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ARCADIS Ms Amaru <br /> June 1, 2010 <br /> If stained soil or elevated photoionization detector(PID) readings are present within <br /> the proposed excavation areas, the excavation will be extended one additional foot if <br /> possible. Soil excavation at or below the groundwater table is not planned. <br /> Excavated soil will be loaded into roll-off bins prior to disposal. <br /> Post-excavation confirmation soil samples will be collected directly from the <br /> excavation sidewalls and bottom using a properly decontaminated hand auger or <br /> trowel or, if conditions warrant, collected from the bucket of earthmoving equipment. <br /> One sidewall confirmation soil sample will be collected from the approximate <br /> midpoint of each of the excavation sidewalls at depth intervals that correspond to <br /> areas exhibiting field indications of potential impact and/or at depths where previous <br /> samples indicated impacts were present. One confirmation sample will also be <br /> collected from the bottom of each excavation area. A maximum of five confirmation <br /> samples will be collected from the excavation area around C51-SB2 and C51-SB13, <br /> and a maximum of four confirmation samples will be collected from the excavation <br /> area around C51-SB4. Sample locations and the number of samples collected may <br /> be adjusted in the field if necessary. <br /> The confirmation soil samples will be sealed, labeled, and placed in an ice-chilled <br /> cooler for delivery to Calscience Environmental Laboratories (Calscience), a <br /> California Department of Public Health-certified analytical laboratory. The soil <br /> samples will be analyzed for the following: <br /> • TPH as gasoline by USEPA Method 8015B (M) <br /> • TPH as diesel by USEPA Method 8015B (M) <br /> • TPH as motor oil by USEPA Method 8015B (M) <br /> • Moisture content by ASTM Method D-2216 <br /> ARCADIS will mark excavation boundaries using a handheld global positioning <br /> system (GPS). Pending the results of confirmation sampling, the excavation will be <br /> backfilled to existing grade with clean fill. <br /> Proposed Groundwater Sampling <br /> As detailed above, groundwater sampling was proposed in the Site Sampling and <br /> Soil Removal Work Plan; however, no groundwater samples were collected during <br /> previous field activities. Therefore, during the proposed excavation field activities, <br /> Page: <br /> 5/8 <br />