O36 Email from Mr Kleinberg

this anywhere on the site. Therefore, the root cohesion must be considerably higher. Various researchers have evaluated root cohesion and determined values typically range from 200 psf for clear cuts and natural wooded/forested land to 500 psf. The site is predominantly wooded; however, if C= 100 psf root cohesion is used, FS values would be well over 1.5 (i.e., 1.7 to 7) for the slopes in question. CME Response: We recommend that Langan provide a formal response to the Planning Board on the basis described herein, to address this issue. 4. The existing slopes are not going to be disturbed and the developer must maintain the vegetation, therefore the analyses demonstrate shallow failures are unlikely. CME Response: We agree that the existing slopes must be protected from disturbance and that the vegetation must be maintained both by the developer and his successors. That is why we have recommended that enforceable requirements based on our review recommendations to the Board be established. | trust this addresses your concerns. Please call with any questions. Mark Mark Seel Associate Principal / Vice President LANGAN Direct: 973.560.4986 Mobile: 724.263.2179 File Sharing Link www.langan.com Technical Excellence e Practical Experience e Client Responsiveness NEW JERSEY NEW YORK CONNECTICUT MASSACHUSETTS PENNSYLVANIA VIRGINIA WASHINGTON, DC OHIO ILLINOIS NORTH CAROLINA TENNESSEE FLORIDA TEXAS ARIZONA COLORADO UTAH WASHINGTON OREGON NEVADA CALIFORNIA ATHENS CALGARY DUBAI LONDON PANAMA From: Kleinberg, Sam <SKleinberg@cmeusal.com> Sent: Monday, December 1, 2025 5:55 PM To: Mark Seel <mseel@Langan.com>; pandersonpe@gmail.com Cc: Hernandez, Nelson <NHernandez@cmeusal.com>; MacNeill, Ryan <rmacneill@cmeusal.com>; Rizzo, Jordan <jrizzo@cmeusal.com>; Mazier, Alejandra <AMazier@cmeusal1.com> Subject: RE: WEHI Importance: High Greetings, We have attached a partial markup of the output for the cases of elevated GW_Critical and Infinite surfaces as submitted to us. We have completed the infinite slope checks using the basic hand calculation equation for Factor of Safety with phreatic surface at the ground surface and seepage flowing parallel to the slope for sections A&B. Our computations indicate factors of safety ranging from 1.178 and 0.88 at sections A & B respectively. The basis for our recommendation to address this case is included the

he slope for sections A&B. Our computations indicate factors of safety ranging from 1.178 and 0.88 at sections A & B respectively. The basis for our recommendation to address this case is included the attachment from Lambe and Whitman which is avalid reference. While the groundwater level has not been established, severe rainfall could develop a perched water condition over the bedrock with seepage parallel to the slope. The output indicates that the infinite slope cases for sections A&B are above the assumed seepage level and do not address our recommendations. 2