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'% . MW <br /> MW-2 is well within drinking water standards. Although the trend is statistically significant, the <br /> County does not believe that this increase can definitively be called a release of leachate. If leachate <br /> were impacting this well, the chloride would likely be seen at a more significant level. The County <br /> will continue to perform trend analyses quarterly. Tolerance limits will be updated for all parameters <br /> which do not shdw increasing trends. <br /> VOC's <br /> Results from the first quarter 2000 event show no detections of any VOC's. Past reports have shown <br /> sporadic detections of VOC's in two wells. Due to the nature of the occurrences, and the variability <br /> of the concentrations, the County believes that these occurrences were due to landfill gas influence <br /> and were not an indication of leachate affecting the groundwater. The County has been working to <br /> make repairs to the gas control system to improve its efficiency. We have recently finished some <br /> repairs that have allowed more vacuum to be applied to the north end of the landfill. System <br /> modifications have been made that have increased vacuum to the entire well field and will allow for <br /> better control of landfill gas migration. Continued monitoring will help to define conditions beneath <br /> the site and determine if the modifications to the landfill gas collection system affect the appearance <br /> of VOC's in groundwater. <br /> Surface Water <br /> When surface water is present, it is to be evaluated using the interwell tolerance interval which <br /> uses the upstream analytical data to set a limit to compare the downstream data. Interwell <br /> tolerance limits are to be updated each time water is collected in order to set the concentration <br /> limit based on the complete upstream data set. During the first quarter monitoring event, water <br /> was present for sampling on January 25, 2000. The five year COC's were also analyzed during <br /> this monitoring event. A tabular summary of the data can be seen on Table 2. A review of the <br /> data shows that the COC's are unable to be statistically analyzed because of insufficient <br /> background data to determine a concentration limit. Those constituents that could be analyzed <br /> all showed that there are no exceedences. <br /> GROUNDWATER FLOW DIRECTION AND VELOCITY <br /> Groundwater levels were measured in monitoring wells MW-1, MW-2, MW-3, and MW-4 on <br /> January 21, 2000. Groundwater flow direction has historically been to the south. First quarter <br /> results show a continuing trend of groundwater flow towards the south with a possible shift towards <br /> the east. In previous quarters the direction of groundwater flow has shifted towards the east. These <br /> changes may have been due to off-site groundwater pumping. Continued monitoring will help to <br /> better define the groundwater conditions beneath the site.Groundwater flow velocitywas calculated <br /> to be approximately 60.6 feet per year and the gradient is 0,0018 foot per foot as shown in Appendix <br /> F. <br /> 6 <br />