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21 March 2006 <br /> AGE-NC Project No 97-0290 <br />' Page 6 of 15 <br />' a data logger to record drawdown data from the wells The depth to ground water was also measured <br /> in selected wells throughout the pump test using a Solinst water level meter The pumping rate was <br /> determined by measuring the time required to fill a 5-gallon bucket from the pumping discharge <br />' hose Afer 24 minutes, the pumping rate was increased The pumping rate was again increased to <br /> maximum output after approximately 3 hours of pumping Approximately 1,450 gallons of water <br /> were removed from VW-1C during the 6-hour and 40-minute test On 19 July 1999, the above <br />' procedures were repeated A constant flow was maintained for approximately 45 minutes to record <br /> initial drawdown The pumping rate was calculated to be approximately 3 9 gallons per minute <br /> (gpm)during the 19 June 1999 test A drawdown of approximately 1 4 feet was observed in VW-1 C <br />' after 45 minutes of pumping <br /> The transmissivity for well VW-IC was calculated to be 6,240 gal/day-ft A well efficiency of <br />' 47 7 percent was then calculated for VW-1C, making the calculated aquifer transmissivity <br /> 13,096 gal/day-ft Transmissivities of 13,116 gal/day-ft, 22,383 gal/day-ft, and 14,420 gal/day-ft <br /> were calculated for MW-2, SW-1, and SW-2, respectively The aquifer transmissivity calculated <br />' from VW-1C and the transmissivities calculated from MW-2 and SW-2, each located 10 feet from <br /> VW-1C, are very similar The transmissivity calculated for SW-1, located 20 feet from VW-1C, is <br /> significantly higher than wells VW-IC, MW-2, and SW-2 The storativity was calculated to range <br /> from 5 03 x 10"3 to 6 55 x 106 A radius of influence from 13 feet to 24 feet was calculated using the <br /> 1-minute data, a radius of influence of 16 feet to 31 feet was calculated using the 10-minute data, <br />' a radius of influence of 20 feet to 40 feet was calculated using the 100-minute data Measurable <br /> drawdown was observed in wells MW-1 and MW-4, located approximately 60 feet and 75 feet, <br /> respectively, from VW-I C Wells SW-I and SW-2 are screened at a different interval than the <br />' extraction well, VW-1C, and may account for some variations in the observed induced drawdown <br />' 6.0. REMEDIATION OF IMPACTED SOIL AND GROUND WATER <br /> A Corrective Action Plan (Corrective Action Plan -June 1999, dated 10 June 1999), prepared by <br /> AGE, recommended soil vapor extraction and air sparging for remediation of the site The San <br /> Joaquin Environmental Health Department (EHD) approved the Corrective Action Cost Estimate, <br /> dated 09 September 1999, by letter dated 09 September 1999 The remediation was conducted in <br /> accordance with the Remedial Action Work Plan, dated 31 January 2000 and approved by permit <br /> dated February 2000 <br /> The highest concentrations of petroleum hydrocarbons in soil were detected near the southeast <br /> portion of the site at depth intervals of 15 feet to 25 feet bsg and 35 feet to 50 feet bsg in borings P3, <br /> MW2,and SW l Lower concentrations of hydrocarbons were detected in borings B4,MW4,and B6 <br /> at depths of 35 feet to 60 feet bsg,corresponding to historical ground water levels Impacted soil at <br /> depth appeared to be concentrated in a silt and clay interval between approximately 40 feet and <br /> Advanced CeoEnvironmentai,Inc <br />