ARCHIVED REPORTS XR0000598 - Laserfiche WebLink

Home Browse Search

T 139 South Center, Stockton, California April 12, 1994 . Chevron U.S.A. Products Company Page 2 assessment conducted at the site. The document will be reviewed and signed by all Groundwater Technology personnel and subcontractors performing work at the site. Groundwater Technology will conduct a technical review of the pertinent information associated with the site. Permits required by the San Joaquin County Public Health Services, Environmental Health Division (SJCPHS-EHD) pertaining to the drilling of soil borings will be obtained prior to drilling. i TASK 2: SOIL BORINGS/SOIL SAMPLING AND ANALYSES Groundwater Technology will drill four soil borings at the locations shown on Figure 2 using a truck- mounted drill rig equipped with 8-inch-diameter hollow-stem augers. The soil borings will be drilled to a depth of approximately 45 feet below ground surface (BGS) or until encountering groundwater. i Soil samples will be collected at 5-foot intervals using a split-spoon sampler lined with 2-inch- diameter by 6-inch-long brass sample tubes. The hollow-stem augers will be steam cleaned before i drilling, and sampling equipment will be cleaned between each sampling interval. Each soil sample will be screened for hydrocarbon vapors using a portable photoionization detector (PID). Soils encountered during drilling will be logged using the Unified Soil Classification System by a • Groundwater Technology field geologist, working under the supervision of a California registered geologist. One sample tube from each sampling interval will be sealed with aluminum foil, capped, taped, labeled, and placed on ice in an insulated container pending laboratory analysis. All soil generated through drilling will be stored on and covered with plastic sheeting on Chevron property pending characterization and disposal. Based on field observations, selected soil samples from each soil boring will be analyzed by a State-certified laboratory for BTEX using EPA method 8020, and for TPH-G using EPA method modified 8015. Upon completion of each boring to the desired depth, it will be backfilled with a portiand cement/bentonite grout. The grout will be placed in the borehole using a tremie pipe. TASK 3: REPORT PREPARATION Groundwater Technology will prepare an assessment report summarizing the data collected under the scope of work detailed above. The report will document the methods and results of the assessment, summarize laboratory analytical results, and include appropriate maps. ` .GROUNDWATER TECHNOLOGY