Laserfiche WebLink
Veco Design Studio <br />June 3, 2024 <br />Project 10112-04 <br />Page 4 <br /> <br />3.3.2 Local Geologic Setting <br /> <br /> The project site area is underlain by young Quarternary-aged alluvium. <br /> <br />3.3.3 Subsurface Conditions <br /> <br />a) A shallow pit was excavated near the western edge of the residence <br />within proximity of the proposed ADU. The exposed material was <br />found to generally consist of moist sandy SILT to a depth of 24 <br />inches below ground surface. The soils existing below 12 inches <br />below ground surface were observed/probed to be moist and <br />medium dense. <br /> <br />b) No seepage or groundwater was noted to appear within the existing <br />excavation. <br /> <br />c) Historical groundwater monitoring well data within the site area <br />was researched on the California Department of Water Resources <br />online water data library. The closest groundwater monitoring <br />well with the most recent data is shown to be located <br />approximately 100 feet east of the project site. Several <br />measurements have been obtained and recorded from the well <br />during the period from 1972 to 1982. Groundwater level data <br />collected from this well indicates that the groundwater levels have <br />ranged from as deep as 50.0 feet below ground surface (October <br />1971) to as shallow as 33.0 feet below ground surface (September <br />1982). <br /> <br />d) The historically shallowest depth to ground water at the project <br />site, per California Geological Survey Seismic Hazard Zone Report <br />03, is indicated to be approximately 5 feet below natural ground <br />surface. <br /> <br />3.4 Potential Seismic Hazards <br /> <br />3.4.1 General <br /> <br />a) The property is located in the general proximity of several active <br />and potentially active faults, which are typical for sites in the <br />Southern California region. Earthquakes occurring on active faults <br />within a 70-mile radius are capable of generating ground shaking <br />of engineering significance to the proposed construction. <br /> <br /> <br />