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' This quarter's measurements of groundwater elevations were contoured and indicate a <br /> delineated line between MW-1 and MW4 The area above the delineation line defined <br /> Sdirectional flow in a north orientation while the area below the delineation line defined <br /> directional flow in a northeasterly orientation The hydraulic gradient averages 0 01401 feet j <br /> per foot across the well field (above the delineation line) and 0 00413 feet per foot across the <br /> well field(below the delineation line) A groundwater elevation summary and directional flow <br /> map for the first quarter groundwater measurements are shown in Figures 4 and 5 <br /> ' The groundwater elevation data collected during this event is typical of the site, and is <br /> gi' g <br /> consistent with historical data and seasonal trends <br /> 1 5.2 Groundwater Sample Analysis <br /> P Y <br /> ' This section presents the results of the most recent(03111105)groundwater sampling event, and <br /> synthesizes these data with other data previously collected Table 2 summarizes the <br /> groundwater monitoring well analytical results from the most recent groundwater monitoring <br /> event Certified analytical laboratory reports and chain-of-custody documentation are included <br /> ' as Appendix C i <br /> TPH-diesel appeared in MW-1 at a concentration of 8800 ppb, a significant increase from last <br /> quarter All other constituents were below the reporting limits <br /> q MW-2 found continued contamination from MTBE, DIPE,BTEX,TPH-diesel, and TPH-motor <br /> oils TBA,DCA12,TPH-gasoline,EDB,ETBE,and TAME were below the reporting limits <br /> I <br /> MW-3 continues to remain free of contamination <br /> • TPH-diesel and TPH- motor oils in MW-4 remain below the reporting limits, ���e BTEX and � <br /> TPH-gasoline increased in their contamination levels DCA12 appeared at�ppb, a decrease <br /> from last quarter, and DIPE significantly decreased to 7-W ppb TBA, EDB, MTBE, ETBE, <br /> and TAME were below reporting limits <br /> Acetone was measured for the first time this quarter and appeared in MW4 — <br /> All groundwater samples secured by EI were logged in a chain-of-custody form, placed in an <br /> ice chest and picked up by a California Department of Health Services (DHS) certified <br /> laboratory for analysis <br /> 5.3 Free Product <br /> A September 1998 sample of groundwater monitoring well MW-2 found black., floating oil that <br /> appeared to be typical of used motor oil Floating oil has been removed from MW-2, using <br /> disposable bailers and absorbent socks, periodically since that tune Approximately 20 1 <br /> gallons of floating oil have been removed(Table 3) <br /> r <br /> 9 i <br /> E <br /> l <br /> i <br /> � I <br /> L- <br /> oi' 3 <br />