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a <br /> Mr. Harlin Knoll <br /> January 13, 2005 <br /> Page 2 of 3 <br /> approximately 45-55 feet below ground surface (bgs), and flow in a northeasterly direction. <br /> PROCEDURES <br /> Resources <br /> Jim Thorpe Oil conducted the excavation. John Lane, a Ground Zero geologist, supervised <br /> excavation activities and sample collection. Mr. Harlin Knoll with San Joaquin County <br /> Environmental Health Department (EHD) conducted a site inspection and observed sampling <br /> activities. Argon Laboratories (DHS Certification#2359) conducted the laboratory analysis. <br /> Soil Excavation and Sampling <br /> Contaminated soil excavation and confirmation sampling occurred on December 28, 2004. <br /> Approximately 175-200 cubic yards of soil was excavated by Thorpe. The dimensions of the <br /> excavation measured approximately 20 feet long (parallel to Waterloo Road), 14 feet wide, and up <br /> to 19 feet deep. Figure 2 depicts the excavated area. <br /> At a depth of approximately 10 feet, petroleum hydrocarbon odors and gray discoloration were <br /> noted. Odors and discoloration extended to approximately 15-16 feet bgs,but had a relatively small <br /> foot print of approximately 10-15 square feet. Excavation proceeded laterally and vertically until <br /> lack of odor and significant photoionization detector (PID) readings indicated that impacted soil <br /> had been removed in all quadrants. The excavated material was stockpiled on and covered by <br /> visqueen plastic pending disposal. Overburden and potentially contaminated soil was segregated <br /> into separate soil piles. Approximately 1/4 to 1/3 of the excavated material was designated as <br /> potentially contaminated. Field notes are included in Attachment A. <br /> Confirmation Soil Sampling <br /> Five confirmation soil samples were collected from the walls and floor of the excavation and two 2- <br /> tube composites from the stockpiled soil. Sampling locations are shown on Figure 2. The samples <br /> collected from the excavation were submitted under chain of custody to Argon Laboratories for <br /> analysis of petroleum hydrocarbon constituents as follows: <br /> 1. Total petroleum hydrocarbons as gasoline(TPHg) and diesel (TPI-1d)by EPA method 8015B; <br /> 2. Benzene,toluene, ethylbenzene, and xylenes (BTEX)by EPA 8021 B; <br /> 3. Oxygenated gasoline additives and lead scavengers including MTBE, ETBE, DIPE, TAME, <br /> TBA, EDB, and 1,2-DCA by EPA 8260B; <br /> 4. Total lead by EPA 7420. <br /> The samples collected from the stockpiled soil were submitted analyzed for TPHg, TPHd, BTEX, <br /> and total lead. <br /> Analytical Results <br /> No confirmation soil samples collected from the excavation contained detectable concentrations <br /> G AGROUNDZEVohnRaylexsum.doc <br />