2211 GIBSON PL Geotech Report 2023-04-06

August 18, 2014 Gibson Bluff L&A Job No. 14-056 Page 3 SITE CONDITIONS Surface Condition The general location of the project site is shown on Plate 1 — Vicinity Map. The site is situated near the base of a moderate to steep, northerly-declining hillside with deep gullies incised by creeks flowing northward down the coastal bluff. The project site is consisted of a gently sloped bench top over most of the site flanked by a steep bluff on its north side a steep gully bank on its west side. It is bounded by Gibson Place to its south and adjoined by residential development to its east. The site is currently occupied by a single-family residence in its northeast quadrant with detached garage and storage shed near the top of the steep gully bank on its west side. The open area on the bench top around the existing residence is covered by lawn grass and flower beds. The steep bluff and gully bank along the north and west sides are dotted by large and tall, mature, evergreen and deciduous trees. These trees are all quite straight with little or no downhill lean and without a bent in their trunks. This indicates that there has been little or no soil movement on the steep slopes over the life times of the trees. Geologic Setting The Preliminary Surficial Geologic Map of the Mukilteo and Everett Quadrangles, Snohomish County, Washington, by Mackey Smith, published by U. S. Geological Survey in 1976, is referenced for the geologic and soil conditions of the project site. According to this publication, the surficial soil units at and in the vicinity of the project site are mapped as Vashon Till (Q,,)underlain by Whidbey formation (QW). LIU & ASSOCIATES, INC.