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INTRODUCTION <br />' At the request of ExxonMobil Refining and Supply Company, ETIC Engineering, Inc has prepared <br /> this quarterly groundwater monitoring report for former Exxon Retail Site 7-3708 This report <br /> presents the results for the most recent groundwater monitoring conducted at the site and summarizes <br />' recent site activities Groundwater monitoring results, well construction details, and a groundwater <br /> monitoring plan are provided in the attached figures and tables Groundwater monitoring protocols, <br /> field data, and analytical results are provided in the attached appendixes <br /> GENERAL SITE INFORMATION <br />' Site name: Former Exxon Retail Site 7--3708 <br /> Site address: 2705 Country Club Boulevard, Stockton, California <br />' Current property owner: Palisades Gas & Wash, Inc <br /> Current site use. Active station operated by U S A Petroleum <br /> Current phase of project Groundwater monitoring, well surveying <br />' Tanks at site. Two underground storage tanks (diesel fuel,unleaded gasohne) <br /> Number of wells. 12 (8 onsite, 4 offsite) <br /> GROUNDWATER MONITORING SUMMARY <br /> Gauging and sampling date 20 November 2001 <br /> Wells gauged and sampled- MW1, MW4-MW10, VEW1 <br /> Wells gauged only. VEW3 <br /> Groundwater flow direction: Northeast <br /> Groundwater gradient: 0 007 <br /> Well screens submerged: MW1, MW4-MW8 <br /> Well screens not submerged: MW9, MW10, VEWI <br /> Liquid-phase hydrocarbons. Not observed or detected <br /> Laboratory: Southern Petroleum Laboratories, Inc , Houston, Texas <br /> Analyses performed• <br /> • Total Petroleum Hydrocarbons as gasoline by modified EPA Method 8015 <br /> • Benzene, toluene, ethylbenzene, and total xylenes by EPA Method 8021B <br /> • Methyl t-butyl ether (MTBE) by EPA Method 8260B <br /> Well VEW3 was dry on 20 November <br /> iAs presented in Figure 1 and Table 2, MTBE was detected in well MW7 at a concentration of 260 <br /> micrograms per liter (gg/L) MTBE was first detected in this well in August 2000, which is more <br />' than six years after Exxon transferred the property to New West Petroleum Well MW7 is located <br /> approximately 60 feet downgradient of the neighboring 7-Eleven facility No 14117, which has had <br /> MTBE detected at concentrations up to 9,800 �tg/L The concentration of MTBE in well MW 1 is <br />' currently at 2,600 µg/L, which is the highest concentration of MTBE detected at the site <br />' G Prolcas1737MMasttrlWP1Q1101 53706tcxt doc 1 <br />