2025 01 14 West Essex Highlands Development Building D Slope Stability Study

14 January 2025 Mark Hoffman Garden Homes Management 820 Morris Turnpike Suite 301 Short Hills, NJ 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 a subsurface investigation and global slope stability evaluation 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 issue being investigated 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 The Subject Slope descends about 150 feet in elevation to the east from the east side of proposed Building D at roughly 10 degrees (or roughly 17%). The distance to the adjacent Rosemont Terrace and Mayfair Drive developments at the bottom of the slope is roughly 700 feet east of the proposed Building D. A site location map showing the approximate limits of the Study Area is provided below. Langan investigated the subsurface conditions within Subject Slope/Study Area along two transects roughly 385 feet apart using a combination of drilled borings and test pit excavations. The locations of the 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 2-dimensional slope stability analysis.