7-Appendix C - Geotechnical Report.pdf

Subsurface Soil Exploration and Geotechnical Engineering Evaluation

Proposed Duplex Lift Station and Pipeline Improvements

Hopkins Park St. Cloud, Osceola County, Florida

Ardaman & Associates, Inc.

CORPORATE HEADQUARTERS

8008 S. Orange Avenue, Orlando, Florida 32809 - Phone: (407) 855-3860 Fax: (407) 859-8121

Branch Office Locations

Florida: Bartow, Cocoa, Fort Myers, Miami, Orlando, Port St. Lucie, Sarasota, Tallahassee, Tampa, West Palm Beach Louisiana: Baton Rouge, New Orleans, Shreveport

Texas: Houston

MEMBERS:

ASTM International Society of American Military Engineers

American Council of Engineering Companies

8008 S. Orange Avenue (32809), Post Office Box 593003, Orlando, Florida 32859-3003 Phone: (407) 855-3860 Fax: (407) 859-8121

Florida: Bartow, Cocoa, Fort Myers, Miami, Orlando, Port St. Lucie, Sarasota, Tallahassee, Tampa, West Palm Beach Louisiana: Baton Rouge, New Orleans, Shreveport

Texas: Houston

November 26, 2025 Ardaman File No. 25-6431

Tetra Tech 201 E. Pine Street, Suite 1000 Orlando, Florida 32801

Attention: Mr. Stefano Ceriana, P.E.

Subject: Subsurface Soil Exploration and Geotechnical Engineering Evaluation Proposed Duplex Lift Station and Pipeline Improvements Hopkins Park St. Cloud, Osceola County, Florida

Dear Mr. Ceriana:

As requested and authorized, we have completed a shallow subsurface soil exploration for the subject project. The purposes of performing this exploration were to evaluate the general subsurface conditions within the proposed duplex lift station and pipeline areas and to provide recommendations for site preparation and foundation/pipeline support. In addition, we have estimated the normal seasonal high groundwater level at the boring locations. This report documents our findings and presents our engineering recommendations.

SITE LOCATION AND SITE DESCRIPTION

The site for the proposed improvements is located along River Road, Mency Street, Bibbens Street, and the north side of Hopkins Park in Osceola County, Florida (Section 12, Township 26 South, Range 30 East). The general site location is shown superimposed on the St. Cloud South, Florida U.S.G.S. quadrangle map presented on Figure 1.

The proposed gravity sewer pipeline will primarily pass beneath existing residential roads and various grass covered areas. The proposed lift station is located on the northeast corner of Hopkins Park, which generally consists of grass covered land and/or playing fields.

PROPOSED CONSTRUCTION AND GRADING

We understand that the proposed pipelines will consist of approximately 900 l.f. of 4 or 6-inch diameter force main and 1,080 l.f. of 8-inch diameter gravity sewer main. We understand that the pipelines will be constructed using cut and cover construction methodology. The force main will be placed with a maximum depth of soil cover of approximately 4 feet, while the gravity sewer may have up to 8 feet of soil cover. We also understand that the proposed lift station will be a maximum of 15 feet deep.

Geotechnical, Environmental and Materials Consultants

Tetra Tech November 26, 2025 Ardaman File No. 25-6431 -2-

REVIEW OF SOIL SURVEY MAPS

Based on information obtained online from the Web Soil Survey as operated by the U.S.

Department of Agriculture Natural Resources Conservation Services, the site is located in an area mapped as the soil series.

The soil series consists of sandy soils in depressions on marine terraces. The internal drainage of the soil series is very poor and the soil permeability is rapid to very rapid. According to the Soil Survey, the seasonal high water table for the soil series is typically at the natural ground surface.

poor and the soil permeability is moderately rapid to rapid. According to the Soil Survey, the within 6 to 18 inches of the natural ground surface.

FIELD EXPLORATION PROGRAM

SPT and Auger Borings

The field exploration program included performing 1 Standard Penetration Test (SPT) boring, 8 auger borings, and 1 hand auger boring. The SPT boring was advanced to 30 feet below the existing ground surface generally using the methodology outlined in ASTM D-1586. A summary of this field procedure is included in Appendix I.

The auger borings were drilled using a truck-mounted, 4-inch diameter, continuous flight auger to depths of 10 and 15 feet below the existing ground surface. A summary of this field procedure is included in Appendix I.

The hand auger borings were conducted using a 3-inch diameter manual bucket auger to a depth of 10 feet below the existing ground surface. A summary of the hand auger boring procedure is included in Appendix I.

Soil samples recovered during performance of the borings were visually classified in the field and representative portions of the samples were transported to our laboratory in sealed sample jars.

The groundwater level at each of the boring locations was measured during drilling of the SPT borings and upon completion of the auger borings. The SPT boring was backfilled with cement grout upon completion and the auger borings were backfilled soil cuttings.

Ardaman File No. 25-6431 -3-

Pavement Cores

The field exploration also included obtaining a total of 2 cores of the existing River Road pavement. At each core location, the asphalt and underlying base course were measured in the field for thickness and the type of base was recorded. The core samples of the asphalt pavement were returned to our laboratory for further examination and measurements. The results of the pavement coring is presented in the following table and in the Roadway and Pavement Core Photographs Logs presented in Appendix II.

Location Thickness of

Asphalt (Inches) Thickness of Base (inches)

Base Type

PC-1 2½ 5

Soil Cement

PC-2 1 7

Test Locations

The approximate locations of the borings and pavement cores are schematically illustrated on aerial photographs shown on Figure 2. These locations were determined in the field by Global Positioning System (GPS) utilizing hand-held GPS equipment and coordinates obtained from Google Earth Pro. Boring locations should be considered accurate only to the degree implied by the method of locating used.

LABORATORY PROGRAM

Representative soil samples obtained during our field sampling operation were packaged and transferred to our laboratory for further visual examination and classification. The soil samples were classified using visual-manual procedures in general accordance with the Unified Soil Classification System (ASTM D-2488). The resulting soil descriptions are shown on the soil boring profiles presented on Figures 3 and 4.

In addition, we conducted 5 percent fines analyses (ASTM D-1140) on selected soil samples obtained from the borings. The results of these tests are presented adjacent to the sample depth on the boring profiles on Figures 3 and 4.

GENERAL SUBSURFACE CONDITIONS

General Soil Profile

The results of the field exploration and laboratory programs are graphically summarized on the soil boring profiles presented on Figures 3 and 4. The stratification of the boring profiles represents our interpretation of the field boring logs and the results of laboratory examinations of

Ardaman File No. 25-6431 -4-the recovered samples. The stratification lines represent the approximate boundary between soil types. The actual transitions may be more gradual than implied.

The results of the borings indicate the following general soil profiles:

Pipeline Improvements

Depth Below Ground Surface (feet) Description From To

0 1 Asphaltic concrete underlain by soil cement base

1 3 Fine sand with silt (SP-SM) and silty fine sand (SM)

3 15 Fine sand with silt (SP-SM), silty fine sand (SM), fine sand with clay (SP-SC), and clayey fine sand (SC)

Lift Station

Depth Below Ground Surface (feet) Description From To

0 3 Silty fine sand (SM)

3 6 Very loose fine sand with silt (SP-SM) 6 12 Loose to medium dense fine sand with silt (SP-SM)

12 30 Loose fine sand with silt (SP-SM) and silty fine sand (SM)

The above soil profiles are outlined in general terms only. Please refer to Figures 3 and 4 for soil profile details.

Groundwater Level

The groundwater level was measured in the boreholes during drilling of the SPT boring and upon completion of the auger borings. As shown on Figures 3 and 4, groundwater was encountered at depths that ranged from approximately 1 to 4 feet below the existing ground surface on the date indicated. Fluctuation in groundwater levels should be anticipated throughout the year primarily due to seasonal variations in rainfall and other factors that may vary from the time the borings were conducted.

Ardaman File No. 25-6431 -5-

NORMAL SEASONAL HIGH GROUNDWATER LEVEL

The groundwater level is affected by a number of factors. The amount of rainfall and the drainage characteristics of the soils, the land surface elevation, relief points such as drainage ditches, lakes, rivers, swamp areas, etc., and distance to relief points are some of the more important factors influencing the groundwater level.

The normal seasonal high groundwater level each year is the level in the August-September period at the end of the rainy season during a year of normal (average) rainfall. The water table elevations associated with a higher than normal rainfall and in the extreme case, flood, would be higher to much higher than the normal seasonal high groundwater level, and could occur at times outside of the August-September period. The normal high water levels would more approximate the normal seasonal high groundwater levels.

Based on our interpretation of the site conditions using our boring logs, we estimate the normal seasonal high groundwater level at the boring locations to be approximately 1½ above groundwater levels measured at the time of our field exploration.

ENGINEERING EVALUATION AND RECOMMENDATIONS

General

The results of our exploration indicate that, with proper site preparation as recommended in this report, the existing soils are suitable for supporting the proposed pipelines and lift station structure.

Silty and/or clayey soil (Strata 2, 3 and 4 on Figures 3 and 4) was encountered near the proposed installation depths of the pipelines and lift stations. Because these soils are difficult to moisture condition and compact, the Contractor may elect to over-excavate this soil approximately one to two feet below the proposed pipelines and lift stations and backfill the excavation with compacted

USCS Classification SP) or gravel, rather than going to the additional effort of compacting the clayey soils. Also, because the silty and/or clayey soils (Strata 2, 3 and 4) are difficult to moisture condition and compact, these soils are generally considered poor quality for use as compacted backfill in excavations. Import fill soils may be needed for this project.

The following are our recommendations for overall site preparation and foundation support which we feel are best suited for the proposed improvements relative to the soil conditions encountered in our borings, as shown on Figures 3 and 4.

Ardaman File No. 25-6431 -6-

Excavation and Backfilling

We anticipate that the majority of the soils encountered should be able to be excavated with standard earthmoving equipment such as backhoes and front-end loaders. The actual method(s) of excavation should be determined by the contractor; however, the excavations should be safely braced to prevent injury to personnel or damage to equipment.

The soils below the bottom of the excavations should not be disturbed by the excavation process.

Following excavation to the foundation level of the proposed pump station, the bottom of the excavation should be compacted to achieve a firm and unyielding condition. The excavated ground surface should be inspected by a representative of Ardaman & Associates using visual observation and probing. Any areas of deleterious, very loose or soft soils should be overexcavated and backfilled. Any overexcavated areas should be backfilled with compacted clean sand (SP). Compaction of the bottom of the excavation is further discussed in the

Backfill placed adjacent to the lift station structure walls (if necessary) should consist of granular soils that are free draining and relatively free of fines. The backfill within 5 feet of the structure walls should be placed in thin lifts and compacted with hand-held compactors to between 95 and 100 percent of the modified Proctor (ASTM D-1557) maximum dry density value. Overcompaction of the backfill should be avoided since it could cause excessively large earth pressures to develop against the walls. Heavy equipment should be kept at least 5 feet away from the walls.

necessary to lower the groundwater level below the bottom of the excavation and compaction

Excavations should be safely braced to prevent injury to personnel or damage to equipment.

Temporary safe slopes should be cut at a minimum 1.5 Horizontal to 1.0 Vertical (1.5H to 1.0V) in accordance with OSHA, 29 CFR Part 1926 Final Rule, Excavation Requirements or successor regulations. Flatter slopes should be used if deemed necessary. Surcharge loads should be kept at least 5 feet from excavations. Spoil banks adjacent to excavations should be sloped no steeper than 2.0H to 1.0V. Provisions for main responsibility of the Contractor.

Suitable Fill Material and Compaction of Fill Soils

All fill materials should be free of organic materials, such as roots and vegetation. We recommend using fill with less than 12 percent by dry weight of material passing the U.S. Standard No. 200 sieve size. The fine sand with silt (Stratum No. 1, as shown on Figures 3 and 4) is suitable for use as fill materials and, with proper moisture control, should densify using conventional compaction methods.

Ardaman File No. 25-6431 -7-

The clayey and silty soils (Strata Nos. 2 through 4 on Figures 3 and 4) having less than about 20 percent fines may be used as structural backfill, however, these soils will be more difficult to moisture condition and compact than the Stratum 1 soils. These soils will be difficult to compact because of their relatively high fines content. They may be used as backfill if it is possible to achieve the required degree of compaction. However, extensive moisture conditioning would likely be required. The contractor may elect at their discretion to import gravel and/or fill with less than 12 percent passing the No. 200 sieve rather than going to additional efforts to moisture condition and compact the silty and clayey soils. Weather conditions during construction may also affect this decision. If elected, the gravel should meet the material requirements by FDOT (Florida Department of Transportation) for No. 89 stone. Each lift of gravel should be compacted to a firm and unyielding condition.

Strata 2 through 4 soils having more than about 20 percent fines are generally considered unsuitable for use as structural fill because of the extreme difficulty in moisture conditioning and compacting these soils.

We note that material removed from below the groundwater table will be wet and will require time to dry sufficiently.

All structural fill should be placed in level lifts not to exceed 12 inches in uncompacted thickness.

Each lift should be compacted to at least 95 percent of the modified Proctor (ASTM D-1557) maximum dry density value. The filling and compaction operations should continue in lifts until the desired elevation(s) is achieved. If hand-held compaction equipment is used, the lift thickness should be reduced to no more than 6 inches.

Foundation Support by Mat and Foundation Compaction Criteria (Lift Station)

After the excavation is complete, verify the in-place compaction for a depth of 2 feet below the foundation bottom. If necessary, compact the soils at the bottom of the excavation to at least 95 percent of the modified Proctor maximum dry density (ASTM D-1557) for a depth of 2 feet below each foundation bottom. Based on the existing soil conditions and, assuming the above outlined proof-rolling and compaction criteria are implemented, a soil bearing pressure of up to 1,000 pounds per square foot (psf) at the bottom of the lift station should result in foundation settlement within tolerable limits (i.e., 1 inch or less).

There are alternative installation techniques for lift station structures (e.g., caisson method) other than installing the structures in a dewatered excavation. If an installation technique other than installation in a dewatered excavation is planned, we should be retained to review the proposed methods. We can then modify our recommendations as appropriate.

Ardaman File No. 25-6431 -8-

Dewatering

Based on the groundwater conditions encountered, the control of the groundwater will be required to achieve the excavation and subsequent construction, backfilling, and compaction requirements presented in the preceding sections. The actual method(s) of dewatering should be determined by the contractor. However, regardless of the method(s) used, we suggest drawing down the water table sufficiently, say 2 to 3 feet, below the bottom of any excavation or compaction surface to preclude "pumping" and/or compaction-related problems with the foundation soils. Use of a relatively deep perimeter sheet pile system may be required for the lift station portion of this project, designed to work in conjunction with the proposed dewatering system and as necessary to provide a stable excavation.

The contractor should be aware that cuts may expose confined aquifers where relatively permeable soils underlie less permeable zones. These relatively permeable zones can require dewatering efforts to include relatively deep full aquifer penetrating wells, airlift of water from wells, trench drains, seepage barriers, etc. Relatively more permeable soil zones that exist below the bottom of excavations will need to be dewatered to stabilize the excavation and prevent

Monitoring wells should be used to verify that water pressures have been reduced sufficiently throughout the soil profile to proceed with construction and the Contractor should be prepared to add additional dewatering during construction if necessary. Multiple forms and/or stages of dewatering may be necessary in order to provide stable excavations particularly as they pertain to the lift station excavation. Dewatering is the responsibility of the Contractor.

Pipeline Bedding

Pipe bedding material should be compacted as necessary to achieve a density equivalent to 95 percent of the maximum dry density, as determined by the Modified Proctor (ASTM D-1557), to a minimum depth of 6 inches below the bottom of the pipe (compact deeper if recommended by the pipe manufacturer).

It is our recommendation that the bedding for the pipe be preshaped by means of a template, prior to placement of the structure, to ensure that the upward reaction on the bottom of the pipe will be well distributed over the width of the bedding contact. Based on the cost involved with preshaping the bedding material, and the construction time requirements, an alternative procedure may be to utilize a level bed for the pipe and require a higher pipe strength class which will adequately carry the load on a lower class of bedding. It would be prudent to perform an economic analyses of the two alternatives, or specify both design conditions within the contract documents, and allow the Contractor to decide the most efficient method.

Ardaman File No. 25-6431 -9-

If level bedding is utilized, it will be necessary to place and compact the haunching backfill (backfill between the bedding and the centerline of the pipe) to the centerline of the pipe. This material should be placed in simultaneous layers on each side of the pipe and must be compacted in such a manner as to ensure an intimate contact with the sides of the pipe. Do not use blocking to raise the pipe to grade. Provide bell holes at each joint to permit the joint to be assembled while maintaining uniform pipe support.

Backfill Requirements (Pipeline)

The final backfill above the haunching or centerline of the pipe must extend all the way to the trench walls and should be placed in level lifts not exceeding 8 inches. Each lift should be compacted to at least 95 percent of the maximum dry density, as determined by the Modified Proctor (ASTM D-1557). Care should be taken not to damage the pipe by compacting directly above the pipe where there is insufficient cover material present. Minimum cover criteria should be in accordance with the pipe manufacturer's recommendations.

A soils engineer or a designated representative from Ardaman & Associates, Inc. should observe and test all prepared and compacted areas to verify that all bedding, haunching and final backfill are prepared and compacted in accordance with the aforementioned specifications.

Pipeline Foundation Support and Estimated Settlements

The permanent structures such as anchor blocks, thrust blocks, air release valves, blow offs, etc., bearing at least 18 inches below adjacent grade can be designed for the maximum vertical bearing capacities presented below.

1,500 psf on undisturbed natural granular soils.

2,000 psf on compacted natural or backfilled subgrade; this value assumes compaction of 95 percent of the standard Proctor maximum density (ASTM D-698, AASHTO T-99) for a depth of 2 feet below the structure.

Pipe settlement during and after construction should be negligible (less than ½-inch), provided the bedding and backfilling criteria in the above sections are satisfied. The volume of soil displaced by the pipe, compared to the weight of the pipe when full, will result in little if any net increase in bearing stress to the subsurface soils.

Resistance to Horizontal Forces on Pipeline Structures

Horizontal forces which act on structures such as thrust blocks or anchor blocks can be resisted to some extent by the earth pressures that develop in contact with the buried vertical face (buried vertical face is perpendicular and in front of the applied horizontal load) of the block structures

Ardaman File No. 25-6431 -10-and by shearing resistance mobilized along the base of the block structures and subgrade interface.

Allowable earth pressure resistance may be determined using an equivalent fluid density of 100 pounds per cubic foot (pcf) for moist soil and 60 pcf for submerged soils below the water table.

Equivalent fluid density (moist soil) = Kp m/S.F. = 100 pcf

Equivalent fluid density (submerged soil) = Kp ( s- w)/S.F. = 60 pcf

Where:

Kp = effective coefficient of passive earth pressure = 3.0 S.F. = safety factor = (values given below) m = unit weight of moist soil = 110 pcf s = unit weight of saturated soils = 118 pcf w = unit weight of water = 62.4 pcf

The passive earth pressures are developed from ground surface (assuming there is no excavation in the vicinity of the block structure that would reduce the available passive pressure) to the bottom of the block structure.

The values presented above presume that the block structures are surrounded by well compacted sand backfill extending at least 5 feet horizontally beyond the vertical buried face. In addition, it is presumed that the block structures can withstand horizontal movements on the order of one-quarter (1/4) to three-eighths (3/8) inch before mobilizing full passive resistance. The factors of safety assumed in the above recommendations are 2.5 for passive pressure with submerged conditions, and 3.0 for passive pressure without submerged conditions.

The sliding shearing resistance mobilized along the base of the block structure may be determined by the following formula:

Allowable Shearing Resisting Force, P=V tan (2/3 )/F.S.

P = Shearing Resistance Force (pounds) V = Net Vertical Force (total weight of block and soil overlying the structure minus uplift forces including buoyancy forces) (pounds) = Angle of Internal Friction of Soil = 30 degrees

S.F. = Safety Factor = 1.5

Ardaman File No. 25-6431 -11-

The vertical earth pressures developed by the overburden weight of soil can be calculated using the following unit weights:

Compacted moist soil = 110 pcf

Saturated soil = 118 pcf

Vertical pressure distributions in accordance with the above do not take into account vertical forces from construction equipment, wheel loads or other surcharge loads.

Uplift Resistance

Permanent structures submerged below the groundwater table will be subjected to uplift forces caused by buoyancy. The components resisting this buoyancy include: 1) the total weight of the structures or pipe divided by an appropriate factor of safety, 2) the buoyant weight of soil overlying the structures or pipe, and 3) the shearing forces that act on shear planes that radiate vertically upward from the perimeter of the structures or pipe to the ground surface. The allowable unit shearing resistance may be determined by the following formula:

Allowable Unit Shearing Resistance, F=Ko mh(2/3 tan )/S.F. (above groundwater table)

Allowable Unit Shearing Resistance, F=Ko[ mhw+ b(h-hw)](2/3tan )/S.F. (below groundwater table)

F = unit shearing resistance (psf) Ko = coefficient of earth pressure at rest = 0.5 m = unit weight of moist soil = 110 pcf b = buoyant unit weight of soil = 55.6 pcf h = vertical depth (feet) below grade at which shearing resistance is determined hw = vertical depth (feet) below grade to groundwater table

= angle of internal friction of the soil = 30 degrees S.F. = safety factor = 2

The values given for the above parameters assume that the permanent structures are covered by clean, well compacted granular backfill that extends horizontally at least 2 feet beyond the structures.

Ardaman File No. 25-6431 -12-

Earth Pressure on Shoring and Bracing

If temporary shoring and bracing is required for any excavations, the system should be designed to resist lateral earth pressure. The design earth pressure will be a function of the flexibility of the shoring and bracing system. For a flexible system restrained laterally by braces placed as the excavation proceeds, the design earth pressure for shoring and bracing can be computed using a uniform earth pressure distribution with depth. It is recommended that soils be de-watered around the excavations. For such de-watered excavations, we recommended using the following uniform pressure distribution over the full braced height as follows:

Uniform Soil Pressure Distribution, p = 0.65Ka sH p = uniform pressure distribution for design of braced excavation Ka = coefficient of active earth pressure = 0.33 s = unit weight of saturated soils = 118 pcf H = depth of excavation

An appropriate factor of safety should be applied for the design of the braced excavations.

Lateral pressure distributions determined in accordance with the above do not take hydrostatic pressures or surcharge loads into account. To the extent that such pressures and forces may act on the walls, they should be included in the design.

Construction equipment and excavated fill should be kept a minimum distance of 5 feet from the edge of the braced or shored excavation. Backfill material placed adjacent to (maintaining a minimum 5-foot horizontal clearance) the braced or shored excavation should have a minimum slope of 2.0H:1.0V, or flatter if required by site specific conditions and/or to meet OSHA requirements.

Means and methods of excavation and bracing should be the responsibility of the Contractor;

however, excavation and/or bracing should at a minimum adhere to the requirements of the Occupational Safety Health Administration (OSHA).

Lateral Earth Pressures

Lateral loads acting on the embedded structures and will include at-rest earth pressures as well as hydrostatic pressures and surcharge loads. The lateral earth pressure will be a function of both the depth below ground surface and the soil unit weight (submerged or moist) plus hydrostatic pressure (if applicable). The following equations can be used to determine the lateral at-rest earth pressure:

Ardaman File No. 25-6431 -13-h = Ko mh (above groundwater table) h = Ko m hw b (h - hw)] (below groundwater table) h = lateral earth pressure (psf) Ko = coefficient of at rest earth pressure (0.5) (this value assumes that the backfill is lightly compacted yet not overcompacted) m = effective moist unit weight of soil = 110 pcf for compacted moist soil above the water table.

b = buoyant unit weight of soil = 55.6 pcf for compacted saturated soil below the water table.

h = vertical depth (feet) below grade at which lateral earth pressure is determined hw = vertical depth (feet) below grade to groundwater table

For design, an appropriate factor of safety should be applied to the lateral earth pressure calculated using the above equation. Lateral pressure distributions determined in accordance with the above do not include hydrostatic pressures or surcharge loads. Where applicable, they should be incorporated in the design.

QUALITY CONTROL

We recommend establishing a comprehensive quality assurance program to verify that all site preparation, excavation, bedding foundation construction and backfilling are conducted in accordance with the appropriate plans and specifications. Materials testing and inspection services should be provided by Ardaman & Associates.

In-situ density tests should be conducted during foundation soil preparation for the lift station, during pipeline bedding installation and during backfilling activities to verify that the required densities are achieved. Backfill for the lift station should be tested at a minimum frequency of two in-place density tests for each 12-inch height of fill. Backfill for the proposed pipelines should be tested at a minimum frequency of one in-place density test for each 12-inch height of fill along the pipelines. Additional tests should be performed beneath foundations and in backfill for other associated structures. In-situ density values should be compared to Laboratory Proctor moisture density results for each of the different natural and fill soils encountered.

Also, we recommend inspecting and testing the construction materials for the foundations and other structural components.

Ardaman File No. 25-6431 -14-

CLOSURE

The analyses and recommendations submitted herein are based on the data obtained from the soil borings presented on Figures 3 and 4 and the assumed loading conditions. This report does not reflect any variations which may occur adjacent to or between the borings. The nature and extent of the variations between the borings may not become evident until during construction. If variations then appear evident, it will be necessary to re-evaluate the recommendations presented in this report after performing on-site observations during the construction period and noting the characteristics of the variations.

In the event any changes occur in the design, nature, or location of the proposed facility, we should review the applicability of conclusions and recommendations in this report. We recommend a general review of final design and specifications by our office to verify that earthwork and foundation recommendations are properly interpreted and implemented in the design specifications. Ardaman & Associates should attend the pre-bid and preconstruction meetings to verify that the bidders/contractor understand the recommendations contained in this report.

through performing the subsurface soil exploration and geotechnical engineering evaluation as presented in this report, Ardaman & Associates is best suited to provide monitoring and testing services during earthwork, and to provide continued evaluation and guidance during construction should variations in the soil conditions be encountered.

This study is based on a relatively shallow exploration and is not intended to be an evaluation for sinkhole potential. This study does not include an evaluation of the environmental (ecological or hazardous/toxic material related) condition of the site and subsurface.

This report has been prepared for the exclusive use of Tetra Tech in accordance with generally accepted geotechnical engineering practices for the purpose of the subject project in St. Cloud, Osceola County, Florida. No other warranty, expressed or implied, is made.

Ardaman File No. 25-6431 -15-

Ardaman & Associates, Inc.

We are pleased to be of assistance to you on this phase of the project. When we may be of further service to you or should you have any questions, please contact us.

Very truly yours, ARDAMAN & ASSOCIATES, INC.

Florida Registry 5950

Colin T. Jewsbury, P.E. Christopher A. de la Cruz, P.E.

Orlando Branch Manager Project Engineer Florida License No. 58074 Florida License No. 98679

THIS ITEM HAS BEEN DIGITALLY

SIGNED AND SEALED BY

COLIN T. JEWSBURY, P.E. NO 58074,

ON THE DATE ADJACENT TO THE SEAL.

SIGNATURE MUST BE VERIFIED

ON ANY ELECTRONIC COPIES.

ARDAMAN & ASSOCIATES, INC.

8008 S. ORANGE AVENUE

ORLANDO, FLORIDA 32809

(407) 855-3860

FLORIDA REGISTRY 5950

CTJ/ATS/lms/bls 25-60-6431 Tetra Tech - Duplex Lift Station and Pipeline Improvements, Hopkins Park, Ct. Cloud.docx (Geo 2025)

APPENDIX I

Standard Penetration Test, Auger Boring and Hand Auger Procedures

STANDARD PENETRATION TEST

The standard penetration test is a widely accepted test method of in situ testing of soils (ASTM D-1586), and Ardaman & Associates generally follows this test method. A 2-foot long, 2-inch O.D.

split-barrel sampler attached to the end of a string of drilling rods is driven 18 or 24 inches into the ground by successive blows of a 140-pound hammer freely dropping 30 inches. The number of blows needed for each 6 inches of penetration is recorded. The sum of the blows required for penetration of the second and third 6-inch increments of penetration constitutes the test result or N-value. After the test, the sampler is extracted from the ground and opened to allow visual examination and classification of the retained soil sample. The N-value has been empirically correlated with various soil properties.

The tests are usually performed at 5-foot intervals. The test holes are advanced to the test elevations by rotary drilling with a cutting bit, using circulating fluid to remove the cuttings and hold the fine grains in suspension. The circulating fluid, which is a bentonitic drilling mud, is also used to keep the hole open below the water table by maintaining an excess hydrostatic pressure inside the hole. In some soil deposits, particularly highly pervious ones, flush-coupled casing must be driven to just above the testing depth to keep the hole open and/or prevent the loss of circulating fluid.

Representative split-spoon samples from the soils are brought to our laboratory in air-tight jars for further evaluation and testing, if necessary.

AUGER BORINGS

Auger borings are used when continuous sampling of soil strata close to ground surface is desired. A 4-inch diameter, continuous flight, helical auger with a cutting head at its end is screwed into the ground in 5-foot sections. It is powered by the rotating action of the Kelly bar of a rotary drill rig. The sample is recovered by withdrawing the auger out of the ground without rotating it. The soil sample so obtained, is classified and representative samples put in bags or jars and brought back to the laboratory for further evaluation and testing, if necessary.

HAND AUGER BORINGS

Auger borings are used when continuous sampling of soil strata close to ground surface is desired. A 3-inch diameter, hand-held bucket auger with a cutting head at its end is rotated into the ground in 1-foot sections. The sample is recovered by withdrawing the auger out of the ground without rotating it. The soil sample so obtained, is classified and representative samples put in bags or jars and brought back to the laboratory for further evaluation and testing, if necessary.

APPENDIX II

Roadway and Pavement Core Photographic Logs

Description

Core No.: 1

Asphalt Thickness (in.):

2.5

Crack Depth (in.):

N/A

Base Thickness (in.):

5.0 (deteriorated)

Base Course Type:

Soil Cement

Description

Core No.: 1

Location:

River Rd - SB

11/11/2025

Roadway Photo

10/20/2025

Tetra Tech, Inc. Proposed Duplex Lift Station and Pipeline Improvements

St. Cloud, Osceola County, Florida 25-6431

Core Photo

Ardaman & Associates, Inc.

Geotechnical, Environmental and

Roadway & Pavement Core Photographic Log Client: Project Name: Project Location: Ardaman Project No.:

Description

Core No.: 2

Asphalt Thickness (in.):

1.0

Crack Depth (in.):

N/A

Base Thickness (in.):

7.0

Base Course Type:

Soil Cement

Description

Core No.: 2

Location:

River Rd - SB

Ardaman & Associates, Inc.

Geotechnical, Environmental and

Roadway & Pavement Core Photographic Log Client: Project Name: Project Location: Ardaman Project No.:

11/11/2025

Roadway Photo

10/20/2025

Tetra Tech, Inc. Proposed Duplex Lift Station and Pipeline Improvements

St. Cloud, Osceola County, Florida 25-6431

Core Photo