815CM3041 LINC Project Manual Spec Bk-02.pdf

APPENDIX I - Geotechnical Report

ECS Mid-Atlantic, LLC

January 31, 2022

ECS Mid-Atlantic, LLC DRAFT Geotechnical Engineering Report

Long Island National Cemetery Facility Renovation, Improvements, and Repairs

NCA 815CM3041

2040 Wellwood Avenue Farmingdale, New York 11735

ECS Project No. 44:1651

May 20, 2022

Mr. Brian Jacobson, RLA Director of Planning and Design Walker Federal Services 7820B Wormans Mill Road, Suite 162 Frederick, MD 21701

ECS Project No. 44:1651

Reference: DRAFT Geotechnical Engineering Report Long Island National Cemetery - Facility Renovation, Improvements, and Repairs

NCA 815CM3041

2040 Wellwood Avenue, Farmingdale, New York 11735

Dear Mr. Jacobson:

ECS Mid-Atlantic, LLC (ECS) has completed the subsurface exploration, soils laboratory testing, and geotechnical engineering analyses for the above-referenced project. Our services were performed in general accordance with the Subconsultant Agreement between Walker Federal Services, LLC (WFS) and ECS for WFS Project Number 2017.006.28, which was executed on June 18, 2021. This DRAFT report presents our understanding of the geotechnical aspects of the project along with the results of the field exploration and laboratory testing conducted, and our design and construction recommendations.

It has been our pleasure to be of service to WFS during this phase of the project. We would appreciate the opportunity to remain involved during the continuation of the design phase, and we would like to provide our services during construction phase operations as well to document subsurface conditions assumed for this report. Should you have any questions concerning the information contained in this report, or if we can be of further assistance to you, please contact us.

Respectfully submitted, Robert S. Valorio, P.E. Jeffrey A. Shelton, P.E., LEED® AP Geotechnical Department Manager Principal Engineer rvalorio@ecslimited.com jshelton@ecslimited.com

44-1651 LINC.docx mailto:rvalorio@ecslimited.com mailto:jshelton@ecslimited.com

LINC Facility Renovation, Improvements, and Repairs May 20, 2022 ECS Project No. 44:1651 Page i

TABLE OF CONTENTS

EXECUTIVE SUMMARY

1.0 INTRODUCTION

2.0 PROJECT INFORMATION

2.1 Project Location

2.2 Proposed Construction

3.0 FIELD EXPLORATION AND LABORATORY TESTING

3.1 Subsurface Characterizations

3.2 Groundwater Observations

3.3 Laboratory Testing

3.4 Pavement Observations

3.4.1 Visual Observations

3.4.2 Pavement Thickness

3.4.3 Subbase and Subgrade Observations

4.0 DESIGN RECOMMENDATIONS

4.1 Ground-Supported Slabs

4.2 Sign Foundations

4.3 Pavements and Walkways

5.0 SITE CONSTRUCTION RECOMMENDATIONS

5.1 Subgrade Preparation

5.1.1 Demolition

5.1.2 Stripping and Grubbing

5.1.3 Undercutting and Replacement

5.1.4 Moisture Sensitive Soils

5.1.5 Site Temporary Dewatering

5.2 Earthwork Operations

5.2.1 Structural Fill

5.2.2 On-site Soil Re-use

5.2.3 Excavation Considerations

5.3 Subgrade Observations

5.4 Utility Installations

6.0 CLOSING

APPENDICES

Appendix A – Diagrams & Reports

• Site Location Diagram

• Soil Survey Map

• Surficial Geology Map

• Boring Location Diagram

• Pavement Core Location Diagram

Appendix B – Field Operations

• Pavement Observation Photolog

• Pavement Core Photolog

• Subsurface Exploration Procedure: Standard Penetration Testing (SPT)

• Reference Notes for Boring Logs

• Geotechnical Borehole Logs

ECS Project No. 44:1651 Page ii

Appendix C – Laboratory Testing

• Laboratory Test Results Summary

• Grain Size Analyses

• Plasticity Chart

• Moisture-Density Relationship Curves

• California Bearing Ratio Determinations

ECS Project No. 44:1651 Page 1

EXECUTIVE SUMMARY

The following summarizes the main findings from our contracted services, particularly those that may have a cost impact on the planned project. Further, our principal recommendations are summarized.

Information gleaned from the Executive Summary should not be utilized in lieu of reading the entire geotechnical engineering report.

• The site is underlain by variable glacial deposition comprised of clay with sand and sand and gravel with varying content of plastic and non-plastic fines.

• Existing flexible pavement was observed to range in condition from good to poor.

• Observed pavement distresses are the result of age and/or poor subgrade.

• Loose, soft, and otherwise unsuitable soils may be encountered during subgrade preparation and some undercutting and replacement of existing soils should be anticipated during construction.

• New pavements and walkways should be underlain with a crushed stone aggregate subbase placed and compacted above subgrade soil previously prepared in accordance with the recommendation of this report.

• New floral/trash/water stations can be supported by ground-supported reinforced concrete slabs designed for a uniform soil contact pressure of 500 pounds per square foot (rigid method) or by assuming a modulus of subgrade reaction, k1, of 95 pounds per cubic inch (flexible method).

• Sign foundations can be designed with a maximum allowable vertical bearing pressure of 1,500 pounds per square foot and allowable lateral bearing pressure computed using 100 pounds per square foot per depth of burial (neglecting the initial 1-foot).

• We believe construction dewatering at this site will be mainly limited to removing accumulated rainwater, localized perched water, and some minor seepage into excavations.

Please refer to the body of the report for further details on subsurface conditions encountered within the completed borings; findings and observations regarding the existing pavements where coring was completed; and, for our specific geotechnical engineering recommendations for the project.

ECS Project No. 44:1651 Page 2

1.0 INTRODUCTION

The purpose of this study was to provide geotechnical information in connection with the design of flexible pavement rehabilitation/replacement, new Cortege Lanes, concrete walkways, ground-supported slabs, and to support new signage at the Long Island National Cemetery located in Farmingdale, New York (project site). The recommendations developed for this report are based upon project information supplied by Walker Federal Services, LLC (WFS). This information consisted of the February 2021 “Scope of Work (SOW), Long Island National Cemetery, FY 21, Facility Renovation, Improvements, and Repairs, Project Number 815CM3041,” and survey coordinates and ground elevations for our completed soil test borings and pavement cores provided via email on January 30, 2022.

Our services were performed in general accordance with the Subconsultant Agreement between WFS and ECS for the project, referenced as WFS Project Number 2017.006.28, which was executed on June 18, 2021.

This report contains the procedures and results of our subsurface exploration and laboratory testing programs, review of existing site conditions, engineering analyses, and recommendations for the design and construction of the project.

The report includes the following items:

• A description of the project site and brief summary of observed site conditions;

• A description of our field and laboratory test procedures and the results of testing conducted;

• Summary of observed roadway pavement condition, pavement thickness, subbase, and subgrade soil encountered at completed pavement core locations;

• A review of subsurface soil stratigraphy with pertinent physical properties;

• Final geotechnical borehole logs;

• Photographic log of completed pavement cores;

• Recommendations for ground-supported slabs, pavements, and sign foundations; and,

• Recommendations for site preparation, including an evaluation of onsite soils for use as compacted fill and identification of potentially unsuitable soils.

2.0 PROJECT INFORMATION

2.1 PROJECT LOCATION

The project site is located at 2040 Wellwood Avenue in Farmingdale, Nassau County, New York, and lies approximately one-quarter mile north of the intersection of Wellwood Avenue with Long Island Avenue.

A Site Location Diagram is included in Appendix A of this report. The approximately 365-acre project site is bound to the north by Colonial Springs Road, to the east by Little East Neck Road, to the south by Pinelawn Cemetery, and to the west by Wellwood Avenue. The perimeter of the cemetery facility in fenced with several points of gated ingress/egress along Little East Neck Road and Wellwood Avenue. The main entrance to the cemetery is located at the intersection of Wellwood Avenue and Main Portal Drive where the Director’s Lodge and administration offices stand. Additionally, the cemetery contains a vast network of internal roadways that facilitate visitor access to the nearly 360,000 interments.

ECS Project No. 44:1651 Page 3

The project site topography generally slopes gently downward from the northwest to the southeast with an approximate vertical change in elevation of about 10 feet. Some standing water was observed at the time of our field exploration program within some of the paved roadways and adjacent grassed areas at the southern end of the facility. The existing flexible paving for the roadways at the project site was observed to range in condition from good to poor. Concrete curb and gutter line the roadways throughout the facility and were observed to be in generally good condition with cracking, spalled areas, and vertical misalignment between adjacent sections being the most frequent defects observed. In some locations spans of concrete curb and gutter have been repaired/replaced over time.

2.2 PROPOSED CONSTRUCTION

Based upon the project SOW and discussions with WFS, ECS understands that the following list of planned facility improvements and repairs require geotechnical engineering recommendations.

• Replacement and/or rehabilitation of deteriorating roadway flexible pavement;

• New and replacement Portland cement concrete walkways;

• Design and construction of new Cortege Lanes near the existing office building 2001;

• Design and construction of new ground-supported slabs for floral/trash/water stations and similar; and,

• Support of new ground-mount cemetery signage.

Given that the cemetery is well-established, we believe no major earthwork will be performed in connection with the above-listed improvements and repairs and that current surface elevations will be maintained. We therefore anticipate that only minimal cuts, about 1.5-foot or less, will be required. No specific details regarding the anticipated loading for the ground-supported slabs or anticipated traffic loading/performance criteria for the roadway pavement was provided to ECS for consideration in advance of report preparation.

3.0 FIELD EXPLORATION AND LABORATORY TESTING

Our field program consisted of drilling and sampling eleven (11) soil test borings and core drilling forty-two (42) locations within existing paved areas. Except for Borings B-4, B-5, and B-11, the test borings were completed in locations exhibiting advanced pavement deterioration/distress and/or poor drainage conditions as identified to ECS by WFS as well as by our own observations. The photographs contained in the Pavement Observation Photolog in Appendix B show selected test boring locations relative to the observed condition. Pavement core locations were selected to represent broader coverage of the facility with the intention to gather data regarding the variation of pavement thickness and below-pavement conditions.

All soil test boring and pavement core locations were scanned for the presence of buried private utilities via non-intrusive detection methods prior to commencing drilling. Our test boring exploration procedures are explained in greater detail in Appendix B in the insert titled Subsurface Exploration Procedures. A small, track-mounted, multi-purpose drill rig equipped with an automatic drop hammer for conducting Standard Penetration Testing (SPT) to measure N-values and obtain samples of the encountered overburden soils was used to complete the test borings. To reduce ground disturbance, 3¼-inch casing was driven after advance of the split-spoon sampler to maintain borehole stability without need to generate cuttings from conventional auger boring techniques. All test borings were continuously sampled

ECS Project No. 44:1651 Page 4 from top of pavement subgrade (ground surface for Boring B-5) and advanced to a depth of 10 feet below surface grade (feet-bsg).

For each soil test boring advanced within a paved area and for all pavement core locations, a portable electric core drill equipped with nominal 4-inch diameter core barrel was used to penetrate the full thickness of the existing bituminous concrete pavement to facilitate measurement of its thickness and to provide access to the subbase material and/or underlying subgrade soil. Except for locations where test borings were subsequently performed after coring, a hand auger was advanced to the maximum requested depth of 18 inches below the pavement surface to examine the subbase and/or subgrade materials.

The test borings and pavement cores were located by ECS using a hand-held Global Positioning System device while in the field and were subsequently located by a licensed land surveyor under subcontract to WFS for the project and the survey information provided to ECS. The approximate, as-completed explorations locations are shown on the Boring and Pavement Core Location Diagrams in Appendix A. The following table lists the location description, coordinates, and surface elevations for the completed test borings and pavement cores.

ID LOCATION NORTHING EASTING SURFACE ELEVATION

(feet)

B-1 Little East Neck Entrance Circle 215562.9369 1153603.8637 90.48

B-2 Southern Drive 214815.8402 1153430.5275 88.42

B-3 Mall Drive West 214145.5678 1151930.5687 91.32

B-4 Proposed Cortege Lane 213303.3426 1150726.4845 90.80

B-5 Proposed Cortege Lane 213247.3495 1150678.3800 90.02

B-6 West First Drive 215213.8155 1151125.8843 95.09

B-7 East First Drive 215605.1794 1151962.8111 93.48

B-8 Cross Drive 216331.2927 1151149.7523 98.51

B-9 Outer Mall Drive 217431.7708 1150022.5213 102.17

B-10 Southern Drive 213963.2039 1151902.5824 91.52

B-11 Comfort Station Parking Area 216281.9762 1149860.3026 100.49

C-1 Main Portal Drive 213951.5859 1151256.7824 90.81

C-2 Main Portal Dr @ Southern Dr 214816.9212 1153253.3714 88.90

C-3 Memorial Drive S 215123.6304 1152726.8130 91.50

C-4 Memorial Circle Dr SW 214565.2956 1151755.7051 92.76

C-5 Memorial Drive N 214328.1212 1150804.5143 91.35

C-6 Entrance 2 214789.3925 1149955.2075 96.27

C-7 Western Dr – N of Center Portal Dr 214919.6850 1150254.3721 96.48

C-8 Mid W Second Dr 215606.1737 1150104.7788 99.40

C-9 Western Dr @ W Third Dr 216207.0023 1150375.5000 99.58

C-10 Mid W Third Dr 216218.8079 1149970.6584 100.31

C-11 Mid W Fourth Dr 216349.1887 1149962.8420 99.65

ECS Project No. 44:1651 Page 5

ID LOCATION NORTHING EASTING SURFACE ELEVATION

(feet)

C-12 Western Dr @ Maint Parking Area 216397.4137 1149822.0526 100.29

C-13 Western Dr @ Comfort Station 216624.0950 1150310.8650 99.32

C-14 Entrance 3 216775.0263 1149898.1548 101.27

C-15 Mid W Fifth Dr 217011.3726 1150201.8335 100.06

C-16 Western Dr – S of W Sixth Dr 217643.5267 1149671.4355 105.95

C-17 Mid W Sixth Dr 217794.9573 1149918.6180 104.42

C-18 Entrance 4 217777.9153 1150569.7451 102.97

C-19 Western Dr – N of Entrance 4 217517.7686 1150462.3788 104.36

C-20 Middle of Outer Mall Dr 216514.0096 1151205.6275 98.32

C-21 Outer Mall Dr – N of Rastrum Dr E 217576.3406 1151457.3401 97.83

C-22 Outer Mall Dr – N of Rastrum Dr E 217577.6416 1151962.6309 96.69

C-23 Rastrum Dr E – W of Outer Mall Dr 217234.2594 1151673.8432 95.15

C-24 Mall Dr – Btwn Rastrum Dr E & W 216917.8253 1151382.6455 98.00

C-25 Rastrum Dr W @ Mall Dr W 216903.1539 1151896.6484 97.11

C-26 Mall Dr W – S of W Fifth Dr 217056.5695 1152427.2174 95.40

C-27 Central Dr – N of Cross Dr 216566.9365 1152117.5557 99.11

C-28 Rastrum Dr W @ Center Dr 216221.4423 1152313.8764 96.51

C-29 Middle of E Sixth Dr 215361.1566 1151406.1113 95.12

C-30 Eastern Dr – N of E Fifth Dr 215256.6575 1152049.3213 91.61

C-31 Middle of E Fifth Dr 216113.9153 1153094.5033 94.06

C-32 Mall Dr E – S of E Fifth Dr 214949.1238 1151675.7566 91.99

C-33 Middle of E Fourth Dr 214351.0926 1151865.5160 90.87

C-34 Eastern Dr – S of E Fourth Dr 213853.5227 1150399.3692 92.05

C-35 Middle of E Third Dr 215480.9795 1150710.4391 96.89

C-36 Middle of E Second Dr 215846.3328 1150539.2109 99.51

C-37 W First Dr @ Mall Dr W 216647.3392 1150778.6244 98.62

C-38 Center Portal Dr @ Mall Dr E 218053.8688 1150271.9934 105.68

C-39 Center Portal Dr @ Eastern Dr 217213.8155 1150873.9146 102.17

C-40 Memorial Circle Dr NW 217909.9789 1151072.4703 101.69

C-41 Mall Dr W @ Main Portal Dr 218141.7539 1151080.2956 103.55

C-42 Flagstaff Dr – N of Southern Dr 218145.4390 1151086.3648 103.28 Note:

(1) Exploration locations, including ground surface elevations, provided by Control Point Associates, Inc. under subcontract to WFS who provided the survey data to ECS in tabular form via email correspondence on January 30 2022.

ECS Project No. 44:1651 Page 6

3.1 SUBSURFACE CHARACTERIZATIONS

The subsurface conditions encountered were generally consistent with the published geologic mapping available from the New York State Geological Survey and the United States Department of Agriculture for the general project site vicinity. Refer to Appendix A for geologic mappings for the general vicinity of the project site.

Below the surface cover materials, natural soils from glacial deposition were encountered through termination depth within the completed soil test borings. Generalized characterizations of the materials encountered within the boreholes are tabulated below. Refer to the Geotechnical Borehole Logs in Appendix B for more detailed information.

STRATUM DESCRIPTION

N/A (Surface Cover)

Surface cover varied within the completed test borings as follows:

• Borings B-1, B-3, B-4, B-6 through B-11: 2 to 7½ inches bituminous concrete pavement underlain by 6 to 8 inches of grading fill – generally comprised of GRAVEL WITH SAND (USCS: GP) and GRAVEL WITH CLAY AND SAND (USCS: GP-GC)

• Boring B-2: 2 inches bituminous concrete pavement underlain by 6 inches of Portland cement concrete

• Boring B-5: 10 inches of topsoil

I

Generally, CLAYEY SILTY SAND WITH GRAVEL (USCS: SC/SM)

• Encountered in Borings B-1 thru B-4, B-6, B-7 and B-11

• Very loose to medium dense (some blow counts may be artificially elevated due to gravel)

• Moist

• Brown and orange-brown

• Depth initially encountered: ±0.6 to ±1.1 feet-bsg

• Thickness in borings: ±0.7 to ±4.0 feet

II

Generally, LEAN CLAY WITH SAND (USCS: CL)

• Encountered in Borings B-1, B-4 thru B-6, B-8, B-10 and B-11

• Contains varying amounts of sand and gravel

• Soft to stiff

• Moist

• Varied coloration: tan, brown, orange-brown, gray, with mottling in some samples

• Depth initially encountered: ±0.7 to ±3.8 feet-bsg

• Thickness in borings: ±0.3 to ±5.7 feet

III

Generally, SAND WITH GRAVEL (USCS: SP)

• Encountered in all borings completed

• Loose to dense

• Moist

• Varied coloration: orange-brown, brown, tan and white

• Depth initially encountered: ±0.8 to ±7.0 feet-bsg

• All borings terminated within this stratum

Soils encountered were visually classified during borehole logging on the basis of texture and plasticity in general accordance with ASTM D2488 – Standard Practice for Description and Identification of Soils (Visual-Manual Procedures) and use of USCS classification symbols. After classification, the samples were grouped in the major zones noted on the Geotechnical Borehole Logs in Appendix B. The group symbols

ECS Project No. 44:1651 Page 7 for each soil type are indicated in parentheses along with the soil descriptions. Divisions between strata on the borehole logs are approximate; in-situ, the transitions may be gradual.

3.2 GROUNDWATER OBSERVATIONS

Groundwater was not observed within any of the test borings at the time of drilling. However, the predominance of fine-grained soil within both Stratum I and Stratum II inhibit and/or restrict infiltration, and there may be unpredictable, transient, perched water conditions at the project site. Therefore, the possibility of groundwater level fluctuations should be considered in design development and construction considerations. It should be noted that variations in perched groundwater levels and long-term water table may occur as a result of changes in precipitation, evaporation, surface water runoff, construction activities, and other factors.

3.3 LABORATORY TESTING

The laboratory testing consisted of index property and compaction tests performed on selected samples obtained during our field exploration operations. Each laboratory test was completed in accordance with the applicable ASTM Standard Test Method as indicated below and on the laboratory testing sheets included in Appendix C.

• ASTM D2216: Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock Mass

• ASTM D6913: Standard Test Methods for Particle-Size Distribution (Gradation) of Soils Using Sieve Analysis

• ASTM D4318: Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils

• ASTM D1557: Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft3 (2,700 kN-m/m3))

• ASTM D1883: Standard Test Method for California Bearing Ratio (CBR) of Laboratory- Compacted Soils

Soil samples from this exploration program will be retained in our laboratory for a period of six (6) months from date of collection, corresponding to the date of borehole completion, as indicated on the borehole logs. After this time, the samples will be discarded unless other instructions are received from WFS regarding their disposition in advance.

3.4 PAVEMENT OBSERVATIONS

ECS was requested to explore pavement thickness, pavement subbase, and subsurface conditions to support WFS in their decision-making and design for rehabilitation and/or replacement of the existing roadway flexible pavement at the cemetery facility. More specifically, WFS desired better understanding as to whether subsurface conditions were a cause or contributor to the various pavement distress observed throughout the project site.

3.4.1 Visual Observations

To select locations for borehole exploration and pavement cores, our senior engineer observed the existing condition of the roadways throughout the cemetery facility. Except for those pavement areas that have received a recent overlay, such as a portion of Memorial Circle, or have been patched, such as

ECS Project No. 44:1651 Page 8 commonly observed around manholes, drainage repairs, and repairs resulting from damage caused by tree roots (see Pavement Observation Photolog in Appendix B), the flexible pavement throughout the roadways exhibits characteristic distress resulting from the oxidation and hardening of the asphalt binder.

Fundamentally, this is age-related distress that all bituminous (asphalt) concrete pavements are susceptible to and is commonly referred to as “weathering.” Transverse and longitudinal cracking, raveling, and block cracking are all indicative of the breakdown of the binder. These telltales were observed in the oldest section of the cemetery (southern one-third) and the later northern expansion.

Except for recent overlays and patching, we understand that the age of the flexible pavement is excess of the service life estimated, which is typically 15 to 20 years for well-maintained light duty, lightly trafficked applications.

In addition to weathering distress, fatigue-related pavement distress was also observed in various locations in the form of alligator cracking. In some locations, high-severity alligator cracking progressed to areas of missing pavement (potholes).

Characteristic distress related to poor subgrade conditions was also observed. This included commonly observed edge cracking, which results from frequent trafficking of pavement underlain by soft, poorly draining, and/or frost-weakened subgrade. Within the cemetery, vehicles are routinely trafficked along the pavement edge/curb line where they are subsequently parked during internments, memorials, and visitations. Standing water from poor drainage was observed coincident with edge cracks in several locations, which can prolong soft conditions in subgrade soils containing fine-grained materials such as encountered in Stratum I and Stratum II. Additionally, in some locations it appeared that water was rising through edge cracking from the underlying subbase/subgrade when driven over indicating trapped water below the pavement and a saturated subgrade that “pumps.” Such subgrade conditions were also evidenced by observed pavement shoves in a few locations around the cemetery facility.

As mentioned, patching was observed in area throughout the roadways. However, many of the patches were not sufficiently edge-sealed. Very few instances of crack sealing were observed, and those observed were incomplete and deteriorated. It is also important to note that many wide transverse cracks were observed to be infilled with soil, and vegetation was observed to be growing from the infilled cracks at some locations.

3.4.2 Pavement Thickness

Pavement cores were obtained from a total of fifty-two (52) locations from the existing roadways and public parking areas throughout the cemetery facility. This includes all test boring locations except Boring B-5, which was advanced within an existing lawn area. As discussed previously, most of the test boring locations were selected to explore subsurface conditions in areas of observed pavement distress and advanced deterioration. However, pavement core locations were selected to represent broader coverage of the facility with the intention to gather data regarding the variation of pavement thickness and below-pavement conditions. This is because the existing flexible pavement was constructed at different time periods in the cemetery history, some original rigid (concrete) pavements were overlain with bituminous concrete pavements, and there has been both historic and recent overlays of the flexible pavement in some areas.

Observed thicknesses of the existing flexible pavement from our pavement cores ranged from about 1¾ to 7½ inches with typical thickness ranging between about 2½ and 3 inches. The Pavement Core Photolog in Appendix B shows each recovered pavement core with an in-frame measurement reference. Further, the core identifications in the photolog correspond to those locations indicated on the Boring and Pavement Core Location Diagrams in Appendix A and as described in the table in Section 3.0 above.

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3.4.3 Subbase and Subgrade Observations

A layer granular grading fill was encountered below the flexible pavement in most pavement core locations. Consistent with observations within the completed test borings, the grading fill was generally comprised of GRAVEL WITH SAND (USCS: GP) or GRAVEL WITH CLAY AND SAND (USCS: GP-GC) where encountered.

In some core locations where a greater thickness of pavement was encountered, particularly where the recovered cores visually appeared to be comprised of two-layer pavement construction (i.e., coarser base course with finer surface course) there appeared to be no grading fill present (e.g., Core Locations C-2, C-4, and C-28). Additionally, in a few locations the flexible pavement was underlain by 6 inches of Portland cement concrete (e.g., Boring B-2). With the limited number of pavement core locations contracted in comparison to the overall quantity of existing paved roadways, it was not possible to delineate where concrete underlies the current flexible pavement surface.

In most of our exploration locations, underlying the grading fill, concrete, and the flexible pavement directly in some locations, subgrade soils were consistent with Stratum I and II as previously described above. In general, these soils provide poor pavement support due to poor drainage and susceptibility to frost, which is exhibited by the condition of the existing pavement at the facility. However, in some locations, the grading fill or, in some instances, the flexible pavement directly was underlain by the POORLY GRADED SAND WITH GRAVEL (USCS:SP) of Stratum III, which characteristically provides better support for pavements. Because of this range of subgrade soils encountered, we collected samples from Stratum II and III, representing the least and most favorable subgrade soils in terms of pavement support, for laboratory testing to determine the California Bearing Ratio of each soil.

4.0 DESIGN RECOMMENDATIONS

4.1 GROUND-SUPPORTED SLABS

Provided subgrades and Structural Fills are prepared as recommended in this report, the new floral/ trash/water stations can be supported by ground-supported reinforced concrete slabs. The anticipated loads to be supported by the reinforced concrete slabs in connection with these features and their regular use by visitors and facility personnel are anticipated to be low. We also anticipate that frost-protection is not required and that some settlement, both total and differential, is acceptable visually and will not impair use of these facilities.

Ground-supported slabs can be designed for a uniform soil contact pressure of 500 pounds per square foot (rigid method) or by assuming a modulus of subgrade reaction, k1, of 95 pounds per cubic inch (flexible method). The modulus of subgrade reaction value is based on a 1-foot by 1-foot plate load test.

Our recommendations are based upon constructing the slabs upon a minimum 4-inch-thick crushed stone aggregate subbase (NYSDOT Type 2) placed and compacted to a firm, unyielding state over a prepared subgrade and/or new Structural Fill as described in this report. A geotextile separation layer between the subgrade and crushed aggregate subbase is recommended such as Mirafi® 140N or equivalent. Subgrade preparation and the subbase placement should be observed by ECS for conformance with our recommendations.

It should be noted that soils encountered within Stratum I and Stratum II are frost-susceptible, and the local frost depth is 36 inches of burial below final exterior grade. If circumstances are such that movements associated with frost action cannot be tolerated by the new features, turned down slabs or piers foundations extending below frost depth could be used. ECS would be pleased to discuss additional services to update our foundation recommendations accordingly, if desired.

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4.2 SIGN FOUNDATIONS

ECS was not provided with the types of signage planned or the loading that will be imparted to foundation elements. As such, our recommendations are general in nature, and we assume the responsible design professional will use the methodology specified in the 2018 International Building Code for embedded posts and poles.

For frost protection, sign foundations should extend below the local frost line, which is 36 inches for the project site location. Provided subgrades and Structural Fills are prepared as recommended in this report, sign foundations can be designed with a maximum allowable vertical bearing pressure of 1,500 pounds per square foot. The allowable lateral bearing pressure can be computed using 100 pounds per square foot per depth of burial but neglecting the initial 1-foot of burial.

It should be noted that the soils encountered in our completed explorations would also be suitable for use of alternative means to support new signage, such as helical foundations. With more specific details regarding planned signage, including structural loads, ECS would be pleased to discuss additional services to update our foundation recommendations for helical foundations, if desired.

4.3 PAVEMENTS AND WALKWAYS

Subgrade Characteristics: Based on the findings from our borings and observation made at pavement core locations, it appears that the existing roadway pavement subgrade and subgrade in cuts for new roadway (Cortege Lanes) consists mainly of Stratum I and II soils. As previously discussed, these soils provide poor pavement support due to poor drainage and susceptibility to frost, which is exhibited by the condition of some of the existing roadway pavement at the project site. Therefore, we recommend pavements and walkways to be constructed at the project site be underlain with a crushed stone aggregate subbase placed and compacted above subgrade soil previously prepared in accordance with the recommendation provided herein. A geotextile separation layer between the subgrade and crushed stone aggregate subbase is recommended, such as Mirafi® 140N or equivalent, to reduce the migration of fines into the subbase.

California Bearing Ratio (CBR) testing was performed in our lab for the least favorable subgrade soil of Stratum II (LEAN CLAY WITH SAND) and the most favorable subgrade soil of Stratum III (POORLY GRADED SAND WITH GRAVEL). CBR values of approximately 8.7-percent for Stratum I and 18.1-percent for Stratum III were determined from our testing assuming proofrolling and subgrade compaction to 95-percent modified Proctor maximum dry density. Given Stratum I and Stratum II soils were primarily encountered below existing roadway pavement within the completed explorations and natural variation of the glacial deposition over short lateral distances, we recommend rehabilitation design for existing pavements consider the CBR value obtained for Stratum II. For design purposes related to new pavement and existing pavement rehabilitation, we recommend using one-half of the laboratory determined CBR value.

Flexible Pavement Sections: We were not provided traffic loading information; therefore, we have made the following assumptions regarding loading and performance of new flexible pavement for roadways.

The anticipated use of the new pavement areas will be primarily by passenger vehicles with occasional heavy vehicle (e.g., hearse and limousine) and truck traffic associated snow removal and facility maintenance. Therefore, we have assumed a maximum daily traffic volume of 100 passenger vehicles and 1 truck for new flexible pavement areas. If the actual traffic volumes anticipated will exceed these assumptions, ECS should be contacted for revised pavement design recommendations; otherwise, increased pavement maintenance and a shortened pavement life should be expected.

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The recommended minimum pavement sections as listed in the following table are based upon the anticipated usage discussed above, a 15-year design life, no growth in traffic rate, and minimum lift thickness predicated by the nominal maximum size of the aggregate in the design mix.

PROPOSED FLEXIBLE PAVEMENT SECTION

MATERIAL(1) THICKNESS(2)

Superpave 9.5 mm

Asphaltic Concrete Surface Course 1.5 inches

Superpave 19.0 mm Asphaltic Concrete Base Course 2 inches

Type 2 Crushed Stone Aggregate Subbase 6 inches

Notes:

(1) Materials and installation shall conform to the New York State Department of

Transportation’s Standard Specifications and Comprehensive Pavement Design Manual, most current revision/edition.

(2) Thicknesses indicated represent compacted material thicknesses.

This pavement section is a guideline that may or may not comply with local jurisdictional minimums.

Portland Cement Concrete Walkways: Based upon the project SOW, we understand that all new walkways, including those replacing existing walkways, will be constructed from Portland cement concrete. In consideration of the anticipated subgrade conditions in cuts, we recommend that new walkways be underlain with a crushed stone aggregate subbase placed to a compacted thickness of no less than 4 inches above subgrade soil previously prepared in accordance with the recommendation provided herein. We further recommend that the new Portland cement concrete walkways be design and constructed in general accordance with the most current edition of the New York State Department of Transportation’s Standard Specifications, Section 608.

5.0 SITE CONSTRUCTION RECOMMENDATIONS

5.1 SUBGRADE PREPARATION

5.1.1 Demolition

Prior to general earthwork and new construction, demolition and off-site disposal of existing pavement, walkways, ground-supported slabs, and any below-grade utilities or structures within the limits of planned construction will be required. Below-grade elements should be removed to a depth of at least 2 feet below the proposed subgrade elevations for new construction. In situations where complete removal is not possible, ECS should be consulted for specific recommendations. Demolition debris must be disposed of off-site in accordance with local, State, and Federal regulations. Excavations to remove existing below-grade utilities or structures within the limits of new construction should be backfilled with Structural Fill placed and compacted as recommended herein.

5.1.2 Stripping and Grubbing

The subgrade preparation should consist of removing all vegetation, trees, stumps, roots, topsoil, existing fill, debris and any soft or unsuitable materials within the limits of planned construction. Based upon the

ECS Project No. 44:1651 Page 12 observations within the completed soil test borings, removal of at least 10 inches of topsoil should be anticipated within existing grassed areas. Deeper topsoil or organic-rich soils may be present in wet, low-lying, and poorly drained areas. ECS should be retained to verify that topsoil and unsuitable surficial materials have been stripped prior to excavation to construct subgrade elevations, placement of Structural Fill, and construction of new earthworks and structures.

5.1.3 Undercutting and Replacement

Prior to placement of engineered fill or other construction on subgrades, the subgrades should be evaluated by ECS. Where new roadway will be constructed, such as for the Cortege Lanes, or where full-thickness replacement of existing flexible pavement and subbase will be performed, the exposed subgrade should be thoroughly proofrolled with construction equipment having a minimum axle load of 10 tons (e.g., fully loaded tandem-axle dump truck) travelling at a maximum of 1.5 feet per second (approximately 1 mile per hour). The subgrade area should be traversed with overlapping passes of the vehicle, and a minimum of two (2) complete coverages are recommended under observation by ECS.

Where proofrolling identifies areas of unstable or “pumping” subgrade or has caused permanent deformation more than ½-inch, those areas are considered unsuitable and should be undercut and replaced prior to the subsequent placement of engineered fill or other construction materials.

Where walkways and ground-supported slabs will be constructed, we recommend the exposed subgrade be thoroughly compacted by use of heavy duty, walk-behind, vibratory plate compactor cable of imparting a force of at least 8,000 pounds to facilitate identification of unsuitable soils and compact soils disturbed by subgrade preparation activities.

Where soft, unstable, or otherwise unsuitable soils are observed, these soils should be undercut and removed. The over-excavation should be extended a horizontal distance of 1-foot for each 1-foot depth of undercut at all sides. Any undercut should be backfilled with compacted Structural Fill up to the design subgrade elevation. Open-graded gravel (e.g., AASHTO No. 57) should not be used to backfill undercuts as this could result in a reservoir condition, allowing the accumulation of water and potential softening of the bearing soils.

5.1.4 Moisture Sensitive Soils

Some soils encountered at the project site are moisture sensitive meaning that that these soils soften and decrease in strength with increasing moisture content. After stripping, grubbing, and grading activities that will expose the moisture sensitive soils, the stability of these soils will be directly related to their moisture condition at the time of construction. These soils may require time to dry and regain strength during subgrade preparation activities. Drying can be accelerated by mechanical aeration such as discing, use of soil drying equipment, or through use of appropriate drying agents (e.g., quicklime). Additionally, in areas where these soils are exposed, construction traffic should be limited to only that necessary for the earthwork to maintain a stable working platform. Performing earthwork and subbase placement activities during dry weather should be considered. Otherwise, exposed moisture sensitive soils that have been dried and prepared should be protected from precipitation and run-on prior to subbase placement.

5.1.5 Site Temporary Dewatering

The contractor must make its own assessment of temporary dewatering needs based upon the limited subsurface groundwater information presented in this report. Soil sampling is not continuous, and thus soil and groundwater conditions may vary between sampling intervals. If the contractor believes

ECS Project No. 44:1651 Page 13 additional subsurface information is needed to assess dewatering needs, they should obtain such information at their own expense. ECS makes no warranties or guarantees regarding the adequacy of the provided information to determine dewatering requirements; such recommendations are beyond our scope of services.

Dewatering systems are a critical component of many construction projects. Dewatering systems must be selected, designed, and maintained by a qualified and experienced (specialty or other) contractor familiar with the succinct geotechnical and other aspects of the project. The failure to properly design and maintain a dewatering system for a given project can result in delayed construction, unnecessary foundation subgrade undercuts, detrimental phenomena such as ‘running sand’ conditions, internal erosion (i.e., ‘piping’), the migration of ‘fines’ down-gradient towards the dewatering system, localized settlement of nearby infrastructure, foundations, slabs-on-grade and pavements, etc. Water discharged from any site dewatering system must be discharged in accordance with all local, State, and Federal requirements.

We anticipate that some perched water conditions and saturated soils could be encountered during construction because of the hydraulically restrictive soils of Stratum I and II. Construction during dry weather should be considered. We anticipated that effective, short-term dewatering operations can be managed by using trash pumps or conventional submersible pumps directly in open excavations, such as those required for the installation of new signage.

5.2 EARTHWORK OPERATIONS

5.2.1 Structural Fill

Prior to placement of Structural Fill, representative bulk samples (about 50 pounds) of the off-site borrow should be submitted to ECS for laboratory testing, which will typically include Atterberg limits, natural moisture content, grain-size distribution, and moisture-density relationships (i.e., Proctors) for compaction. Import materials should be tested prior to being hauled to the site to determine if they meet project specifications. Alternatively, Proctor data from other accredited laboratories can be submitted if the test results are within the last 90 days.

Satisfactory Structural Fill Materials: Materials satisfactory for use as Structural Fill must be free of deleterious materials such as construction debris, wood, glass, ash, trash, refuse, roots and other organic matter; and, conform to the following engineering properties and compaction requirements.

Additionally, imported materials for use as Structural Fill should also meet the New York State Department of Environmental Conservation Program Policy DER-10 – Technical Guidance for Site Investigation and Remediation, Appendix 5 for Allowable Constituent Levels for Imported Fill or Soil.

STRUCTURAL FILL INDEX PROPERTIES

Subject Property Liquid Limit < 40 Plasticity Index < 20 Maximum Particle Size 3 inches Fines Content (percent passing the No. 200) 15% maximum Maximum Organic Content 5% by dry weight

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STRUCTURAL FILL COMPACTION REQUIREMENTS

Subject Requirement Compaction Standard Modified Proctor, ASTM D1557 Required Compaction 95% of Maximum Dry Density

Moisture Content within -2 to +3 percentage points of optimum

Loose Lift Thickness 8 inches

Fill Placement: Fill materials should not be placed on frozen soils, on frost-heaved soils, and/or on excessively wet soils. Borrow fill materials should not contain frozen materials at the time of placement, and all frozen or frost-heaved soils should be removed prior to placement of fill soils and aggregates.

Excessively wet soils or aggregates should be scarified, aerated, and moisture conditioned.

5.2.2 On-site Soil Re-use

Existing on-site soils consisting of inorganic soils classified as USCS: ML, SM, SC, SW, SP, GW, GP, GM and GC, or a combination of these group symbols, per ASTM D2487, resulting from excavations may be re-used. The materials should be suitably dry; free of organic matter, debris, and other deleterious material;

and, should contain no particle sizes greater than 4 inches in the largest dimension.

Prior to re-use of on-site soils, representative bulk samples (about 50 pounds) of the material should be submitted to ECS for laboratory testing, which will typically include Atterberg limits, natural moisture content, grain-size distribution, and moisture-density relationships (i.e., Proctors) for compaction.

COMPACTION REQUIREMENTS FOR ON-SITE SOIL RE-USE

Subject Requirement

Compaction Standard Modified Proctor, ASTM D1557

Required Compaction 95% of Maximum Dry Density

Moisture Content within -2 to +3 percentage points of optimum

Loose Lift Thickness 8 inches

Fill Placement: Fill materials should not be placed on frozen soils, on frost-heaved soils, and/or on excessively wet soils. Materials being re-used should not contain frozen materials at the time of placement, and all frozen or frost-heaved soils should be removed prior to placement of fill soils and aggregates. Excessively wet soils or aggregates should be scarified, aerated, and moisture conditioned.

5.2.3 Excavation Considerations

All excavations and slopes should be constructed and maintained in accordance with OSHA excavation safety standards. The contractor is solely responsible for designing, constructing, and maintaining stable temporary excavations (both sides and bottom of the excavations) and slopes. The contractor’s responsible person, as defined in 29 CFR Part 1926, should evaluate the soil exposed in the excavations as part of the contractor’s safety procedures. In no case should slope height, slope inclination, or excavation depth, including utility trench excavation depth, exceed those specified in local, State, and Federal safety regulations. ECS is providing this information solely as a service to our client. ECS is not

ECS Project No. 44:1651 Page 15 assuming responsibility for construction site safety or the contractor’s activities; such responsibility is not being implied and should not be inferred.

5.3 SUBGRADE OBSERVATIONS

Protection of Subgrade: Exposure to the environment may weaken the soils at design subgrade elevation if the excavations remain open for too long a time. Therefore, foundation concrete for new signage should be placed the same day that excavations are made. If the bearing soils are softened by surface water intrusion or exposure, the softened soils must be removed from the excavation bottom immediately prior to placement of concrete. Each excavation should be observed for the presence of water or softened soils prior to placement of concrete.

Subgrade Verification: Prior to placement of a Structural Fill or Crushed Stone Aggregate, the subgrade should be proofrolled and compacted in accordance with the recommendations found herein. It is also important to have ECS observe proofrolling to determine if undercutting is required where flexible pavement will be constructed.

5.4 UTILITY INSTALLATIONS

Utility Subgrades: The soils encountered in our exploration are expected to be generally suitable for support of utility pipes and conduits. The subgrade for utility excavations should be observed and probed for stability by ECS. Any loose or unsuitable materials encountered at the subgrade elevation should be removed and replaced with suitable compacted Structural Fill or bedding material.

Utility Backfilling: The granular bedding material (e.g., AASHTO No. 57) should be at least 4 inches thick, but not less than that specified by the civil engineer’s project drawings and specifications. We recommend that the bedding material be placed up to the springline of the pipe. Fill placed for support of the utilities, as well as backfill over the utilities, should satisfy the requirements for Structural Fill and Fill Placement.

Utility Excavation Dewatering: It is possible that water may be encountered by utility excavations which extend below existing grades. It is anticipated that removal of water which seeps into excavations can be accomplished by pumping from sumps excavated in the trench bottom in which open-graded bedding material (e.g., AASHTO No. 57) has been placed. Nevertheless, the contractor shall make its own assessment of temporary dewatering needs, and should submit a Dewatering Plan in accordance with project specifications.

6.0 CLOSING

ECS has prepared this report to guide the geotechnical-related design and construction aspects of the project. We performed these services in accordance with the standard of care expected of professionals in the industry performing similar services on projects of like size and complexity at this time in the region.

No other representation, expressed or implied, and no warranty or guarantee is included or intended in this report.

The description of the proposed project is based on information provided to ECS by WFS. If any of this information is inaccurate or changes, either because of our interpretation of the documents provided or site or design changes that may occur later, ECS should be contacted so we can review our recommendations and provide additional or alternate recommendations that reflect the proposed construction.

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We recommend that ECS review the project plans and specifications so we can confirm that those plans/specifications are in…