1212 GRAND AVE 2016-01-01 MF Import

March 31, 2008 Mr. }'aul Tessier L&A Job No. 8A027 Pagc 5 prccipitation, surfacc runotT, vcgetation cover, site utilization, etc.. It may dry up completely in the dryer summer months and accumulatc and rise in the wet winter months. The perched groundwater would tlow down-gradient ulong the surface oF the underlying fine sandy silt deposit. It is our opinion thc shallow perchcd groundwater should have little impact on the stability of the steep slope within and lx:low the site, provided vegetation cover on lhe steep slope be preserved and maintaincd and that no concentrated stortnwater tx; discharged uncontrolled within the subject site or onto thc adjacent steep slope. DISCUSSION AND RECOMMENDATIONS LANDSLIDE HAZARD Thc subject project site is most likcly mantled by a thin layer of topsoil undedain by a layer of dense fine to meJium sund about 2 ro 3 fect thick, which is in tum undedain by a hard fine sandy silt deposit. "Phe dense sand and hard silt soil laycrs underlying the subject residence site are of high shcar strength and havic exccllent resistancc against soil movement and slope failure. Although lhe slope bordering the west side of the site stands at an inclination over 40 Fx;rcenl with a vertical rclicf of about 30 to 35 feet, the core of the slope is formed with the dense sand and hard silt soils. '1'heroforc, it would bc unlikely lor deep-scated landslides cutting into these unJerlying compctent soils to occur on thc sitc and, thereforc, thc landslidc hazard for the subject sitc should bc minimal. EROSION HAZARD The surlicial topsoil and the wcak sails in thc root zone drnping the stcep slope flanking the west side of thc subject residence site may be eroded if ihcy arc devoid of ve�etation cover and overly salurated. Progressive crosion may result in shallow, skin-type mudflows on the steep slope. To mitigatc such havard, thc vegetation co��cr outside of construction limits should be prescrved and LIU & ASSOCIATES, INC.