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1 1 1 1 1 1 1 1 FJ n [1 Consent Decree Exhibit C data from these wells indicate that even where there is no separation between the shallow aquifer and the deep aquifer, there has not been a significant impact to the deep aquifer. • Existing cover soils on the Everett Landfill/Tire Fire Site have significantly reduced potential recharge from precipitation and near surface stormwater recharge to the shallow aquifer. Improvements in site cover will further reduce the amount of leachate generated. • Contaminant concentrations detected in the shallow aquifer are below cleanup levels in most instances. Variable exceedances have occurred in discrete wells. Overall, the data do not indicate that widespread contamination remains in the leachate, which, as presented in the previous section, is consistent with the landfill setting and history. Analytical testing indicates that only four compounds (bis(2-ethylhexyl)phthalate, copper, lead, and zinc) have been detected in the deep aquifer in exceedance of cleanup levels. Bis(2- ethylhexyl)phthalate was the only such exceedance in the most recent (1999) deep aquifer sampling event, and this compound exceeded cleanup levels in only two wells. Because the sampling procedures and monitoring well network have varied between sampling rounds, Evaluation Monitoring will determine if deep aquifer exceedances are statistically significant (e.g., bis(2-ethylhexyl)phthalate may be a laboratory contaminant; metal exceedances may be due to excess sample turbidity or describe area background conditions). 3.3 DIRECT CONTACT EXPOSURE PATHWAY 3.3.1 Direct Contact ARARs Potential ARARs for the Everett Landfill/Tire Fire Site are described in an attachment CAP-1. ARARs specific to the direct contact exposure pathway are listed below. • Occupational Safety and Health Act (OSHA), 29 U.S.C. 653, 655, 657; Occupational Safety and Health Standards, 29 CFR 1910 • Washington Industrial Safety and Health Act (WISHA), RCW 49.17; Washington Industrial Safety and Health Regulations, WAC 296-62, WAC 296-155 3.3.2 Direct Contact Cleanup Standards In order to address the potential direct contact hazards of buried refuse and tire fire ash, performance objectives, rather than cleanup levels, are proposed. Prevent public contact with landfill materials. In this case, the public is defined as any individual not trained in health and safety precautions, and not associated with construction or maintenance activities at the Site. 2. Control vector and nuisance conditions, such as human pathogen vectors and exposed refuse. The point of compliance for this pathway is at the surface of the Site, where either humans or wildlife could come in direct contact with contaminated material. Under both existing and future FINAL - March 2001 3-5 Everett Landfill Tire Fire Site Cleanup Action Plan 11