Laserfiche WebLink
GeoTest Services, Inc. <br />2405 Hillside Lane, Everett, WA <br />October 8, 2021 <br />Project No. 21-0845 <br />Groundwater levels are variable and groundwater conditions will fluctuate depending on local <br />subsurface conditions, precipitation, and changes in on -site and off -site use. <br />GEOLOGICALLY HAZARDOUS AREAS <br />Our geotechnical investigation included an assessment of potential geologic hazards that include <br />landslide, erosion, flood, liquefaction, and seismic hazards. According to Chapter 19.37 of the <br />Everett Municipal Code (EMC), Geologically Hazardous Areas include areas that are "susceptible <br />to erosion, landslide, seismically induced soil failure, or other geological events." Based on this <br />information and our observations of the subject property, it does not appear that flood, <br />liquefaction, or seismic hazards are present on or in the immediate vicinity of the subject <br />property. We have provided commentary on landslide, erosion, and seismic hazards in the <br />following sections. <br />Landslide Hazard Areas <br />According to Chapter 19.37.080.A.1 of the EMC, Landslide Hazard Areas include those areas <br />defined as "high and very high/severe risk of landslide hazard in the Dames and Moore <br />Methodology for the Inventory, Classification and Designation of Geologically Hazardous Areas, <br />City of Everett, Washington: July 1,1991, or a revised through best available science". This section <br />further defines areas of very high/severe risk as those areas "with slopes greater than fifteen <br />percent in the Qtb, Qw, and Qls geologic units; and slope greater than fifteen percent with <br />uncontrolled fill". <br />A slope approximately 32 feet in height comprises the subject property. The slope did not appear <br />to be showing signs of springs, seeps, cracks, or evidence of instability. We did not observe <br />noticeable signs of instability on this slope during our visits to the subject property. Existing <br />residences surround the development on all sides of the slope, in which GeoTest did not observe <br />apparent cracking within the neighboring building's exterior foundations. The slope comprising <br />the property (specifically, the slope that comprises Lots 2 and 3 on the southern half of the <br />proposed development) is classified to be "very high/severe risk" per the EMC due to the <br />underlying soils consisting of Transitional Beds. This is consistent with the mapped Geologic <br />Hazard Area information obtained from the City of Everett GIS web application. <br />Chapter 19.37.080.13 of the EMC provides guidelines regarding setback buffers. Since Lots 2 and <br />3 of the proposed development consist of a slope that is slightly above 15 percent and may <br />contain seasonal perched groundwater, the minimum setback buffer that is required by the City <br />of Everett would normally preclude the construction of a residence on the subject property. <br />However, Chapter 19.37.080.0 of the EMC also states that alterations may be allowed subject to <br />specified criteria. Some of this specified criteria state that alterations may be allowed, provided <br />that the proposed development "will not create a hazard to the subject property, surrounding <br />properties, or rights -of -way ..."; that the proposed method of construction "will reduce erosion <br />5 <br />