ARCHIVED REPORTS XR0010094 - Laserfiche WebLink

Home Browse Search

t V The groundwater sample was collected with a new disposable bailer The groundwater sample was then poured with minimum cavitation into the appropriate, laboratory prepared sample containers leaving no headspace The sample container was then immediately capped, labeled and placed in a chilled ice chest for shipment to Chromalab, Inc in Pleasanton, California (a State Certified Testing Lab) under chain-of-custody documentation Groundwater Contour Map and Flow Gradient A groundwater contour map to a known datum was prepared for the data listed in Table 1 above (see Figure 1) The groundwater flow direction was to the north-northeast under a calculated gradient of 0 0039 The flow direction is consistent with historic observed trends, and remains relatively flat A small groundwater mound appears near the former tank pit location and water levels appear to have risen approximately 1 2- to 1 6-feet in the wells, indicating aquifer recharge from recent winter rainfall Chemical Analytical Methods and Results Nine groundwater samples were analyzed using EPA Methods 5030/8015, 602 and 8260 for Total Petroleum Hydrocarbons as Gasoline (TPHG), Benzene, Toluene, Ethylbenzene and Xylene (BTEX) and fuel oxygenates including Methyl-tert-butyl-ether (MTBE) The analytical results of the groundwater samples are attached and listed with historic data below (see Table 2), Table 2 Groundwater Chemical Data Well Date TPHG Benzene Toluene Ethylbenzene Xylene Fuel Ox No Sampled ----------------------------- ug/l ------------------------------- MW_1 ------------------------------MW-1 3/28/96 NO NO NO NO NO NA MW-1 6/27196 280 0 7 0 6 2 4 9 1 NA MW-1 12/19/96 NO NO NO NO NO NO MW-1 3/10/97 NO NO NO NO ND ND MW-1 6/30197 NO NO NO NO NO NO MW-1 8120197 ND ND NO NO NO ND MW-1 12/12/97 NO ND NO NO NO NO MW-1 3131198 150 16 9 5 5 3 36 NO MW-2 3128196 12,000 8 0 5 0 7 7 20 NA MW-2 6127/96 4,900 72 48 21 25 NA MW-2 12/19/96 4,400 9 9 8 6 25 26 NO MW-2 3110/97 4,000 5 5 2 1 13 12 NO MW-2 6/30/97 3,500 3 9 1 3 11 15 NO MW-2 8/20/97 4,700 1 1 0 5 10 17 NO MW-2 12/12/97 760 63 38 110 180 NO MW-2 3/31198 3,600 20 11 340 270 NO Page 3