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INITIAL RELEASE DDJC Tracy No public health hazards are likely to occur from exposure to VOCs in soil gas. VOC are not expected to accumulate in on-site buildings or nearby residences at concentrations that contribute to adverse human health effects. Consumption of Locally Grown Foods Walnuts, fruits, and vegetables were grown for commercial and private use on the Tracy Annex. Until 1995, three agricultural wells located in the Tracy Annex were used for flood irrigation of commercial or homegrown crops. Two of the wells were located in the VOC plume and contained TCE and PCE at levels above comparison values for drinking water. These wells have since been appropriately abandoned and sealed, and they no longer provide irrigation water for the surrounding agricultural community. ATSDR evaluated whether VOCs in irrigation water accumulated in crops to levels, if any, associated with health effects. The most accurate method for determining concentrations of these contaminants in crops is through laboratory analysis. Samples of walnuts, alfalfa, and beans were collected from the property in September 1991 for use in assessing potential contamination by PCE or TCE, or other VOCs. Although no TCE or PCE were detected in the samples, the quality of the data is in question(Woodward-Clyde Consultants, 1992b). Even if crops were irrigated with water containing the maximum detected concentration of TCE (12 ppb) or PCE (4.3 ppb), it is unlikely that plants took up significant contaminant concentrations into their edible portions. Nonpolar chemicals such as TCE tend to adsorb to root surfaces rather than pass through the outer layer of the root to the plant tissue (EPA, 1992b). Where TCE does pass through to the tissue, it most likely will transpire through the leaves, rather than accumulate in the edible portion of the plant. Therefore, trees and crops irrigated with water containing TCE and PCE levels slightly above the MCLs would not be expected to accumulate and store these chemicals in nuts, fruits, or vegetables. No public health hazards are expected to occur from consumption of locally grown fruits, nuts, and vegetables. Locally grown foods most likely have not accumulated site-related contaminants, if any, to harmful levels. Consumption of Recreationally-Caught Fish from the On-Site Stormwater Lagoon A stormwater lagoon located in the northwest corner of the site (see Figure 2) was built in 1972 to collect stormwater runoff from the depot. Through a network of underground stormwater sewers and open-surface drainage ditches, runoff and rinse water from paint stripping, degreasing, and steam-cleaning operations collected in the lagoon. Although detailed information on the use 16