exposure to lead and to control transport of lead and zinc downriver. Major cleanup activities by mining companies, the state of Idaho, and EPA have included regrading and/or removing mine tailings and sediment from many areas in the floodplain of the Coeur d’Alene River; constructing a central impoundment area (CIA) for the storage and isolation of mine tailings and contaminated sediments; operating the central (water) treatment plant (CTP) for treatment of acid mine drainage; remediating contaminated areas in the former smelter complex; and removing contaminated soil from yards and public areas to lower the exposure of children to lead contamination. The ROD for OU-3 was developed through the remedial investigation/feasibility study (RI/FS) process and is intended to interact with and take advantage of remedial actions taken under the RODs for OU-1 and OU-2. In essence, the ROD for OU-3 was the next step in addressing basin-wide human health and environmental issues caused by past mining operations.
As provided in the statement of task (see Appendix A), the committee is charged with assessing the scientific and technical aspects of EPA’s remedial objectives and approaches set forth to address environmental contamination in OU-3 of the Coeur d’Alene River basin Superfund site.
One of the purposes of the feasibility study (FS) (URS Greiner, Inc. and CH2M Hill 2001a), which was prepared under contract for EPA, was to develop remedial action objectives (RAOs). The RAOs are long-term goals for cleanup and recovery from historic effects of mining in the Coeur d’Alene River basin and focus on protecting human health and ecologic receptors (for example, fish and wildlife). They are intended to provide a general description of the goals of the overall cleanup (EPA 2002, p. 8-1). These objectives, described below, are inclusive of the expected sources of contaminants and routes of exposure to humans and ecologic receptors.
RAOs for protection of human health are designed primarily to reduce human exposure to lead-contaminated soils, sediments, and house dust to protect children; reduce human exposure to contaminated soils and sediments to lower the risks of cancer; and reduce ingestion of groundwater and surface waters from private, unregulated sources that do not meet drinking water standards (EPA 2002, p. 8-1). RAOs for protecting human health that are specific to environmental media (for example, water and soil) are described in Table 8-1 (EPA 2002, Table 8.1-1) and applicable and