Laserfiche WebLink
1 <br /> 3) OVEREXCAVATION OF SOILS AND CONFIRMATION SAMPLING <br /> ' Based on the sampling data collected during the tank excavation, an additional phase <br /> of excavation was undertaken In total, 1 ,728 cubic yards of soil were removed from <br /> ' this site A total of 30 confirmation samples were taken at the completion of the <br /> overexcavation work The majority of these samples were "non-detect" for all <br /> constituents One sample did show residual gasoline at a level of 43 ppm, with a <br />' residual benzene concentration of 070 ppm The results of all soil sampling is <br /> provided in Table 2 <br /> ' 4) GROUNDWATER MONITORING <br /> Four monitoring wells currently exist on this site (One of these wells, MW-3A, is a <br /> replacement for well MW-3 which was abandoned during the overexcavation phase <br /> of soil remediation ) A total of 11 quarters of groundwater monitoring have been <br /> completed for this site A gradient analysis for the enure period shows that the <br /> ' shallow water table gradient can shaft up to 90 degrees from the Northeast to the <br /> Northwest During that time frame, monitoring wells MW-1 , MW-2, MW-3A, and <br /> MW-4 have consistently shown non-detect for all parameters MW-3, which was the <br /> ' well located nearest to the tank pit, had shown 240 parts per billion of petroleum <br /> hydrocarbons as gasoline before it was abandoned during the overexcavation project <br /> The replacement well, MW-3A, is located approximately 25 feet to the northeast (and <br /> occasionally downgradient) has shown non-detect for all four quarters of testing <br /> Additional site data, figures, and supporting documentation are included in the <br /> ' remainder of this package <br /> 2 iftelhauser <br /> 216SR00E w9 c o A P O B A T I O r <br />