ARCHIVED REPORTS_XR0009565 - Laserfiche WebLink

Home Browse Search

SITE BACKGROUND • CANEPA'S CAR WASH, PARK STREET The Site is located in the downtown business district of Stockton, lon leadedne and one 1lon 5 Q00--ga lon gasoline underground storage tank {UST), one 5,000 g g diesel fuel UST were removed from the Site in 1990 Aon from approximately matelyEnvironmentalccording to WHF Consultants, 16 feet below the ground (WHF), soil samples collected from the UST exwe S surface (bgs)contained elevated concentrations of gasoline n monitor wellsasoline cons I unt aBe aro d t Sit1993 interval and March 1994, WHF installed six soil borings and seven Three of the monitor wells (MW-1, MW-2, and MW we eecarconstructed otructedtwit�a screened ith a screened fron�40�o to 65 feet bgs Monitor wells MW-4 through MW-7 60 feet bgs Beginning in April 1997, Condor implemented a quarterly groundwater monitoring program at the Site Following the July 1998 quarterly groundwater monSJCEHD)ring event, reqMr sted the Rowe,tallation of addbanal Joaquin County Environmental Health Department were monitor wells The tops of the screened Intervals monitor is through 7maed oundwater table during the period study Condor prepared a work plan d below the gr l monitor wells ough November 17, 1998, for the installation of four ffreitWon of the SJCEHD requested ed hat ar additional letter dated September 7, 2001, however, Mr J y 8 groundwater work plan be submitted by Octobetr Oof so 001 contaLamination at the Site andfine the lateral vertical Wong lal of requested submittal contamination and the vertical erten 10, 2001 In of a Sensitive Receptor Survey Report fora 2n0odotheradius T'ijork Pian for Addtteona Soil andrGroundwater response to Mr Wang's request, Condor sub Investagataon, dated October 17, 2001 The ocontamlan ination adtion anded laps stun the siting of additional • osed direct push b rings intended to investigate the lateral and vertical extent monitor wells in a subsequent phase of work, if 2eec necessary Mr Wong subsequently approved the work plan,with modifications, in a letter dated October 9, 2001 Site investigation activities pursuant to the abovea described �reseri ed m Condor'ork plan were s Additional Soil and rmed from March 25 through March 28, 2002, details of the investigation p Groundwater Investigation Report, dated May 8, 2002 Investigation activities included the installation`inof two Cone Penetrometer test (CPT) borings, one soil o indicated that relate eldyirect push elevated concentrations borings Laboratory analytical results of the soilsamples of gasoline constituents were present down toithc nstpuez�ts pre detected ited n 82 feet ted at However, the lowest concentrations of gasoline l tertiary feet bgs, indicating the potential for some a bove the laboratory reported detection limit enuation of concentrations at that iin anyyaf the soil butyl ether (MTBE) was not detected a samples In addition, laboratory analytical results on� thntgroundwater oundwatep phase with proximal to the d fficulty, soil samples indicated that the gasoline wasp g probably as a result of the relatively fine-grained soil texture The laboratory analytical results of the hydropunch groundwater samples indicated that relatively elevated concentrations of gasoline constituents Were p�esent at depths formeroUSTs Ththe e es uts asle sociated th w th al ( CPTI) to and down gradient (CPT2) from the 1catiozi ofthe ons CPT1 indicated an increasing trende bgof s, µglLen he deepest sdample col ect d at 119 to 23pth with benzene if et ranging from 65 µg11-µg11- at 79 to 83 f g , to bgs As opposed to CPTI, the results associated with CPT2 indicated a trend of decreasing groundwater