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Geo Design Approval-PLN20120021-Ritter.pdfLIU& ASSOCIATES, INC. Geotechnical En y _ ........ Engineering ...m g' ng Engineering Geology October 30, 2017 Mr. Joe Smeby Omega Engineering, Inc.. 2707 Wetmore Avenue Everett, WA 98201 Dear Mr. Smeby: Subject: Design Plans Review Ritter Short Plat 8364 Olympic View Drive Edmonds, Washington L&A Job No. 5A112 Earth science At your request, we have completed a geotechnical review of the complete set of design plans, including Vegetation Management Plan, prepared by Omega Engineering, Inc., for the subject project. The project site is mostly covered by steep sloped area of 40% grade or more. The surficial soil unit of the site, however, is consisted of medium -dense to dense, fine to coarse sand with trace gravel, of advance outwash. This soil unit is quite stable. There are no signs of groundwater seepage or erosion. Furthermore, there are no known landslides occurred at or in the vicinity of the site. Therefore, although the site is classified as in critical areas due to its steepness, its actual landslide hazard should only be moderately high. Our review was for the design plans' compliance of ECDE Chapters 23.40, 23.80, 23.80.060, and 23.80.070. Our comments of this review are presented below: 19213 Kenlake Place NE - Kenmore, Washington 98028 Phone (425) 483-9134 - Fax (425) 486-2746 October 30, 2017 Ritter Short Plat L&A Job No. SA112 Page 3 ECDE 23.80.060 The design plans Will not increase the threat of the geological hazard to adjacent properties beyond predevelopment conditions; Will not adversely impact other critical areas; Are designed so that the hazard to the project is eliminated or mitigated to a level equal to or less than predevelopment conditions; and Are certified as safe as designed and under anticipated conditions by a qualified engineer or geologist, licensed in the state of Washington. ECDE 23.80.070 The design plans Allow alterations of an erosion or landslide hazard area, minimum building setback and/or buffer may only occur for activities for which a hazards analysis is submitted and certifies that: The alteration will not increase surface water discharge or sedimentation to adjacent properties beyond predevelopment conditions; The alteration will not decrease slope stability on adjacent properties; and Such alterations will not adversely impact other critical areas; Allow alteration of vegetation retention, but will re -vegetate the site to mitigate erosion and achieve slope stability; Will restrict clearing only from May 1 st to October 1 st of each year; LIU & ASSOCIATES, INC. October 30, 2017 Ritter Short Plat L&A Job No. 5A112 Page 5 Please contact us if you have questions. Yours very truly, LI J & ASSOCIATES, INC. J. S. (Julian) Liu, Ph.D., P.E. Principal LIU & ASSOCIATES, INC.