WORK PLANS - Laserfiche WebLink

Home Browse Search

INITIAL RELEASE DDJC Tracy the excavated material with soil that has been certified as clean. The clean soil has been capped with a layer of sod (DDJC Tracy 1995; 1997a). ATSDR evaluated whether children who attend the Day Care Center are potentially exposed to the contaminants via incidental ingestion of the play yard surface soil at levels known to cause health effects. In evaluating exposure to soil contaminants via incidental ingestion, ATSDR assumes that uptake via ingestion is greater than through skin ingestion. The methods used and assumptions applied are presented in Appendix C. ATSDR believes that the assumptions used to estimate exposure doses are very conservative and, therefore, overestimate the level of actual exposure for a child playing in the Day Care Center yard. The estimated exposure doses for a child are provided in Appendix C, Table C-3. Even using very conservative assumptions about exposure, the estimated exposure doses are lower than corresponding MRLs or RfDs. Therefore, incidental ingestion of surface soil is not expected to result in adverse health effects for young children playing in the Day Care Center yard. Even if one assumes the highly conservative assumption that contaminant concentrations entering the body through dermal contact are approximately equal to ingestion, dermal contact with surface soil likewise is unlikely to lead to adverse health effects. Areas Under Investigation A total of 66 areas have been investigated at DDJC Tracy, including 28 SWMUs, 28 USTs, and 10 areas of soil contamination. For a majority of these areas, no public health hazard exists because the levels of contamination in soil.are lower than levels associated with health hazard, exposure has been prevented by access restrictions (i.e., site security), and/or contaminated areas will be remediated. DDJC Tracy has designated certain areas of soil contamination for remediation (i.e., SWMUs 8 and 24) because they pose a potential threat to the underlying groundwater. After considering the limited access to the site and reviewing the pertinent environmental monitoring data, ATSDR determined that workers and visitors at the site are not likely to have frequent or long-term contact with contaminated soil in these areas. Exposure, if any, is not expected to result in adverse health effects. Areas of Exposed Surface Soil Most of the areas are paved or contain buildings. Few areas of exposed soil exist along the boundaries. DDJC Tracy analyzed samples from the exposed soil areas in 1993 and 1994, and Table 7 shows the results of these analyses. As the table indicates, the metals arsenic and beryllium have frequently been detected at levels above the comparison values, whereas the 14