Laserfiche WebLink
REG 603 UPDATE-9 9/14/92 <br /> • <br /> E <br /> 1 . 0 INTRODUCTION <br /> This update, STATUS UPDATE #9 , represents data collected at the <br /> site for the months of July and August, 1992 . During this time a <br /> thermal oxidation unit has been operating and vapor extraction for <br /> soil and ground water remediation is taking place. Also <br /> presented in this report xs the offsite monitor well workplan - <br /> July 6 , 1992 . <br /> 1 . 1 LOCATION <br /> The station is located at 6425 Pacific Avenue at the intersection <br /> of Douglas Road, in San Joaquin County , Stockton, California. The <br /> site lies in Section 21 ; T2N; R6E; MDB&M at approximately 12 feet <br /> above mean sea level (MSL ) (see Figures 1 , 2 , and 3 ) . The parcel <br /> is # 31 and can be located in Assessor's Book 97 on page 41 ( 97- <br /> 041-31 ) . <br /> 1 . 2 PREVIOUS REPORT (UPDATE STATUS REPORT #8 , June, 1992 <br /> Quarterly Report) . <br /> The following are the conclusions and recommendations of the <br />. UPDATE STATUS REPORT #8 : <br /> 4 . 0 DISCUSSION AND CONCLUSIONS <br /> As stated in earlier reports , the soil is contaminated with <br /> gasoline range hydrocarbons beneath the tank field (MW10 ) and <br /> along the capillary fringe of the ground water , (MW1 , MW2 , MW3 and <br /> MW10 ) . Ground water beneath the site contains the dissolved <br /> constituents of gasoline range hydrocarbons and has spread out <br /> from beneath the site to the north (MW-6 ) , to the south (MW-7 ) , to <br /> the west (MW-9 ) , and to the east (MW-8 ) . The latest ground water <br /> samplings , March 10 and June 18 , 1992 , have shown a decline in the <br /> lateral extent of the plume, see Figures 5A ( 12-17-91 ) and 5B (6- <br /> 18-92 ) . <br /> Vapor extraction commenced on October 17 , 1991 and until March 18 , <br /> 1992 has operated for 2611 hours out of a possible 3674 hours for <br /> a 71% run time , destroying 16,156 pounds of gasoline range <br /> hydrocarbons . Since the last status report, February 3 , 1992 , a <br /> total of 4884 pounds of gasoline range hydrocarbons have been <br /> removed/destroyed. DCE, TCE and PCE screening indicates that <br /> these compounds are not present in the vapor stream at this site. <br /> i <br /> Ground water elevation measurements show that the ground water is <br /> being mounded at the lower K value wells MW3 and MW10 , while the <br />• overall flow direction is to the northeast and southeast . <br /> PAGE 1 <br />