ARCHIVED REPORTS_XR0013090 - Laserfiche WebLink

Home Browse Search

Each of the sidewall soil samples was obtained by Thorpe using a backhoe to scope soil from the selected Iocation. The top 4-inches of soil in the backhoe bucket was scraped away and a sample was collected in a 6-inch brass sleeve, the ends covered with Teflon® sheets and capped, uniquely labeled, placed into an ice chest cooled to approximately 4°C for transportation to Argon under chain of custody protocol for analysis. Based on the analytical results, Mr. Knoll requested we excavate along the northwest wall and the southeast wall. On February 1, 2011, Mr. Vasquez supervised the additional excavation. Excavation to the northwest was halted once the gas line was exposed and the excavation to the southeast was halted once the sewer line was exposed. There was an additional 150 yd removed during this expanded excavation. On February 2, 2011 northwest and southeast sidewall samples were collected from the new excavation extents using the protocol above. On February 1, 2011, Mr. Vasquez collected soil for compaction analysis as requested by Ms. Ogrey and delivered the soil to Condor Earth Technologies, Inc. Iocated in Stockton, California. The results are found in the UST B, Hydraulic Oil Tank and Backfill Compaction Testing Report prepared by John Minney, CE dated February 23,2011 and included as Attachment C. 2.4.2 Soil Excavation —Bunker On January 26, 2011, Thorpe began the excavation of the Bunker area under the oversight of Mr. Vazquez. An area was prepared using a visquene cover on the surface. Contaminated soil was stockpiled near the truck route and clean soils were stockpiled further from the excavation area. The soils were separated based on PID readings. All soils reading above 50 parts per million(ppm) were considered contaminated. The excavation activities continued until the backhoe bucket was damaged. Additional excavation work was halted until repairs could be made. However, soil hauling and disposal activities continued. On February 1, 2011, the Bunker excavation continued under the oversight of Mr. Vasquez. On February 2, 2011, Thorpe continued excavating the Bunker area. A liquid was noted at the bottom of the excavation with a sweet odor and appeared to be molasses. The excavation pit was opened to a depth of approximately 13 feet and approximately 500 yd was removed. The excavation was limited by the presence of a fire hydrant and piping to the south, concrete foundation to the east and a railroad spur to the west. Mr. Knoll selected the sample locations based on PID and visual indicators and observed the collection of sidewall and floor samples. Each of the sidewall and floor samples was obtained by Thorpe using a backhoe to scope soil from the selected location. The top 4-inches of soil in the backhoe bucket was scraped away and a sample was collected in a 6-inch brass sleeve, the ends covered with Teflon® sheets and capped, uniquely labeled, placed into an ice chest cooled to approximately 4°C for transportation to Argon under chain of custody protocol for analysis. Based on the analytical results, Mr. Knoll requested we perform additional excavation along the east wall of the Bunker. On February 7, 2011, Mr. Vasquez supervised the additional excavation. There was an additional 115 yd3 removed during this expanded excavation. On February 7, 2011, a sample from east wall of the excavation was collected using the protocol above. -6-