Laserfiche WebLink
Treaadmfell&R to <br /> 31 August 2000 <br /> Project 2597.03 <br /> Ms. Kitty Walker <br /> Principal Analyst <br /> Stockton Department of Housing and Redevelopment <br /> 305 North El Dorado Street <br /> Stockton, California 95202-1997 <br /> Subject: Information Required for <br /> Evaluation of Soil and Groundwater Contamination <br /> At Areas 15 and 16, Stockton, California <br /> Dear Ms. Walker: <br /> This letter discusses the information required by Treadwell & Rollo to evaluate the extent of soil <br /> and groundwater contamination, the effectiveness of remedial measures, and the required <br /> conditions for site closure at 423 North Madison Street(Area 15) and 424 North Van Buren <br /> Street (Area 16) in Stockton, California. Both sites were previously operated by Chase <br /> Chevrolet, and quarterly monitoring and remedial efforts are currently being performed by <br /> Advanced GeoEnvironmental Inc. (AGE). It is our understanding that the City of Stockton is <br /> considering purchasing Areas 15 and 16 and requires an evaluation of the current and future <br /> environmental risk and liability associated with the sites. <br /> AREA 15 <br /> Several underground storage tanks (USTs) and associated contaminated soil have been removed, <br /> but no additional soil or groundwater remediation has been conducted. The predominant <br /> contaminants at the site are petroleum hydrocarbons, but volatile organic compounds (VOCs) <br /> including chlorinated solvents have also been detected. Jeff Wong of San Juaquin County <br /> Environmental Health (SJCEH), has indicated that additional soil excavation could still be <br /> required, and that no cleanup criteria for soil or groundwater (other than the Maximum <br /> Contaminant Limits allowed for drinking water)have been established. Additionally, the <br /> California Department of Toxic Substance Control (DTSC) has expressed concern that the <br /> source and extent of VOCs in groundwater have not been adequately characterized, and both the <br /> DTSC and the SJCEH have commented that potential contaminant migration between the first <br /> and second aquifer has not been adequately addressed. <br /> During the September 1999 and April 2000 soil and groundwater investigations performed as <br /> part of the City's RI/FS study,previously uncharacterized soil and groundwater contamination <br /> (which appears to be similar to mineral spirits), was detected near borings 1513-6, 15B-8, and <br /> 1513-9. DTSC comments to our 29 June 2000 Draft Remedial Investigation Report include the <br /> Treadwell&Rollo,Inc. Environmental&Geotechnical Consultants <br /> 555 Montgomery Street,Suite 1300,San Francisco,CA 94111 <br /> Telephone(415)955-9040 Facsimile(415)955-9041 <br />