Laserfiche WebLink
WELLS FARGO BANK PROPERTY <br /> 49 SOUTH WILSON WAY <br /> STOCKTON, CALIFORNIA <br /> DECEMBER 28, 1998 <br /> Page 3 <br /> September 1997, Additional Phase II Subsurface Investigation and <br /> Quarterly Monitoring <br /> Building Analytics completed an additional Phase II Subsurface Investigation and Quarterly <br /> Groundwater Monitoring in September 1997, which included the installation of one <br /> additional 80-foot deep soil boring and groundwater monitoring well (in the area of well <br /> MW-2), and the monitoring and sampling of the one new and three existing groundwater <br /> monitoring wells. The following is a summary of the findings from the investigation and <br /> monitoring event: in <br /> • The groundwater flow direction was measured to be to the northeast with a <br /> hydraulic gradient of 0.0055; <br /> � • TPH-g up to 75 ppm were reported in the soil samples collected from Boring B4 at <br /> depths between 35 and 45 feet bgs; <br /> 0 Benzene up to 0.057 ppm was reported in the soil samples collected from Boring <br /> B4 at depths between 35 and 45 feet bgs; <br /> • TPH-g and BTEX were not reported in groundwater samples collected from <br /> monitoring wells MW-1 or MW-3; <br /> • TPH-g was reported in the groundwater samples collected from MW-2 and MW-4 <br /> at concentrations of up to 3.4 ppm; <br /> • TPH (Carbon Range C8-C44+) was also reported in the groundwater sample <br /> collected from MW-2, at a concentration of 2.3 ppm; <br /> b. • Benzene was reported in the groundwater samples collected from MW-2 and MW-4 <br /> at concentrations of 1.2 � <br /> nand 11 pKM, respectively; and <br /> - • MTBE was not reported in the soil or groundwater samples collected. <br /> May 1997, Workplan - Additional Phase II Subsurface Investigation <br /> 4th <br /> Subsequent to the September 1997 Additional Phase II Subsurface Investigation, the <br /> SJCEHD requested that an additional soil boring be installed down-gradient from <br /> -� groundwater monitoring wells MW-2 and MW-4. Building Analytics submitted a Work <br /> Plan for the Additional Soil Boring and Quarterly Groundwater Monitoring to the SJCEHD <br /> on May 4, 1997, which was approved with comments on January 20, 1998. Final <br /> ,.. approval was issued after the SJCEHD received reports from adjacent LUST sites on July <br /> 20, 1998. <br /> October 1998, Additional Phase II Subsurface Investigation and Quarterly <br /> Monitoring <br /> In August 1998, Building Analytics completed an additional Phase II Subsurface <br /> Investigation and Quarterly Groundwater Monitoring, which included the installation of <br />