft)

Tip Stress UNC (tsf) 0 8000

Sleeve Stress (tsf)

Pore Pressure (psi) 0 70

SPT

(blows/ft) 0 80

SBT FR

(RC 1983)

1 sensitive fine grained 2 organic material 3 clay

4 silty clay to clay 5 clayey silt to silty clay 6 sandy silt to clayey silt

7 silty sand to sandy silt 8 sand to silty sand 9 sand

10 gravelly sand to sand 11 very stiff fine grained (*) 12 sand to clayey sand (*)

*SBT/SPT CORRELATION: UBC-1983

0 12

4 INCHES ASPHALT PAVING

SANDY FILL

SAND

CLAY

SAND

FIRM/VERY FIRM

VERY FIRM/DENSE

SOFT

GROUNDWATER AT 6 FT

VERY DENSE

COMBINED SOUNDING PLOT

test #1: C-1.cpt test #2: C-2.cpt

Depth (ft)

Tip Stress UNC (tsf) 0 800

SPT

(blows/ft) 0 140

REMARKS

PROPOSED: NEW BRIDGE

CUSTOMER: JADE CONSULTING

JOB NUMBER: DL 4207-23

LOCATION: GULF SHORES, AL

ANALYTICAL REPORT

PREPARED FOR

Attn: Dave McKee

GeoCon Engineering 22885 Mcauliffe Dr

Robertsdale, Alabama 36567 Generated 1/29/2024 12:05:07 PM

JOB DESCRIPTION

4th St. Bridge Project - Gulf Shores, AL

JOB NUMBER

400-249845-1

See page two for job notes and contact information.

Pensacola FL 32514 3355 McLemore Drive Eurofins Pensacola https://eol.et.eurofinsus.com/myEOL/

Eurofins Pensacola

Eurofins Pensacola is a laboratory within Eurofins Environment Testing Southeast, LLC, a company within Eurofins Environment Testing Group of Companies

Job Notes This report may not be reproduced except in full, and with written approval from the laboratory. The results relate only to the samples tested. For questions please contact the Project Manager at the e-mail address or telephone number listed on this page.

The test results in this report relate only to the samples as received by the laboratory and will meet all requirements of the methodology, with any exceptions noted. This report shall not be reproduced except in full, without the express written approval of the laboratory. All questions should be directed to the Eurofins Environment Testing Southeast, LLC Project Manager.

Authorization

Generated

1/29/2024 12:05:07 PM

Authorized for release by Isabel Enfinger, Project Manager I isabel.enfinger@et.eurofinsus.com Designee for Taylor Bruzzio, Project Manager I Taylor.Bruzzio@et.eurofinsus.comTaylor.Bruzzio@et.eurofinsus.com (850)471-6226

Page 2 of 21 1/29/2024

Table of Contents

Client: GeoCon Engineering Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Laboratory Job ID: 400-249845-1

Eurofins Pensacola

1/29/2024

Cover Page

Table of Contents

Sample Summary

Detection Summary

Client Sample Results

Definitions

Case Narrative

Method Summary

Chronicle

QC Association

QC Sample Results

Chain of Custody

Receipt Checklists

Certification Summary

Sample Summary Client: GeoCon Engineering Job ID: 400-249845-1 Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Lab Sample ID Client Sample ID Matrix Collected Received

400-249845-1 WATER SAMPLE Water 01/17/24 14:30 01/19/24 16:15

400-249845-2 SOIL SAMPLE (C-1 4-6FT) Solid 01/17/24 14:45 01/19/24 16:15

Eurofins Pensacola Page 4 of 21 1/29/2024

Detection Summary Job ID: 400-249845-1Client: GeoCon Engineering

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Client Sample ID: WATER SAMPLE Lab Sample ID: 400-249845-1

Resistivity

RL

0.000010 Mohm-cm

MDL

0.000010

Analyte Result Qualifier Unit Dil Fac D Method Prep Type

Total/NA10.000033 120.1 pH SU Total/NA17.8 HF 150.1

Chloride 10000 mg/L7000 Total/NA500017000 SM 4500 Cl- E

Sulfate 250 mg/L70 Total/NA501900 SM 4500 SO4 E

Client Sample ID: SOIL SAMPLE (C-1 4-6FT) Lab Sample ID: 400-249845-2 pH

NONE

SU

NONEAnalyte Result Qualifier Unit Dil Fac D Method Prep Type

Total/NA14.8 9045D

Resistivity 0.00020 Mohm-cm0.00020 Soluble10.013 9050A

Eurofins Pensacola

This Detection Summary does not include radiochemical test results.

Page 5 of 21 1/29/2024

Client Sample Results

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Lab Sample ID: 400-249845-1Client Sample ID: WATER SAMPLE Matrix: WaterDate Collected: 01/17/24 14:30

Date Received: 01/19/24 16:15

General Chemistry

NONE NONE

7.8 HF SU 01/23/24 10:50 1

Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier pH (EPA 150.1)

RL MDL

0.000033 0.000010 0.000010 Mohm-cm 01/26/24 13:52 1

Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

Resistivity (EPA 120.1)

10000 7000 mg/L 01/25/24 14:01 500017000Chloride (SM 4500 Cl- E)

250 70 mg/L 01/26/24 16:06 501900Sulfate (SM 4500 SO4 E)

Eurofins Pensacola

Page 6 of 21 1/29/2024

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Lab Sample ID: 400-249845-2Client Sample ID: SOIL SAMPLE (C-1 4-6FT) Matrix: SolidDate Collected: 01/17/24 14:45

Date Received: 01/19/24 16:15

General Chemistry

NONE NONE

4.8 SU 01/23/24 13:38 1

Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier pH (SW846 9045D)

General Chemistry - Soluble

RL MDL

0.013 0.00020 0.00020 Mohm-cm 01/26/24 13:46 1

Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

Resistivity (SW846 9050A)

Eurofins Pensacola

Page 7 of 21 1/29/2024

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Lab Sample ID: 400-249845-2Client Sample ID: SOIL SAMPLE (C-1 4-6FT) Matrix: SolidDate Collected: 01/17/24 14:45

Percent Solids: 93.8Date Received: 01/19/24 16:15

Method: SW846 9056A - Anions, Ion Chromatography - Soluble

RL MDL

<2.4 21 2.4 mg/Kg ☼ 01/24/24 15:10 1

Analyte Dil FacAnalyzedPreparedUnit DResult Qualifier

Chloride

21 7.6 mg/Kg 01/24/24 15:10 1☼<7.6Sulfate

Eurofins Pensacola

Page 8 of 21 1/29/2024

Definitions/Glossary

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Qualifiers

HPLC/IC

Qualifier Description

4 MS, MSD: The analyte present in the original sample is greater than 4 times the matrix spike concentration; therefore, control limits are not applicable.

Qualifier

E Result exceeded calibration range.

F2 MS/MSD RPD exceeds control limits

J Result is less than the RL but greater than or equal to the MDL and the concentration is an approximate value.

General Chemistry Qualifier Description

4 MS, MSD: The analyte present in the original sample is greater than 4 times the matrix spike concentration; therefore, control limits are not applicable.

Qualifier

F1 MS and/or MSD recovery exceeds control limits.

HF Parameter with a holding time of 15 minutes. Test performed by laboratory at client's request. Sample was analyzed outside of hold time.

J Result is less than the RL but greater than or equal to the MDL and the concentration is an approximate value.

Glossary These commonly used abbreviations may or may not be present in this report.

¤ Listed under the "D" column to designate that the result is reported on a dry weight basis

Abbreviation

%R Percent Recovery

CFL Contains Free Liquid

CFU Colony Forming Unit

CNF Contains No Free Liquid

DER Duplicate Error Ratio (normalized absolute difference)

Dil Fac Dilution Factor

DL Detection Limit (DoD/DOE)

DL, RA, RE, IN Indicates a Dilution, Re-analysis, Re-extraction, or additional Initial metals/anion analysis of the sample

DLC Decision Level Concentration (Radiochemistry)

EDL Estimated Detection Limit (Dioxin)

LOD Limit of Detection (DoD/DOE)

LOQ Limit of Quantitation (DoD/DOE)

MCL EPA recommended "Maximum Contaminant Level"

MDA Minimum Detectable Activity (Radiochemistry)

MDC Minimum Detectable Concentration (Radiochemistry)

MDL Method Detection Limit

ML Minimum Level (Dioxin)

MPN Most Probable Number

MQL Method Quantitation Limit

NC Not Calculated

ND Not Detected at the reporting limit (or MDL or EDL if shown)

NEG Negative / Absent

POS Positive / Present

PQL Practical Quantitation Limit

PRES Presumptive

QC Quality Control

RER Relative Error Ratio (Radiochemistry)

RL Reporting Limit or Requested Limit (Radiochemistry)

RPD Relative Percent Difference, a measure of the relative difference between two points

TEF Toxicity Equivalent Factor (Dioxin)

TEQ Toxicity Equivalent Quotient (Dioxin)

TNTC Too Numerous To Count

Eurofins Pensacola

Page 9 of 21 1/29/2024

Job Narrative 400-249845-1

Receipt The samples were received on 1/19/2024 4:15 PM. Unless otherwise noted below, the samples arrived in good condition, and where required, properly preserved and on ice. The temperature of the cooler at receipt was 0.0º C.

HPLC/IC

Method 9056A: Due to the high concentration of Sulfate, the matrix spike / matrix spike duplicate (MS/MSD) for preparation batch 400-658552 and analytical batch 400-658592 could not be evaluated for accuracy and precision. The associated laboratory control sample (LCS) met acceptance criteria.

Method 9056A: The method blank for preparation batch 400-658552 and analytical batch 400-658592 contained Chloride and Sulfate above the method detection limit. This target analyte concentration was less than the reporting limit (RL) in the method blank; therefore, re-extraction and/or re-analysis of samples was not performed.

No additional analytical or quality issues were noted, other than those described above or in the Definitions/Glossary page.

General Chemistry Method SM 4500 Cl- E: The matrix spike / matrix spike duplicate (MS/MSD) recoveries for analytical batch 400-658736 were outside control limits for one or more analytes. See QC Sample Results for detail. Sample matrix interference and/or non-homogeneity are suspected because the associated laboratory control sample (LCS) recovery is within acceptance limits.

Method SM 4500 Cl- E: The following sample was diluted to bring the concentration of target analytes within the calibration range:

WATER SAMPLE (400-249845-1). Elevated reporting limits (RLs) are provided.

Method SM 4500 SO4 E: The following samples were diluted to bring the concentration of target analytes within the calibration range: WATER SAMPLE (400-249845-1) and (400-250051-D-1). Elevated reporting limits (RLs) are provided.

Method SM 4500 SO4 E: The matrix spike / matrix spike duplicate (MS/MSD) recoveries for analytical batch 400-658897 were outside control limits for one or more analytes. See QC Sample Results for detail. Sample matrix interference and/or non-homogeneity are suspected because the associated laboratory control sample (LCS) recovery is within acceptance limits.

No additional analytical or quality issues were noted, other than those described above or in the Definitions/Glossary page.

Case Narrative Client: GeoCon Engineering Job ID: 400-249845-1 Project: 4th St. Bridge Project - Gulf Shores, AL

Eurofins Pensacola

Job ID: 400-249845-1 Eurofins Pensacola

Page 10 of 21 1/29/2024

Method Summary

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Method Method Description LaboratoryProtocol

SW8469056A Anions, Ion Chromatography EET PEN

EPA120.1 Conductivity, Specific Conductance EET PEN

EPA150.1 pH (Electrometric) EET PEN

SW8469045D pH EET PEN

SW8469050A Specific Conductance EET PEN

EPAMoisture Percent Moisture EET PEN

SMSM 4500 Cl- E Chloride, Total EET PEN

SMSM 4500 SO4 E Sulfate, Total EET PEN

ASTMDI Leach Deionized Water Leaching Procedure EET PEN

Protocol References:

ASTM = ASTM International

EPA = US Environmental Protection Agency

SM = "Standard Methods For The Examination Of Water And Wastewater"

SW846 = "Test Methods For Evaluating Solid Waste, Physical/Chemical Methods", Third Edition, November 1986 And Its Updates.

Laboratory References:

EET PEN = Eurofins Pensacola, 3355 McLemore Drive, Pensacola, FL 32514, TEL (850)474-1001

Eurofins Pensacola

Page 11 of 21 1/29/2024

Lab Chronicle

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Client Sample ID: WATER SAMPLE Lab Sample ID: 400-249845-1 Matrix: WaterDate Collected: 01/17/24 14:30

Date Received: 01/19/24 16:15

Analysis 120.1 CAC1 658874 EET PEN

Type

Batch Batch

MethodPrep Type LabAnalystRun

Prepared or Analyzed

Batch

Number

Dilution

Factor

Total/NA 01/26/24 13:52

Analysis 150.1 1 658429 JP EET PENTotal/NA 01/23/24 10:50

Analysis SM 4500 Cl- E 5000 658736 CJK EET PENTotal/NA 01/25/24 14:01

Analysis SM 4500 SO4 E 50 658897 CJK EET PENTotal/NA 01/26/24 16:06

Client Sample ID: SOIL SAMPLE (C-1 4-6FT) Lab Sample ID: 400-249845-2 Matrix: SolidDate Collected: 01/17/24 14:45

Date Received: 01/19/24 16:15

Analysis 9045D JP1 658463 EET PEN

Type

Batch Batch

MethodPrep Type LabAnalystRun

Prepared or Analyzed

Batch

Number

Dilution

Factor

Total/NA 01/23/24 13:38

Leach DI Leach 658835 CAC EET PENSoluble 01/26/24 11:01

Analysis 9050A 1 658873 CAC EET PENSoluble 01/26/24 13:46

Analysis Moisture 1 658363 TMP EET PENTotal/NA 01/22/24 14:26

Client Sample ID: SOIL SAMPLE (C-1 4-6FT) Lab Sample ID: 400-249845-2 Matrix: SolidDate Collected: 01/17/24 14:45

Percent Solids: 93.8Date Received: 01/19/24 16:15

Leach DI Leach JN658552 EET PEN

Type

Batch Batch

MethodPrep Type LabAnalystRun

Prepared or Analyzed

Batch

Number

Dilution

Factor

Soluble 01/24/24 10:10

Analysis 9056A 1 658592 JN EET PENSoluble 01/24/24 15:10

Laboratory References:

EET PEN = Eurofins Pensacola, 3355 McLemore Drive, Pensacola, FL 32514, TEL (850)474-1001

Eurofins Pensacola

Page 12 of 21 1/29/2024

QC Association Summary

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

HPLC/IC

Leach Batch: 658552

Lab Sample ID Client Sample ID Prep Type Matrix Method Prep Batch

Solid DI Leach400-249845-2 SOIL SAMPLE (C-1 4-6FT) Soluble

Solid DI LeachMB 400-658552/1-A Method Blank Soluble

Solid DI LeachLCS 400-658552/2-A Lab Control Sample Soluble

Solid DI LeachLCSD 400-658552/3-A Lab Control Sample Dup Soluble

Solid DI Leach400-249951-A-1-B MS Matrix Spike Soluble

Solid DI Leach400-249951-A-1-C MSD Matrix Spike Duplicate Soluble

Analysis Batch: 658592

Lab Sample ID Client Sample ID Prep Type Matrix Method Prep Batch

Solid 9056A 658552400-249845-2 SOIL SAMPLE (C-1 4-6FT) Soluble

Solid 9056A 658552MB 400-658552/1-A Method Blank Soluble

Solid 9056A 658552LCS 400-658552/2-A Lab Control Sample Soluble

Solid 9056A 658552LCSD 400-658552/3-A Lab Control Sample Dup Soluble

Solid 9056A 658552400-249951-A-1-B MS Matrix Spike Soluble

Solid 9056A 658552400-249951-A-1-C MSD Matrix Spike Duplicate Soluble

General Chemistry

Analysis Batch: 658363

Lab Sample ID Client Sample ID Prep Type Matrix Method Prep Batch

Solid Moisture400-249845-2 SOIL SAMPLE (C-1 4-6FT) Total/NA

Solid Moisture400-249833-E-21 MS Matrix Spike Total/NA

Solid Moisture400-249833-E-21 MSD Matrix Spike Duplicate Total/NA

Solid Moisture400-249895-A-2 DU Duplicate Total/NA

Analysis Batch: 658429

Lab Sample ID Client Sample ID Prep Type Matrix Method Prep Batch

Water 150.1400-249845-1 WATER SAMPLE Total/NA

Water 150.1LCS 400-658429/4 Lab Control Sample Total/NA

Water 150.1400-249715-A-1 DU Duplicate Total/NA

Analysis Batch: 658463

Lab Sample ID Client Sample ID Prep Type Matrix Method Prep Batch

Solid 9045D400-249845-2 SOIL SAMPLE (C-1 4-6FT) Total/NA

Solid 9045DLCS 400-658463/5 Lab Control Sample Total/NA

Solid 9045D400-249845-2 DU SOIL SAMPLE (C-1 4-6FT) Total/NA

Analysis Batch: 658736

Lab Sample ID Client Sample ID Prep Type Matrix Method Prep Batch

Water SM 4500 Cl- E400-249845-1 WATER SAMPLE Total/NA

Water SM 4500 Cl- EMB 400-658736/14 Method Blank Total/NA

Water SM 4500 Cl- EMB 400-658736/47 Method Blank Total/NA

Water SM 4500 Cl- ELCS 400-658736/15 Lab Control Sample Total/NA

Water SM 4500 Cl- EMRL 400-658736/16 Lab Control Sample Total/NA

Water SM 4500 Cl- E400-249922-A-1 MS Matrix Spike Total/NA

Water SM 4500 Cl- E400-249922-A-1 MSD Matrix Spike Duplicate Total/NA

Leach Batch: 658835

Lab Sample ID Client Sample ID Prep Type Matrix Method Prep Batch

Solid DI Leach400-249845-2 SOIL SAMPLE (C-1 4-6FT) Soluble

Solid DI LeachMB 400-658835/1-A Method Blank Soluble

Eurofins Pensacola

Page 13 of 21 1/29/2024

QC Association Summary

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

General Chemistry (Continued)

Leach Batch: 658835 (Continued)

Lab Sample ID Client Sample ID Prep Type Matrix Method Prep Batch

Solid DI LeachLCS 400-658835/2-A Lab Control Sample Soluble

Solid DI Leach400-249845-2 DU SOIL SAMPLE (C-1 4-6FT) Soluble

Analysis Batch: 658873

Lab Sample ID Client Sample ID Prep Type Matrix Method Prep Batch

Solid 9050A 658835400-249845-2 SOIL SAMPLE (C-1 4-6FT) Soluble

Solid 9050A 658835MB 400-658835/1-A Method Blank Soluble

Solid 9050A 658835LCS 400-658835/2-A Lab Control Sample Soluble

Solid 9050A 658835400-249845-2 DU SOIL SAMPLE (C-1 4-6FT) Soluble

Analysis Batch: 658874

Lab Sample ID Client Sample ID Prep Type Matrix Method Prep Batch

Water 120.1400-249845-1 WATER SAMPLE Total/NA

Water 120.1MB 400-658874/1 Method Blank Total/NA

Water 120.1LCS 400-658874/2 Lab Control Sample Total/NA

Water 120.1400-249845-1 DU WATER SAMPLE Total/NA

Analysis Batch: 658897

Lab Sample ID Client Sample ID Prep Type Matrix Method Prep Batch

Water SM 4500 SO4 E400-249845-1 WATER SAMPLE Total/NA

Water SM 4500 SO4 EMB 400-658897/24 Method Blank Total/NA

Water SM 4500 SO4 ELCS 400-658897/25 Lab Control Sample Total/NA

Water SM 4500 SO4 EMRL 400-658897/26 Lab Control Sample Total/NA

Water SM 4500 SO4 E400-250051-D-1 MS Matrix Spike Total/NA

Water SM 4500 SO4 E400-250051-D-1 MSD Matrix Spike Duplicate Total/NA

Eurofins Pensacola

Page 14 of 21 1/29/2024

QC Sample Results

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Method: 9056A - Anions, Ion Chromatography

Client Sample ID: Method BlankLab Sample ID: MB 400-658552/1-A Matrix: Solid Prep Type: Soluble Analysis Batch: 658592

RL MDL

Chloride 2.32 J 19 2.2 mg/Kg 01/24/24 14:19 1

MB MB

Analyte Dil FacAnalyzedPreparedDUnitResult Qualifier

<7.1 7.119 mg/Kg 01/24/24 14:19 1Sulfate

Client Sample ID: Lab Control SampleLab Sample ID: LCS 400-658552/2-A Matrix: Solid Prep Type: Soluble Analysis Batch: 658592

Chloride 99.0 90.1 mg/Kg 91 80 - 120

Analyte

LCS LCS

DUnitResult Qualifier %Rec

Spike

Added

%Rec

Limits

Sulfate 99.0 98.1 mg/Kg 99 80 - 120

Client Sample ID: Lab Control Sample DupLab Sample ID: LCSD 400-658552/3-A Matrix: Solid Prep Type: Soluble Analysis Batch: 658592

Chloride 99.9 89.7 mg/Kg 90 80 - 120 0 15

Analyte

LCSD LCSD

DUnitResult Qualifier %Rec

Spike

Added

%Rec

Limits LimitRPD

RPD

Sulfate 99.9 97.7 mg/Kg 98 80 - 120 0 15

Client Sample ID: Matrix SpikeLab Sample ID: 400-249951-A-1-B MS Matrix: Solid Prep Type: Soluble Analysis Batch: 658592

Chloride 6300 E B F2 110 4480 E 4 mg/Kg -1669 80 - 120☼

Analyte

MS MS

DUnitResult Qualifier %Rec

Spike

Added

Sample

Result

Sample

Qualifier

%Rec

Limits

Sulfate 1900 E 110 2230 E 4 mg/Kg 338 80 - 120☼

Client Sample ID: Matrix Spike DuplicateLab Sample ID: 400-249951-A-1-C MSD Matrix: Solid Prep Type: Soluble Analysis Batch: 658592

Chloride 6300 E B F2 109 5500 E 4 F2 mg/Kg -754 80 - 120 20 15☼

Analyte

MSD MSD

DUnitResult Qualifier %Rec

Spike

Added

Sample

Result

Sample

Qualifier

%Rec

Limits LimitRPD

RPD

Sulfate 1900 E 109 2260 E 4 mg/Kg 368 80 - 120 1 15☼

Method: 120.1 - Conductivity, Specific Conductance

Client Sample ID: Method BlankLab Sample ID: MB 400-658874/1 Matrix: Water Prep Type: Total/NA Analysis Batch: 658874

RL MDL

Resistivity 1.37 0.000010 0.000010 Mohm-cm 01/26/24 13:52 1

MB MB

Analyte Dil FacAnalyzedPreparedDUnitResult Qualifier

Client Sample ID: WATER SAMPLELab Sample ID: 400-249845-1 DU Matrix: Water Prep Type: Total/NA Analysis Batch: 658874

Resistivity 0.000033 0.0000325 Mohm-cm 0.6 10

Analyte

DU DU

DUnitResult Qualifier

Sample

Result

Sample

Qualifier LimitRPD

RPD

Eurofins Pensacola

Page 15 of 21 1/29/2024

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Method: 150.1 - pH (Electrometric)

Client Sample ID: DuplicateLab Sample ID: 400-249715-A-1 DU Matrix: Water Prep Type: Total/NA Analysis Batch: 658429 pH 5.3 5.3 SU 0.8 5

Analyte

DU DU

DUnitResult Qualifier

Sample

Result

Sample

Qualifier LimitRPD

RPD

Method: 9045D - pH

Client Sample ID: SOIL SAMPLE (C-1 4-6FT)Lab Sample ID: 400-249845-2 DU Matrix: Solid Prep Type: Total/NA Analysis Batch: 658463 pH 4.8 4.8 SU 0.4 5

Analyte

DU DU

DUnitResult Qualifier

Sample

Result

Sample

Qualifier LimitRPD

RPD

Method: 9050A - Specific Conductance

Client Sample ID: Method BlankLab Sample ID: MB 400-658835/1-A Matrix: Solid Prep Type: Soluble Analysis Batch: 658873

RL MDL

Resistivity 0.0532 0.00020 0.00020 Mohm-cm 01/26/24 13:46 1

MB MB

Analyte Dil FacAnalyzedPreparedDUnitResult Qualifier

Client Sample ID: SOIL SAMPLE (C-1 4-6FT)Lab Sample ID: 400-249845-2 DU Matrix: Solid Prep Type: Soluble Analysis Batch: 658873

Resistivity 0.013 0.0127 Mohm-cm 1 10

Analyte

DU DU

DUnitResult Qualifier

Sample

Result

Sample

Qualifier LimitRPD

RPD

Method: SM 4500 Cl- E - Chloride, Total

Client Sample ID: Method BlankLab Sample ID: MB 400-658736/14 Matrix: Water Prep Type: Total/NA Analysis Batch: 658736

RL MDL

Chloride <1.4 2.0 1.4 mg/L 01/25/24 11:07 1

MB MB

Analyte Dil FacAnalyzedPreparedDUnitResult Qualifier

Client Sample ID: Method BlankLab Sample ID: MB 400-658736/47 Matrix: Water Prep Type: Total/NA Analysis Batch: 658736

RL MDL

Chloride <1.4 2.0 1.4 mg/L 01/25/24 11:58 1

MB MB

Analyte Dil FacAnalyzedPreparedDUnitResult Qualifier

Client Sample ID: Lab Control SampleLab Sample ID: LCS 400-658736/15 Matrix: Water Prep Type: Total/NA Analysis Batch: 658736

Chloride 50.0 50.2 mg/L 100 90 - 110

Analyte

LCS LCS

DUnitResult Qualifier %Rec

Spike

Added

%Rec

Limits

Eurofins Pensacola

Page 16 of 21 1/29/2024

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Method: SM 4500 Cl- E - Chloride, Total (Continued)

Client Sample ID: Lab Control SampleLab Sample ID: MRL 400-658736/16 Matrix: Water Prep Type: Total/NA Analysis Batch: 658736

Chloride 2.00 1.48 J mg/L 74 50 - 150

Analyte

MRL MRL

DUnitResult Qualifier %Rec

Spike

Added

%Rec

Limits

Client Sample ID: Matrix SpikeLab Sample ID: 400-249922-A-1 MS Matrix: Water Prep Type: Total/NA Analysis Batch: 658736

Chloride 5.5 F1 10.0 26.0 F1 mg/L 205 73 - 120

Analyte

MS MS

DUnitResult Qualifier %Rec

Spike

Added

Sample

Result

Sample

Qualifier

%Rec

Limits

Client Sample ID: Matrix Spike DuplicateLab Sample ID: 400-249922-A-1 MSD Matrix: Water Prep Type: Total/NA Analysis Batch: 658736

Chloride 5.5 F1 10.0 26.3 F1 mg/L 209 73 - 120 1 8

Analyte

MSD MSD

DUnitResult Qualifier %Rec

Spike

Added

Sample

Result

Sample

Qualifier

%Rec

Limits LimitRPD

RPD

Method: SM 4500 SO4 E - Sulfate, Total

Client Sample ID: Method BlankLab Sample ID: MB 400-658897/24 Matrix: Water Prep Type: Total/NA Analysis Batch: 658897

RL MDL

Sulfate <1.4 5.0 1.4 mg/L 01/26/24 15:51 1

MB MB

Analyte Dil FacAnalyzedPreparedDUnitResult Qualifier

Client Sample ID: Lab Control SampleLab Sample ID: LCS 400-658897/25 Matrix: Water Prep Type: Total/NA Analysis Batch: 658897

Sulfate 15.0 14.7 mg/L 98 90 - 110

Analyte

LCS LCS

DUnitResult Qualifier %Rec

Spike

Added

%Rec

Limits

Client Sample ID: Lab Control SampleLab Sample ID: MRL 400-658897/26 Matrix: Water Prep Type: Total/NA Analysis Batch: 658897

Sulfate 5.00 7.00 mg/L 140 50 - 150

Analyte

MRL MRL

DUnitResult Qualifier %Rec

Spike

Added

%Rec

Limits

Client Sample ID: Matrix SpikeLab Sample ID: 400-250051-D-1 MS Matrix: Water Prep Type: Total/NA Analysis Batch: 658897

Sulfate 43 10.0 43.2 4 mg/L 0.4 77 - 128

Analyte

MS MS

DUnitResult Qualifier %Rec

Spike

Added

Sample

Result

Sample

Qualifier

%Rec

Limits

Eurofins Pensacola

Page 17 of 21 1/29/2024

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Method: SM 4500 SO4 E - Sulfate, Total (Continued)

Client Sample ID: Matrix Spike DuplicateLab Sample ID: 400-250051-D-1 MSD Matrix: Water Prep Type: Total/NA Analysis Batch: 658897

Sulfate 43 10.0 43.6 4 mg/L 4 77 - 128 1 5

Analyte

MSD MSD

DUnitResult Qualifier %Rec

Spike

Added

Sample

Result

Sample

Qualifier

%Rec

Limits LimitRPD

RPD

Eurofins Pensacola

Page 18 of 21 1/29/2024

Page 19 of 21 1/29/2024

Login Sample Receipt Checklist

Client: GeoCon Engineering Job Number: 400-249845-1

Login Number: 249845

Question Answer Comment

Creator: Roberts, Alexis J

List Source: Eurofins Pensacola

List Number: 1

N/ARadioactivity wasn't checked or is </= background as measured by a survey meter.

N/AThe cooler's custody seal, if present, is intact.

N/ASample custody seals, if present, are intact.

TrueThe cooler or samples do not appear to have been compromised or tampered with.

TrueSamples were received on ice.

TrueCooler Temperature is acceptable.

TrueCooler Temperature is recorded. 0.0°C IR10

TrueCOC is present.

TrueCOC is filled out in ink and legible.

TrueCOC is filled out with all pertinent information.

TrueIs the Field Sampler's name present on COC?

TrueThere are no discrepancies between the containers received and the COC.

TrueSamples are received within Holding Time (excluding tests with immediate HTs)

TrueSample containers have legible labels.

TrueContainers are not broken or leaking.

TrueSample collection date/times are provided.

TrueAppropriate sample containers are used.

TrueSample bottles are completely filled.

N/ASample Preservation Verified.

TrueThere is sufficient vol. for all requested analyses, incl. any requested MS/MSDs

N/AContainers requiring zero headspace have no headspace or bubble is <6mm (1/4").

TrueMultiphasic samples are not present.

TrueSamples do not require splitting or compositing.

N/AResidual Chlorine Checked.

Eurofins Pensacola Page 20 of 21 1/29/2024

Accreditation/Certification Summary

Project/Site: 4th St. Bridge Project - Gulf Shores, AL

Laboratory: Eurofins Pensacola All accreditations/certifications held by this laboratory are listed. Not all accreditations/certifications are applicable to this report.

Authority Program Identification Number Expiration Date

Alabama State 40150 06-30-24

ANAB ISO/IEC 17025 L2471 02-22-26

Arkansas DEQ State 88-00689 08-01-24

California State 2510 06-30-24

Florida NELAP E81010 06-30-24

Georgia State E81010(FL) 06-30-24

Illinois NELAP 200041 10-09-24

Kansas NELAP E-10253 10-31-24

Kentucky (UST) State 53 06-30-24

Louisiana (All) NELAP 30976 06-30-24

Louisiana (DW) State LA017 12-31-24

North Carolina (WW/SW) State 314 12-31-24

Oklahoma NELAP 9810 08-31-24

Pennsylvania NELAP 68-00467 01-31-24

South Carolina State 96026 06-30-24

Tennessee State TN02907 06-30-24

Texas NELAP T104704286 09-30-24

US Fish & Wildlife US Federal Programs A22340 06-30-24

USDA US Federal Programs P330-21-00056 05-17-24

USDA US Federal Programs FLGNV23001 01-08-26

Virginia NELAP 460166 06-14-24

West Virginia DEP State 136 03-31-24

West Virginia DEP State 136 03-31-24

Eurofins Pensacola

Page 21 of 21 1/29/2024

Geotechnical-Engineering Report Important Information about This

Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes.

While you cannot eliminate all such risks, you can manage them. The following information is provided to help.

The Geoprofessional Business Association (GBA) has prepared this advisory to help you – assumedly a client representative – interpret and apply this geotechnical-engineering report as effectively as possible. In that way, you can benefit from a lowered exposure to problems associated with subsurface conditions at project sites and development of them that, for decades, have been a principal cause of construction delays, cost overruns, claims, and disputes. If you have questions or want more information about any of the issues discussed herein, contact your GBA-member geotechnical engineer.

Active engagement in GBA exposes geotechnical engineers to a wide array of risk-confrontation techniques that can be of genuine benefit for everyone involved with a construction project.

Understand the Geotechnical-Engineering Services Provided for this Report Geotechnical-engineering services typically include the planning, collection, interpretation, and analysis of exploratory data from widely spaced borings and/or test pits. Field data are combined with results from laboratory tests of soil and rock samples obtained from field exploration (if applicable), observations made during site reconnaissance, and historical information to form one or more models of the expected subsurface conditions beneath the site. Local geology and alterations of the site surface and subsurface by previous and proposed construction are also important considerations. Geotechnical engineers apply their engineering training, experience, and judgment to adapt the requirements of the prospective project to the subsurface model(s). Estimates are made of the subsurface conditions that will likely be exposed during construction as well as the expected performance of foundations and other structures being planned and/or affected by construction activities.

The culmination of these geotechnical-engineering services is typically a geotechnical-engineering report providing the data obtained, a discussion of the subsurface model(s), the engineering and geologic engineering assessments and analyses made, and the recommendations developed to satisfy the given requirements of the project. These reports may be titled investigations, explorations, studies, assessments, or evaluations.

Regardless of the title used, the geotechnical-engineering report is an engineering interpretation of the subsurface conditions within the context of the project and does not represent a close examination, systematic inquiry, or thorough investigation of all site and subsurface conditions.

Geotechnical-Engineering Services are Performed for Specific Purposes, Persons, and Projects, and At Specific Times Geotechnical engineers structure their services to meet the specific needs, goals, and risk management preferences of their clients. A geotechnical-engineering study conducted for a given civil engineer will not likely meet the needs of a civil-works constructor or even a different civil engineer. Because each geotechnical-engineering study is unique, each geotechnical-engineering report is unique, prepared solely for the client.

Likewise, geotechnical-engineering services are performed for a specific project and purpose. For example, it is unlikely that a geotechnical-engineering study for a refrigerated warehouse will be the same as one prepared for a parking garage; and a few borings drilled during a preliminary study to evaluate site feasibility will not be adequate to develop geotechnical design recommendations for the project.

Do not rely on this report if your geotechnical engineer prepared it:

the original site); or

• before important events occurred at the site or adjacent to it;

e.g., man-made events like construction or environmental remediation, or natural events like floods, droughts, earthquakes, or groundwater fluctuations.

Note, too, the reliability of a geotechnical-engineering report can be affected by the passage of time, because of factors like changed subsurface conditions; new or modified codes, standards, or regulations; or new techniques or tools. If you are the least bit uncertain about the continued reliability of this report, contact your geotechnical engineer before applying the recommendations in it. A minor amount of additional testing or analysis after the passage of time – if any is required at all – could prevent major problems.

Read this Report in Full Costly problems have occurred because those relying on a geotechnical-engineering report did not read the report in its entirety. Do not rely on an executive summary. Do not read selective elements only. Read and refer to the report in full.

You Need to Inform Your Geotechnical Engineer About Change Your geotechnical engineer considered unique, project-specific factors when developing the scope of study behind this report and developing the confirmation-dependent recommendations the report conveys.

Typical changes that could erode the reliability of this report include those that affect:

function or weight of the proposed structure and the desired performance criteria;

As a general rule, always inform your geotechnical engineer of project or site changes – even minor ones – and request an assessment of their impact. The geotechnical engineer who prepared this report cannot accept responsibility or liability for problems that arise because the geotechnical engineer was not informed about developments the engineer otherwise would have considered.

Most of the “Findings” Related in This Report Are Professional Opinions Before construction begins, geotechnical engineers explore a site’s subsurface using various sampling and testing procedures. Geotechnical engineers can observe actual subsurface conditions only at those specific locations where sampling and testing is performed. The data derived from that sampling and testing were reviewed by your geotechnical engineer, who then applied professional judgement to form opinions about subsurface conditions throughout the site. Actual sitewide-subsurface conditions may differ – maybe significantly – from those indicated in this report. Confront that risk by retaining your geotechnical engineer to serve on the design team through project completion to obtain informed guidance quickly, whenever needed.

This Report’s Recommendations Are Confirmation-Dependent The recommendations included in this report – including any options or alternatives – are confirmation-dependent. In other words, they are not final, because the geotechnical engineer who developed them relied heavily on judgement and opinion to do so. Your geotechnical engineer can finalize the recommendations only after observing actual subsurface conditions exposed during construction. If through observation your geotechnical engineer confirms that the conditions assumed to exist actually do exist, the recommendations can be relied upon, assuming no other changes have occurred. The geotechnical engineer who prepared this report cannot assume responsibility or liability for confirmation-dependent recommendations if you fail to retain that engineer to perform construction observation.

This Report Could Be Misinterpreted Other design professionals’ misinterpretation of geotechnical-engineering reports has resulted in costly problems. Confront that risk by having your geotechnical engineer serve as a continuing member of the design team, to:

specifications; and

• be available whenever geotechnical-engineering guidance is needed.

You should also confront the risk of constructors misinterpreting this report. Do so by retaining your geotechnical engineer to participate in prebid and preconstruction conferences and to perform construction-phase observations.

Give Constructors a Complete Report and Guidance Some owners and design professionals mistakenly believe they can shift unanticipated-subsurface-conditions liability to constructors by limiting the information they provide for bid preparation. To help prevent the costly, contentious problems this practice has caused, include the complete geotechnical-engineering report, along with any attachments or appendices, with your contract documents, but be certain to note conspicuously that you’ve included the material for information purposes only. To avoid misunderstanding, you may also want to note that “informational purposes” means constructors have no right to rely on the interpretations, opinions, conclusions, or recommendations in the report. Be certain that constructors know they may learn about specific project requirements, including options selected from the report, only from the design drawings and specifications. Remind constructors that they may perform their own studies if they want to, and be sure to allow enough time to permit them to do so. Only then might you be in a position to give constructors the information available to you, while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. Conducting prebid and preconstruction conferences can also be valuable in this respect.

Read Responsibility Provisions Closely Some client representatives, design professionals, and constructors do not realize that geotechnical engineering is far less exact than other engineering disciplines. This happens in part because soil and rock on project sites are typically heterogeneous and not manufactured materials with well-defined engineering properties like steel and concrete. That lack of understanding has nurtured unrealistic expectations that have resulted in disappointments, delays, cost overruns, claims, and disputes.

To confront that risk, geotechnical engineers commonly include explanatory provisions in their reports. Sometimes labeled “limitations,” many of these provisions indicate where geotechnical engineers’ responsibilities begin and end, to help others recognize their own responsibilities and risks. Read these provisions closely. Ask questions.

Your geotechnical engineer should respond fully and frankly.

Geoenvironmental Concerns Are Not Covered The personnel, equipment, and techniques used to perform an environmental study – e.g., a “phase-one” or “phase-two” environmental site assessment – differ significantly from those used to perform a geotechnical-engineering study. For that reason, a geotechnical-engineering report does not usually provide environmental findings, conclusions, or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Unanticipated subsurface environmental problems have led to project failures. If you have not obtained your own environmental information about the project site, ask your geotechnical consultant for a recommendation on how to find environmental risk-management guidance.

Obtain Professional Assistance to Deal with Moisture Infiltration and Mold While your geotechnical engineer may have addressed groundwater, water infiltration, or similar issues in this report, the engineer’s services were not designed, conducted, or intended to prevent migration of moisture – including water vapor – from the soil through building slabs and walls and into the building interior, where it can cause mold growth and material-performance deficiencies.

Accordingly, proper implementation of the geotechnical engineer’s recommendations will not of itself be sufficient to prevent moisture infiltration. Confront the risk of moisture infiltration by including building-envelope or mold specialists on the design team.

Geotechnical engineers are not building-envelope or mold specialists.

Copyright 2019 by Geoprofessional Business Association (GBA). Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly prohibited, except with GBA’s specific written permission. Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission of GBA, and only for purposes of scholarly research or book review. Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind. Any other firm, individual, or other entity that so uses this document without being a GBA member could be committing negligent

Telephone: 301/565-2733 e-mail: info@geoprofessional.org www.geoprofessional.org

TERMS AND CONDITIONS

SERVICES TO BE PROVIDED. GeoCon Engineering & Material Testing, Inc. (hereinafter GeoCon) is an independent consultant and agrees to provide Client, for…