bld20120858_NGA report comments-1.pdf
Comments provided directly to project contact, architect James Thomas.
MEMORANDUM
Date:
November 21, 2012
To:
Leif Bjorback, Assistant Building Official
From:
JoAnne Zulauf, Engineering Technician
Subject:
Olson Residential Construction Proposal
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15500 75 Pl W
The comments provided below are based upon review of the Nelson Geotechnical Associates,
Inc (NGA) revised report dated July 15, 2011 and the submitted civil sheets. Clarification on
the following issues are necessary prior to moving forward with the resubmittal of plans to the
Engineering Division for review.
1.On page 2 of the NGA revision letter states that the Stormwater handling plans have
not been finalized at this time.. and therefore does not include any specific review of
the proposed system. TheOlson Property Geotechnical Hazard Assessment includes
a letter from JC McDonnell Engineering, PC in which he states that he will defer
geotechnical risk to NGA; therefore a comprehensive review of the project civils shall
be required and a letter of approval shall be required to be submitted with the revised
plans.
2.There appears to be two walls in the right of way west of the property. One is an old
landscape wall and the other runs along the road under the guardrail. Page 1 of the
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July 15 revision letter states A small soldier pile retaining wall is planned to replace
a failed ecology block retaining wall. In the following report there are what appear to
be conflicting references to which wall this statement refers. On page 3 of the report is
a reference to a failing landscape wall. On page 8, the last paragraph states an
approximate 6 foot tall block retaining wall is located just to the east of the eastern
property line, directly below the road. On page 16, the reference is the same as page
8 though the portion directly below the road is not mentioned. The plans do not
show any wall under the roadway. Nor do they reference any repair. The submittal
did not include any structural plans for this wall.
3.NGA recommends the use of silt fences and straw bales for erosion control. CECSL
training now indicates that the use of silt fences are generally not encouraged in areas
where additional disturbance of soils could contribute to the instability of the site.
City of Edmonds
Also, straw bales are discouraged and will no longer be included as an approved
erosion control measure under the new DOE Stormwater permit. Please confirm that
these measures are appropriate for this site. If not, please recommend other measures
for the site.