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a <br /> z <br /> { <br /> Groundwater Conditions <br /> Groundwater occurred at depths of about eight feet below the surface (see Table 1). A <br /> northwesterly groundwater flow direction was plotted from the monitoring well data <br /> under a gradient of 0.008 (see Figures 1 and 2). Water levels in the wells declined since <br /> the previous quarter. The water levels and groundwater flow direction are consistent with <br /> those previously observed. <br /> Chemical Analysis <br /> Three groundwater samples were analyzed at a Chromalab, Inc., a State certified <br /> analytical laboratory from the monitoring and domestic wells. These samples were tested <br /> for the following; Total Petroleum Hydrocarbons as Gasoline (TPHG) and Diesel <br /> (TPHD), Benzene (B), Toluene (T), Ethylbenzene (E) and Xylene (X), Methyl-tert-butyl- <br /> ether (MTBE) and fuel oxygenates, 1,2 Dichloroethane and Ethylene Dibromide using <br /> EPA Methods 3510/8015, 8020, 8240 and 8260. The analyses were run on a "normal" <br /> turnaround (five- to ten working days). The results are presented in Table 2 and historic <br /> data in Tables 3 and 4 below. <br /> Table 2. Groundwater Monitoring Well Chemical Data, September,2002 <br /> Sample TPHD TPHG Ben Tol Ethyl Xyl TBA MTBE DIPE ETBE TAME 12 EDB <br /> DCA <br /> # ug/1 ugll ug/i ug/1 ug/I ug/l ug/I ug/I ug/I ug/l ug/I ug/I ug/i <br /> MW-1 ND ND ND ND ND ND ND ND ND ND ND ND ND <br /> MW-2 ND ND ND ND ND ND ND ]NDJ <br /> ND ND ND ND ND <br /> MW-3 900' ND ND ND ND ND NDND ND NDND ND <br /> ND ND ND ND ND ND NDND ND ND ND ND <br /> ' <br /> -Laboratory reports that this did not match the pattern of the lab diesel standard. ND—None detected,see laboratory reports. <br /> Discussion <br /> TPHD was observed in Well MW-3 at the former UST tank pit location at 900 <br /> micrograms per liter. All other contaminants were not detected for this monitoring <br /> period. The reported TPHD did not match the laboratory diesel standard and is <br /> interpreted to be a highly degraded remnant of petroleum depleted in volatile content. <br /> Highly degraded TPHD has been observed at MW-3 previously and has declined over <br /> four quarters of site monitoring. The rise of the TPHD is attributed to drainage of <br /> residual TPHD due to declining water levels. Presence of highly degraded TPHD is <br /> expected to continue at the former UST pit location interpreted as a result of residual <br /> drainaize from T1'HD absorbed to soil. This is consistent with historically observed <br /> ..� _._ncs Jor T?HD <br />