Laserfiche WebLink
Work Plan for Environmental Investigation May 18 , 1989 <br /> Proposed ARCO Station Woodbridge, Cal-ifornia AGS 39044-1W <br /> Equipment used to sample soil vapor includes a hardened steel <br /> drive-tip, a downhole sampling assembly with vacuum vials, steel <br /> probe rods withanoutside- diameter of 1.75 inches, and a driving <br /> unit. The vapor probe is pushed or driven to the desired depth, <br /> and the sampling assembly containing an evacuated sample vial is <br /> lowered through the hollow center of the probe rod to collect a <br /> sample. After allowing sufficient time for collection, the <br /> sample assembly is withdrawn from the probe rod. The sample vial <br /> is removed from the sampling assembly, and a gas sample is <br /> withdrawn with a syringe and injected into the Photovac 1OS70 , <br /> portable gas chromatograph. This procedure can be repeated at <br /> multiple depth points at each sampling location. <br /> Sampling locations are placed in an appropriate grid pattern: on <br />%W the surface with spacings that allow data to be reasonably <br /> interpreted. Alternatively, locations are selected based on <br /> available information relating to plume migration. Initial <br />%W samples are generally collected at the perimeter of the property; <br /> subsequent locations are chosen based on the results -of earlier <br /> sample analyses. Analytical results are evaluated at the time of <br /> isr collection with computer assistance to allow field interpretation <br /> and decisions for locating subsequent sampling points. This <br /> real-time analytical procedure significantly improves the <br /> - 9 <br /> App/ied GeoSystemS <br />