Laserfiche WebLink
5400-5606 Pacific Avenue - 2 - 3 May 2005 <br /> Stockton, San Joaquin County <br /> EthyIbenxene(E), 840 gg/L, Toluene (T), 1,200µg/L, and Xylenes(X),2,800 gg/L With the exception of <br /> Benzene detected at 2 2 pg/L on IS October 2004, MW-23S (located north of MW-3 across Robmhood Drive) <br /> has been non-detect for four of the last five quarters The Workplan proposes sampling AS-33 soil and ' <br /> groundwater for TPHg, BTEX, MtBE, Ethylene Dibromide and 1,2-Dichlorethane <br /> The Remedial Alternatives Report presents a Remedial Alternatives Screening Matrix, which is similar to a ' <br /> feasibility study table, for six alternatives (No Further Action,Natural Attenuation&Monitoring, Air Sparging <br /> with Soil Vapor Extraction(SVE), Enhanced In-Situ Bioaugmentation,Groundwater Recovery and Treatment, <br /> and In-situ Chemical Oxidation(Ozone)) The Remedial Alternatives Report choice is AS and states the 1 <br /> proposed modifications(one new AS well and one MW modified into an AS well}are cost effective and do not <br /> entail a major revision to the existing treatment system <br /> I concur to the proposed Workplan with the following modifications ' <br /> • Add the following analytes to the fuel oxygenate (MtBE) list tertiary butyl alcohol (TBA),tertiary ' <br /> amyl methyl ether(TAME), di-isopropyl ether(RIPE), and ethyl tertiary butyl ether(ETRE) <br /> All work must be done in accordance to Appendix A -Reports, Tri-Regional Board Staf'Recommendation for ' <br /> Preliminary Investigations and Evaluation of Underground Tank Sites, April 2004,which may be downloaded <br /> from the Internet website in the header of this letter Please procure the appropriate permits from San Joaquin <br /> County Environmental Health Department(SJCEHD), and provide SJCEHD and myself at least 3 working days ' <br /> notice prior to starting fieldwork. Also provide a report (electronic submittal to GeoTracker and paper copy to <br /> this office) of the soil and groundwater sampling and modifications to the AS system in the next monitoring <br /> report, due 1 August 2005. <br /> You may call me at(916)464-4615 for questions or additional information <br /> �, f1 <br /> JAMES L BARTON,P G ' <br /> Engineering Geologist <br /> Enclosure , <br /> cc Mr Mark Owens,UST Cleanup Fund, SWRCB, Sacramento <br /> Mr Mike Infurna,San Joaquin County Environmental Health Division, Stockton ' <br /> Ms Jill Tracy,Esq,UNOCAL,Brea <br /> Mr Ben Henmgburg,ENSR International, Sacramento <br /> Mr Gary Hall,GHH Engineering,Inc,Auburn, CA e <br />