ARCHIVED REPORTS XR0006976 - Laserfiche WebLink

Home Browse Search

• Town and Country Contractors removed two 20,000-gallon and one 12,000-gallon USTs (Tanks T-5, T-6, and T-8) and associated dispenser island in March 1999, and excavated the dispenser area in April 1999 Pinnacle Environmental Solutions (Pinnacle) collected compliance soil samples during UST, fuel dispenser, and product line removal activities in March and April 1999 • Stratus advanced boring B-17 in September 1999 • Stratus properly destroyed monitoring wells MW-3 through MW-5 and MW-9 through MW-12 in February 2000 • Stratus collected compliance soil samples during the removal of a waste oil UST (Tank T-4) by Savidge Construction in October 2000 3.2 2006 Site Characterization Activities ' The objectives of the site assessment activities were to further characterize the geologic and hydrogeologic conditions beneath the site, and to characterize the lateral and vertical extent of 1,2-DCA impact to groundwater To accomplish these objectives, Stratus advanced nine (9) tCPT borings (CPT-1 through CPT-9) to depths ranging from approximately 85 to 150 feet bgs at the locations depicted on Figure 2 Depth-discrete groundwater samples were collected from separate borings situated immediately adjacent to each CPT boring location ' Prior to implementation of field activities, a drilling permit was obtained from SJCEHD Drilling locations were marked 48 hours prior to fieldwork Underground Service Alert, ' SJCEHD, and Teichert were notified 48 hours prior to beginning work activities Field practices and procedures utilized during this investigation are described in Appendix B All work was conducted under the direct supervision of a State of California Professional Geologist A copy of ' the drilling permit is provided in Appendix C 3 2 1 Field Activities A Stratus geologist was on-site to oversee Fugro Geosciences, Inc (Fugro) of Santa Fe Springs, California (C57-742013) complete the CPT testing and direct push sampling between January 23 t and 29, 2006 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 estimates soil lithology by comparing the force (cone bearing pressure) ' required to advance the probe (QJ to the friction ratio (FR) [(FR equals sleeve friction (FS) divided by the probe tip load times the penetration pore pressure (UdA Computer generated CPT logs were plotted in the field to provide a graphical log of subsurface soil lithology A report prepared by Fugro, which includes logs of all CPT data and graphical geologic logs, is presented in Appendix D CPT tests were performed in accordance with American Society of Testing and Materials (ASTM) Method D3441 The approximate locations of borings CPT-1 ' through CPT-9 are included on Figure 2 Following advancement to total depth, each borehole was pressure grouted to surface grade with high-solids bentonite slurry Groundwater samMples were collected from a separate boring adjacent to the CPT boring, using the HydropunchT technique Two-inch diameter steel rods pushed the HydropunchTM sampler • to the desired sampling depth The rods were then retracted to expose a 3-foot long perforated ' KITe,chc,1Stockton-I031Report,1scm 04-2006 doc Page 6 STRATUS