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<br /> QUARTERLY GROUNDWATER MONITORING REPORT
<br /> THIRD QUARTER, 1999
<br /> Herman & Helen's Marina
<br /> Venice Island Ferry
<br /> Stockton, CA
<br /> October 26, 1999
<br /> 1 INTRODUCTION
<br /> On September 23, 1999, Condor Earth Technologies, Inc (Condor) conducted quarterly groundwater and surface
<br /> water monitoring at Herman & Helen's Marina located at Venice Island Ferry in Stockton, California (Figures 1
<br /> and 2, Appendix A) fhe work described in this report was conducted in accordance with sampling procedures
<br /> included in the Work Plan - Monitor Well Installation and the Work Plan Addendum, prepared by Condor and
<br /> dated May 30, 1997, and July 9, 1998, respectively The work plan was conditionally approved by Mr Ronald
<br /> Rowe of the San Joaquin County Public Health Services/Environmental Health Department (PHS/EHD) in
<br /> correspondence dated July 8, 1997 The work plan addendum was approved by Mr Rowe in correspondence
<br /> dated July 27, 1998 The third quarter, 1999, monitoring described in this report is the eighth quarterly
<br /> groundwater monitoring event and the fifth surface water sampling event to be conducted at the site This report
<br /> was prepared at the request of Mr David Smith of Herman & Helen's Marina
<br /> Laboratory analyses of the groundwater and surface water samples included benzene, toluene, ethyl benzene and
<br /> total xylenes (BTF,X), total petroleum hydrocarbons quantified as gasoline (TPH-G), and selected gasoline
<br /> oxygenates/additives flus report includes a site history, a summary of the current monitoring event (including a
<br /> description of the sampling and laboratory analytical results), and a summary with conclusions
<br /> 2. SITE BACKGROUND
<br /> On October 30, 1991, Warren E Gomes Excavating, Inc , of Rio Vista, California, excavated and removed three
<br /> underground storage tanks (USTs) from the site (Figure 2, Appendix A) The USTs (TKI, TK2, and TK3)
<br />' contained gasoline and diesel fuel A small hole was found on the lower fill end of TK3 (diesel tank) Petroleum
<br /> staining and odors were noted in the soil beneath the former locations of the USTs Six soil samples were
<br /> collected by Condor from the UST excavation at depths of 9 to 12 feet below the ground surface Laboratory
<br />' analyses indicated elevated concentrations of TPH-G, BTEX, and total extractable petroleum hydrocarbons
<br /> quantified as diesel (TEPH) in the soil samples
<br />' On August 22, 1995, three hydropunch borings were drilled at the site Gasoline odors were noted in each
<br /> borehole Laboratory analyses indicated concentrations of TPH-G and BTEX in the soil and groundwater
<br /> samples analyzed from each borehole Based on the results of the August 1995, investigation, Condor
<br /> recommended additional investigation be conducted to evaluate the extent of the hydrocarbon plume On August
<br /> 29, 1996, five Geoprobe boreholes were installed at the site The results of the laboratory analyses indicated that
<br /> elevated concentrations of TPH-G, BTEX, and methyl tertiary butyl ether (MTBE) were present in soil and
<br /> groundwater samples collected from the northern portion of the site and that further investigation was necessary
<br /> to evaluate the extent of soil and groundwater contamination
<br /> Based on the results of the Geoprobe investigation, Condor recommended that monitor wells be installed at the
<br />' site to investigate and monitor the lateral extent of the gasoline and diesel contammation plume in the
<br /> groundwater On September 10, 1997, Condor installed four monitor wells at the site The Report - Additional
<br /> Sod and Groundwater Investigation, dated December 11, 1997, was prepared by Condor to describe the
<br /> investigation results
<br />' L� CONDOR
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