Laserfiche WebLink
28 May 1991 <br /> GeoAudit CV 43C4 . 1. 1 - Work Plan for Vacuum Extraction <br /> Page 2 of 10 <br /> By installing the unit in a well-insulated operation area and by <br /> ' extending the stack up to 20 feet high, the noise problem is <br /> significantly minimized. The operation and installation procedures <br /> are detailed in Sections 3 and 9 . 1. <br /> ' Based upon the above mentioned criteria, we believe that this <br /> proposed cleanup method represents the most effective method, both <br /> in cost and in operation. <br /> 1. 2 . REGIONAL GEOLOGICAL SETTING AND HYDROGEOLOGY <br /> ' The site is located in a flat, residential/commercial area (Figure <br /> 1 - Location Map, 7 . 5 Minute Stockton West Quadrangle, USGS <br /> ' Topographic Series, 1981) . <br /> Physiographically, the site is located in the northeastern portion <br /> of San Joaquin Valley approximately 25 miles west of the Sierra <br /> Nevada foothills. The foothills consist of highly sheared and <br /> folded Mesozoic and Paleozoic crystalline rocks that are <br /> unconformably overlain by Cretaceous to Quaternary sedimentary and <br />' volcanic deposits. These strata dip a few degrees southwestward and <br /> underlie the site. Tertiary rocks, which are moderately well <br /> exposed east of the site, include the Eocene Ione Formation, the <br /> Oligocene-Miocene Valley Springs Formation and the Pliocene Mehrten <br />' Formation. <br /> Late Pliocene and Quaternary deposits are mostly arkosic sand, silt <br />' and clay mapped as non-marine deposits in the Geologic Map of <br /> California. These most recent deposits probably represent run-off <br /> from the surrounding highlands and local fluvial deposits . The <br />' Turlock Lake, the Riverbank and the Modesto Formations belong to <br /> this group. The Modesto Formation of Late Pleistocene is the <br /> youngest and occurs at the surface in the Stockton area. This <br /> formation is approximately 100 feet thick here but thickens <br />' westward toward the axis of the San Joaquin Valley (The geological <br /> data were obtained from the San Jose Sheet - Geologic Map of <br /> California, 1966, California Divisions of Mines and Geology and <br />' from United States Geological Survey Open-File Report 77-748 , <br /> 1977) . <br /> The site lies within the limits of San Joaquin Valley Water Basin <br /> (Basin No. 5-22) of the San Joaquin Basin Hydrologic Study Area, <br /> which is drained primarily by the San Joaquin River. Two aquifers <br /> are recognized to exist at the site; a deep and a shallow aquifer. <br />' The deeper aquifer contains connate water occurring in the semi- <br /> consolidated to consolidated Mehrten and Valley Spring Formations. <br />