wet season letterI>
October 8, 2020
Project No. 20190373EO01
Ms. Charlie Lieu
16515 741" Place West
Edmonds, Washington 98026
a s s o c i a t e d
earth sciences
i n c o r p o r a t e d
Subject: Wet Season Grading Request
Lieu Residence Underpinning
16515 74t" Place West
Edmonds, Washington
Dear Ms. Lieu:
RECEIVED
Nov 03 2020
CITY OF EDMONDS
DEVELOPMENT SERVICES
DEPARTMENT
bld2020-0831
Associated Earth Sciences, Inc. (AESI) prepared this letter in support of a request to allow site
grading during the designated City of Edmonds wet season (October 151 through May 15t). AESI
completed a "Subsurface Exploration and Geotechnical Engineering Report," dated November
13, 2019, for the subject project. The topography of the site generally slopes moderately
downward to the west, with a steep slope area at the western portion of the site. The shallow
soils on the site are primarily fill and pre -Fraser -age (Whidbey Formation) sediments.
Based on review of the plans prepared by CIS Engineering, dated December 2, 2019, we
understand that the project will involve only minor earthwork in the form of limited, "pocket"
excavations along the existing residence for foundation underpinning. Also, construction will
occur on a fully developed lot with well -established landscaping. Therefore, provided that the
"Erosion Hazard and Mitigation" recommendations provided in our November 13, 2019 report
are followed, it is our opinion that the impacts to erosion will be minimal. Based on site or
weather conditions encountered during earthwork activities, adjustments can and will be made
in the field to better suit the conditions encountered if the circumstances require such changes.
In our opinion, due to the site conditions and the planned methods of construction, performing
the planned work at this site during the City of Edmonds's wet season of 2020-2021 is
acceptable. Provided the recommendations contained in our previous report are followed and
sound construction practices are utilized, the increase in risk to the public, the environment,
worker safety, or adjoining properties should be minimal as compared to construction prior to
October 151. AESI will conduct site inspections after each significant rain event until the work
site is completely stabilized, and notify the City of Edmonds by field report upon completing
final stabilization.
Kirkland I Tacoma I Mount Vernon
425-827-7701 1 www.aesgeo.com
If there are any further questions, feel free to contact Bruce Blyton at (425) 827-7701.
Sincerely,
ASSOCIATED EARTH SCIENCES, INC.
Kirkland, Washington
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Bruce L. Blyton, P.E.
Senior Principal Engineer
BLB/ms-20190373E001-3
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