SITE INFORMATION AND CORRESPONDENCE

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t i A temporary groundwater monitoring well of unknown depth and construction was installed on the site to evaluate the groundwater quality and to provide additional soil quality information. Groundwater is present beneath the site at a depth of approximately 50 feet below ground surface with a southerly flow direction. Three groundwater monitoring wells were installed during November 1991. The wells, SRKMW-1, SRKMW-2 and SRKMW-3 were completed to depths of 65, 60 and 59 feet respectively. Selected soil samples were analyzed for BTX TPH and total lead. A number of quarterly groundwater monitoring events were conducted commencing on 11/25/91 and continuing to the present. Samples have typically been analyzed for BTEX, TPH and total lead. Test results are provided. Discussion of Results Park reviewed the water level data between November 1991 and November 1993, and found a consistent direction of flow in a southerly direction using the SRK data. We do not understand how SRK arrived at a northeasterly flow direction using the April 1992 data. The soil analytical test results suggest that most of the TPH and BTEX were removed during the tank removal and over excavation of the tank pit. TPH values at 17, 25 and 30 feet below ground surface in the vicinity of the abandoned temporary well TW-1 confirm this. Total lead results in the soils have been non detect at detection limits of 7.5 and 10 mg/kg. The groundwater analytical test results for TPH and BTEX confirm that little or no gasoline has reached the groundwater. There have been a few minor BTEX levels reported that were at or just above detection limits. Several of the findings were not confirmed by the duplicate analyses that were run on the samples. None of the findings appear to require additional assessment and/or remediation. However, there have been some significant levels of total lead reported in waters from all three monitoring wells. The lead levels have ranged from non detect to as high as 260 pg/l with no apparent pattern for occurrence. The lead levels were higher than we have ever seen related to a release of leaded gasoline without the lead still being in an organic form still in the free product. Park reviewed the sampling field sheets,the chain of custody documents,the analytical laboratory reports, and discussed the sampling protocol used to purge and sample the wells with Messrs. Rob Gwilym and David Schwieger of SRK to see if a possible reason for the disparity in test results could be found. The field sheets indicate that all samples collected were cloudy or muddy. The chain of custody and laboratory check in sheets indicated that with one exception, all samples were acidified without filtering to preserve the samples. Park contacted several California Certified analytical laboratories to discuss whether the lead levels found in the water samples could be the result of 501641 2