Geotechnical Engineering Report 12 10 2024 submission

Mavis Store #2296 December 10, 2024 ECS Project No. 44:2100 Page 3 2.0 PROJECT INFORMATION 2.1 PROJECT LOCATION The project site is located at 460 Prospect Avenue, West Orange, Essex County, New Jersey and lies north of the intersection of Prospect Avenue with Rooney Circle as shown in Figure 2.1.1 below. The project site is bound by an office building and its associated parking to the north, Prospect Avenue to the west, Blueberry Bend to the south, and residential properties to the east. Figure 2.1.1 - Site Location (outlined) The project site is the location of an existing realtor office building equipped with paved parking, drive through lanes, and driveways. The current topography slopes generally from south to north with an estimated variation in ground surface elevation of about ±5 feet. No standing water was observed at the time of our field exploration. 2.2 PROPOSED CONSTRUCTION Based upon the Concept Plan provided to ECS, we understand the proposed project will consist of the demolition of the existing building and construction of a new, one-story, ±7,700 square-foot retail auto service building with 8 vehicle service bays, sales and customer waiting areas, and offices. ECS understands no below-grade levels or service pits are planned. A new paved parking area for 21 passenger vehicles will be constructed to the east and south of the building with a point of ingress/egress each from Prospect Avenue and Blueberry Bend. A dumpster enclosure will be located southeast of the building. Information regarding stormwater management (SWM) facilities were not provided, nor were they requested; therefore, evaluation of SWM facilities is not included in this scope. The following information summarizes our understanding of the structure and assumed loads:

Mavis Store #2296 December 10, 2024 ECS Project No. 44:2100 Page 4 SUBJECT DESIGN INFORMATION / EXPECTATIONS Building Footprint 7,700 square foot in plan view # of Stories 1-story above grade (no below grade levels) Usage Tire Service Facility Column Loads 50 kips Wall Loads 3 kips/linear foot Floor Elevation (FFE) Assumed within 1 to 2 feet of existing grade We understand an allowable soil bearing pressure of 3,000 pounds per square foot (psf) is desired for shallow foundations as preferred by Mavis for its typical single-story, masonry block and steel-framed building. No specific details regarding the anticipated structural loads to be supported by foundations, or proposed ground-level finished floor elevation (FFE) were provided to ECS. However, we anticipate the ground-level FFE for the new store building will be similar to current ground surface elevation and minimal cuts or fills, on the order of 1-foot or less, will be required for site development.

Mavis Store #2296 December 10, 2024 ECS Project No. 44:2100 Page 5 3.0 FIELD EXPLORATION AND LABORATORY TESTING Our exploration procedures are explained in greater detail in Appendix B in the inserts titled Subsurface Exploration Procedures. Our overall scope of work, completed with one (1) authorized mobilization, consisted of drilling eight (8) soil test borings. Each exploration location was located using a hand-held Global Positioning System device, and their approximate, as-completed locations are shown on the Boring Location Diagram in Appendix A. Prior to mobilizing to the site to conduct the soil borings, each of the boring locations were scanned for the presence of buried private utilities via non-intrusive detection methods prior to exploration. Soil test borings were completed with a track-mounted, hollow-stem auger drill rig equipped with an automatic drop hammer for conducting Standard Penetration Testing (SPT). SPT testing is utilized to measure N- values and obtain samples of the encountered subsurface materials. 3.1 SUBSURFACE CHARACTERIZATIONS Generally, the subsurface conditions encountered were consistent with the published geologic mapping available from the New Jersey Geological and Water Survey via NJ-GeoWeb and the United States Department of Agriculture Natural Resources Conservation Service (USDA-NRCS) via Web Soil Survey for the general site vicinity. Refer to Appendix A for geologic maps for the general vicinity of the project site. Generalized characterizations of the materials encountered within the completed explorations are tabulated below. Refer to the Generalized Subsurface Soil Profiles in Appendix A and the Geotechnical Borehole Logs and Test Pit Logs in Appendix B for more complete soil descriptions. APPROXIMATE DEPTH RANGES OF SPT(1) STRATUM DESCRIPTIONS ENCOUNTERED N-VALUES (bpf)(2) (feet-bgs) N/A  6

ENCOUNTERED N-VALUES (bpf)(2) (feet-bgs) N/A  6 inches of asphalt (B-01 through B-03, and B-08) (Surface 0.0 – 0.5 N/A  6 inches of topsoil (B-04 through B-07) Cover)  USCS: SM, ML  Varying amounts of gravel and fine-grained soils STRATUM I  Loose to very dense granular materials 0.5 – 4.0 4 – 71/7” (Probable Fill)  Moist  Encountered below surface cover in each boring except B-04 and B-05  USCS: ML, ML/CL, CL/ML, SM, GC-GM  Varying amounts of gravel and fine-grained soils  Medium dense to very dense granular materials STRATUM II 0.25 – 15.0  Stiff to very hard fine-grained materials 12 – 82/9” (Natural Soils)  Moist  Encountered below surface cover and/or Stratum I in each boring STRATUM III  USCS: Sampled as SM (Weathered 13.0 – 15.0  Very dense granular material 50/3” Rock)  Encountered below Stratum II in Boring B-02 Notes: (1) Standard Penetration Testing (2) Blows per foot

Mavis Store #2296 December 10, 2024 ECS Project No. 44:2100 Page 6 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 Unified Soil Classification System (USCS) symbols. After classification, the samples were grouped in the major zones noted on the Generalized Subsurface Cross- Sections A-A’ through B-B’ in Appendix A and the exploration logs in Appendix B. The group symbols for each soil type are indicated in parentheses along with the soil descriptions. Divisions between strata on the exploration logs are approximate; in-situ, the transitions may be gradual. 3.2 GROUNDWATER OBSERVATIONS Water levels were measured in our boring logs in Appendix B. Groundwater was not observed within the borings at the time of drilling and backfilling. However, it must be noted that variations in perched water 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 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 D4318: Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils  ASTM D6913: Standard Test Methods for Particle-Size Distribution (Gradation) of Soils Using Sieve Analysis  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 Methods for California Bearing Ratio (CBR) of Laboratory- Compacted

Modified Effort (56,000 ft-lbf/ft3 (2,700 kN-m/m3))  ASTM D1883: Standard Test Methods 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 sixty (60) calendar days from date of collection, corresponding to the date of completion indicated on the exploration logs. After this time, the samples will be discarded unless other instructions are received from Mavis regarding their disposition in advance.

Mavis Store #2296 December 10, 2024 ECS Project No. 44:2100 Page 7 4.0 DESIGN RECOMMENDATIONS 4.1 SHALLOW FOUNDATIONS A site grading plan including the proposed FFE was not provided and should be provided to ECS to confirm the recommendations included herein; however, we have assumed the FFE will be within 1 to 2 feet of existing grades. Provided subgrades and Structural Fills are prepared as recommended in this report, the proposed building can be supported by shallow foundations including column footings and continuous wall footings. We recommend the foundation design use the following parameters. DESIGN PARAMETER COLUMN FOOTING WALL FOOTING (1) Net Allowable Bearing Pressure 3,000 psf 3,000 psf Stratum II with SPT N- Stratum II with SPT N- Acceptable Bearing Soil Material value ≥ 5 bpf value ≥ 5 bpf or new Structural Fill or new Structural Fill Minimum Width 24 inches 24 Inches Minimum Footing Embedment Depth 36 inches 36 inches (below slab or finished grade)(2) Estimated Total Settlement (3) Less than 1-inch Less than 1-inch Less than 0.5-inch Less than 0.5-inch Estimated Differential Settlement(3) between columns over 50 feet Notes: (1) Net allowable bearing pressure is the applied pressure in excess of the surrounding overburden soils

between columns over 50 feet Notes: (1) Net allowable bearing pressure is the applied pressure in excess of the surrounding overburden soils above the base of the foundation. (2) Minimum footing depth recommended for frost protection. Interior foundations located within permanently heated portions of the structure may be established at conventional depths below the floor slab, provided that they are established within the intended bearing stratum. (3) Based on an assumed maximum column load of 50 kips and wall load of 3 kips per foot. When final design loads are determined, ECS must be contacted to update foundation recommendations and settlement calculations. bpf = blows per foot Potential Undercuts: As indicated in the above table, shallow foundations may be supported by Stratum II materials provided the material at bearing depth is homogeneous with at least an SPT N-Value of ≥ 5 or newly placed Structural Fill. It is important to have ECS observe and test footing subgrade prior to placing foundation concrete to confirm soil conditions are as anticipated (granular soil with SPT N-value ≥ 5 bpf) and consistent with our recommended foundation design parameters. The existing fill materials on the site do not appear to be suitable for support of the building foundations as they appear to be variable in both composition and strength (based on SPT N-values), therefore we recommend these materials be removed below foundation elements. As stated in the Executive Summary, it may be beneficial to perform test pitting within the building footprint to further evaluate the existing fill materials. Generally, existing fills are not suitable for support of foundations as the method of their placement and compaction effort (or lack thereof) is unknown, therefore, they maybe prone to settlements which are unpredictable. If existing fills, soft or unsuitable soils are observed at the footing bearing elevations, the unsuitable soils should be undercut and removed. Any undercut should be backfilled with lean concrete (f’ c ≥ 1,000 psi at 28 days) up to the original design bottom of footing elevation; the original footing shall be constructed on top of the hardened lean concrete.

Mavis Store #2296 December 10, 2024 ECS Project No. 44:2100 Page 8 4.2 FLOOR SLAB Provided subgrades and Structural Fills are prepared as discussed herein, proposed floor slabs can be constructed as ground-supported slabs (slab-on-grade). The floor slab can bear on Stratum I or Stratum II soils provided that the entire footprint of the slab is proofrolled (see Section 5.1.3) and compacted (see Section 5.1.4) prior to placing the Granular Capillary Break/Drainage Layer. It is important to have ECS observe the subgrade and proofrolling to confirm the soil conditions are as anticipated. Soft or yielding soils, or otherwise unsuitable materials may be encountered in some areas and should be removed and replaced with compacted Structural Fill in accordance with the recommendations included in this report. The following graphic depicts our ground-supported slab recommendations. Vapor Barrier Concrete Slab Granular Capillary Break/Drainage Layer Drainage Layer Thickness: 6 inches (minimum) Drainage Layer Material: ¾-inch clean, crushed stone Compacted Subgrade 95% modified Proctor maximum dry density (ASTM D1557) Figure 4.2.1 – Ground-supported Concrete Slab Subgrade Modulus: Provided the Structural Fill and Granular Capillary Break/Drainage Layer are constructed in accordance with our recommendations, floor slabs may be designed assuming a modulus of subgrade reaction, k1, of 85 pounds per cubic inch (pci). The modulus of subgrade reaction value is based on a 1-foot by 1-foot plate load test. Vapor Barrier: Before the placement of concrete, a vapor barrier may be placed on top of the Granular Capillary Break/Drainage Layer to provide additional protection against moisture penetration through the floor slab. When a vapor barrier is used, special attention should be given to surface curing of the slab to reduce the potential for uneven drying, curling and/or cracking of the slab.

on through the floor slab. When a vapor barrier is used, special attention should be given to surface curing of the slab to reduce the potential for uneven drying, curling and/or cracking of the slab. Depending on proposed flooring material types, the structural engineer and/or the architect may choose to eliminate the vapor barrier. Slab Isolation: Floor slabs should be isolated from the foundations and foundation-supported elements of the structure so that differential movement between the foundations and slab will not induce excessive shear and bending stresses in the floor slab. Where the structural configuration prevents the use of a free-floating slab such as in a drop-down footing/monolithic slab configuration, the slab should be designed with suitable reinforcement and load transfer devices to preclude overstressing of the slab. 4.3 SEISMIC DESIGN CONSIDERATIONS Seismic Site Classification: The 2021 International Building Code – New Jersey edition (2021 IBC-NJ), which references ASCE/SEI 7-16 – Minimum Design Loads and Associated Criteria for Buildings and Other Structures, requires site classification for seismic design based on the upper 100 feet of a soil profile. Our authorized scope of services for the project did not include a site-specific seismic Site Class determination (e.g., 100 -foot soil profile). Therefore, to determine the seismic Site Class using Section 4.5 of the 2024 New Jersey State Hazard Mitigation Plan was referenced. The statewide seismic Site Class map contained in Section 4.5 (Figure 4.5-3), indicates the appropriate seismic Site Class is “C.” The Site Class definition should not be confused with the Seismic Design Category designation, which the Structural Engineer typically assesses.