4730 COLBY AVE SEPA 016 - 027 - YMCA Geotech Report 2025-04-14

October 25, 2015 YMCA - Everett L&A Job No. 15-089 Page 3 SITE CONDITIONS Surface Condition The project site is elongated in the north-south direction and is bounded by 47th Street SE to the north, Colby Avenue to the east, Rucker Avenue to the west, and is bordered by a utility easement to the south side with residential development beyond. The site is situated on a gentle, north-trending plain. The terrain within the site is turtle-shell like, with the interior of the site generally rises a few feet to 12 feet or more above the street level bounding the site, and flanked by gentle to moderately-steep perimeter banks dropping to its north, east and west boundaries. The interior of the site generally slopes down gently northward and down towards its northwest corner. The unpaved ground within the site is mostly covered with lawn grass with few isolated trees dotting the perimeter of the site and the edges of the existing parking lot. Geologic Setting The Geologic Map of the Everett 7.5-Minute Quadrangle, Snohomish County, Washington, James P. Minard, published by U. S. Geological Survey in 1985, was referenced for geologic and soil conditions of the project site. According to this publication, the surficial soil unit at and in the immediate vicinity of the project site is mapped as Vashon till (Qv,) Deposits. An advance outwash (Q,) soil unit is mapped at a short distance to the north and the east of the project site. This soil unit normally underlies the Vashon till soil unit. The geology of the Puget Sound Lowland has been modified by the advance and retreat of several glaciers in the past one million years or so and the subsequent deposits and erosions. The latest glacier advanced to the Puget Sound Lowland is referred to as the Vashon Stade LIU & ASSOCIATES, INC.