ARCHIVED REPORTS XR0011228 - Laserfiche WebLink

Home Browse Search

r July 27,2001 Project No 2005-2050-01 page 3 • Advanced three soil borings to depths of 110 to 115 feet bgs using hollow stem augers, completing the borings as monitoring wells MW-10 through MW-12, • Developed and sampled the groundwater monitoring wells, and • Surveyed the elevations of the 12 monitoring wells, the locations of CPT borings, and pertinent site features Prior to initiating field activities, permits to advance the soil borings were obtained from San Joaquin County PHS/EHD Stratus obtained access agreements to work at 2040 East Fremont Street, 2050 East Fremont Street, and 2075 East Fremont Street In addition a revocable encroachment permit was obtained from the City of Stockton Soil borings were marked and Underground Service Alert (USA) was contacted 48 hours prior to work activities San Joaquin County PHS/EFID was subsequently notified of the work schedule Between February 5 and March 12, 2001 a Stratus geologist observed Gregg Drilling & Testing, Inc of Martinez, California advance the CPT soil bonngs and drill/install the groundwater monitoring wells All work was performed under the direction of a California Registered Geologist The locations of the CPT borings and monitoring wells are shown on Figure 2 CPT soil borings were advanced to obtain a continuous log of the subsurface lithology The logs of the CPT bonngs were subsequently used to evaluate . soil and groundwater sampling intervals The depth of the CPT borings was modified from the work plan because a soil sample collected at 138 feet bgs at CPT-1 was impacted with petroleum hydrocarbons The other CPT borings were subsequently advanced to a minimum depth of 140 feet bgs An additional CPT boring (CPT-10) was added because the vertical extent of petroleum hydrocarbon impact to soil and groundwater was not fully assessed at boring CPT-1 Bonng CPT-10 was advanced southeast (downgradient) of CPT-1 (Figure 2) The location of boring CPT-13 was modified from the location proposed in the work plan due to the location of underground utilities CPT_io LsSfi a1e�.». CPT TESTING AND DIRECT PUSH SAMPLING ff" ger 4 The CPT method consists of advancing a cone-tipped cylindrical probe (1 7 inches in diameter) into the ground while simultaneously measuring the resistance to penetration The CPT method determines soil lithology by comparing the force (cone bearing pressure) required to advance the probe (Qt) to the friction ratio (Rf) [(Rf equals sleeve friction (FS) divided by the probe tip load times the penetration pore pressure (Ud)] A graphical diagram illustrating CPT interpretations of soil types is included in Appendix A Computer generated CPT logs were plotted in the field, providing the field representative a graphical log of subsurface soil lithology The CPT test data report, which includes logs of all CPT data, graphical geologic logs, and additional information on the CPT technique is presented in Appendix A CPT tests were performed in accordance with American Society of Testing and Matenals (ASTM) Method D3441 C 1Project Files\Apache PlasUcs\Reports\Apache Soil&GW 072001A doc