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gound water to the total depth of the boring. Samples will be collected for soil description, field <br /> hydrocarbon vapor screening, and select samples will be submitted to an onsite, state certified, <br /> mobile laboratory for analysis. Refer to Appendix A for general field procedures. <br /> Select soil samples will be analyzed for the following: <br /> • total petroleum hydrocarbons (TPH) using EPA Method 8015 modified for gasoline <br /> (TPH-G) and diesel (TPH-D); <br /> • benzene, toluene, ethylbenzene, and total xylenes (BTEX) using EPA Method 8020 and; <br /> • total lead-using EPA Method 5010. <br /> 4.3 MONITORING WELL CONSTRUCTION <br /> Select borings may be converted to monitoring wells based on mobile laboratory field analyses. <br /> Borings located proximal to existing monitoring wells will not be converted to monitor wells. <br /> Monitoring wells will be constructed using 4-inch-diameter PVC casing with an expected <br /> screened interval from 5 to 20 feet below grade. Well construction details and development <br /> procedures are outlined in Appendix A. <br /> 4.4 ELEVATION SURVEY AND FLUID-LEVEL MONITORING <br /> Well top elevations will be surveyed relative to a city benchmark to the nearest 0.01 foot by a <br /> licensed surveyor. Fluid level monitoring will be combined with regularly scheduled quarterly <br /> ground water monitoring. Fluid levels in the monitoring wells will be measured to obtain data <br /> regarding the depth to ground water and presence of free product, if any. Field procedures are <br /> described in Appendix A. <br /> 4.5 GROUND WATER SAMPLING <br /> Ground water samples will be collected, in accordance with EPA protocol, from both newly <br /> installed, if any, and existing monitoring wells which do not contain free product. <br /> Ground water samples will be analyzed for the following: <br /> • TPH-G and TPH-D using EPA method 8015 modified for gasoline and diesel; <br /> • BTEX using EPA Method 8020. <br /> All laboratory analyses will be performed by a state-certified laboratory. Chain of Custody <br /> protocol will be followed for all samples selected for analysis, thus providing a continuous record <br /> of sample possession prior to actual analysis. <br /> 6 <br />