Laserfiche WebLink
i <br /> ADDITIONAL ON-SITE AND OFFSITE SOIL AND GROUNDWATER <br /> INVESTIGATION <br /> AT <br /> QUIK STOP MARKET NO. 121 <br /> 1196 WEST LOUIS AVENUE, MANTECA, CALIFORNIA <br /> Introduction <br /> Compliance & Closure, Inc (CCI) conducted an Additional On-site and Offsite Soil and <br /> Groundwater Investigation at Quik Stop Market No 121, located at 1196 West Louis Avenue in <br /> the City of Manteca, San Joaquin County, California during the month of June 2000 (Figure 1) <br /> The investigation was conducted at the request of the San Joaquin County Public Health <br /> Division, following CCI's Work Plan for Additional On-Site and Offsite Soil and Groundwater <br /> Investigation dated March 27, 2000 <br /> Background Information <br /> On January 20, 2000, Compliance & Closure, Inc (CCI) conducted quarterly monitoring at Quik <br /> Stop Market No 121 Groundwater samples collected from the three on-site wells in January <br /> were reported by the laboratory to contain elevated concentrations of methyl tertiary butyl ether <br /> (MTBE) The three wells were reported to have MTBE concentrations of 59 micrograms per <br /> liter (ug/1) in well MW-2, 21,000 ug/l in well MW-1 and 58,000 ug/l in well MW-3 These <br /> samples were analyzed using EPA Test Method 8020 In order to confirm the MTBE <br /> concentrations, CCI re-sampled the three wells on February 17, 2000 During the re-sampling of <br /> the wells, monitoring well MW-3 had a moderate product odor No odor was noted in the other <br /> two wells The three water samples were analyzed using EPA Test Method 8260 The <br /> laboratory reported all three wells to have detectable concentrations of MTBE Monitoring well <br /> MW-3 was reported to contain the highest MTBE level, at a concentration of 49,000 ug/l <br /> Monitoring wells MW-2 and MW-1 were reported to have detectable concentrations of MTBE, <br /> at 3 ug/l and 11,000 ug/l, respectively <br /> Groundwater measurements taken during the confirmation sample event indicated the water table <br /> • had risen approximately 1 foot since the January sample round The groundwater gradient was <br /> virtually flat, with a slight gradient of 0 001 feet per foot to the northeast The flow direction <br />