18102 Aw Residence Grading Ext Letter 08-29-2019Aw Residence August 29, 2019
9527 1901" Place SW Project #18102
Edmonds, Washington
Strobl Design LLC
aacob@strobldesign.com
Attention: Jacob Strobl
Subject: Grading Season Extension — Aw Residence
City of Edmonds Permit #: BLD20190116
Mr. Strobl:
The purpose of this letter is to provide our opinion with respect to a grading season extension.
Based on our recent correspondence, it is our understanding that the normal grading season
restriction for geologically hazardous areas is from October 1st through May 1st. To facilitate
efficient construction, a reduction of the grading restriction is desired. For the sake of brevity,
we presume that people reading this letter are highly familiar with the subject property and the
proposed development. The remainder of this letter will set forth our opinions on extending
the grading season for the proposed development of the subject property.
The native Vashon advance outwash soils are dense in -place, relatively permeable, and
moderately resistant to erosion, except when subjected to concentrated flows. Based on our
review of the site topography, the native soils present, and the proposed grading and
temporary erosion and sediment control plan prepared by CG Engineering, it is our opinion that
the site work may be performed through the wet season and this construction, the areas
disturbed by construction will remain stable, there will not be an increase in the potential for
soil movement, and the risk of damage to the subject property and adjacent properties will be
minimal.
Also, it is our understanding that there is an intent to limit earthwork through the entire wet
season. The intent is to have the foundation excavation, foundation concrete placed, and
foundation backfill completed by mid -November and then temporary soil stabilization
completed until final grading and landscaping can be completed next year. This construction
scheduling and phasing is consistent for the standard of practice for the Puget Sound region.
Closure
We have enjoyed working with you and we are confident that this letter will aid in the
permitting roject. If there are any questions, please feel free to contact us.
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Sincerer �
Andrew L. Glandon, LEG
Engineering Geologist / Owner
South Fork Geosciences, PLLC
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Andrew L. Glandon Cc: City of Edmonds
Attention: Building Department
SOUTH FORK GEOSCIENCES, PLLC Page 1
PO Box 1 275
NORTH BEND, WA 98045
425-890-4858 1 INFOPSFGEO.COM