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ARCADIS Ms. Amaru <br /> June 1, 2010 <br /> ARCADIS will attempt to collect one grab groundwater sample from a newly installed <br /> temporary well point. <br /> The temporary well point location will be cleared to a minimum depth of 5 feet bgs <br /> with a hand auger or air knife/vacuum truck equipment prior to drilling. Once cleared, <br /> the temporary well point will then be installed using a direct push drill rig equipped <br /> with an acetate liner. <br /> The temporary well point(C51-TW-01)will be installed to a total depth of <br /> approximately four feet below encountered groundwater with the intention of <br /> intersecting the groundwater table in the screened interval. The temporary well point <br /> will be installed using pre-packed well materials consisting of five feet of 1-inch <br /> diameter PVC screen with 0.010-inch slotting and surrounding pre-packed sand. The <br /> pre-packed screens and riser will be inserted into the borehole, and the water level <br /> inside the screen will be allowed to equilibrate. <br /> Before sampling, the temporary well point will be purged at a rate of no more than <br /> 500 milliliters per minute(mL/min) using a peristaltic pump until field parameters <br /> have stabilized. After purging activities are complete, a groundwater sample will be <br /> collected through the pump into laboratory provided sample containers. The sample <br /> will be stored on ice in coolers and transported to Calscience under proper chain of <br /> custody procedures. The groundwater sample 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 /> • Naphthalene by USEPA Method 8260B <br /> Concentrations of analytes in groundwater will be compared to State Water <br /> Resources Control Board Water Quality Goals (2010). Following groundwater <br /> sampling, the temporary well point will be removed, and the associated boring will be <br /> tremie grouted from the total depth to ground surface using neat cement. <br /> Investigation Derived Waste <br /> All excavated soil will be placed in roll-off bins. Additional investigation derived waste <br /> (IDW) generated during excavation and sampling activities (including soil cuttings, <br /> Page: <br /> 6/8 <br />