Geotech plan approval letter.pdfa s s o c i a t e d
earth sciences
December 4, 2017
Project No. 140265E001
Mr. Roy Gursli
c/o Cornerstone Architectural Group
6161 NE 175th Street, Suite 101
Kenmore, Washington 98028
Attention: Mr. Steve Barnes
Subject: Geotechnical Plan Review and Response to City Comments
Edmonds Apartments
8509 244th Avenue SW
Edmonds, Washington
Dear Mr. Barnes:
As requested, we have reviewed geotechnical engineering aspects of project plans that were
provided to us, which are listed below. We are familiar with the project as a result of
completion of subsurface explorations and issuance of a geotechnical engineering report for
the project titled "Subsurface Exploration, Geologic Hazard, and Preliminary Geotechnical
Engineering Report," dated February 11, 2016, for the subject project, along with the
subsequent design -phase geotechnical consultation.
For our use in preparing this letter, we have been provided with the following review comment
letters:
• Civil Review Comments — Engineering Division, prepared by City of Edmonds staff,
dated September 21, 2017. (Civil Comments)
Stormwater Review, prepared by City of Edmonds staff, dated August 15, 2017.
(Stormwater Comments)
We have been requested to respond to Item 3 in the Civil Comments and Item 11 in the
Stormwater Comments. These items, along with our responses, are in
th ��paragraphs.
RESUB
Kirkland Office 1911 Fifth Avenue I Kirkland, WA 98033 P 1425.827.7701 F 1425.827.54 2U11
Everett Office 12911 % Hewitt Avenue, Suite 2 1 Everett, WA 98201 P 1425.259.0522 F 1425. 2
Tacoma Office 1 1552 Commerce Street, Suite 102 1 Tacoma, WA 98402 P 1 253.722.2992 FCWWWEPPARTMENT
www.aesgeo.com CITY OF FaMONDS
Civil Comments, Itern 3: "Please provide a written response from the geotech that the civil plans
are consistent with the geotech report."
Plans that were provided for our review included:
a Civil Sheets C0.1, C0.2, C1.1, C1.2, C2.1, C3.1, C3.2, C4.1, C5.1, C6.1 through C6.4, and
Water/Sewer Sheets 1 through 4, prepared by TerraForma Design Group, Inc., dated
December 4, 2017 (Sheet C6.4, prepared by Associated Earth Sciences, Inc. (AESI), dated
November 2017).
Based on our review of our February 11, 2016 report and the currently proposed project, it is
our opinion that the plans provided to us are generally consistent with the recommendations
we provided in the above -referenced report.
Stormwater Comments, Item 11: "Sheet C3.1: Detention system specifies a chamber system
with an open bottom. The geotech does not recommend infiltration. Additionally, the proximity
of the retaining wall immediately to the east will express "infiltrated" groundwater."
Based on our review of the provided plans, the open bottom detention system mentioned in
the City's comment has been replaced with a closed tank detention system.
The bioretention planter also infiltrates and therefore does not meet the geotech's
recommendation."
We understand that the proposed bioretention planter is intended as a filtration system, with
an underdrain that discharges to the detention system, and that no infiltration was assumed
in the sizing of the detention system.
We appreciate the opportunity to be of continued service. If you have any questions regarding
this letter or other geotechnical engineering aspects of the project, please do not hesitate to
call.
Sincerely,
ASSOCIATED EARTH SCIENCES, INC.
Kirkland,..W,as,hington
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Kurt D. Merriman, P.E.
Senior Principal Engineer
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