ARCHIVED REPORTS XR0005813 - Laserfiche WebLink

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DEPTH TO WATER MEASUREMENTS Depth to water was measured at all wells on June 2, 1998 The measurements were made from the surveyed elevation at the top of casing at each well using an electrical air/water interface probe (Table 1) No free product or product sheen was observed in any of the monitor wells COLLECTION AND CERTIFIED ANALYSIS OF GROUNDWATER SAMPLES Following depth to water measurements, WEGE and LTT personnel used a truck mounted vacuum lift pump and dedicated one inch diameter PVC tubing to purge each well of three volumes of water Aftei puiging, the wells were allowed to recover to at least 80% of their original well volumes A gioundwatei sample was then collected from each well with a polyethylene bailee and decanted with no headspace into foul 40 ml VOA vials containing 0 5 ml HCL acid as a preservative The samples were deliveied with accompanying chain of custody documentation to American Enviioniriental Netwoik (AEN) The certified laboratory (DHS #1172) analyzed the Nvater samples fiom each monitor well for concentrations of TPH-G using EPA method 5030/GC-FID BTEX using EPA method 8020 and the oxygenants MBTE, TBA DIPE, ETRE, and TAME using EPA method 8260 DISPOSITION OF WASTEWATER The purged wastewater was contained on-site in labeled 55 gallon DOT approved dtunns This wastewater was tianspoited by Eveigieen Environmental Services to then recycling facility on July 20, 1998 under a non-hazardous waste manifest (see Appendix D) RESULTS OF QUARTERLY GROUNDWATER MONITORING GROUNDWATER GRADIENT AND FLOW DIRECTION Figure 4 shows the groundwater elevation gradient and flow direction determined fiom depth to \vatei measurements at the five on-site monitor wells on June 2, 1998 The groundwater elevation has decreased by an average of 0 79, feet at the five monitor wells since the previous quarterly monitoring sound on March 18, 1998 The general flow direction is to the west, tiom the former UST's towards MW') and Mission Road The overall gradient is 0 002 feet/lineal foot RESULTS OF CERTIFIED ANALYSIS OF GROUNDWATER SAMPLES The results of the c.citified analyscs of groundwater sannples collected fionl the five nnbnitor 1"ells on June 2, 1998 ale shown in Table I Copies of the laboratory reports ate included as Appendix C of this i eport TPH-G concentrations ranged from a maximum of 16, 000 ug/1 at MW1 to less than the laboratory detection limits of 50 ug/1 at monitor wells MW2, MW4, and MW5 Benzene concentrations ranged from a maximum of 2700 ug/l at MW1 to less than the laboratory detection Inuits of 0 5 ug/l at monitoi wells MW2, MW4, and MW5 MTBE concentrations ranged from a maximum of 210 ug/I in MW1 to less than laboratory detection limits of 5 ug/l in monitor wells MW2, MW4, and MW5 2 Sanchez QM 6-98