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q <br /> tube was removed and replaced by a 1-inch diameter soil vapor sampling tube The top of <br /> the vapor probe was then coupled to a Tedlar® bag within a seated vacuum box using <br /> 1/4"-diameter Teflon® tubing The vacuum box was evacuated with an electric pump, <br /> allowing the sample bag to fill with soil vapor from the sample interval A minimum of one <br /> probe volume (approximately 6 cubic inches per vertical foot of probe) was purged from <br /> the probe before a sample was collected. <br /> The soil vapor samples were then analyzed by a Department of Health Services certified <br /> mobile laboratory However, the soil vapor analysis did not effectively characterize the <br /> petroleum hydrocarbon distribution, therefore soil vapor sampling was discontinued In <br /> order to assess potential offsite migration of petroleum hydrocarbons, soil samples were <br /> collected and analyzed from all borings <br /> On 28 February 1995, discrete soil samples were collected from sampling locations SV4, <br /> SVS, SV6, and SV7 at depths of 16, 21 , 23, 25, and 28 feet bgs as described above <br /> An eighth boring, SV8 was installed and sampled on 1 March 1995 The purpose of this <br /> boring was to evaluate whether the former tank excavation could be a possible petroleum <br /> hydrocarbon source area Discrete soil samples were collected from SV8 at depths of 12, <br /> 14, 16, 18, 20, 22, 23 5, and 25 feet bgs from the boring <br /> Collection of Groundwater Samples <br /> The drive casing and soil core tube were advanced until the water table was reached <br /> Once the water-bearing zone was penetrated, the sample barrel and inner rods were <br /> removed from the borehole A five-foot section of 1-inch-diameter, Schedule 40 PVC <br /> slotted well screen with a slot size of 0 010-inch was installed in the borehole to facilitate <br /> the collection of groundwater samples The drive casing was then pulled up to expose the <br /> slotted interval of PVC well screen to the water-bearing material, and a groundwater grab <br /> sample was collected with a 1 -inch-diameter stainless steel bailer Groundwater grab <br /> samples were collected from borings SV1 through SV7 <br /> • <br /> 9�ab*W40549Vcvort doc 4 940549 00 <br />