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ARCADIS Ms. Donna DeMartino April 17, 2013 Installation of Soil Borings ARCADIS retained Gregg Drilling & Testing, Inc. (Gregg Drilling), a C-57 licensed drilling subcontractor (license 485165); to advance nine soil borings at the site using a direct push drilling rig (DPT). Prior to drilling the soil borings ARCADIS submitted drilling permits and paid fees to the SJCEHD. Borings SB-1 and SB-6 were advanced to a depth of approximately 5 feet bgs near the subsurface piping that runs from the USTs to the fuel dispensers (see Figure 2). Originally, two soil borings were proposed to be located near the fuel dispensers but based on the proximity of the fuel dispensers to the fuel pipelines, these two soil borings were not required. Soil borings SB-2 through SB-5 were advanced near the existing four USTs that contain diesel fuel, the one UST that contains unleaded gasoline, and the one UST that contains automatic transmission fluid (see Figure 2). Soil borings S13-7 through S13-9 were advanced near the two existing USTs that contain used oil and virgin oil (see Figure 2). The seven soil borings located near the USTs were advanced to approximately 17 feet bgs. Groundwater was not observed in any of the soil borings. The first 5 feet of each boring was advanced using hand auguring equipment to ensure that any subsurface utilities or structures would not be struck during drilling activities. The remainder of each boring was advanced using the DPT rig. Upon completion, each soil boring location was abandoned with Portland cement grout, in accordance with the guidelines provided by the permit issued by SJCDEH. The locations of soil borings SB-2 through SB-5 were adjusted to avoid the pea gravel that is suspected to be part of the backfill for the USTs. The presence of the pea gravel would not allow for the advancement of the soil boring (as the pea gravel would cave into the soil boring). Collection of Soil Samples Soil samples were collected on a continuous basis at each soil boring location using a soil core barrel that is designed to operate with the DPT rig. The soil cores were visually logged in accordance with the unified soil classification system (USCS) and screened in the field using a photoionization detector (PID) to evaluate the presence of hydrocarbons or other volatile organic compounds (VOCs). Soil descriptions and PID readings were recorded on the soil boring logs that are included as Attachment 1. Two depth-discrete soil samples were collected from each soil boring placed near the fuel dispensers and pipelines (soil borings SB-1 and SB-6) and three soil samples were collected from each boring placed near the USTs (soil borings SB-2 though SB-5 and SB-7 through SB-9). The soil samples were submitted for Page: FINAL 2013-04-17-Report SJRTD Bus Depot..doc 4/8