REVIEWED RESUB2 BLD2023-0640+Geotechnical_Report+4.11.2024_4.46.45_PM+4191960RECEIVED BLD2023-0640
Apr 12 2024 17311-135th Ave. N.E. Suite A-500
CITY OF EDMONDS
DEVELOPMENT SERVICES Woodinville, WA 98072
NELSON GEOTECHNICAL DEPARTMENT (425) 486-1669
ASSOCIATES. INC. www.nelsongeotech.com
MEMORANDUM
DATE: April 11, 2024
TO: Michael Koh Being Chye
FROM: Khaled M. Shawish, PE
Alex B. Rinaldi, LG, EIT
RE: Geotechnical Plan Review
Proposed Koh Residence
15604 — 75`h Place West
Edmonds, Washington
NGA File No. 1360822
This memorandum documents our review of the latest civil plans regarding the proposed residence
development project located at 15604 — 751h Place West in Edmonds, Washington. The parcel number
for the subject property is 00513100002410. We previously prepared a geotechnical report for the
proposed site development dated May 23, 2023.
For use in preparing this review, we were provided with a complete plan set as well as updated civil plan
sheets C1.0 to C4.1, dated March 29, 2024. We have reviewed the geotechnical aspects of the updated
plans and found them to be in general accordance with the recommendations provided. Specifically, we
have reviewed the structure setbacks in relation to site geologic hazards and they appear to be suitably
placed in accordance with the geotechnical recommendations and in a manner that reduces potential
instability.
All stormwater runoff generated from the proposed house and driveway are to be directed to a Type 1
catch basin just below the residence, which outlets water downslope through a surface -mounted 4-inch,
inside diameter, HDPE pipe. The HDPE pipe terminates along the toe of the slope with a short diffuser T
beyond the property line and within BNSF right-of-way. We understand the proposed outfall, as discussed
with BNSF, is to extend the HDPE pipe over the 2- to 3-foot-tall existing timber retaining wall and
terminate in a relatively short diffuser T suspended over the existing BNSF ditch, which generally consists
of railroad ballast. In our opinion, the proposed outfall discussed above and generally shown on the
termination detail on Sheet C4.1 is acceptable from a geotechnical standpoint.
We trust this memorandum satisfies your needs at this time. Please contact us if you have any questions
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or require additional services. o-o-o