HomeMy WebLinkAbout601342028 Geotech Assessment (2007)6
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February 15, 2007
Larry Laporte
921 Daily Street
Edmonds, WA 98020
Re: Storm water
and other site development r~
Tax Parce1601342015 ~~;r`
Jefferson County, Washington
Dear Mr. Laporte:
It is my understanding that you are pr.
my geology evaluation of your proper
three building areas on the site and pr
those areas including recommendation
storm water management recommend
recommendations for building area 1.
management, septic drain field and of
where you are planning to build: buil~
evaluation of the site.
Storm water
It is my understanding that at least 65°~
underling the areas of the property pro
drained and have enough storage capai
home sites and access roads as long as
access roads are left in a natural state
area 1 and area 2 should readily qualif
water manual.
Building Area 1
Storm water from the access road wits
a manner that will allow sheet flow of
Storm water from the home site in bui
simply allowed to drip off of the roof
discharged within the 15-foot setback
tATUM GROUP
Street, Bellingham, WA 98225
'hone (360) 714-9409
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Jff~EN~UN~UUNir~ii;r~
;eding with site development plans on your property. In
dated November 8, 2005 I concluded that there were
ided you with recommendations for site development of
for storm water management. I inadvertently left out
ons, septic drain field and vegetation management
~r clarity I am providing you a description of storm water
station management recommendations for the two areas
~g area 1 and building area 2 as described in the geology
of the trees on the subject property will be retained. Soils
used for development at building areas 1 and 2 are well-
ty that they should readily infiltrate storm water from the
he native soils outside the immediate home sites and
~d are not compacted or removed. As such building in
for full dispersion of storm water per the Ecology storm
n building area 1 should be handled by grading the road in
the road surface onto the forest floor adjoining the road.
ing area 1 should be directed to a dispersion trench or
nto the ground surface. No storm water should be
om the steep slopes north and south of the building area.
1 '
Building Area 2
Storm water on the access road within
in a manner that will allow sheet flow c
adjoining the road. Storm water from 1
dispersion trench as much away from t:
site consist ofwell-drained sand and g1
infiltrate into the ground. No storm wa
steep shoreline bluff or with 15 feet of
Septic Drain Fields
Septic drain fields for the home sites s:
drain fields are located within the built
building area 1 should be setback at le,
should be setback at least 30 feet from
and at least 15 feet back from the steeX
Vegetation management
At building area 1 no trees should be
slopes north or south of the building ;
limbed or topped to create view corri
removed from the setback or steep sly
building area 2 should be handled by grading the road
water off of the road surface onto the forest floor
home site in building area 2 should be directed to
steep shoreline slope as practical. Because soils on the
gel, water from the dispersion trench should readily
should be discharged within 30 feet of the top of the
steep ravine slope.
ould not cause any slope stability problems as long as the
ing 1 and building 2 slope areas. The septic drain field in
st 15 feet from the steep ravine slopes. The drain field
he top of the steep shoreline bluff slope in building area 2
ravine slope.
~ved from within the 15-foot setback or from the steep
Trees within the setback or on the steep slope may be
Any debris from limbing or topping should be
At building area 2 no trees should be r moved from the steep shoreline slope. Within the 30-foot
setback from the top of the steep shore ine slope at least one tree per 30-foot center should be left
in place. Trees within the setback or o the steep slope may be limbed or topped to create view
corridors. Any debris from limbing or opping should be removed from the setback or steep
slope.
Stratum Group appreciates the o~
questions regarding our reconnai
Sincerely yours,
S tum Group
Dan McShane, M.Sc., L.E.G.
Licensed Engineering Geologist
Stratum Group
lity to be of service to you. Should you have any
please contact our office at (360) 714-9409.
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File: 6.6.OSllB
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