O38 Email from Nov 13 2025 to Dec 9 2025 between Mr Kleinberg and Mr Seele

, Direct: 973.560.4986 Mobile: 724.263.2179 ile Shari ink www.langan.com Technical Excellence ¢ 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 CALIFOR NIA ATHENS CALGARY DUBAI LONDON PANAMA From: Kleinberg, Sam <SKlein usai.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 eusal.com>; Rizzo, Jordan <jrizzo@cmeusal.com>; Mazier, Alejandra <AMazier@cmeusal.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 attachment from Lambe and Whitman which is a valid 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. If you have any questions concerning our evaluation, please do not hesitate to call. Vty, Sam Kleinberg From: Mazier, Alejandra <AMazier@cmeusal.com> Sent: Wednesday, November 26, 2025 4:54 PM To: Mark Seel <mseel@ angan.com>; Kleinberg, Sam <SKleinberg@cmeusa com> Ce: Hernandez, Nelson <NHernand. usal.c Subject: RE: WEHI Understood. Thank you Mark. Sam will get in touch with you on Monday in case he requires additional information. Have a Happy Thanksgiving! Alejandra