Laserfiche WebLink
NELSON GEOTECHNICAL <br />ASSOCIATES. INC. <br />July 1, 2022 <br />Dennis and Chelsea Miller <br />VIA Email: doccaribb0icloud.com <br />c hordoPhotmail.com <br />Geotechnical Engineering Evaluation <br />Miller Property Slope Stabilization <br />2702 — 591h Street SW <br />Everett, Washington <br />NGA File No. 1333322 <br />Dear Mr. and Mrs. Miller: <br />17311-1351h Ave. N.E. Suite A-500 <br />Woodinville, WA 98072 <br />(425) 486-1669 <br />www.nelsongeotech.com <br />We are pleased to submit the attached report titled "Geotechnical Engineering Evaluation — Miller <br />Property Slope Stabilization —2702 - 59`h Street SW— Everett, Washington." This report summarizes our <br />observations of the existing surface and subsurface conditions within the site and provides <br />recommendations for site stabilization. Our services were completed in general accordance with the <br />proposal signed by you on January 26, 2022. <br />The following study documents our investigation of the recent landslide activity that occurred within the <br />property during December 2021. The subject property is one of four residential tract lots situated at the <br />end of 59t" Street Southwest and generally perched above a tributary ravine of Powder Mill Gulch. The <br />site is occupied by a single-family residence within the central portion and is bound by moderate to steep <br />south -facing ravine slopes to the south. <br />Our involvement with the project began on January 14, 2022, when we were asked to visit the site after <br />initial observations of signs of instability were noted by the homeowner. Upon arrival, we observed a <br />landslide scarp trace measuring approximately 220 feet in length, spanning from the east -central property <br />line to the south-central side of the adjoining property to the west. We were subsequently retained to <br />evaluate the extent of the failure and provide preliminary mitigation options for the landslide. During our <br />review, we gathered additional data from instrumentation installed on the site and explored the <br />subsurface soil and groundwater conditions with drilled geotechnical borings. <br />We conducted three geotechnical borings, four hand tool explorations, mapping, and instrumentation to <br />better understand the landslide mechanisms and soil and groundwater conditions within areas disturbed <br />by landslide activity. <br />