SITE INFORMATION AND CORRESPONDENCE_1992

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MEMORANDUM CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD - CENTRAL VALLEY REGION 3443 Routier Road, Suite A Phone: (916) 361-5600 Sacramento, CA 95827-3098 ATSS Phone: 8-495-5600 TO: Antonia K. J. Vorster FROM: Camilla Williams Senior WRC Engineer Engineering Geologist DATE: 21 May 1992 SIGNATURE: 'UCs�i%G'q%YJ/iY/ SUBJECT: REVIEW OF THE DRAFT DECLARATION FOR THE RECORD OF DECISION FOR THE GROUND WATER OPERABLE UNIT AND RESPONSIVENESS SUMMARY, DEFENSE DISTRIBUTION REGION WEST (DDRW), SHARPE, SAN JOAQUIN COUNTY I have reviewed the Draft Record of Decision (ROD) for Ground Water and Responsiveness Summary (RS) for DDRW, Sharpe, submitted on 6 April 1992. The Draft ROD and RS was prepared and submitted prior to our review of the Soils Feasibility Study (FS) Report. I believe that a conscientious effort was made to address our concerns with the Ground Water FS Report and Proposed Plan and that overall , Sharpe has conducted a good investigation of ground water contamination by solvents. However, as you are aware, the Soils FS Report revealed new sources of ground water contamination. In our 17 April 1992 letter on the Soils FS Report, we stated the Ground Water ROD could not be considered comprehensive because it does not address all of the ground water contamination. In the 7 May 1992 Project Manager's Meeting, it was decided to limit the scope of this ROD and to include the investigation of the new sources of ground water contamination into the Soils ROD. The Draft Soils ROD would be delayed until April 1994 to allow for additional investigation of the new sources of ground water contamination. With the inclusion of ground water, the Soils ROD would then be considered comprehensive. Based on the recent decisions by the Project Managers and Sharpe's new commitment to investigate the ground water contamination apparently resulting from non-fuel underground storage tanks (USTs), the Draft Ground Water ROD should be revised to reflect these decisions. Sharpe should consider resubmitting the ROD as a draft, and not a draft final , to reflect the new findings of the waste management unit (WMU) and USTs investigations and to address our comments. As presented, the Draft ROD is unacceptable. The following comments are on the general areas and specific issues of the Draft Ground Water ROD which need to be revised in order to be acceptable. GENERAL COMMENTS Non-Fuel and Fuel Ground Water Contamination. The Draft Ground Water ROD needs to be revised to differentiate between the ground water investigation which has primarily focused on solvent (primarily by trichloroethylene (TCE)) contamination versus ground water contamination by other constituents such as polychlorinated biphenyls (PCBs) , heavy metals, and benzene, toluene, xylene and ethylbenzene (BTXEs) . The PCB and heavy metal ground water contamination appear to be associated with the non-fuel USTs whereas the BTXEs may be associated with the fuel USTs. Ground water contamination by non-solvents should be included in the Soils ROD which would be comprehensive for both soils and ground water. The Remedial Investigation (RI) and FS did not focus on petroleum based ground water contaminants and thus, contaminant concentration contour maps of BTXE's were not