6907 COLUMBIA CT 2016-01-01 MF Import

� � DAVID L. NELSON AND ASSOCIATES, INC. � Consulting Engineering Geology Ir� May 31 , 1991 � Project No. 4791 Page 5 r> loose surficial or fill soils for bearing support. The observed extent of . thi:; loose material should not be a significant risk to the development, as a minor failure would not involve much of the site of down hill properties. ,.. Erosion Hazard Alttiough this type of hazard is not specifically referred to in the new � ordinance, we commonly conduct our evaluations to include erosion hazards. The erosion hazard criteria used for determination of affected areas include " soil type, slope gradient, vegetation cover and g-ound water conditions. The erosion sensitivity is related to veqetative cover and the specific surface � � soils types (group classification) , which are related to the underlying � geologic soil/rock units. The following table is outlines erosion hazard for the on site soils that have been stripped of vegetation. The surface soils found within the site have been classified in accordance with the Soil Conservation Servica (SCS) classification system and have been grouped with i � respect to the corresponding geologic unit. � � � ' Geologic Unit Surface Soil Sensitivity At Slope 0-15� 16-394 >40� � � Outwash Everett Med High High � : � � Glacial Till Alderwood Low Med High � . � Landslide Hazard (Unstable Soils Hazards Areas) An evaluation of landslide hazard was performed for this site. This � ' evaluation includes soil type, underlying stratigraphy, slope qradient, ground 4y water conditions and veqetation cover. Using these criteria, it is our opinion that the site slopes are relatively stable, and presently show no I � � apparent signs of sliding or slumping ground conditions. ■ !4