Laserfiche WebLink
r <br /> PUBLICIEALTH SERI CES OPquly <br /> SAN JOAQUIN COUNTY ?• 'o� <br /> 2` z <br /> ENVIRONMENTAL HEALTH DIVISION y' , <br /> Ernest M. Fujimoto, M.D., M.P.H., Acting Health Officer <br /> 304 E.Weber Ave., 3rd Floor • P. 0. Box 388 • Stockton, CA CS <br /> 209/46468-3420 �FbnDAVE CAMILLE <br /> UNOCAL CORPORATION <br /> PO BOX 5155 MAILED AUG 2 81995 <br /> SAN RAMON CA 94583 <br /> RE: Unocal Service Station #6981 SITE CODE: 1217-123 <br /> 4707 Pacific Avenue <br /> Stockton CA <br /> San Joaquin County Public Health Services, Environmental Health Division (PHS/EHD) has <br /> completed review of the "Second Quarter 1995 Status Report" dated July 27, 1995 and prepared by <br /> GeoStrategies. <br /> The report indicated that the vapor extraction/destruction system has not been in operation <br /> continuously since January 23, 1995. Please continue efforts to correct system design/operation so <br /> that remediation of soil contamination can be completed. <br /> PHS/EHD has evaluated the request to reduce the sampling frequency at the site and agrees that a <br /> reduction is reasonable. As PHS/EHD has indicated previously, a groundwater remediation system <br /> may be necessary should it appear as if the plume of contamination was migrating off site. Since <br /> the proposed modified sampling plan includes quarterly sampling of the perimeter wells, MW6, <br /> MW9, MW10, MW11, MW12 and MW13 and semi-annual sampling of all other wells, PHS/EHD <br /> approves of the proposed modification. It should be noted that it would be prudent to begin <br /> evaluation of a groundwater remediation system, given that significant groundwater contamination <br /> continues to be evidenced. Please submit a feasibility study work plan which should include air <br /> sparge and bioventing so that groundwater remedial options can be compared. <br /> The site has now been in the remedial process since September 22, 1994 and a yearly evaluation <br /> of the system should be submitted within the next quarterly report. The analysis should include an <br /> estimated time line and any modifications which could be made to enhance the effectiveness of the <br /> remedial efforts. <br /> If you have any questions or comments, please contact Mary Meays at (209) 468-0337. <br /> Donna Heran, REHS, Director <br /> Environmental Health Division <br /> Mary Meays, Seni EHS Diane M. Hinson, REHS <br /> Site Mitigation Unit Supervisor <br /> MM\4707PAC <br /> c: Elizabeth Thayer, CVRWQCB <br /> C: Dayton Hudson Corp <br /> c: Greg Gurss, GeoStrategies <br /> A Division of San Joaquin County Health Care Services <br />