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C\TATC <br /> A S S O C I A T E S I N C <br /> groundwater is encountered. While the sampler is advanced, O-ring seals and an expendable drive <br /> point will provide a watertight system to ensure sample integrity. <br /> When the tool has been advanced to the desired depth, extension rods will be sent downhole to <br /> brace the bottom of the sample screen as the tool casing is retracted. When the casing is <br /> retracted, up to 41-inches of screen with slot sizes of 0.004 inches will be.exposed. Teflon tubing <br /> with .a check valve attached to one end will be:inserted down the casing until it is-immersed in <br /> groundwater. Water will :then be pumped through the tubing and to the ground surface by <br /> oscillating the tubing up and down. <br /> Following soil and groundwater sample collection, the-borings will be backfilled with neat cement <br /> grout to the ground surface. All drill cuttings, if any, will be stored on-site in a 5-gallon container <br /> pending laboratory results. <br /> Sample Analysis <br /> Selected samples will be immediately placed on ice and delivered under chain-of-custody <br /> documentation to Sequoia Analytical laboratory, a State-certified:laboratory, for analysis. Soil <br /> samples will be analyzed for total petroleum hydrocarbons as gasoline (TPHg) using EPA Method <br /> 8015 modified; benzene, toluene, ethylbenzene, and xylenes (BTEX) using EPA Method 8020; <br /> oxygenate fuel additives, and total lead. Groundwater samples will be analyzed for TPHg, BTEX, <br /> oxygenate fuel additives using EPA Method 8260, and total lead. <br /> Report Preparation <br /> Upon completion of all field activities, a summary report will be prepared for submittal to <br /> PHS/EHD. ATC will prepare a report that. will include a description of all field activities, <br /> laboratory analytical results, boring logs, and recommendations. <br /> All work described in this workplan will be performed under the direction of a California <br /> Registered Professional Engineer. All work.will be completed in accordance with the Site Safety <br /> Plan{SSP) and Quality Control/Quality Assurance Plan that were submitted in ATC's Workplan <br /> for Subsurface Investigation at Ripon Unified School District, 304 North Acacia Avenue, Ripon, <br /> California, dated March 25, 1998. <br /> wA13099\Mortslw42.doc 3 <br />