Laserfiche WebLink
KLEINFELDER <br />' stored in an Iced chest under chain-of-custody The samples were then submitted to <br /> . Y P <br />' the analytical laboratory for analysis Groundwater samples were analyzed for BTEX, <br /> TPH-G, oxygenate analytes (TBA, MTBE, DIPE, ETRE, TAME), and 1,2-DCA <br /> 2 2 GROUNDWATER ELEVATION AND WELL DEPTH DATA <br /> ' Free product was not, nor ever has been observed among the wells, based on the <br /> measurements obtained utilizing the oil/water Interface probe and/or the visual <br /> observations <br /> Groundwater elevations decreased approximately 1 30 feet from the previous event <br /> performed in April 2005 During this event, the average depth to groundwater among <br /> the wells was 45 03 feet bgs (--28 36 feet msl) The elevations ranged from —27 37 to — <br /> ' 28 91 feet msl The groundwater flow direction is easterly to southeasterly at a gradient <br /> of approximately 0 003 feet per linear foot i <br /> The well depth measurements at the air-sparging locations SP-1, SP-5, and SP-6 <br /> indicated an appreciable amount of fill material has entered the wells The sparging <br /> wells were never intended to be used for monitoring purposes and were never <br /> ' developed as such Furthermore, the screen placements of these air-sparging wells <br /> were selected to facilitate the infection of air into the subsurface and not the collection of <br /> representative groundwater samples The tops of the screens in the air-sparging wells <br /> ' are approximately 20 feet below the groundwater table If further sampling or <br /> remediation activities are to be conducted at these locations, the air-sparging wells will <br /> need to be developed <br /> 2 3 BTEX AND TPH-G ANALYTICAL RESULTS <br /> ' Typical petroleum-hydrocarbons (BTEX and TPH-G) were detected in the groundwater <br /> samples from the following wells MW-1, MW-7, MW-11, MW-12, SP-1, SP-2, SP-4, SP- <br /> 6, PZ-1, and PZ-2 There were no detectable BTEX or TPH-G concentrations <br /> ' measured in the samples collected from the remaining wells <br /> ' The benzene concentration Increased in wells MW-1, MW-7, MW-11, SP-1 , and PZ-1 <br /> The remaining wells remained stable or decreased in benzene concentration The <br /> detectable benzene concentrations ranged from 0 99 micrograms-per-Liter (pg/L) at well <br /> C23-484517-BOO/SAC5R610 Page 8 of 12 September 14, 2005 <br /> Copynght 2005 Kleinfelder Inc <br />