ARCHIVED REPORTS_XR0007697 - Laserfiche WebLink

Home Browse Search

' 31 March 2004 AGE-NC Project No 03-1077 ' Page 2 of 7 ' Soil borings for sounding were as follows • CPT-2 was established in the vicinity of the north-bound left travel lane of Wilson Way, west of monitoring well MW-3, to a depth of 109 feet below surface grade (bsg) The location for ' CPT-2 was dictated by previously discussed traffic control logistics at the site • CPT-3 was established in the vicinity of the southern property line, south of TB-7 and east of ' TB-10, to a depth of 120 feet bsg This boring location was chosen by Thnfty Oil Co as described in the approved workplan • CPT-4 was established in the vicinity of MW-3 (the suspected source location)to a depth of 109 ' feet bsg This boring location was requested by SJCEHD in the approval letter for the workplan, in order to determine linear depth of impacted soil and groundwater ' At each CPT boring location, sensors in the piezocone continuously measured tip resistance, sleeve friction and pore water pressure(physical soil parameters)as the piezocone was advanced to total depth ' (see Appendix A), the soil parameters were stored in an onboard computer The onboard Hogentogler Co computer program subsequently analyzed the soil parameters by comparing them to laboratory experimental results, and interpreted general lithology types as described in CPT Soil Behavior Classification System (Robertson, P K, Campanella, R G, Gillespie, D , and Greig, J , 1986), the computer-interpreted lithologies were displayed on a continuous CPT boring log Soil-bonng locations are depicted in Figure 2, the CPT interpretive logs are presented in Appendix A Rinseate generated during drilling activities was containenzed in properly labeled DOT-approved 55- gallon drums and was stored on-site in an area lacking public access After data collection,the CPT soil Iborings were backfilled over their entire depth range with a bentonite/portland cement grout mix ' 2 2. SOIL AND GROUNDWATER SAMPLE COLLECTION Grab groundwater and soil samples were collected in two soil borings advanced immediately adjacent to the initial CPT boring in accordance with standard environmental industry practices The samples were collected utilizing the 25-ton truck-mounted CPT drill rig equipped with 1 75-inch diameter hollow-stem rods fitted with a HydroPunch groundwater or a piston soil sampling assembly,which was I pushed to specified sampling depths in each soil boring, diagrams of the sampling assemblies are illustrated in Appendix A 2 2 1 Soil Sample Collection IDiscrete soil samples were collected from the soil borings at 10-foot intervals between 10 feet and 70 . feet bsg, at 5-foot intervals between 70 to 90 feet bsg, and at 10-foot intervals from 90 feet bsg to the total depth of the borings Soil samples were collected using a steel-tipped soil sampler which was Advanced GeoEnvironmental,Inc I