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Deadwell&Rollo <br /> • <br /> 3.1 Remedial Action Objectives <br /> Remedial action objectives are the post-remediation goals for protecting human health and the <br /> environment, specific to the contaminated media and operable unit. For the North Shore Parcels, <br /> the contaminated medium in OU 1 is soil. OU 2 contains both contaminated soil and <br /> groundwater. The basis for identifying remedial action objectives are worker and public health <br /> concerns, environmental concerns, and compliance with Applicable or Relevant and Appropriate <br /> Requirements (ARARs). <br /> Remedial action objectives for each OU are summarized in Table 2. For human health <br /> protection, the aggregate risks associated with a remediated site should fall within the excess <br /> cancer risk range of 1x10-4 and 1x10-6, and aggregate noncarcinogenic risks should have a <br /> Hazard Index of less than 1.0. Selected remedial actions for OU 1 and 2 result in residual risks <br /> within these ranges. <br /> • <br /> 3.2 Operable Unit 1 <br /> Operable Unit 1 (OU 1) is comprised of Areas 10, 11, and 20. As described in Section 2.0, these <br /> sites are characterized by shallow soil contamination comprised of heavy petroleum <br /> hydrocarbons, polynuclear aromatic hydrocarbons (PNAs) and metals, specifically total lead and <br /> arsenic. As discussed in the Risk Assessment,the current unremediated total excess cancer risk <br /> for Areas 10, 11, and 20 ranges from 3.0E-04 (Area 20 landscape maintenance worker)to 1E-06 <br /> (Area 11 construction worker). All arsenic concentrations, including those at and below <br /> background level,have been included in these calculations, to be conservative. Predicted blood <br /> lead concentrations exceed 10 ug/dl at Area 11 only, at 11.4 ug/dl for residential children. <br /> No specific source areas have been identified at any of the three sites. No significant <br /> groundwater contamination has been found at OU 1. <br /> Cancer risk at Area 10 is driven by PNAs and arsenic in soil. PNAs were found in the upper 3 to <br /> • 6 feet of soil at eight sampling locations (1013-3, 4, 6, 7, 15, 17, 18, and 23). Arsenic exceeds the <br /> 17 <br /> 25970318.PGS 15 November 2000 <br />