2020/10/14 Council Agenda Packet

40% in "other" geologic units. (Note; Studies are required for these areas when combined with springs or seeps, immature vegetation, and/or no vegetation.) City of Everett Erosion Hazard Critical Areas Map 3 (see inset snap) depicts the area on the west side of Grand Avenue for the Subject Site as containing High Slopes of 25-40% in Qva (Vashon Advance Outwash) and Qa1 (Yoirnger Alluvium) geologic units; and Slopes of greater than 40% in other geologic units for the Subject Site. -36111-1 437T1-{ ST PL I ` It was necessary to confirm site -specific soils conditions to further the conceptual site plan design process. The Geotechnical Engineering Report, February 28, 2020, was prepared by The Riley Group, Inc. and confirms the soil types and existence of the steep slopes along a portion of the east side of the Subject Site. Findings are consistent with the City of Everett snapping, but provided greater site -specific conditions. The report confirmed that based on designations in the Everett Municipal Code an area of the site (along Grand Avenue) meets the criteria of a very high/severe landslide hazard area due to slopes greater than 15 percent with uncontrolled fill, and a high erosion hazard area due to slopes greater than 40 percent. That slope continues into the property to the north, where gradients reduce to about 25 percent, which meets the criteria of a high landslide area due to slopes 25 to 40 percent, and a high erosion hazard area due to slopes 25 to 40 percent in the Qva geologic unit. co What generall types of soils are found on the site (for example, clay, sand, gravel, peat, muck)? if you know the classification of agricultural soils, specify them and note any .. gricuT1tural land of long=term commercial_ significance and whether the proposall results in removing any of these soils. The Snohomish County Agricultural Map denotes the site as underlain primarily with Alderwood gravelly sandy loam (2 to 8 percent slopes). It is also mapped containing Alderwood gravelly sandy loam (15 to 25 percent slopes). Per the Geotechnical Engineering Report, Section 4.3: The soils encountered during field exploration include 2.5 to greater than 10.5 feet of loose to medium dense fill comprised of silty sand with varying amounts of gravel over native soils comprised of loose to very dense silty sand with varying amounts of gravel and localized stiff to hard silt. do Are there surface indications or history of unstable soils in the immediate vicinity? I11 so, describe. There are no known indications of unstable soils. eo Ii escribe tine purpose, type, total area, and approdiun ate quantities and total affectec area of any filling, excavation, and grading proposed. Indicate source of f 10 N,Q EVALUATION IF0 AGENCY USE ONLY Environmental. Checklist - CCrnnprehensive Plan Amendment/Concurrent 1Re.'one BRENT PLANNING SOLUTIONS, LLC FOR HOUSING HOPE 12 AUGUST 2020 REv'D