Laserfiche WebLink
RIPONA MARKET <br /> 223 W. Washington Street, Ripon, California <br />' Vertical Groundwater Investigation II <br /> 1.0 PROJECT IDENTIFICATION <br />' The objective of this phase of work is to provide further definition of the vertical extent <br /> of the hydrocarbon plume in the groundwater between existing monitoring wells MW-1 <br />' and MW-3 at the Ripona Market facility as directed by San Joaquin County <br /> Environmental Health Department in their letter dated April 13, 2005 The work <br /> included the installation of a deep, discretely screened monitoring well, targeting a <br /> permeable zone to define the vertical extent of the plume <br /> 1.1 Site Description and History <br /> Two underground fuel tanks were removed on February 11, 1999 by SEMCO under <br /> permit Low levels of xylene were disclosed in laboratory soil samples collected at 13 <br /> feet in depth, primarily in the area of Tank 1 (TK-1) (Figure 2) Moderately high <br /> levels of specific oxygenated compounds were present in the stockpiled soil that had <br /> surrounded the tanks Since no apparent contamination was noted during the removal <br /> this soil was placed back into the excavation <br /> Table of Laboratory Sample Results (February 11, 1999 <br /> Sample I D Gasoline Benzene Toluene E-Benzene I X lens 82b0 <br /> TK1-S 15' ND ND ND ND ND ND <br />' TK1-N 13' ND ND ND ND 47 ND <br /> TK2-S 13' ND ND ND ND ND ND <br /> TK2-N 15' ND ND ND ND ND ND <br />' SP-1 ND ND ND ND ND 190 MTBE, 1200 t avti <br /> SP-2 ND ND ND ND ND ND <br /> ND=Non Detect Gasoline in mg/Kg 8260 inµg/Kg <br />' On January 31, 2000 M J Kloberdanz & Associates drilled a single soil boring to 30 <br /> feet in depth Groundwater was measured at 29 feet below grade surface (bgs) The <br /> former tank excavation had been filled with the previously excavated soils and topped <br />' with about eight feet of pea gravel so sampling started at ten feet an depth The <br /> boring was located near the center of the backfilled tank excavation (Figure 2 Site <br /> Map) <br /> Laboratorysoil samples were obtained five feet, below the gravel layer, for <br /> laboratory <br /> P every <br /> y analysis since contaminated soils were placed back in the tank pat The ten <br />