SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

California Regional Water Quality Control Board - Central Valley Region • Steven T.Butler,Chair Winston H. Hickox Gray Dais Secretan•for Sacramento Main Office Governor Environinental Internet Address: http://www.swrcb.ca.gov/—rwgcb5 Protection 3443 Routier Road,Suite A,Sacramento,California 95827-3003 Phone(916)255-3000•FAX(916)255-3015 1 March 2000 Mr. Alfonso T. Jesena, Jr. Navy Environmental Facility Activity-West Code 6424 900 Commodore Drive San Bruno, CA 94066-2402 DRAFT REMEDIAL INVES TIGA TION REPOR T, OPERABLE UNIT#3, NAVAL COMPUTER AND TELECOMMUNICATIONS STATION(NCTS), SAN DIEGO DETACHMENT, STOCKTO.Y We have reviewed the Draft Remedial Investigation Report, Operable Unit (OU) #3, for NCTS, Stockton, dated 15 December 1999, as prepared by Tetra Tech EM, Inc. The U.S. Navy (Navy) is conducting a remedial investigation (RI) for installation restoration (IR) sites at NCTS, Stockton. This report presents the results of RI activities at the 10, OU-3 landfill sites. Soil and groundwater chemicals of potential concern (COPCs) at varying concentrations were detected at all OU-3 sites. Major chemical classes detected at the OU-3 sites include petroleum hydrocarbons, volatile organic compounds, semivolatile organic compounds, polychlorinated biphenyls, pesticides, and metals. Based on the past waste disposal practices employed by the Navy, the source of COPCs detected at these sites was determined to be the landfill cells and soil. Based on the concentrations of COPCs detected at each site, a human health risk assessment(HHRH), an ecological risk assessment (ERA), and a water quality assessment were conducted to assess the potential effects of COPCs on human and ecological receptors and water quality. The following comments represent our major concerns that should be addressed by the Navy in the next revised RI report. Because these issues are holistic approaches to all the IR sites in the Landfill Area, we are presenting general statements rather than site specific comments. Specific language from individual sites has been extracted from text in support of our comments. Groundwater Management Approach The Navy proposes a water quality study to show that the beneficial uses of the groundwaters at NCTS, Stockton meet exception criteria identified in the State Water Board Resolution No. 88-63, "Sources of Drinking Water Policy" as set forth in the Water Quality Control Plan (Basin Plan)for the Sacramento River and San Joaquin River Basins (Fourth Edition). As stated in the Sources of Drinking Water Policy, unless otherwise designated by the Regional Water Board, all groundwaters in the Region are considered as suitable or potentially suitable, at a minimum, for municipal and domestic water supply(MUN ), agricultural supply (AGR), industrial service supply (IND), and industrial process supply(PRO). The criteria for exceptions relative to the Navy's purposes are: California Environmental Protection Agency 0a Recycled Paper