ARCHIVED REPORTS_XR0007142 - Laserfiche WebLink

Home Browse Search

The groundwater in the vicinity of the site is unconfined Groundwater elevation at the site varies from a wet year high of 25 feet bgs to at least 50 feet bgs during the previous drought period Groundwater flow direction at the site has varied from north to south through the northeast and southeast quadrants SAMPLE POINT SITING DETERMINATION A review of previous reports associated with this site and the Advanced GeoEnvironmental, Inc (AGE) reports "Cone Penetrometer Testing Site Investigation Report, Fernando's Place, dated December 2001 and "Quarterly Report — Fourth Quarter 2002, Fernando's Place, dated September 2003 indicates that first groundwater is located between 23 and 30 feet below the surface, and flows to the east, southeast AGE's investigation of the neighboring site (Fernando's) show similar depth to first ground water and also depicts five Hydrogeologic Units Hydrogeologic Unit 1 contains three sub- units, the upper zone (25 to 52 feet below the surface), the middle zone (48 to 75 feet below the surface) and the lower zone (60 to 90 feet below the surface) Hydrogeologic Unit 2 is defined between 112 to 125 feet below the surface, Hydrogeologic Unit 3 is defined between 140 to 160 feet below the surface, Hydrogeologic Unit 4 is defined between 160 to 170 feet below the surface and Hydrogeologic Unit 5 is defined between 190 to 199 feet below the surface . To assess current subsurface soil and groundwater conditions beneath ARC Pump, five direct push core borings were performed to depths between 40 and 51 feet (T2-1, T2-2, T2-3, T2-4, T2-5 and T3-4), near the former underground storage tank area Three core borings were performed to depths between 82 and 94 feet (T3-1, T3-2 and T3-3) As borings were advanced discrete groundwater samples were obtained at the first water bearing zone by lowering 1/2 inch screened PVC and a mini bailer The "hydropunch" method was used for deeper water bearing zones The current investigation obtained soil core samples to a maximum depth of 92 feet below the surface at Arc Pump Lithologic cross sections were developed from plotting the cores, see Figures 14, 15, 16 and 17 The first water bearing zone Ices within a channel sand that is located between 15 and 35 feet below the surface A sequence of interbedded sands and clayey silts harbor the second water bearing sands, located between 45 and 92 feet Review of AGE's investigation and cross sections show similar water bearing units DRILLING AND SAMPLING METHODS AND PROCEDURES DIRECT P USH A limited access direct push rig was used The dead weight of the rig is used to push the drive rod which is attached to a core barrel with acrylic core sleeves using a hydraulic ram Soil cores are obtained and examined for lithology, the presence of soil 4 ARC Pump, ASSESSMENT 2006