2730 W MARINE VIEW DR 2025-09-03

associated 3 earth sciences incorporated 4.1 August 9, 2019 Project No. 190315E001 Skotdal Holdings, LLC 2707 Colby Avenue Everett, Washington 98201 Attention: Craig Sanderson Subject: StoneTerra Wall Detail 2730 West Marine View Drive Everett, Washington Dear Mr. Sanderson: Attached to this letter is our StoneTerra wall detail for use in the above-referenced project. Our detail and design calculations were based on the following documents provided to us in an email dated August 6, 2019: • A survey drawing by ORCA Land Surveying, titled "Record of Survey for Art Skotdal," dated July 4, 2019. • A wall plan/profile drawing by StoneTerra, Inc., titled "2730 West Marine View Drive," dated July 22, 2019. Additionally, we based foundation and retained soil parameters and groundwater level information on our environmental report titled "Supplemental Phase II Environmental Site Assessment, Everett Herald Property West Parcels, Everett, Snohomish County, Washington," dated April 16, 2014. Based on the documents above and our telephone correspondence with you on August 8, 2019, the following assumptions were used in our design calculations to develop the attached wall detail: • The maximum wall height is 28 feet. • The final grade elevation of the wall backfill is about 40 feet and approximately level. • The ground surface at the base of the wall is approximately level. • A traffic load of 250 pounds per square foot (psf) was added to the top of wall backfill at a 5-foot offset from the wall face. • A building load of 3,000 psf was added to the top of wall backfill at a 25-foot offset from the wall face. Kirkland Office 1911 Fifth Avenue I Kirkland,WA 98033 P 1425.827.7701 Mount Vernon Office 1508 S.Second Street,Suite 101 I Mount Vernon,WA 98273 P 1425.827.7701 Tacoma Office 11552 Commerce Street,Suite 102 I Tacoma,WA 98402 P 1253.722.2992 www.aesgeo.com