Laserfiche WebLink
Analytical Results <br /> Data from the July 1999 sampling event indicate that the groundwater beneath the Disco site <br /> contains detectable levels of total petroleum hydrocarbons(TPH) as gasoline and BTEX <br /> compounds (benzene,toluene,ethyl benzene and total xylenes). Analytical results are <br /> presented in Tables 4 and 5. Table 4 presents groundwater sample analysis for TPH-gasoline <br /> and benzene, toluene,ethyl benzene,and xylenes (BTEX).Table 5 presents analytical results <br /> for MTBE and other oxygenate compounds. The results are summarized below,dependent <br /> upon the location of the well in relation to the plume:upgradient,cross-gradient,or within <br /> the plume. <br /> The original sampling event occurred on July 15 and 16, 1999.The results were typical of <br /> previous sampling events with the exception of the results from MW-DIS-2. Petroleum <br /> hydrocarbon concentrations have been decreasing considerably in this well since <br /> monitoring began,but were not detected at all during this event for the first time since <br /> monitoring began. <br /> ` Upgradient Wells-MW-DIS-5,-6, -7S,-713,-8S,and-81D. <br /> TPH as gasoline and BTEX compounds were not detected in groundwater samples collected <br /> from upgradient wells MW-DIS-5,-6,-7S,-7D,-8S, and-8D. <br /> Petroleum hydrocarbons have never been detected in wells MW-DIS-5,and--6. <br /> Benzene and toluene were detected one time in MW-DIS-7S in March 1995 at concentrations <br /> just above the detection limit,and have not been detected the last 6 sampling events. <br /> Petroleum hydrocarbons were detected in MW-DIS-7D during the two sampling events <br /> 4 following installation of the well(September 1991 and June 1992),and in April 1994. <br /> Petroleum hydrocarbons have not been detected in MW-DIS-7D the last 9 sampling events. <br /> Petroleum hydrocarbons were detected in MW-DIS-8S one time in December 1996,and have <br /> not been detected in the last 8 sampling events. <br /> Petroleum hydrocarbons were detected in MW-DIS-8D during the two sampling events <br /> following installation of the well (March 1995 and June 1995),and have not been detected in <br /> the last 11 sampling events. <br /> I <br /> Cross-gradient Wells- MW-DIS-3, -9,and-10. <br /> TPH as gasoline and BTEX compounds were not detected in groundwater samples collected <br /> from cross-gradient wells MW-DIS-3,-9,and-10. <br /> Petroleum hydrocarbons have not been detected in MW-DIS-3 in the last 7 sampling events. <br /> Petroleum hydrocarbons have not been detected in MW-DIS-9 and-10 in the last 6 <br /> sampling events. <br /> Wells Within the Plume- MW-DIS-1, MW-DIS-2, NP-1-70', NP-1-80', NP-1-90',SVE-South and <br /> SVE-North <br /> TPH as gasoline and BTEX compounds were detected in groundwater samples collected <br /> s. from monitoring wells MW-DIS-1,NP-1-70',NP-1-80',NP-1-90',SVE-South and SVE-North. <br /> TPH as gasoline and BTEX compounds were not detected in a groundwater sample <br /> 1 collected from monitoring well MW-DIS-2, The concentrations detected in wells NP-1-70', <br /> f <br /> 2 <br />