APPENDIX C

GEOTECHNICAL REPORT

CARLIN SIMPSON & ASSOCIATES, LLC

Consulting Geotechnical and Environmental Engineers

61 Main Street, Sayreville, New Jersey 08872 Tel. (732) 432-5757 Fax. (732) 432-5717

28 August 2025

Updated 7 November 2025

Principal:

Robert B. Simpson, P.E.

Associates:

Meredith R. Anke, P.E.

Catherine K Andersen, P.E.

Michal Wroblewski, P.E.

Kurt W. Anke Eric J. Shaw

H2M Architects + Engineers

538 Broad Hollow Rd., 4th Floor East

Melville, NY 11747

Attn: Chelsea Martinez, P.E.

Project Engineer I

Re: Report on Subsurface Soil and Foundation Investigation

Proposed Renovations Kennedy Memorial Park Pool Facility

Village of Hempstead

335 Greenwich Street

Hempstead, NY (CSA Job #25-86)

Dear Ms. Martinez:

In accordance with our proposal dated 3 June 2025 and your subsequent authorization, we have completed a Subsurface Soil and Foundation Investigation for the referenced site. The purpose of this study was to determine the nature and engineering properties of the subsurface soil and the groundwater conditions, to recommend a practical foundation scheme, to determine the allowable bearing capacity of the site soils, and to preliminarily determine the permeability of the site soils. We understand that construction will take place in 2026 and therefore will be under the 2025 New York State Building Code. This report has been updated to reflect the new code.

The planned construction will consist of renovations to the existing pool facility. To guide us in our study, you have provided us with an aerial that indicates the location of existing site conditions.

Our scope of work for this project included the following:

1. Reviewed the existing site conditions, the expected soil conditions, and planned this study.

2. Retained Environmental Technical Drilling, Inc. to advance four (4) borings at selected locations on the subject site.

3. Laid out the boring locations in the field, visually identified the soil layers encountered, obtained soil samples, and prepared detailed boring logs and a Boring Location Plan.

4. Performed soil identification tests on selected soil samples in our laboratory.

5. Analyzed the field and laboratory test data and prepared this report containing the results of this study.

1.0 SITE DESCRIPTION AND PROPOSED CONSTRUCTION

The project site is located at 335 Greenwich Street in Hempstead, New York. The site is also know as Kennedy Memorial Park Pool Facility in the Village of Hempstead. The area of proposed renovations is currently occupied by several pools and bathhouse facility. The remainder of the site is covered by landscaping, a community center, sport courts and asphalt paved walkways, driveways, and parking areas. Site grades are generally flat.

The planned construction will consist of renovations to the existing pool facility. The type and extent of the renovations were unknown as of the date of this report. We expect that the site improvements could include new structures, new asphalt pavement, hardscape, new utilities, and/or new stormwater management areas. The following evaluation is based on the very limited information that has been provided to our office as of the date of this report. Once the construction plans have been further developed, a copy of the plans should be forwarded to our office so that we can review them along with the recommendations in this report. At that time, any changes or additional recommendations can be provided, if required.

2.0 SUBSURFACE CONDITIONS

To determine the subsurface soil and groundwater conditions at the site, four (4) borings were advanced by Environmental Technical Drilling Inc. at the locations shown on the enclosed

Boring Location Plan. The borings were performed using hollow stem augers and split spoon sampling. Detailed boring logs have been prepared and are included in this report. The borings were completed in June 2025, under the full-time inspection of Carlin-Simpson & Associates.

Our field engineer visually identified all of the soil samples obtained during the boring operations and selected samples were tested in our laboratory.

2.1 Soils

The soil descriptions shown on the boring logs are based on the Burmister Classification

System. In the Burmister Classification System, the soil is divided into three components: Sand

(S), Silt ($) and Gravel (G). The major component is indicated in all capital letters, the lesser in lower case letters.

The following modifiers indicate the quantity of each lesser component:

Modifier Quantity trace (t) 0 -10% little (l) 10% - 20% some (s) 20% - 35% and (a) 35% - 50%

In addition, the Unified Soil Classification System (USCS) group symbol has been provided for each of the major soil stratum. The subsurface soil conditions encountered in the soil borings can be summarized as follows:

Stratum 1

Topsoil

At the surface in each of the borings is topsoil that is approximately 6 to 10 inches in thickness.

Stratum 2

Existing Fill

Below the topsoil in each of the borings is loose to medium dense existing fill that generally consists of dark brown, black, gray, brown, orange coarse to fine SAND, varying amounts of Silt, little (to some) coarse to fine Gravel. Debris consisting of ash and roots were encountered within the existing fill at the boring locations. The existing fill extends to depths ranging from 4’0” to 6’0” below the existing ground surface at the boring locations.

Stratum 3

Sand with Gravel

[USCS: SP]

Beneath the existing fill in each of the borings is medium dense to dense orange, brown coarse to fine SAND, trace Silt, little (to and) coarse to fine

Gravel. All of the borings were terminated in this stratum at depths ranging from 30’0” to 50’0” below the existing ground surface.

2.2 Groundwater

Observations for groundwater were made during sampling and upon completion of the drilling operations at each boring location. During this investigation, groundwater was encountered in borings B-1 and B-4 at a depth of 31’0” below the existing ground surface, respectively.

Based on the groundwater observations and anticipated construction, groundwater will not likely be encountered during the construction. However, trapped or perched water could be encountered within the existing fill stratum, especially during wet periods. In the event that groundwater is encountered, proper groundwater control measures (i.e., sumps and pumps) will be required in the site excavations. Variations in the location of the long-term water table may occur as a result of changes in precipitation, evaporation, surface water runoff, and other factors not immediately apparent at the time of this exploration.

2.3 Summary of Boring Observations

Table 1 – Summary of Boring Observations

Boring

No.

Depth to

Groundwater

Depth to Bottom of

Existing Fill

B-1 31’0” 6’0”

B-2 NE to 31’0” 4’0”

B-3 NE to 30’0” 5’0”

B-4 31’0” 4’0”

NE – Not Encountered

3.0 SUMMARY OF DESIGN RECOMMENDATIONS

Below is a summary of the major design and construction considerations for this project.

Additional recommendations are provided in the following sections of this report.

• Subsurface Conditions (Section 2.0)

- Existing fill was encountered throughout the site to depths ranging from 4’0” to 6’0” below the existing ground surface.

- Groundwater was encountered in borings B-1 and B-4 at a depth of 31’0” below the existing ground surface.

- A summary of the subsurface observations is provided in Table 1 above.

• Structure Subgrade Preparation (Section 4.1)

- Existing structures must be demolished and surface materials (i.e. asphalt, topsoil) must be stripped from the proposed construction area.

- The existing fill is not suitable for support of the new structure foundations or structure floor slab. Where existing fill is encountered within a planned structure area, it shall be completely removed and replaced with new structural fill.

- The subgrades shall be densified with several passes of a vibrator roller prior to the placement of new structure fill or prior to the excavation of foundations.

- New backfill shall be compacted to at least 95% of its Maximum Modified Dry

Density (ASTM D-1557).

• Structure Foundation Recommendations (Section 4.2)

- New foundations (if required) may be designed as a shallow spread foundation bearing on virgin soil or new compacted fill.

- Net design bearing pressure is 4,000 psf.

- Minimum depth for frost protection is 36 inches.

- Seismic Site Class is DE – Loose Sand or Medium Stiff Clay

• Structure Floor Slab (Section 4.3)

- The structure slab (if required) can be designed as slabs on grade supported by new compacted fill or virgin soil.

- Modulus of subgrade reaction is 200 pci.

4.0 STRUCTURE EVALUATION

The planned construction will consist of renovations to the existing pool facility. The type and extent of the renovations were unknown as of the date of this report. We expect that the site improvements could include new structures, new asphalt pavement, hardscape, new utilities, and/or new stormwater management areas. A summary of the boring observations can be found in Table 1, above.

Existing fill is present throughout the site to depths ranging from 4’0” to 6’0” below the existing ground surface. The depth of the existing fill is variable and may be deeper or shallower in unexplored areas of the site. The existing fill is not an acceptable bearing material for the new foundations or structure floor slab. The consistency and density of the fill are not predictable.

Certain areas may contain clean dense soils while other areas may contain loose material, void spaces, and/or debris, as shown by the boring data. The existing fill material creates the possibility of intolerable differential settlements under loading. To eliminate the potential for damaging differential settlements, the existing fill within any planned structure areas must be completely removed and replaced with new structural fill.

Provided that the structure areas are prepared as outlined in Section 4.1 below, it is our opinion that new foundations may be designed as shallow spread foundation bearing on the virgin Sand with Gravel (Stratum 3, USCS: SP) or new engineer approved compacted fill.

Recommendations for preparation of the site area are provided in Section 4.1. Design parameters for the new foundations can be found in Section 4.2. In addition, the proposed structure floor slab may be designed as slab on grade bearing on new structural fill or densified virgin soils.

Floor slab recommendations can be found in Section 4.3 below.

4.1 Structure Subgrade Preparation

In order to prepare the site for construction, all surface materials such as asphalt, gravel, and surface vegetation shall be removed from the planned structure area, extending at least 10 feet beyond the new construction limits, where practical.

Where existing utilities are encountered within a planned structure area, they should be either abandoned or rerouted around the new structure. Once the utility has been rerouted or abandoned, the section of pipe and any associated structure within the structure area should be completely removed. The removal of the pipe and structure must also include any loose fill around the pipe or structure. After the pipe, associated structure, and associated loose backfill have been removed, the resulting excavation shall be backfilled with new controlled fill as described below.

Removal of Existing Fill For New Structures

Existing fill was encountered in the borings to depths ranging from 4’0” to 6’0” below the existing ground surface. The existing fill is expected to vary in thickness and may extend deeper or shallower in the unexplored areas.

The excavation for the structure pad shall extend through the existing fill, down to the virgin sand with gravel (Stratum 3, USCS: SP). At the bottom of the excavation, the removal of the unsuitable material shall extend horizontally beyond the structure limits a minimum distance of 1’0” plus a distance equal to the depth of the excavation below the planned foundation bearing elevation. For example, if the removal of the existing fill extends vertically 2’0” below the planned structure area, the excavation must extend horizontally a minimum of 3’0” (1’0” plus

2’0”) beyond the new structure limits at that location.

The removal of the existing fill from the structure area shall be performed under the full time inspection of Carlin-Simpson & Associates or a qualified geotechnical engineering firm.

The on-site representative from Carlin-Simpson & Associates or a qualified geotechnical engineering firm shall direct the contractor during this operation to ensure that all of the unsuitable material has been removed from the proposed structure area.

During the removal of the unsuitable material, the contractor should segregate the potentially re-usable existing soil/fill material from the non-reusable fill (i.e. debris and topsoil).

The on-site representative from Carlin-Simpson & Associates or a qualified geotechnical engineering firm shall evaluate the suitability of the excavated materials for use as compacted fill during the excavation and prior to its re-use. Potentially usable fill should be stockpiled and covered with tarps or plastic sheeting for protection from excess moisture. Any fill material that is or becomes wet must be dried prior to its re-use.

Densification of Subgrade Soils (Proofrolling)

After the surface materials and existing fill (where required) are removed as outlined above and prior to the placement of new structural fill, the exposed subgrade soil must be graded level shall be proofrolled with at least five (5) passes of a large vibratory drum roller (i.e.

Dynapac CA 250 or equivalent). The proofrolling is necessary to densify the underlying soils.

Proofrolling must be performed prior to the excavation for new foundations and/or the installation of new compacted fill in the structure areas.

A representative from Carlin-Simpson & Associates or a qualified geotechnical engineering firm shall observe the proofrolling operation. If any excessive movement is noted during the proofrolling, the soft soil shall be removed and replaced with new compacted fill. The

Carlin-Simpson & Associates or a qualified geotechnical engineering firm representative shall be responsible for determining what material, if any, is to be removed and will direct the contractor during this operation. The subgrade proofrolling may be eliminated, if in the opinion of the geotechnical engineer, the proofrolling will cause pumping or otherwise disturb the stability of the subgrade.

Installation of New Structural Fill

New fill required to achieve final grades shall consist of either engineer-approved on-site soil or imported sand and gravel. The new fill shall be placed in layers not exceeding one (1) foot in thickness and each layer shall be compacted to at least 95% of its Maximum Modified Dry

Density (ASTM D1557). Each layer must be compacted, tested, and approved by the Carlin-

Simpson & Associates or a qualified geotechnical engineering firm field representative or a qualified geotechnical engineering firm prior to placing subsequent layers. The suitability of the excavated soil for reuse as compacted structural fill is discussed in Section 5.5 below. If imported structural fill will be required during construction, the imported structural fill shall meet the following specified gradation:

US Standard Sieve Size Percent Finer By Weight

3 inch 100

No. 4 30-80

No. 40 10-50

No. 200 0-20

4.2 Foundation Design Parameters

Once the planned structure area has been prepared as described in Section 4.1 above, the new foundations may be constructed on the virgin site soils or new structural fill. All of the exterior footings shall bear at the minimum depth listed below for protection from frost. Interior column footings may bear on the virgin soil or new structural fill just below the floor slabs provided the structure is heated during winter. The footings shall have minimum dimensions as listed below.

Table 2 – New Foundation Design Parameters

Description Value

Foundation Bearing Material Virgin Soil or New Structural Fill

Net Design Bearing Pressure 4,000 psf

Minimum Frost Depth 36 inches

Minimum Column Dimension 30 inches

Minimum Wall Dimension 18 inches

The excavations for the new foundations shall be performed under the full-time inspection of Carlin-Simpson & Associates or a qualified geotechnical engineering firm. The on-site representative shall confirm that the foundation bearing material is capable of supporting the design bearing pressure.

Prior to the placement of formwork, reinforcement steel, and concrete, the bearing subgrade soil shall be cleaned of all loose soil and where soil is encountered at the subgrade elevation, it shall be compacted with several passes of a small vibratory drum trench compactor

(i.e. Wacker Model RT560), a heavy vibratory plate tamper (i.e. Wacker BPU 3545A or equivalent), or “jumping jack” style tamper (i.e. Wacker Model BS 600). This must be performed under the observation of Carlin-Simpson & Associates or a qualified geotechnical engineering firm. If instability is observed during the compaction of the bearing subgrade, the soft soil shall be removed and replaced with new compacted fill.

AKouromenos Highlight Net Design Bearing Pressure 4,000 psf Minimum Frost Depth 36 inches Minimum Column Dimension 30 inches Minimum Wall Dimension 18 inches

4.3 Structure Floor Slabs

New fill for floor slabs shall consist of either suitable on-site soil or imported sand and gravel. In the event that backfill soil is imported, it shall meet the gradation in Section 4.1

“Installation of New Structural Fill”. The new fill shall be placed in layers not exceeding one (1) foot in loose thickness and each layer shall be compacted to at least 92% of its Maximum

Modified Dry Density (ASTM D1557). Fill layers shall be compacted, tested, and approved before placing subsequent layers.

In the even that floor slabs are required, the floor slabs may be designed as a slab on grade bearing on virgin soil or new engineer-approved structural fill. Floor slab design parameters are provided in Table 3 below. A layer of 3/4-inch clean crushed stone is recommended beneath the concrete slab for additional support and drainage. These slab recommendations are for a slab on grade. If a basement or lower level is planned, additional stone thickness and a sump pump will be required.

Table 3 – Structure Floor Slab Design Parameters

Slab Subgrade Material Virgin Soil or New Structural Fill

Modulus of Subgrade Reaction (k) 200 pci

Crushed Stone Cushion Thickness 6 inches (minimum)

4.4 Foundation Walls

In the event that foundation walls are required, the soil adjacent to the structure walls will exert horizontal pressure against the wall. This pressure is based on the soil density and

Coefficient of Earth Pressure at Rest (ko), which is applicable to non-yielding structure walls.

Foundation wall design parameters are listed in Table 4 below.

Table 4 – Foundation Wall Design Parameters

Soil Type On-Site Soils

Moist Unit Weight (γ) 130 pcf

Friction Angle (, deg) 30

Cohesion (c, psf) 0

Coefficient of Earth Pressure at Rest (ko) 0.5

Equivalent Fluid Pressure 65 psf/ft

Foundation Sliding Coefficient 0.45

Where foundation walls are required, we recommend that a footing drain be placed around the exterior of the new structure to prevent water from accumulating against the foundation wall. The drain shall be placed at the lowest elevation possible adjacent to the new foundation wall. Typically, the drain is placed just above or adjacent to the new footing. This drain may consist of a minimum 4-inch diameter, rigid wall perforated PVC pipe surrounded by at least 12 inches of 3/4-inch clean crushed stone. The stone shall be wrapped in a geotextile

AKouromenos Pen Kp

AKouromenos Pen tan

AKouromenos Pen

AKouromenos Pen

AKouromenos Pen

AKouromenos Pen

AKouromenos Pen ka=tan(45-8)

AKouromenos Pen

AKouromenos Pen = .33

AKouromenos Highlight Modulus of Subgrade Reaction (k) 200 pci Crushed Stone Cushion Thickness 6 inches (minimum)

AKouromenos Highlight Moist Unit Weight (γ) 130 pcf Friction Angle (, deg) 30 Cohesion (c, psf) 0 Coefficient of Earth Pressure at Rest (ko) 0.5 Equivalent Fluid Pressure 65 psf/ft Foundation Sliding Coefficient 0.45 fabric, such as Mirafi 140N or equivalent. The foundation drainpipe should be extended to daylight or to the stormwater collection system. The outside face of the foundation wall, where it extends below grade, must be dampproofed. In addition, all below-grade levels areas must be equipped with at least one sump pit and pump. The exterior footing drain must not be connected to the interior sump pit.

Outside the structure, the backfill placed adjacent to the foundation walls and above the footing drain shall consist of either clean crushed stone or an imported sand and gravel mixture containing less than 10% by weight passing a No. 200 sieve and placed in layers not exceeding

12 inches in thickness. This clean sand and gravel or crushed stone backfill shall extend a minimum of 12 inches horizontally from the back face of the foundation walls and shall extend vertically up the wall face to 2 feet below the finished ground surface elevation. Where retained soils are not covered by concrete or pavement and are exposed to weather, the top 2 feet of backfill should consist of low permeable soil. This will help to minimize water infiltration behind the wall. Surface grades should be sloped away from the structure to prevent water from accumulating adjacent to the wall.

Beyond this point, the foundation walls should be backfilled with suitable soil placed in layers up to 12 inches in thickness. The suitability of the on-site soil for reuse as compacted fill is discussed in a separate section below. The new fill should be compacted with a vibratory drum trench compactor (i.e. Wacker Model RT560), a heavy vibratory plate tamper (i.e. Wacker BPU

3545A or equivalent), or “jumping jack” style tamper (i.e. Wacker Model BS 600) to at least

92% of its Maximum Modified Dry Density (ASTM D1557). Heavy equipment should not be operated near the walls as damage to the walls could occur.

4.5 Settlement

Settlement of individual footings, designed in accordance with recommendations presented in this report, is expected to be within tolerable limits for the proposed structure. For footings placed on natural soils or new engineer-approved compacted fill and constructed in accordance with the requirements outlined in this report, maximum total settlement is expected to be on the order of 1-inch or less. Maximum differential settlement between adjacent columns or load bearing walls is expected to be ½-inch or less.

The above settlement values are based on our engineering experience with similar soil conditions and the anticipated structural loading. These estimated settlements are intended to guide the structural engineer with their design. These estimated settlement values do not include the possibility of settlement during a seismic event. It is critical that Carlin-Simpson &

Associates, or a qualified geotechnical engineering firm be retained to observe the foundation bearing surfaces and to confirm the recommended bearing pressures during construction.

4.6 Seismic Design Considerations

From site-specific test boring data, the Site Class was determined from 2025 New York

State Building Code and ASCE 7-22. The site-specific data used to determine the Site Class typically includes soil test borings to determine Standard Penetration resistances (N-values).

Based on estimated shear wave velocities in the upper 100 feet of soil profile, the site can be classified as Site Class DE – Loose Sand or Medium Stiff Clay.

New structures should be designed to resist stress produced by lateral forces computed in accordance with Section 1613 of the 2025 New York State Building Code and ASCE 7-22. The values in Table 5 shall be used for this project.

Table 5 – Seismic Design Values*

Mapped Spectral Response Acceleration for Short Periods SS=0.250g

Mapped Spectral Response Acceleration at 1-Second Period S1=0.048g

Max Considered Earthquake Spectral Response for Short Periods SMS=0.260g

Max Considered Earthquake Spectral Response at 1-Second SM1=0.099g

Design Spectral Response Acceleration for Short Periods SDS=0.170g

Design Spectral Response Acceleration for 1-Second Period SD1=0.066g

*The above design values are based on the NYS 2025 Building Code and were obtained from

ASCE Hazard Tool website.

We expect that the proposed structure will have a Risk Category of II. Based on this assumption and the above Seismic Design Values, the Seismic Design Category (SDC) for the structure is B. The Risk Category and SDC should be verified by the project structural engineer.

In the event that the structure has a different Risk Category, the SDC should be updated in accordance with Section 1613 of the 2025 New York State Building Code and ASCE 7-22.

Liquefaction Potential

Liquefaction is a phenomenon in which saturated or partially saturated soils lose strength and stiffness when subjected to earthquake-induced ground shaking. Ground shaking of sufficient duration results in the loss of grain-to-grain contact and collapse of the soil skeleton which causes stresses in the soil to be completely transferred to the pore water fluid.

Liquefaction is most often observed in saturated, loose sandy soils at depths shallower than 50 feet below the ground surface. Factors known to influence liquefaction potential include composition and thickness of soil layers, grain size, relative density, groundwater level, degree of saturation, and both intensity and duration of ground shaking.

The liquefaction potential was evaluated with the available data, including the SPT blow counts, soil classification, total unit weight, soil fines content, and depth to groundwater. We have determined the potential for liquefaction is negligible for the site and is unlikely to occur during a seismic event.

5.0 SITE EVALUATION

Our recommendations for the proposed site development including new stormwater management, new asphalt pavement and hardscape, utilities, temporary excavation and bracing, and suitability of the existing site soils for reuse are provided below.

AKouromenos Highlight Mapped Spectral Response Acceleration for Short Periods SS=0.250g Mapped Spectral Response Acceleration at 1-Second Period S1=0.048g Max Considered Earthquake Spectral Response for Short Periods SMS=0.260g Max Considered Earthquake Spectral Response at 1-Second SM1=0.099g Design Spectral Response Acceleration for Short Periods SDS=0.170g Design Spectral Response Acceleration for 1-Second Period SD1=0.066g

AKouromenos Highlight Risk Category of II

AKouromenos Highlight Seismic Design Category (SDC) for the structure is B

5.1 New Stormwater Management Areas

It is our understanding that a new stormwater management area will be constructed at the site. The type of system, invert elevation, and exact location(s) of the proposed stormwater management areas were unknown at the time of writing this report. Boring B-1 was performed for the new stormwater management area.

The soil conditions at SB-1 generally consist of topsoil that is underlain by existing fill.

Below the existing fill is medium dense to dense sand with gravel that extends to a depth of

50’0” below the existing ground surface. Groundwater was observed at a depth of 31’0” below the existing ground surface.

One (1) borehole infiltration test was performed at the site during this subsurface investigation. A summary of the borehole infiltration test results are provided in Table 6 below.

The permeability of the site soil was also calculated and can be found in Table 6 below. The calculated permeability (K) was determined using the equation provided below.

Table 6 – Stormwater Management Systems Test Results

Boring No Borehole Test

Depth

Field Infiltration

Rate

Calculated

Permeability, K

B-1/P-2 15’0” Greater than 24 in/hr 20 in/hr

The stormwater management systems must be designed in accordance with the applicable

New York State Department of Environmental Conservation (NYSDEC) regulations and the

New York State Stormwater Management Design Manual. The testing requirements are outlined in Appendix D of the manual.

5.2 New Pavement and Hardscape

We understand that the proposed construction could also include new asphalt paved parking areas and driveways and new hardscape areas. Densified existing fill, virgin site soils, and new compacted fill may be used to support the pavement.

To prepare the new pavement and hardscape areas, the existing surface materials (i.e.

topsoil, vegetation, etc.) must be removed from the planned areas. In the proposed pavement and hardscape areas, the existing structures and debris resulting from the demolition of these structures must be completely removed from the new pavement and hardscape area, extending at least five (5) feet beyond the new paving limits, where practical. The excavations resulting from the removal of existing structures shall be backfilled using controlled compacted fill. New fill shall consist of either suitable on-site soil or imported sand and gravel placed in one (1) foot loose layers and compacted to at least 92% of its Maximum Modified Dry Density (ASTM D-

1557).

After all surface materials have been removed, the area can be excavated to the planned subgrade elevation. Where soil is encountered at the subgrade elevation, the subgrade shall be proofrolled with a large vibratory drum roller (i.e. Dynapac 250 or equivalent) to densify the underlying soils. The on-site representative from Carlin-Simpson & Associates shall witness the proofrolling operation. If any excessive movement is noted during the proofrolling, the soft or unsuitable soil shall be removed and replaced with new compacted fill.

Areas where existing fill is encountered shall be compacted in place. Carlin-Simpson &

Associates or a qualified geotechnical engineering firm must evaluate these areas for the presence of soft or unsuitable material within the existing fill matrix. Portions of this fill may have to be removed and replaced with new compacted fill. Carlin-Simpson & Associates or a qualified geotechnical engineering firm will determine this during construction.

Where new fill is required to achieve final grades, it shall consist of either suitable on-site soil or imported sand and gravel. Imported sand and gravel shall contain less than 20% by weight passing a No. 200 sieve, and meet the gradation in Section 4.1 “Installation of New Structural

Fill”. New fill shall be placed in layers not exceeding one (1) foot in loose thickness and each layer shall be compacted to at least 92% of its Maximum Modified Dry Density (ASTM D-

1557). After the planned subgrade has been proofrolled and new compacted fill has been placed as required, the new pavement subbase may be placed on the existing site soils, bedrock, and new compacted fill.

Asphalt Pavement Section

After the planned subgrade has been proofrolled and new compacted fill has been placed as required, the new pavement subbase may be placed on the existing site soils or new compacted fill. Dense graded aggregate (DGA) is recommended for the subbase layer for additional pavement support. We recommend that the following pavement section be used for the parking lots and driveways. This pavement section is subject to local government approval.

Light Duty – Parking Lots

1.5” Asphalt Top Course NYSDOT, Type 6F

2.5” Asphalt Base Course NYSDOT, Type 3

6” Stone Subbase (DGA) NYSDOT, Type 1

Approved Compacted Subgrade (Minimum CBR = 10)

Medium Duty – Driveways/Roadways

2” Asphalt Top Course NYSDOT, Type 6F

3” Asphalt Base Course NYSDOT, Type 3

8” Stone Subbase (DGA) NYSDOT, Type 1

Based on the boring data, we anticipate that the densified existing site soils and new compacted fill will provide a CBR value that is equal to or greater than 10, which can adequately support the above pavement sections.

Rigid (Concrete) Pavement

We expect that the proposed construction may also include rigid concrete pavement in portions of the site. The new concrete pavement should be designed for light vehicles (autos, pickup trucks, vans) and occasional delivery or trash pick-up truck traffic. This pavement section is subject to local government approval.

5.5” Concrete Section 4,000 psi

6” Gravel Subbase Course NYSDOT Type 4

The rigid concrete pavement should be reinforced with welded wire fabric or reinforcing steel bars for crack control. Contraction joints should also be provided with a maximum spacing of 10 feet. The project structural engineer or the site engineer shall determine the type, size, and spacing of the reinforcement based on the anticipated loading.

5.3 Utilities

New utilities may bear in the densified existing fill, virgin soils, or new compacted fill.

The bottom of all trenches shall be excavated clean so a hard bottom is provided for pipe support. If any soft areas or unsuitable existing fill conditions are encountered during the construction operation, these materials must be removed and replaced with new compacted fill.

For areas where existing fill is encountered within the utility excavations, the subgrade at bottom of the utility excavation shall be compacted in place with a vibratory drum trench compactor or “jumping jack” style tamper. Carlin-Simpson & Associates or a qualified geotechnical engineering firm must evaluate these areas for the presence of soft or unsuitable material within the existing fill matrix. If instability is observed, portions of this fill may have to be removed and replaced with new compacted fill. Carlin-Simpson & Associates or a qualified geotechnical engineering firm will determine this during construction.

In the event that water is encountered within the utility trench excavation or if the trench bottom becomes soft due to the inflow of surface water or trapped water, a layer of geotextile filter fabric and a minimum of six (6) inches of crushed stone shall be placed on the bearing soil to provide a firm base for support of the pipe. Sump pits and pumps should be used to keep the excavations dry.

After the utility is installed, the trench must be backfilled with compacted fill. In the event that imported fill is required, it shall meet the gradation in Section 4.1 “Installation of New

Structural Fill”. Controlled compacted fill shall be placed in one (1) foot loose layers and each layer shall be compacted to at least 92% of its Maximum Modified Dry Density (ASTM D1557).

The backfill must be free of topsoil, debris, and large boulders.

5.4 Temporary Construction Excavations and Excavation Protection

Temporary construction excavations should be conducted in accordance with the most recent OSHA guidelines or applicable federal, state or local codes. A qualified person should evaluate the excavations at the time of construction to determine the appropriate soil type and allowable slope configuration. Based on the boring data, we believe the site soils would have the following classifications as defined by the OSHA guidelines.

Soil Type Possible Classification Maximum Slope or Bench

Existing Fill Type “C” 1½H:1V

Virgin Soil Type “B” or Type “C” 1H:1V or 1½H:1V

A New York State licensed professional engineer must design all temporary and permanent support systems. The contractor will select the shoring type and submit design calculations for the proposed shoring method to Carlin-Simpson & Associates for review.

The soil adjacent to the temporary support system will exert a horizontal pressure against the system. This pressure is based on the soil unit weight, coefficient of active earth pressure, and depth of the excavation. In addition, the surcharge loads from adjacent driveways, construction equipment, or stored materials near the excavation must be incorporated into the design of the support system, as applicable. The design parameters for temporary excavation support systems are listed in Table 7 below.

Table 7 – Temporary Excavation Support System Design Parameters

Moist Unit Weight (pcf) 130

Friction Angle (, deg) 30

Cohesion (c, psf) 0

Active Earth Pressure Coefficient (ka) 0.33

Equivalent Fluid Pressure (pcf) 43.0

Passive Earth Pressure Coefficient (kp) 3.0

5.5 Suitability of the In-Situ Soils for Use as Compacted Fill

The suitability of each soil stratum for use as compacted fill is discussed below.

Stratum 1

Topsoil

Topsoil is not suitable for use as compacted fill. During construction, it shall be stripped from the construction areas. The topsoil may be reused in non-structural, non-sloped landscape areas or hauled offsite.

Stratum 2

Existing Fill

The existing fill generally consists of dark brown, black, gray, brown, orange coarse to fine SAND, varying amounts of Silt, little (to some) coarse to fine

Gravel. Debris consisting of ash and roots were encountered within the existing fill at the boring locations. The existing fill material may be suitable for use as backfill, provided that it remains relatively dry for optimum compaction and all debris has been removed prior to use.

Stratum 3

Sand with

Gravel

[USCS: SP]

The virgin sand with gravel consists of orange, brown coarse to fine SAND, trace Silt, little (to and) coarse to fine Gravel. Provided that the soil remains relatively dry for optimum compaction, this stratum is generally suitable for reuse as compacted fill.

The boring observations indicate that the on-site soils contain a varying percentage of silt

(3% to 45%). The moderate silt content soils, particularly some of the existing fill, will be moisture sensitive. If the soil becomes too wet, it will be difficult to achieve adequate compaction. Soil excavated from below the groundwater table will be completely saturated and not suitable for immediate reuse.

New compacted fill should be within 2% (+/-) of its optimum moisture content at the time of placement. In the event that the on-site material is too wet at the time of placement and cannot be adequately compacted, the soil should be aerated and allowed to dry or the material removed and a drier cleaner fill material used. In the event that the on-site material is too dry at the time of placement and cannot be adequately compacted, water may be needed to increase the soil moisture content for proper compaction.

The in-situ soils which exist throughout the site may become soft and weave if exposed to excessive moisture and construction traffic. The instability will occur quickly when exposed to these elements and it will be difficult to stabilize the subgrade. We recommend that adequate site drainage be implemented early in the construction schedule and if the subgrade becomes wet, the contractor should limit construction activity until the soil has dried.

The minimum compaction requirements for the various areas of the site are summarized in Table 8 below.

Table 8 – Minimum Compaction Requirements

Area Maximum Modified Dry Density

(ASTM D-1557)

Structure (below foundations) 95%

Structure Slab (above foundations) 92%

Foundation Walls 92%

Pavement Areas 92%

Exterior Slabs and Sidewalks 92%

Utility Trenches 92%

Landscape Areas – non sloped areas 90%

6.0 GENERAL

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

Regardless of the thoroughness of a geotechnical exploration, there is the possibility that conditions between borings and test pits will differ from those encountered at specific boring or test pit locations, that conditions are not as anticipated by the designers and/or the contractors, or that either natural events or the construction process have altered the subsurface conditions.

These variations are an inherent risk associated with subsurface conditions in this region and the approximate methods used to obtain the data. These variations may not be apparent until construction.

The professional opinions presented in this geotechnical report are not final. Field observations and foundation installation monitoring by the geotechnical engineer, as well as soil density testing and other quality assurance functions associated with site earthwork and foundation construction, are an extension of this report. Therefore, Carlin-Simpson & Associates should be retained by the Owner to observe all earthwork and foundation construction, to document that the conditions anticipated in this study actually exist, and to finalize or amend our conclusions and recommendations Carlin-Simpson & Associates is not responsible or liable for the conclusions and recommendations presented in this report if Carlin-Simpson & Associates does not perform the observation and testing services.

Therefore, in order to preserve continuity in this project, the Owner must retain the services of Carlin-Simpson & Associates to provide full time geotechnical related monitoring and testing during construction. At a minimum, this shall include the observation and testing of the following: 1) the removal of unsuitable soil, where required; 2) the proofrolling of the subgrade soil prior to the placement of new compacted fill; 3) the placement and compaction of controlled fill; 4) the excavation for the new foundations; and 5) the preparation of the subgrade for the floor slab, pavement areas, and hardscape areas.

This report has been prepared in accordance with generally accepted geotechnical engineering practice. No other warranty is expressed or implied. The evaluations and recommendations presented in this report are based on the available project information, as well as on the results of the exploration. Carlin-Simpson & Associates should be given the opportunity to review the final drawings and site plans for this project to determine if changes to the recommendations outlined in this report are needed. Should the nature of the project change, these recommendations should be re-evaluated.

This report is provided for the exclusive use of H2M Architects + Engineers and the project specific design team and may not be used or relied upon in connection with other projects or by other third parties. Carlin-Simpson & Associates disclaims liability for any such third party use or reliance without express written permission. Use of this report or the findings, conclusions or recommendations by others will be at the sole risk of the user. Carlin-Simpson & Associates is not responsible or liable for the interpretation by others of the data in this report, nor their conclusions, recommendations or opinions.

If the conditions encountered during construction vary significantly from those stated in this report, this office should be notified immediately so that additional recommendations can be made.

Thank you for allowing us to assist you with this project. Should you have any questions or comments, please contact this office.

Very truly yours, CARLIN-SIMPSON & ASSOCIATES, LLC

CATHERINE K. ANDERSEN, P.E.

Project Engineer

ROBERT B. SIMPSON, P.E.

Principal

File No. 25-86

CARLIN-SIMPSON & ASSOCIATES TEST BORING LOG BORING NUMBER

Sayreville, NJ B-1

Project: Proposed Renovations, 335 Greenwich St, Hempstead NY SHEET NO.: 1 of 3

Client: H2M Architects + Engineers JOB NUMBER: 25-86

Drilling Contractor: Environmental Technical Drilling ELEVATION: -

GROUNDWATER CASING SAMPLE CORE TUBE DATUM: -

DATE TIME DEPTH CASING TYPE HSA SS START DATE: 25/Jun/25

1111 31'0" HSA DIA. 3 1/4" 1 3/8" FINISH DATE: 25/Jun/25

WGHT 140# DRILLER: B Tolbert

FALL 30" INSPECTOR: JP

Depth

(ft.)

Casing

Blows per

Foot

Sample

Number

Blows on

Sample

Spoon per 6"

S y m

IDENTIFICATION REMARKS

2 Topsoil 0'6" 1 S-1 3 FILL (Br cf S, l (-) $, l cf G) Rec = 7"

6 moist

2 7

3 S-2 5 FILL (same, gr, a $, s (-) cf G) Rec = 25"

7 FILL (Brown coarse to fine SAND, moist

4 9 some Silt, little coarse to fine Gravel)

6 S-3 8 FILL (same, br, gr s (+) $) 6'0" Rec = 21"

23 Br cf S, t $, s cf G moist

7 19

8 S-4 27 same, l (+) cf G Rec = 0"

15 moist

9 17

11 S-5 10 same, or l (-) cf G Rec = 16"

10 moist

12 11

Brown coarse to fine SAND, trace Silt, 13 some coarse to fine Gravel

[USCS: SP]

16 S-6 9 same Rec = 10"

8 moist

17 8

21 S-7 7 same Rec = 21"

7 moist 22 8

25/Jun/25

Project: Proposed Renovations, 335 Greenwich St, Hempstead NY SHEET NO.: 2 of 3

Client: H2M Architects + Engineers JOB NUMBER: 25-86

Depth

(ft.)

Casing

Blows per

Foot

Sample

Number

Blows on

Sample

Spoon per 6"

S y m

IDENTIFICATION REMARKS

26 S-8 8 Lt br cf S, t $, l cf G Rec = 17"

7 moist

27 7

31 S-9 8 same Rec = 13"

9 wet

32 10

Light brown coarse to fine SAND, 34 trace Silt, little coarse to fine Gravel

[USCS: SP]

36 S-10 6 same Rec = 8"

7 wet

37 10

41 S-11 6 same Rec = 10"

9 wet

42 9

46 S-12 7 same Rec = 11"

8 wet 47 11

Project: Proposed Renovations, 335 Greenwich St, Hempstead NY SHEET NO.: 3 of 3

Client: H2M Architects + Engineers JOB NUMBER: 25-86

Depth

(ft.)

Casing

Blows per

Foot

Sample

Number

Blows on

Sample

Spoon per 6"

S y m

IDENTIFICATION REMARKS

48 Light brown coarse to fine SAND, 9 trace Silt, little coarse to fine Gravel

49 S-13 9 [USCS: SP] Rec = 12"

10 Lt br cf S, t $, l cf G wet

50 10 50'0"

End of Boring @ 50'0"

CARLIN - SIMPSON & ASSOCIATES TEST BORING LOG BORING NUMBER

Sayreville, N.J. B-2

Project: Proposed Renovations, 335 Greenwich St, Hempstead NY SHEET NO.: 1 of 2

Client: H2M Architects + Engineers JOB NUMBER: 25-86

Drilling Contractor: Environmental Technical Drilling ELEVATION: -

GROUNDWATER CASING SAMPLE CORE TUBE DATUM: -

DATE TIME DEPTH CASING TYPE HSA SS START DATE: 23/Jun/25

DIA. 3 1/4" 1 3/8" FINISH DATE: 23/Jun/25

WGHT 140# DRILLER: S Pierce

FALL 30" INSPECTOR: JP

Depth

(ft.)

Casing

Blows per

Foot

Sample

Number

Blows on

Sample

Spoon per 6"

S y m

IDENTIFICATION REMARKS

3 Topsoil 0'6" 1 S-1 11 FILL (Br, dk gr cf S, l $, s (-) cf G) Rec = 15"

13 FILL (Brown, dark gray coarse to fine moist

2 9 SAND, little Silt, some (-) coarse to fine

5 Gravel with roots)

3 S-2 5 FILL (same, dk br s (-) $, l cf G, w/roots) Rec = 13"

5 moist

4 6 4'0"

5 S-3 7 Lt br cf S, t $, s (-) cf G Rec = 10"

15 moist

6 14

7 S-4 16 same, a (+) cf G Rec = 17"

16 moist

8 19

10 S-5 7 same, or, t (+) f G Rec = 8"

8 moist

11 7 Light brown coarse to fine SAND, trace Silt, some (-) coarse to fine Gravel

12 [USCS: SP]

15 S-6 4 same Rec = 15"

5 moist

16 7

20 S-7 6 same Rec = 17"

6 moist

21 6

22 22'0"

No Groundwater Encountered

Sayreville, N.J. B-2

Project: Proposed Renovations, 335 Greenwich St, Hempstead NY SHEET NO.: 2 of 2

Client: H2M Architects + Engineers JOB NUMBER: 25-86

Depth

(ft.)

Casing

Blows per

Foot

Sample

Number

Blows on

Sample

Spoon per 6"

S y m

IDENTIFICATION REMARKS

25 S-8 6 Lt br cf S, t $ Rec = 21"

8 moist

26 10 Light brown coarse to fine SAND, trace Silt [USCS: SP]

30 S-9 6 same, l (-) cf G Rec = 14"

8 moist

31 9 31'0"

End of Boring @ 31'0"

Sayreville, N.J. B-3

Project: Proposed Renovations, 335 Greenwich St, Hempstead NY SHEET NO.: 1 of 2

Client: H2M Architects + Engineers JOB NUMBER: 25-86

Drilling Contractor: Environmental Technical Drilling ELEVATION: -

GROUNDWATER CASING SAMPLE CORE TUBE DATUM: -

DATE TIME DEPTH CASING TYPE HSA SS START DATE: 25/Jun/25

DIA. 3 1/4" 1 3/8" FINISH DATE: 25/Jun/25

WGHT 140# DRILLER: B Tolbert

FALL 30" INSPECTOR: JP

Depth

(ft.)

Casing

Blows per

Foot

Sample

Number

Blows on

Sample

Spoon per 6"

S y m

IDENTIFICATION REMARKS

1 4 Topsoil 0'10"

S-1 3 FILL (Dk br cf S, s (-) $, l (+) cf G, w/ash) Rec = 14"

2 3 moist

3 S-2 2 FILL (same, l $, w/ash) Rec = 5"

5 FILL (Dark brown coarse to fine SAND, moist

4 9 some (-) Silt, little (+) coarse to fine

Gravel, with ash)

5 5'0"

6 S-3 4 Lt br cf S, t $, s (+) cf G Rec = 10"

15 moist

7 15

8 S-4 16 same, s (-) cf G Rec = 14"

19 moist

9 19

11 S-5 7 same, l (-) cf G Rec = 10"

9 moist

12 6 Light brown coarse to fine SAND, trace Silt, some (+) coarse to fine Gravel

13 [USCS: SP]

16 S-6 12 same Rec = 13"

14 moist

17 16

21 S-7 19 same Rec = 14"

21 moist 22 18 22'0"

No Groundwater Encountered

Sayreville, N.J. B-3

Project: Proposed Renovations, 335 Greenwich St, Hempstead NY SHEET NO.: 2 of 2

Client: H2M Architects + Engineers JOB NUMBER: 25-86

Depth

(ft.)

Casing

Blows per

Foot

Sample

Number

Blows on

Sample

Spoon per 6"

S y m

IDENTIFICATION REMARKS

26 S-8 17 Br cf S, t $, l cf G Rec = 10"

17 Brown coarse to fine SAND, trace Silt, moist

27 17 little coarse to fine Gravel

[USCS: SP]

29 S-9 18 same Rec = 11"

17 moist

30 14 30'0"

End of Boring @ 30'0"

Sayreville, N.J. B-4

Project: Proposed Renovations, 335 Greenwich St, Hempstead NY SHEET NO.: 1 of 2

Client: H2M Architects + Engineers JOB NUMBER: 25-86

Drilling Contractor: Environmental Technical Drilling ELEVATION: -

GROUNDWATER CASING SAMPLE CORE TUBE DATUM: -

DATE TIME DEPTH CASING TYPE HSA SS START DATE: 23/Jun/25

- 31'0" HSA DIA. 3 1/4" 1 3/8" FINISH DATE: 23/Jun/25

WGHT 140# DRILLER: S Pierce

FALL 30" INSPECTOR: JP

Depth

(ft.)

Casing

Blows per

Foot

Sample

Number

Blows on

Sample

Spoon per 6"

S y m

IDENTIFICATION REMARKS

2 Topsoil 0'6" 1 S-1 4 FILL (Bk, or, br cf S, t $, l cf G, w/ash, debris) Rec = 14"

5 FILL (Black, orange, brown coarse to fine moist

2 8 SAND, trace Silt, little coarse to fine

1 Gravel, with ash, debris, roots)

3 S-2 2 FILL (same, br a (-) $, w/roots) Rec = 12"

3 moist

4 10 4'0"

6 S-3 12 Br, or cf S, t $, s cf G Rec = 17"

15 moist

7 15

8 S-4 13 same Rec = 15"

14 moist

9 14

11 S-5 5 same, l (-) cf G Rec = 19"

7 Brown, orange coarse to fine SAND, moist

12 6 trace Silt, some coarse to fine Gravel

USCS: SP]

16 S-6 6 same Rec = 16"

6 moist

17 6

21 S-7 8 same, l cf G Rec = 24"

9 moist 22 8 22'0"

23/Jun/25

Sayreville, N.J. B-4

Project: Proposed Renovations, 335 Greenwich St, Hempstead NY SHEET NO.: 2 of 2

Client: H2M Architects + Engineers JOB NUMBER: 25-86

Depth

(ft.)

Casing

Blows per

Foot

Sample

Number

Blows on

Sample

Spoon per 6"

S y m

IDENTIFICATION REMARKS

26 S-8 11 Lt br cf S, t $, l cf G Rec = 24"

12 moist

27 13 Light brown coarse to fine SAND, trace Silt, little coarse to fine Gravel

28 [USCS: SP]

31 S-9 9 same Rec = 18"

12 wet

32 10 32'0"

End of Boring @ 32'0"

B-1

B-2

B-3

B-4

GR…