SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Woodward-Clyde V Ms. Linda Turkatte y San Joaquin County Environmental Health Division August 5, 1996 Page 3 4, B-5, and B-6) were advanced to approximately 30 feet bgs, one soil boring (B-3) was advanced to 51 feet bgs, and one soil boring (B-7) was advanced to 100 feet bgs. Thirty six total of 36 soil samples were collected during the site characterization activities. Concentrations of TPH as diesel were found in soil samples collected from three borings adjacent to and within the north end of the former tank excavation. Concentrations were below the allowable limit �- (100 mg/Kg) set forth in the State of California, Tri-Regional Board Staff Recommendations and the Leaking Underground Fuel Tank (LUFT) Guidelines dated March 1989. Groundwater was encountered in soil boring B-7 at approximately 76.5 feet, and a groundwater sample was collected. No detectable concentrations of TPH as diesel, TPH as gasoline, or benzene, toluene, ethylbenzene, and total xylenes (BTEX) were reported for the groundwater sample. A Preliminary Investigation and Evaluation Report (PIER) describing the site investigation `d activities at the KJAX site was prepared by WCFS and submitted to SJCEHD in August, 1995. �. Based on analytical results from the tank removal program and site characterization activities, it appeared that contaminated soil in excess of 100 mg/Kg existed in the north end of the former UST excavation at an approximate depth of 18 to 22 feet bgs. Furthermore, the polyethylene liner left in the excavation during tank removal activities was potentially allowing surface water to accumulate in the former tank excavation by preventing perculation into deeper soils. �.. FIELD ACTIVITIES Field activities were performed to remove by excavation diesel soil contamination below the north end of the former UST. The soil excavation included the collection of four soil samples from the northern floor and walls of the excavation. In addition, field screening samples were collected to aid the confirmation sampling process. V On April 30 and May 2, 1996, WCFS and their subcontractor, ECOLOGIX of Chico, California, conducted field activities involving excavation to remove diesel contaminated soil, y collect soil samples to confirm the absence of diesel contaminated soil, backfilling of the excavation, and transporting and disposing of contaminated soil removed during excavation ,r activities. The excavation activities were conducted by track-mounted backhoe provided by Manley and Sons Trucking, Inc. of Sacramento, California, under contract with ECOLOGIX of Chico, California. V V V