HomeMy WebLinkAboutGeotechnical Site Assessment - GEO General - 7/20/2015 ceot ° Ewv rnwvLewtA°Drui vae °><e170(wa
July 20.2015
Grant Callin
21631 NE 24"'Street
Sammamish,Washington 98074
Reference: Geotechnical Site Assessment for Property Located on NE North Shore Road(Parcel
.3 -50-0095 1),Tahuya,Washington
Dear Mr.Callin,
Envirotech Engineering has completed a site assessment of the general soils and surface conditions for the
referenced property.This site assessment was partially based on a site visit performed on July 13,2015 in
order to evaluate geological hazards,and identify the feasibility of constructing a single family residential
structure on the referenced property.
The referenced property is located within an area of geologic concern as delineated by the Mason County
Resource Ordinance. It appears that due to slopes exceeding 40%, that Mason County will require a
geotechnical report in conjunction with a permit for any new development planned for the property.
Significant landslide indicators were not present at the time of our site visit. Although unlikely,there is a
potential of landslides of near surface soils. Due to the possibility of debris flow, the building location
should have a minimum setback from the ascending slope toe equal to 'h the slope height.The toe of the
ascending slope is delineated as a grade break in which the ascending slope is in excess of 40%.
The required setbacks may be reduced, if necessary.The setback for descending slopes may be decreased
by utilizing a catchment wall between the building and ascending slope.Alternatively,_the catchment wall
may be incorporated into the structure.This could include the foundation wall extending anywhere from 2
feet to 5 feet above ground along the upslope side of the structure.
Thank you for the opportunity to work on this project. If you have any questions or need any further
assistance,please contact Michael Staten at 360-275-9374.
Sincerely,
Envirotech Engineering
X,CLYDE
a'Tsy� tj
C
?_43M5 .o .�-
G.�y, £otsTV
Ss�o�.at_Ew
Michael Staten,P.E.
Project Director
PO SC%C R24
beifaC•r,Wasl,i,wgtov°18523
Dom:
CeU: 36G-G8q-t 04.5
ewv�r�tech�geotecM:n.i.cati.wfe.cows.