Laserfiche WebLink
Mr Ronald Rowe <br /> CAM B R I A August 26, 1999 <br /> HYDROCARBON DISTRIBUTION <br /> Separate-Phase Hydrocarbons (SPH) <br /> SPH was detected in well MW-1 immediately Figure A <br /> SPH Thickness <br /> following installation However, as indicated in (Well MwA <br /> Figure A, no SPH has been detected since March 05 ° <br /> 0 4 �ru+«a.x. 10 <br /> 1993 Between May 1989 and December 1989, 03 - - 20 <br /> 45 gallons of SPH was bailed from the well As x °z 30 <br /> °1 e° <br /> indicated in the adjacent graph, the SPH was ° 50 <br /> removed from the well prior to the rise in water �0 0e o 000, 00'0,0,0,� le'V/ <br /> table that has occurred at this site No SPH were ®SPH Gwe Top of Screen <br /> detected in other wells SPH data are included on the groundwater analytic tables in Attachment <br /> D <br /> Horizontal Soil Distribution <br /> The highest hydrocarbon concentrations detected in soil borings were from boring SB-3 This <br /> boring contained 2,500 mg/kg TPHg and 41 mg/kg benzene at 15 fbg The highest <br /> concentrations detected in the subsurface were generally at the north and east sides of the <br /> dispenser islands Based on the hydrocarbon concentrations and boring locations, hydrocarbon <br /> concentrations decrease relatively quickly away from the dispensers and the extent is defined by <br /> the existing well and boring samples <br /> Vertical Soil Distribution <br /> Soil samples have been collected from as deep as 45 ft The groundwater depth during the initial <br /> investigations was about 40 ft In the letter requesting this work plan, the San Joaquin County <br /> Environmental Health Division(SJCEHD) suggested that comments on the boring logs indicated <br /> that hydrocarbons were in soil deeper than 45 ft There were comments on the borings logs <br /> indicating that hydrocarbon odors ranging from slight to very strong were detected in some <br /> samples However, as shown on Table A below, the majority of qualitative comments regarding <br /> hydrocarbon odor for which there were analytic results did not correspond to elevated TPHg <br /> concentrations In fact, only one "strong odor" comment correlated to an elevated hydrocarbon <br /> concentration No hydrocarbons were detected in two samples with "strong odor" comments <br /> Therefore, it does not appear appropriate to assume that the qualitative odor comments for <br /> samples deeper than 45 ft correlate to elevated hydrocarbon concentrations in soil <br /> I! <br /> 3 <br />