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I 2.3.2 Destruction of MW-A f On February 11, 2011, Ground Zero supervised the destruction ofMW-A located near the former UST A on south side of the Site approximately 100 feet north of Arbor Avenue. ,The well was f destroyed by V&W under the extended EFID well destruction permit number SR#61285. Prior to well destruction the dtb was monitored to insure no obstructions were present. The well was destroyed by pressure grouting with neat cement grout. Neat cement grout was pumped into the well in one slow continuous operation, through a tremie pipe until completely full. 'The well was pressurized to 30 pounds per square inch (psi). The grout level was checked for subsidence and approximately 7 gallons ofout was added to the �' well casing. The upper 3 feet was over-drilled and 1-foot of grout added to the borehole. The soil cuttings were used to backfill and the remaining two feet of the borehole. Unused soil was added to the excavation stockpile. ' 2.4 Soil Excavation On January 19, 2011, the San Joaquin Valley Air Pollution Control District was given notification of the upcoming excavation of contaminated soil, Mr. Vasquez received an extension on the USA utility clearance ticket, PG&E was given notice of the excavation timeline, and Ground Zero submitted a waste profile, laboratory analytical results, and a statistical analysis for lead to Republic Services of Manteca, California. Republic Services accepted the waste profile. Laboratory analytical data are included in Attachment A-2. A copy of the waste profile and statistical lead analysis are included in Attachment B-1. On January 26, 2011, Ground Zero submitted a waste profile and laboratory analytical results to Republic Services for the Bunker pothole samples. Republic Services accepted the waste profile. Laboratory analytical data are included in Attachment A-3. A copy of the waste profile is included in Attachment B-2. i Sidewall soil samples collected from the UST B and Bunker locations are shown iwFigure 5 and Figure 4, respectively. 2.4.1 Soil Excavation—UST B On January 24, 2011, Thorpe began the excavation of the UST B area under the oversight of Mr. Vazquez. A large 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 volume(ppmv)were considered contaminated. ' On January 25, 2011, Thorpe began two phases of work under the oversight of Eric Price of Ground Zero. The first phase was the loading of trucks used to haul soil to Republic Landfill. Two trucks began to make continuous runs to the landfill. Between truck loading operations, Thorpe continued to excavate the UST B area. The excavation pit was opened to a depth of approximately 16 feet G and approximately 1,200 yd3 was removed. The excavation was limited by the presence of an eight inch gas line to the north, a sewer line to the south, a storm drain to the west, and decreased PID readings to the east. Mr. Knoll selected the sample locations based on PID and visual indicators and observed the collection of sidewall samples. -5 - .o I }