1136 GRAND AVE A&B 2016-01-01 MF Import

� � April �3, 2007 Mc Scott Andcrson L&A Job No. 6A 126 Pagc 4 permeable soils would perch on the surface of thc tmderlying fresh till soils. This near-surface perched groundwater may dry up completcly in the drycr summer months and accumulate and rise in the wet winter months. The groundwater would flow down-gradient along the sudace of the fresh till soils. This perched gmundwater would seep easily into the underlying advance outwash deposit where it is in contact with the fresh till soils. Groundwater flowing into the advance outwash deposit would perch over a fine sandy to clayey silt deposit underlying ihe advance outwash soil unit. It is o•ir opinion the shallow perched groundwater will not have any significant impact on the stability of the steep slope �vithin and below the site. The vegetation cover on the steep slope, howevcr, should be maintained for erosion protection of the topsoil and weathered till soils mantling the slope. S17'E STA131LITY EVALUATION ANU REMEDIATION Landslidc HazarJ 'fhc site is most likcly underlain by fresh till ;oil� at shallow depth. The fresh till and the underlying advancc outwash soils are of very-high to high shear strength and have excellent resistance against soil movement and slope failum. Although the slope bordering thc west side of the site is of a gradicnt over 40 peroent with a vertical relicf of more than 15 feet, the core of the slope is formcd with thc fresh till and advance outwash soils of high shear strength. Therefore, it would be unlikcly for decp-scated landslides cutting into the underlying competent soils to occur on thc sitc, and thc landslidc hazard lor thc sitc shoufd be minimal. Erasiun Hazard The surlicial topsoil and �vcaihercd till soils draping the steep slope may be eroded if devoid of vegetation cover and overly saturated. Progressive erosion may result in shallow, skin-rype mudllows on thc stcep slope. "Co mitigate such hazard, the vegetation covered on the slope LIU & ASSOCIATES, INC.