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2) Off-site sampling of existing private wells was a recommendation of the previous regulatory comments dated May 26, 1988. It is not included as an activity under the Interim Work Plan. Off-site sampling continues to be a recommendation by the Department. The Navy prefers to ascertain whether contaminants are migrating off NCS Stockton via the ground-water pathway prior to conducting sampling at off-site wells. Gaining an understanding of the geological conditions and direction of ground-water flow prior to initiating off-site activities will permit determination of the areas most likely to be affected if contaminants are concluded to be migrating off-site in ground water. This information could then be used to focus subsequent off-site sampling efforts. 3) The Interim Workplan proposes to limit water samples (surface and ground) to volatile organic compounds contained in EPA's test Method 8240. Previous studies have detected compounds that are not part of Method 8240. Detected compounds include arsenic, selenium, various pesticides, chloride, sulfate, and petroleum products. It is recommended that the sampling parameters be expanded. Additional reasons for not limiting the sampling parameters are: • The limited number of groundwater samples taken from the intermediate zone. • Questions concerning the validity of past ground water samples. • The three to four year gap in sampling periods. The Department is aware of the time and expense required to collect water samples. We, therefore, propose that any water sampling program be established. The program should determine the frequency of sampling events, the range of chemicals to be sampled, and provide guidance for deleting chemicals from the sampling protocol. Sampling parameters have been expanded. Soil samples will be analyzed for volatile organic compounds (VOCs), metals, organochlorine pesticides and polychlorinated biphenyls (PCBs), purgeable petroleum hydrocarbons, and extractable petroleum hydrocarbons. Surface and ground-water samples will be analyzed for VOCs, metals, organochlorine pesticides and PCBs, purgeable petroleum hydrocarbons, extractable petroleum hydrocarbons, and general minerals (common ions). Table 1 lists the analytical methods for soil, surface water, and ground-water 4