25 10 28 Slope Stability Review

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.