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3.0 FIELD ACTIVITIES <br /> utility lines outside the excavation limits were abandoned in place and capped under <br /> direction and supervision of PG&E representatives. Figure 2 illustrates the locations of <br /> abandoned monitoring well and piezometers, concrete slabs,former utilities, and former <br /> process equipment removed from the site. <br /> 3.5 Northern Perimeter Soil Sampling <br /> Six soil samples were collected from the northern perimeter of the site prior to excavation <br /> activities to further characterize the horizontal and vertical extent of soil containing <br /> petroleum hydrocarbons. These samples were collected with either a hand auger or a <br /> standard backhoe bucket(approximately 2.5 feet wide). <br /> A hand auger was used to advance one soil boring to assess the vertical extent of soil <br /> containing petroleum hydrocarbons along the northern border. Soil samples were collected <br /> by advancing a slide hammer direct push hand tool containing a 2-inch by 6-inch brass <br /> sleeve. Individual samples were collected in brass sleeves,capped with Teflon sheeting and <br /> plastic end caps,labeled,placed in ice,and submitted under chain of custody (COC) to <br /> APPL Laboratories,Inc.for analysis.One of the three soil samples was not submitted based <br /> on low photoionization detector (PID) readings, lack of petroleum hydrocarbons odors, and <br /> visual observations. <br /> Three soil samples were also collected from two test pits located on the northwest perimeter, <br /> one of which was not submitted based on the same criteria outlined above for the hand <br /> auger samples (Table 2).The data from these tests pits were collected to characterize the <br /> horizontal extent of soil containing petroleum hydrocarbons.Three separate test pits were <br /> excavated to a depth of about 5 feet bgs. The northern perimeter (auger and test pit) <br /> sampling results are discussed in Section 3.7.2. <br /> 3.6 Soil Excavation <br /> The goal of the remedial program was to remove soil containing petroleum hydrocarbons <br /> from accessible excavation areas within the constraints of active utilities and nearby <br /> structures (e.g.,railroad embankment, power poles, and remaining equipment).Prior to <br /> excavation,the locations of underground utilities within the excavation limits and <br /> peripheral areas were identified and marked using paint and flag stakes. The planned <br /> combined excavation areas (Areas 1 and 2) comprised an area of approximately 4,100 square <br /> feet and extended to 12 feet bgs (Figure 3). <br /> The excavation limits were constrained to the west by active utilities and a railroad <br /> embankment and in all other directions by active utilities. All excavations performed near or <br /> around utilities were completed under the oversight of PG&E personnel and followed <br /> approved PG&E guidelines and protocols. <br /> During excavation,soil was field-screened for the presence of petroleum hydrocarbons. <br /> Field screening included observation for suspected sources (underground pipelines,sumps, <br /> and other equipment),visual inspection of the soil, and noting the presence of odors <br /> believed to be associated with petroleum hydrocarbons. In addition,a PID was used <br /> periodically to qualitatively measure the presence of volatile organic compounds (VOCs) in <br /> SF01(THORNTON COMPLETION REPORT_6-21-05.DOC) 3.3 <br />