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CjeoCo,guatTechn I Page 5 <br /> Groundwater Monitoring Report <br /> Project No 425 2 <br /> January 12, 2001 <br />' • Contaminant concentrations in MW-2 continue to fluctuate See Figure 5 for graph of <br /> Benzene and TPH-G versus time in MW-2 <br />' • Wells MW-4 and MW-5 contaminant concentrations exhibit a stable trend <br /> • Wells MW-102 and MW-202 contained BTEX concentrations at or just above the <br /> laboratory reporting limits <br /> • Two of the domestic wells were non-detect for the event The domestic well at 1600 <br /> "A" Durham Ferry Road contained 0 3 and 0 6 ug/l toluene and xylene, respectively <br /> This well was re-sampled on November 15, 2000, and it did not contain contaminant <br /> concentrations above the laboratory reporting limits <br /> 3.0 CONCLUSIONS AND RECOMMENDATIONS <br /> The following conclusions have been drawn regarding the status of the groundwater at this <br /> site and recommendations for future work <br /> Conclusions <br /> 1 The water table groundwater gradient historically flows in a northern direction at about <br /> 0 002 ft/ft However, over the past year and a half, the gradient has shifted towards the <br /> east The cause for this is not known at this time <br /> 2 The intermediate depth groundwater flows easterly, which is consistent with previous <br /> monitoring events <br /> 3 Vertical groundwater gradients have been found to be flowing upward during early <br /> spring and downward during late spring and summer This may be due to the annual <br /> 1 cycle of groundwater pumping needs of the community The upward flow of <br /> groundwater during certain portions of the year may be responsible for preventing these <br /> contaminants from significantly impacting the deeper aquifer zones <br />' 4 The shallow water table groundwater plume is laterally defined except to the west <br /> 5 Petroleum hydrocarbon concentrations in the groundwater at the site fluctuate with each <br /> monitoring event <br />' 6 The deeper groundwater plume is defined vertically since MW-102 and MW-202 <br /> exhibit trace to non-detect contaminants <br /> 7 Two domestic wells associated with this site remain non-detect A third well has <br /> lintermittently shown traces of benzene, toluene and/or Xylene, which may be residual <br /> effects of cross contamination <br /> 8 With several domestic wells associated with the residences surrounding the property and <br />' the wells for the elementary school located a short distance northeast of this property, <br /> this groundwater plume appears to continue to pose a significant threat to public health <br />' and the environment <br />