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. Qulk Stop Market No 121 CCI Project No 12118-3 Page 2 for chemical analysis y The laboratory employed methods approved by the California Regional Water Quality Control Board (CRWQCB) and the EPA The groundwater samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg) and benzene,toluene, ethyl benzene and total xylenes(BTEX), using EPA Test Method 8015 and 8020 Summary of Laboratory Results Groundwater samples collected from the monitoring wells indicated all three wells (MW-1, MW-2 and MW-3)to have detectable TPHg contamination The laboratory reported monitoring well MW- 1 to contain TPHg at 8,600 micrograms per liter (ug/1), MW-2 was reported to contain 200 ug/l TPHg and MW-3 was reported to contain 25,000 ug/l TPHg Monitoring well MW-2 was also reported to have 2 2 ug/l benzene None of the other wells were reported to have detectable concentrations of BTEX compounds The laboratory also reported the three monitoring wells to have detectable MTBE The highest concentrations of MTBE were reported in MW-3 at 58,000 ug/l Monitoring wells MW-1 and MW- 2 were reported to have MTBE at concentrations of 21,000 ug/1 and 59 ug/l, respectively The results of the groundwater analysis are summarized in Table 2 The analytical reports from Entech and chain-of-custody documents are attached in Appendix B Discussion Groundwater measurements taken in the three onsite monitoring wells on January 20, 2000 indicated the depth-to-groundwater ranged from approximately 16 64 to 17 37 feet below the top of the well casings The water table has risen approximately 2 5 feet since the October 1999 sample round Groundwater contours in the vicinity of the three monitoring wells indicate the groundwater flow direction to be toward the south-southeast, at a relatively flat gradient of approximately 0 0007 feet per foot (Figure 2) The groundwater flow direction determined during this sample round is approximately same flow direction reported in COI's October 1999 quarterly monitoring report During sampling of the wells, a moderate petroleum odor was noted in well MW-3 No unusual odors were noted in the other two wells Groundwater samples collected during this quarterly sample round indicate all three wells to contain detectable concentrations of TPHg and MTBE compounds The TPHg and MTBE concentrations in wells MW-1 and MW-3 increased significantly over the last quarter It should be noted that all three wells were reported to be free of MTBE in the October 1999 sample • round To date, monitoring wells MW-1 and MW-3 have been reported to be free of detectable MTBE contamination two of the four quarters since the wells were installed Based on the data collected to date, no trend in the MTBE concentrations has been established in the three monitoring