SITE INFORMATION AND CORRESPONDENCE FILE 1

Home Browse Search

PUBLIC H?ALTH SERVICIL' FILE COPY q4. .o SAN JOAQUIN COUNTY ENVIRONMENTAL HEALTH DIVISION Karen Furst, M.D., M.P.H., Health Officer cq.. Nw 304 East Weber Avenue, Third Floor • Stockton, CA 95202 `'FOR 209/465-3420 GEORGE AND MEI TERANISHI SEP 1 5 2000 1600 WEST DURHAM FERRY RD TRACY CA 95376 Re: George's Service Site Code: 1550 1600 West Durham Ferry Rd. Tracy,CA 95376 On June 20,2000,your consultant, Geological Technics,submitted a work plan for the above referenced site to the San Joaquin County Public Health Services Environmental Health Division(PHS/EHD)for review. PHS/EHD subsequently disapproved of the work plan because it lacked specific information and data to support conclusions presented in the plan regarding remedial alternatives proposed for the site. PHS/EHD informed you in a letter dated July 3,2000,that further information would be necessary prior to approval of the remedial alternatives work plan. Moreover, in a letter dated May 5,2000 and submitted to you several weeks prior to the submittal of the June 20 work plan,PHS/EHD specifically outlined the information that would be needed in the work plan before approval would be provided. Additionally, PHS/EHD staff met with you and your consultant on location at the site on July 24,2000 to discuss corrective action requirements. To further ensure that the appropriate and necessary elements were included in the new work plan the consultant was encouraged by PHS/EHD to review documentation for an Air Sparging and Soil Vapor Extraction(AS/SVE)technique that is being successfully utilized at a nearby site with similar lithology. PHS/EHD provided the file for the nearby site for the consultant's review. PHS/EHD received and reviewed a revised Remedial Alternative Feasibility Study Work Plan(Work Plan) dated August 17,2000 prepared by Geological Technics for the above referenced site. The preferred remedial alternative,as stated in the work plan, is excavation of contaminated soil instead of AS/SVE. However,PHS/EHD conditionally approves the Work Plan in the interest of facilitating corrective action at the site. Specific data to support contaminated soil removal in lieu of soil vapor extraction and air sparging for this site will be necessary. The following conditions must be met prior to scheduling the work: 1. Prior to employing source removal as a remedial method,calculations for groundwater velocity at the site and the time frame calculated for the contaminant plume to contact the nearest receptor must be provided to PHS/EHD. Calculations must begin at the time of the original contaminant release. If the time frame for contaminant plume travel to the nearest receptor is less than one year,the more aggressive AS/SVE remedial method must be employed at this site. 2. Soil and groundwater mass balance calculations for the contaminant volume currently estimated to be in place at this site must be provided to PHS/EHD,as well as mass balance calculations for the amount of soil and water contaminants proposed to be removed by excavation and attenuation. Pre-treatment contaminant concentrations and the post-treatment contaminant concentration goals must be clearly stated. 3. Confirmation of contaminant mass balance concentrations in the contaminated soil removed from the site and the mass contaminant concentrations that will be left in place must be submitted in a post- excavation report. A report evaluating the soil excavation and sampling work must be submitted to PHS/EHD within 60 days of the excavation work:a report of findings for the source reduction and attenuation remedial method must be submitted within 60 days of the fourth quarterly groundwater- monitoring event following the excavation work. A Division of San Joaquin County Health Care Services