10.10.2014-Geotech consultants declaration.pdfMeadowview Estates, LLC
12515 Willows Road Northeast, #220
Kirkland, Washington 98034
Attention: E. Kent Halvorson:
13256 Northeast 20th Street, Suite 16
Bellevue, Wasbabton 98005
(425) 747-5613 FAX (425) 747-8561
October 10, 2014
JN 13245
via email kent@halvorsonconstruction.com
Subject: Geotechnical Hazard Identification/Declaration and Mitigation Statement of Risk
Proposed Five -Lot Short Plat, Meadowview Estates
15620 — 72nd Avenue West
Edmonds, Washington
Dear Mr, Halvorson:
Our firm has prepared a geotechnical engineering study for the proposed Meadowview Estates
short -plat project. However, because the project site is located in the Earth Subsidence and
Landslide Hazard Area of North Edmonds, a declaration letter with a statement of risk is also
required, In preparation of this letter, we reviewed the project civil plans, which include Sheets 1
through 11; these were prepared by LDC dated September 12, 2014. The last sheet is a tree
removal plan.
We make the following declaration and statement of risk regarding this project and our review of
the plans:
In our opinion, the civil plans and specification for the project conform to the
recommendations in our study. This includes a review of the erosion and sedimentation
control plan (Sheet 2) for the project.
The risk of damage to the proposed development, or to adjacent properties, from soil
instability will be minimized subject to the conditions set forth in our study, and the
proposed development will not increase the potential for soil movement. This includes
an evaluation regarding the statistical probability of earth movement within a 25 and
125 -year period. Buffer and building setback recommendations were included in our
study regarding this probability and an analysis of potential deep-seated soil movement.
The guidelines of the 2007 Landau Summary Report were included in the analyses,
conclusions, and recommendations presented in our study.
A very steep slope is located on the western side of the property. As with any steep
slope, there is a potential for deep-seated movement of the western slope. However,
we analyzed the slope against deep -skated movement and have made buffer and
setback recommendation to mitigate the risks against deep-seated movement. One of
the strongest recommendations against movement of the western slope provided in our
study is to control water from impervious surfaces of the project; the project civil plans
clearly indicate that this recommendation is included in the project.
GEOTECN CONSULTANTS, INC.
Meadowview Estates, LLC
October 10, 2014
JN 13245
Page 2
We recommended in our study that a non -disturbance buffer be maintained from the
steep western slope. However, one minor area of disturbance is proposed within the
25 -foot buffer for the installation of the stormwater system just north of an existing catch
basin. The system must tie-in the existing catch basin, which requires the disturbance.
We believe that this minor disturbance is suitable because it will occur near where the
past slope repair was done, which is an area where the top of the steep slope is most
stable; and no significant trees will be removed. The newest plans indicate that four
trees located near, but not in, the 25 -foot buffer will be removed for the installation of
Storm Stub -1. This is suitable in our opinion and consistent with our study because this
removal work is outside of the 25 -foot buffer.
We trust that this report meets your immediate needs for the proposed development. Please
contact us if we can be of further service.
cc: LDC, Inc. v Steve Anderson
via email to: sanderson@ldccorp.com
DRW:at
Respectfully submitted,
GEOTECH CONSULTANTS, INC.
D. Robert Ward, P.E.
Principal
GEOTECH CONSULTANTS. INC.
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