2025 06 18 WEH Slope Stability Analysis Letter Report

14 January 2025 Revised 18 June 2025 Mark Hoffman Garden Homes Management 820 Morris Turnpike, Suite 301 Short Hills, New Jersey 07078 Re: Global Stability Study for Eastern Slope near Building D West Essex – Highlands Development West Orange, New Jersey Langan Project No.: 101049801 Dear Mr. Hoffman: This letter report documents the findings of subsurface investigations and global slope stability analysis performed by Langan Engineering and Environmental Services, LLC (Langan) for the eastern portion (the “Study Area”) of the proposed West Essex Highlands development site located in West Orange, New Jersey. The purpose of the study is to address perceived slope stability concerns (the “Subject Slope”) raised by the public during previous Site Plan review meetings, related to the proposed construction of Building D on the West Essex Highlands Development. This report provides an overview of the study and statements of our opinions in that regard. Details concerning our subsurface investigation, analysis, and evaluation are provided as Attachment A in support of the statements and opinions herein. OVERVIEW DISCUSSION Langan initially investigated the subsurface conditions within the Subject Slope/Study Area along two transects roughly 385 feet apart using a combination of drilled borings and test pit excavations. These findings were presented in a report dated 14 January 2025, and the undersigned provided testimony during a public hearing on 29 January 2025. Based on comments received from the public during that hearing, Langan performed additional investigation and analysis immediately north of the original study area. Those findings are presented in this report, and include two additional transects along which slope stability was evaluated. The locations of all transect lines and boring/test pit locations are shown on attached Figure 1. Soil and rock samples were collected and laboratory testing was performed to determine physical and strength parameters, which along with data from our logs of borings and test pits were utilized in our 2dimensional slope stability analysis.