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VI f; • Quik Stop Market No 121 CCI Project No 12118-2 Page 3 of-custody s ody documents are attached in Appendix B Discussion Based on the groundwater data obtained during the quarterly sample round, it appears the groundwater continues to be impacted with petroleum hydrocarbons, mainly in the vicinity of Quik Stop Market's fuel tanks on the southeast side of the site, near monitoring wells MW-3, MW-4 and RW-1 (Figures 3) Groundwater samples collected from the perimeter wells MW-2, MW-5 and MW-7 were reported to be virtually free of detectable TPHg and BTEX compound and were reported to have no or relatively low levels of MTBE As previously mentioned, monitoring well MW-8 was found to be dry this quarter Groundwater in the vicinity of monitoring wells MW-3, MW-4 and RW-1 were reported to have the highest contaminant concentrations of TPHg and MTBE at the subject site It appears MTBE has migrated to a lower portion of the aquifer, at a depth of 33 to 43 feet, as detected in the water sample collected at MW-4 and was also detected in the deepest site well (screened from 65 to 75 feet) as reported at MW-6 • Groundwater measurements taken in the in six of the eight monitoring wells screened within the upper shallow aquifer on July 17, 2001 indicated the depth-to-groundwater ranged from approximately 22 00 to 22 90 feet below the top of the well casings The water level in monitoring well MW-4 (screened from 33 to 43 feet) was measured at 22 00 feet below the top of the well casing and monitoring well MW-6 (screened from 65 to 75 feet) was measured at 28 45 feet The water table has fallen approximately 6 feet since the second quarter sample round Groundwater contours in the vicinity of the site monitoring wells indicate the groundwater gradient to range from 0 003 to 0 009 feet per foot to the northeast(Figure 2) In response to San Joaquin County Public Health Services, Environmental Health Division (County) April 23, 2001 letter, CCI submitted a Work Plan in late May for additional Well Installations at and near by the subject site The Work Plan was approved by the County and CCI is in the process of installing two addition deep wells on site and two additional shallow wells, one on-site and one off-site The wells are scheduled to be installed in early August 2001 In addition, CCI recently completed a 24 hour pump test on recovery well RW-I on July 26, 2001 The results of that test will be presented in the up-coming well installation report Quik Stop Markets, Inc will continue to conduct 8-hour dual-phase treatment events at the site • on a monthly basis, using a mobil treatment system (MTS) operated by TRC of Concord,