25 10 28 Slope Stability Review

1 Tower Center Blvd. 20th Floor East Brunswick, NJ 08816 732.727.8000 www.cmeusa1.com October 28, 2025 Chairman and Members of the West Orange Planning Board 66 Main Street West Orange, NJ 07052 Re: Application No. PB24-01 West Essex Highlands, LLC Warner Road Block 179, Lot 32 Review of Applicant’s Engineer’s Slope Stability Analysis Reports, the Objector’s Engineer’s Response Reports; and the Applicant’s Engineer’s Rebuttal Report Our File: 115.WRP0179.V01 Dear Planning Board: In accordance with your authorization, Geotechnical Engineers from our office have reviewed the Applicant’s and Objector’s Engineering reports concerning slope stability along the ridge line on the eastern side of the site in the area of proposed Building D. For the purpose of this memorandum, the Applicant is West Essex Highlands, LLC. (“Applicant”). The Applicant’s Engineer for analysis of the slope stability is Langan Engineering, LLC (“Langan”). The opposition is We Care (“Objector”). The Objector’s Engineer is Princeton Hydro (“Princeton Hydro”). INTRODUCTION The purpose of our work was to review the Applicant’s Engineer’s Stability Analysis Reports and the Objector’s Engineer’s Response reports and to: 1. Provide a technical opinion on the findings of each report. 2. Assess the need for additional evaluation by the Applicant. 3. Provide recommendations to the Board for the setting of requirements for monitoring and maintenance of the stability of the slopes during the construction and for maintenance thereafter. CME’s Geotechnical Engineers performed the following scope of work to accomplish this purpose: 1. We read and evaluated the reports submitted to the Planning Board as summarized in the list of references in the following section of this letter. 2. We visited the area of the site in question on October 2, 2025, along with Paul W. Anderson, PE, the Applicant’s Site Engineer, to evaluate conditions along the ridge in relation to the descriptions contained in the Applicant’s and the Objector’s reports.

Chairman and Members of the West Orange Planning Board Application No. PB24-01, West Essex Highlands, LLC, Warner Road, Block 179, Lot 32 Review of Applicant’s Engineer’s Slope Stability Analysis Reports, the Objector’s Engineer’s Response Reports; and the Applicant’s Engineer’s Rebuttal Report October 28, 2025 Page 2 of 21 3. We reviewed the project Architectural and Civil Site Plans contained in our files. 4. We reviewed the geologic reports and reference standards cited in the Applicant’s and Objector’s Engineer’s reports. 5. We performed a qualitative evaluation of the stability calculations based on approximate methods of stability evaluation based on our experience with similar projects. 6. We provided recommendations for limiting stormwater infiltration in the area where it would potentially reduce the stability of the slope. 7. We provided recommendations for monitoring and maintenance of slope stability during construction. Our scope of services did not include an independent analysis of the stability of the slope in the area of the study. This memorandum is based on review of the field and laboratory data, calculations and evaluation contained within the analysis reports prepared by the Applicant’s and Objector’s Engineers based on our experience as Geotechnical Engineers on similar projects. REFERENCE DOCUMENTS Our review is based primarily on the information contained in the following outline of References: 1. Applicant’s Engineer’s reports prepared by Langan Environmental and Environmental Services LLC (“Langan”): A. Report Entitled “Global Stability Study for Eastern Slope near Building D; West Essex – Highlands Development West Orange, New Jersey” dated January 14, 2025. B. Report Entitled “Global Stability Study for Eastern Slope near Building D; West Essex – Highlands Development West Orange, New Jersey” originally dated January 14, 2025 as revised on June 18, 2025. C. Rebuttal Report Entitled “Global Stability Study for Eastern Slope near Building D; West Essex – Highlands Development, West Orange. New Jersey” dated September 15, 2025. 2. Applicant’s Engineer’s Report prepared by Anderson Consulting Services LLC.: A. Report Entitled “Drainage Report West Essex Highlands, Block 179, Lot 32, West Orange New Jersey” dated March 12, 2023, revised through October 3, 2023. B. Rebuttal Letter Entitled “Drainage Report West Essex Highlands, Block

Report West Essex Highlands, Block 179, Lot 32, West Orange New Jersey” dated March 12, 2023, revised through October 3, 2023. B. Rebuttal Letter Entitled “Drainage Report West Essex Highlands, Block 179, Lot 32, West Orange New Jersey” dated March 12, 2023, revised through October 3, 2023. 3. Applicant’s Engineer’s Subsurface Investigation Reports for the Site Stormwater Management System prepared by Sor Consulting Engineers, Inc.: A. Report Entitled “Subsurface Investigation Report, Proposed Residential Developments, West Orange., New Jersey, Report No. 21-C-01” dated April 19, 2021.

Chairman and Members of the West Orange Planning Board Application No. PB24-01, West Essex Highlands, LLC, Warner Road, Block 179, Lot 32 Review of Applicant’s Engineer’s Slope Stability Analysis Reports, the Objector’s Engineer’s Response Reports; and the Applicant’s Engineer’s Rebuttal Report October 28, 2025 Page 3 of 21 B. Report Entitled “Subsurface Investigation Report, Subsurface Stormwater Management System, West Orange, New Jersey, Report No. 23-C-16” dated May 23, 2023. C. Report Entitled “Subsurface Investigation Report, Subsurface Stormwater Management System, West Orange., New Jersey, Report No. 24-C-02” dated February 12, 2024. (This report contains Test Pit data for the Recharge Basin Design in the Area of Building D and Howell Road Cul de Sac.) D. Report Entitled “Supplementary Subsurface Investigation Report, Subsurface Stormwater Management System, West Orange., New Jersey, Report No. 24-C-02” dated April 4, 2024. 4. Objector’s Engineer’s Reports prepared by Princeton Hydro: A. Letter Report entitled “PB-24-01 West Essex Highlands, Inc. Block 179, Lot: 32 Zone 1H-1, Warner Road, West Orange Township, Essex County” dated March 10, 2025. (This report is primarily a review of Stormwater Management Issues.) B. Letter Reports entitled “Review of Langan Slope Stability Analysis” dated January 14, 2025, revised June 18, 2025, and “PB-24-01 West Essex Highlands, Inc., Block 179 Lot:32: Zone 1H-1” dated July 16, 2025. C. Letter Reports entitled “Further Evaluation of Langan Slope Stability Analysis” dated January 14 2025, revised June 18, 2025, and “PB-24-01 West Essex Highlands, Inc, Block 179 Lot 32: Zone 1H-1, Warner Road” dated August 12, 2025. 5. Drawing Files Submitted to the Planning Board: A. “Proposed Building D , Garden Homes Diagrammatic Site Study Sections” prepared by Appel Group Architects and Issued for Planning Board, 05/09/2023. B. Architectural Drawings entitled “West Essex Highlands Garden Homes” prepared by Appel Group Architects Issued for Planning Board on 12/20/23. C. Drawings entitled: “Preliminary and Final Site Plan, West Essex Highlands. Block 179, Lot 32 and Block 179.17 Lots 8 and 9” prepared by Anderson Consulting Services LLC, originally dated 06/07/2023, revised through 10/01/2024 (per NJDEP comments). 6. Miscellaneous References: A. “Bedrock Geologic Map of the Caldwell Quadrangle, Essex and Morris Counties”

Services LLC, originally dated 06/07/2023, revised through 10/01/2024 (per NJDEP comments). 6. Miscellaneous References: A. “Bedrock Geologic Map of the Caldwell Quadrangle, Essex and Morris Counties” by Richard A Volkert. The relevant section of this Map was included in the Langan report of June 18, 2025, as Figure No. 2 and is attached herewith for ease of reference. B. “Surficial Geology of the Caldwell Quadrangle, Essex and Morris Counties, New Jersey” by Scot D. Stanford, 2005 prepared in cooperation with the U.S. Geological Survey National Geologic Mapping Program. C. Map entitled: “Landslide Susceptibility for Essex County, New Jersey” by Scott D. Standford for the New Geological Society and dated 2001.

Chairman and Members of the West Orange Planning Board Application No. PB24-01, West Essex Highlands, LLC, Warner Road, Block 179, Lot 32 Review of Applicant’s Engineer’s Slope Stability Analysis Reports, the Objector’s Engineer’s Response Reports; and the Applicant’s Engineer’s Rebuttal Report October 28, 2025 Page 4 of 21 PROJECT UNDERSTANDING General This section of the Memorandum describes our review of the proposed construction features as they relate to the evaluation of the slope stability of the ridge in the area of Building D. Our description is based on the interpretation of the drawings submitted for Planning Board Review and included in the CME files as Planning Board Engineer. These are in addition to the Applicant’s and the Objector’s reports and correspondence related to the slope stability and stormwater management submittals as referenced above. We have attached a copy of Langan Drawing entitled “Investigation Plan” for use in understanding the discussion in this memorandum. We have added markup notes using Acrobat Tools with references to the discussion in the text to assist the readers. Proposed Building D We understand that the building design is at a preliminary phase. Our review of the reference Architectural Drawings (Reference 5A) and the Preliminary and Final Site Plan (Reference 5C) indicate the following considerations for this evaluation of the slope stability issues raised by the Applicant’s and Objector’s Engineers: 1. Building Footprint Layout: The footprint of the proposed Building D consists of 2 parallel end sections with a center segment angled at approximately 40 degrees from the alignment of the end sections. The centerline alignment of the building roughly follows the line of the ridge. The nearly uniform width of the footprint is 80 feet. The length of the southern section is approximately 200 feet, the central section is approximately 405 feet and the northerly section of the footprint is approximately 220 feet. The overall length of the building, measured along a line drawn between the centers of the north and south end walls, is approximately 800 feet. 2. Basement Floor Levels: We understand that the uniform first residential floor level is Elevation 618 feet. We understand that the lowest building floor grades are for the parking levels under the building. Our review of the Preliminary & Final Site Plan indicates

idential floor level is Elevation 618 feet. We understand that the lowest building floor grades are for the parking levels under the building. Our review of the Preliminary & Final Site Plan indicates that the garage level on the northern entrance will be +606 feet which is 3 to 4 feet below existing grade along the north building wall and approximately 9 feet above the top of rock encountered at Langan test boring NLB-4. The proposed parking entrance on the south side of the building is shown at elevation 582 feet which is approximately 14 feet below the existing grade at the entrance. The high point of the ridge is near Boring No. LB-3.

Chairman and Members of the West Orange Planning Board Application No. PB24-01, West Essex Highlands, LLC, Warner Road, Block 179, Lot 32 Review of Applicant’s Engineer’s Slope Stability Analysis Reports, the Objector’s Engineer’s Response Reports; and the Applicant’s Engineer’s Rebuttal Report October 28, 2025 Page 5 of 21 The elevation of rock at Boring LB-3 was reported at elevation 605 which is approximately 23 feet above the level of the entrance to the parking level at the south building wall. The grading of the garage floor levels below the building is not indicated on the reference drawings. We have considered that the floor will be approximately level for the purpose of this evaluation. 3. Building Height and Loading as Considered for the Slope Stability Evaluation: The Architectural and Site Plans divide the building into two parts separated at the main entrance. The part to the north of the entrance is designated as Building D.1 and the segment to the south is designated as Building D.2. Review of the Architectural elevation details indicates that Building D.1 includes 5 floor levels from the garage to the 4 th Residential Floor. Review of the architectural elevations indicate that the southern section of the building will include 2 garage floor levels at elevations at 582 and 594, respectively, and that there will be 4 residential levels. In addition, there will be a roof-top assembly area. We anticipate that code-required floor live loads will range from 40 to 100 pounds per square foot. Langan has assigned an average area footprint load of 1,000 psf for Building D. The assumed loading is equivalent to an average combined dead and live loading of 144 psf for Section D.2 and 166 psf for Building D.1. Structural drawings indicating the building floor details, and construction type were not available to check the likely distributed dead loading. The assumed loading is not, in our opinion, an upperbound assumption, and assumes a relatively low average area dead load for the structure. The load distribution indicated in the Langan report indicates that the building influence on the slope is likely not to be a determinant in the stability of the slope. The evaluation did not include an evaluation of the benefits of “weight credit” achieved by removal of the existing soils in the basement, or directly consider the maximum past pressure that

he slope. The evaluation did not include an evaluation of the benefits of “weight credit” achieved by removal of the existing soils in the basement, or directly consider the maximum past pressure that was imposed on the glacial soil deposits and underlying rock by prior glacial activity. Proposed Yard Grading Along Ridge Line Our review indicates that the building location shown on the Stability Investigation drawings conforms to the layout shown on the Preliminary & Final Site Plan drawings. The rear wall line of the building measures approximately 10 to 40 feet from the line on the reference drawing connecting the high points on the ridge. We have marked out a line representing the line at which the slope steepens to more than 15 degrees downward to the east and northeast. The line is shown on the markup and ranges from approximately 40 feet at the northeast corner of Building D.1 to 140 feet at a point opposite the main entrance to the building.

Chairman and Members of the West Orange Planning Board Application No. PB24-01, West Essex Highlands, LLC, Warner Road, Block 179, Lot 32 Review of Applicant’s Engineer’s Slope Stability Analysis Reports, the Objector’s Engineer’s Response Reports; and the Applicant’s Engineer’s Rebuttal Report October 28, 2025 Page 6 of 21 Proposed Grading in Front of Building D The grading indicated on the Preliminary & Final site plans SP15 and SP16 indicate that the finished grading will conform closely to the existing grade to the rear of the proposed building. The finished grades in front of the building are shown on the drawing markup attached to this letter for reference. The proposed grade follows the centerline profile of “Road D”. The roadway grade at the southwest corner of Building D.2 is shown at elevation 585 feet which is approximately 5 feet below the existing grade at that location. The roadway climbs to approximately elevation 592 at the entrance to the upper parking deck at the entrance. The proposed grade is approximately 2 feet above the existing grade at that point. The grade at the northern end of the building is near elevation 608 which is about 2 feet below the existing grade. The existing grades at the front building lines are generally higher than the finished grade at the wall and the grades along Road D. Cuts of up to 10 feet are indicated near the south end of Building D.2 near to the high point of the ridge. Stormwater Management (SWM) and Infiltration Basins The proposed limits of site grading are shown on the Langan Investigation Plan and correspond to the limits indicated on the Preliminary & Final Site Plan. The mapping indicates that the limits of grading will be 5 to 20 feet from the rear building line. The limit is within the line defining the high point of the ridge indicating that site runoff from the landscaped zone would be directed towards the building and to a stormwater collection system of yard inlets along the rear of Building D.1. The plan indicates that the discharge from the rear yard drains will be directed through the building to Stormwater Infiltration Basin 11. We understand that all the building roof drainage and the yard drainage including Road D will be directed to Basins 10 and 11. We further understand that these basins have been designed to retain a volume of runoff determined in accordance with the current