Langan Rebuttal Report 9 15 2025

15 September 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: As requested, in conjunction with the above-referenced study Langan Engineering and Environmental Services, LLC (Langan) has reviewed letters prepared by Princeton Hydro (“Princeton”), who has been retained by Objectors to the proposed Development. The Princeton letter, dated 16 July 2025, summarized their comments under four primary issues (below): 1. 2. 3. 4. Building Layout Currently Proposed Closer than Concept Parameters of Slope Stability Analysis Do Not Match Actual Conditions Geologic Hazard Review Unjustified in Dismissing the Risks Blasting Implications and Threats to Stability of the Slope Must be Addressed Before Approval In a follow up letter dated 12 August 2025, Princeton provided a slope stability analysis at site locations they defined as “Model Cross Sections C and D”, which loosely correspond to analysis sections C-C and D-D from Langan’s letter report dated 18 June 2025. In the following sections, Langan provides responses to the four primary issues raised in Princeton’s 16 July 2025 letter. In general, it is very important to note that Princeton’s slope stability analyses at the two above referenced cross sections indicated the slope to be stable with adequate factors of safety, even after Princeton assigned a much lower strength value to the rock at the site than was used in Langan’s analysis. Princeton’s slope stability results, therefore, are in general agreement with the Langan conclusions and contradict the basis for Princeton’s slope concerns which they expressed in their aforementioned letters and 16 July 2025 testimony by Geoffrey Goll. To make abundantly clear, our analysis demonstrates that the existing slopes are stable and that the new building does not change the loading condition on the slope; therefore, no change in the slope stability. Schematics below show the general area beneath the central and northern portions of the building where foundation loading occurs and will be distributed in soil. These schematics show the limited influence of the building loading, and specifically no influence on the slope.