Geotech Letter recd 1-24-2012.pdfMike Thies
Code Enforcement
City of Edmonds
121 5th Avenue North
Edmonds, WA 98020
(425) 771-0220
thisOci.edinonds.wa.0
Case: # COD-2011-0241
Subject Property: 16856 76"' Ave, W., Edmonds, WA 98026
Dear Mr. Thies,
Robert Brunette
16856 761h Avenue West
Edmonds, WA 98026
RECEIVED
JAN 2 4 2012
DEVELOPMENT SEPVI�LS
Per my conversation with the City of Edmonds Planning Department on October 17, 2011, 1 am enclosing
the requested geotechnical report. As outlined in paragraph two of the report, our plans to landscape
our yard while maintaining the city's access to the easement includes:
• Remove new rocks on the western edge of property
• Place a cover of top soil over a gentle sloping area covering approximately 1,350 square feet
• Install sod
• Provide drainage improvements
• Replant perimeter
We will contact you upon completion of the project to schedule an inspection. If you have any
questions, I can be reached at (206) 660-7307.
Sincerely;
Robert Brunette
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October 27, 2011
JAN 2 4 2012
DEVELOPMENT SERVICES
Robert Brunette
18856-761h Avenue West
Edmonds, WA 98026
Re: Geotechnical Critical Areas Assessment for
Steep Slope near Back Yard Improvements at
Parcel 27040700101300, Edmonds, Washington
Our Reference: J 050 - 01-11
Dear Bob:
Adams Resource Consultants (ARC) is pleased to provide this brief letter report (following ECDC 23.40)
covering observations and opinions of the Critical Area - Steep Slope based on our site visit (October 23,
2011) at the property (project site) previously described. We measured the steep slope (geologically
hazardous area as defined in ECDC 23.80) that is partly on your property and partly on the City of
Lynnwood's property south of your home and lawn. We also observed the subsurface soil conditions in
shallow hand auger explorations extending to about 4 feet below the ground surface in your project area,
back yard and on the slope.
We understand from our conversations with you that no heavy equipment will be used near the slope and
that the project will consist of placing a cover of relatively pervious topsoil less than 12-inches thick over a
gently (less than 2 percent) sloping area covering about 1,350 square feet. In addition, we understand
that the newly constructed 1 to 2 feet high rockery along the western edge of the property will be
removed prior to topsoil placement. You are also planning to provide drainage improvements (rounded
drain rock), replant the perimeter and maintain current drain pipes to ensure they remain tight -lined to the
current points of positive discharge.
The steep slope is about 10 to 12 feet high and covers an area of 500 to 1000 square feet. The slope
rests at angles between about 22 and 28 degrees (about 40 and 50 percent). The soil on the slope
consists of medium dense silty sand and rounded gravel of glacial till origin consistent with local geology
mapping (Minard, 1983). We did not observe, on or near the area, any indications of; a) groundwater
seepage, b) surface erosion or c) past slope movement or landsliding.
Based on our observations, indications of past slope conditions and the relatively low impact of the
proposed yard improvement project it is our opinion that in terms of slope stability or erosion; 1) there
will be no net change or adverse effects/impacts to the steep slope or adjacent properties and 2) the
current yard improvements can proceed as planned.
Brunette Property Critical Area - Steep Slope
October 27, 2011
LIMITATIONS
J-050-01-11
Our work for this project was performed, and this report prepared, in accordance with our original
contract with you, signed and executed on October 23, 2011. We have completed this work in
accordance with generally accepted professional practices for the nature and conditions of the work done
in the same, or in similar localities, at the time the work was performed. This report is intended for the
exclusive use of you and your contractors and/or consultants for specific application to the referenced
property. We make no other warranty, express or implied.
Subsurface conditions interpreted from observed soil materials and seepage conditions encountered
formed the basis for developing the recommendations in this report. The nature and extent of conditions
may change over time, often vary between observation locations and differences may not become
evident until after the start of site work. If significant variations then appear evident, we should be
consulted to re-evaluate the conclusions and recommendations in this report. It should be noted that
groundwater seepage and any fluctuations in the level of the groundwater are dependent on seasonal
variations in rainfall, temperature, and other climatic factors.
If we may provide any additional information or clarification about this report, please do not hesitate to
contact me on my cell at 425.248,8441 or by message at 425.788.3244.
Sincerely,
ADAMS Resource Consultants Company
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WAYNE C. ADAMS, PE, PENG, EG
President/CEO
wayne@AdamsResource.com