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<br /> Site Heston
<br /> Canepa's Car Wash(Pacific Avenue)
<br />' Page—2-
<br /> Ili-nits from 20 feet bgs to the capillary ftnnge A summary of the soil and groundwater analytical data is
<br />' contained in Inter rm Stains Repoi t Phase H Investigation, by WHF Based on the initial data, the vertical
<br /> and lateral limits of contamination were not sufficiently defined WHF proposed the installation of four(4)
<br /> additional monitor wells (MW-5 tluough MW-8) to fully characterize the groundwater plume The
<br />' PHS/EHD gianted approval of the additional investigation on January 19, 1994 Between March 9 and 11,
<br /> 1994, WTD' installed MW-5 through MW-8 TPH-G was detected in the soil sample collected frons MW-6
<br /> at 50 and 55 feet bgs and from MW-7 at 50 feet bgs TPH-G and BTEX were detected in groundwater
<br />' samples collected from MW-6, MW-7, and MW-8 A summary of the soil and groundwater analytical data
<br /> is c,ontamed in Phase H Stte Chmacter-rzatron, by WHF The wells were surveyed and groundwater
<br /> elevation measurements indicated that a groundwater mound existed beneath the site This suggested that
<br />' recharge or leakage into the groundwater in the vicinity of MWA and MW-2 was occurring Three
<br /> potential sources of recharge were identified 1)the car wash water recycling pit systenn under the building,
<br /> 2) a leaking or broken sewer line that crosses the area, and 3) a leaking water supply line An MBAS
<br /> (Methyl Blue Active Surfactants) test was eoiiduc.ted on groundwater samples collected at the site in July,
<br /> 1994, to investigate the piesence of detergents MBAS was not detected in the samples
<br /> Aquifer testing(24-hour pump test)was conducted at the site by WI4P on December 22 and 23, 1994 MW-
<br /> 1 was used as a pumpiing well, and MW-4, MW-6, MW-7, and MW-8 were used as observation wells The
<br /> results indicated an optimum pumping rate of 5 gpm with an effective radius of 140 feet Aquifer
<br /> permeability was estimated at 126 gpd/ft2
<br /> Quarterly groundwater monitoring was conducted at the site by WHF from March, 1994, through June,
<br /> 1995 Historical gioundwatei analytical data indicated elevated concentrations of TPH-G and BTEX in
<br />' MW-1, MW-2, MW-6, and MW-7 Low concentrations of TPH-G and BTEX were detected in MW-3,
<br /> MW-4, MW-5 and MW-8 Condor has been conducting quarterly groundwater monitoring at the site since
<br /> August, 1996 Analysis of groundwater samples collected from selected SVE wells (SVE-1, 2, 3, 5, 7, 8,
<br /> and 9) indicate that high concentrations of lPH-G BTEX, and MTBE are present in the former location of
<br /> the fuel dispenser islands The groundwater table has risen approximately 18 5 feet since quarterly
<br /> monitoi ing of all eight site monitoi wells began in March, 1994
<br /> IA site investigation was conducted by Condor Earth Technologies, Inc (Condor) on July 31, 1996, at the
<br /> Canepa's Car Wash facility The investigation included a review of existing investigative reports and an
<br /> I evaluation of the existing SVE system located at the site The fieldwork was conducted in accordance with
<br /> Condor's proposal for SVE evaluation,dated April 8, 1996, and the addendum to the proposal, dated May 2,
<br /> 1996 The subsequent report was titled Soil Vapor Extraction (SVE) System Elaluatron, dated September
<br /> 2-3, 1996
<br /> Based on the soil analytical data available for the site, Condor estimated that the volume of hydrocarbons
<br /> present in the soil beneath the site i4 approximately 13,000 pounds or 2 050-gallons (6 34 lbs/gal) Due to
<br /> unknown variations in the hthology and contaminant concentrations, the actual volume of hydrocarbon
<br /> beneath the site may vary by an order of magnitude or more from the estimate
<br /> Ba-ed on the results of the SVE system e%aluation and site background Condor recommended that -
<br /> operation of the ICU be suspended since the system slid not appear to meet APCD permit conditions (i e,
<br /> 95% destruction effieienc,y) Condor further recommended that a 150 SCFM catalytic oxidation unit(CAI-
<br /> I OX) be installed at the site to c\tract and tical the gasoline, contamination in the vadose zone It was
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