SITE INFORMATION AND CORRESPONDENCE_1

Home Browse Search

PUBLIC`HEALTH SERVICES r,'Qq1t4 �oG SAN JOAQUIN COUNTY a: x ENVIRONMENTAL HEALTH DIVISION Ernest M. Fujimoto, M. D., M.P.H., Acting Health Officer 4CICOR? 304 East Weber Avenue, Third Floor • Stockton, CA 95202 APRT G 1 209/468-3420 PARMACEAST RICHARD FISH W L SIMMONS DEL MONTE FOODS C/O SIDNEY RUDY ESQ 205 N WIGET LANE 333 MARKET STREET WALNUT CREEK CA 94958 SAN FRANCISCO CA 95105 SITE CODE: 2498 RE: DEL MONTE/DISCO 110 N.FILBERT STREET STOCKTON, CA As a result of an extensive review of existing data for the above referenced site,follow up to our January 24, 1997 meeting and subsequent telephone conferences, San Joaquin County Public Health Services Environmental Health Division (PHS/EHD) provides the following directives. It should be noted that the directives which follow are intended to ultimately bring closure to this investigation in a cost efficient and effective manner in accordance with current corrective action regulations. Given the current documented conditions which include rising ground water elevations (all monitoring wells over screen), contaminant distribution in ground water at depths in excess of 90 feet bus (30 feet below current static water level) and an estimated 180 degree change in ground water flow direction PHS/EHD will require the responsible parties listed to install an appropriate number of soil borings and ground water monitoring wells sampled and screened at intervals which when implemented will fully define the vertical and lateral extent of contaminant distribution. Geophysical data shall be collected, analyzed and reported including permeability, dry bulk density, moisture content and carbon content employing acceptable and defensible methods for each significantly different lithological unit to further define attenuation and migration potentials. Limited continuous core sampling shall be employed to provide a more comprehensive understanding of the site subsurface. Appropriate cross-sectional depictions shall be prepared and included in the next report utilizing data from previous investigations and data obtained by this scope of work. These data collection points will require permits for encroachment and subsurface investigation which shall be obtained with written approval from the appropriate agencies prior to engaging in site work. PHS/EHD recommends that the responsible parties begin the pemitting processes as soon as possible in order to reduce any further delays in delineation or degradation to ground water quality. In reviewing the quarterly monitoring report, cover date February 1997, it is apparent that dilutions to ground water samples analyzed by CH2M HILL are,at times, required to achieve defensible and accurate reporting for most constituents analyzed. However, with respect to MTBE a more refined analytical result other than <100 ug/I, for example is required. After discussing this issue with Brian Moore on March 14, 1997 at the CH2M HILL laboratory in Redding, California, PHS/EHD will require that all subsequent analyses be performed by a laboratory using the lowest possible detection limits and dilution in order to more accurately quantify MTBE and other constituents. In order to virtually assure this analytical approach is adhered to all subsequent sample chain of custody forms shall include the following statement (*Note: Use the lowest possible detection limits and dilutions in order to more accurately quantify MTBE and other consituents). A Division of San Joaquin County Health Care Services