Managing residual contaminants—reuse and isolation case studies

Abstract

Contaminants remaining onsite after regulatory-approved environmental remediation operations are complete represent continued risk to human health and the environment. Many sites require continued management efforts to: (1) protect the integrity of the engineered remedy/control, (2) limit the exposure of individuals to residual contamination by limiting reuse activities, (3) maintain ready access to accurate records/information, and (4) INTRODUCTIONThe return of environmentally contaminated sites to pristine conditions is often not achievable (National Research Council [NRC], 2000). Many of today's waste management techniques do not eliminate contaminants, such as hazardous and radioactive waste, but rather only concentrate and/or attempt to contain the contaminants of concern (Applegate & Dycus, 1998; NRC, 1997;Rumer & Mitchell, 1995;Russell, 2000;Suter, Luxmoore, & Smith, 1993; US EPA, 1998). Remedial decisions concerning these complex challenges often focus on mitigation actions to reduce risk (Burger, 2004b;Greenberg et al., 2002;Mayer, Faass, Greenberg, & Lewis, 2006). However, risks to human health and the environment frequently remain at many sites even after regulatory-approved environmental remediation operations are complete (US DOE, 1997DOE, , 1999DOE, , 2001. The resulting risks are associated with the residual wastes left in place or disposed of onsite in shallow burial cells, as well as residual contamination of soils, facilities, surface water, and groundwater.This article examines two prevailing management approaches for addressing the risks associated with long-term contaminant isolation. These approaches are illustrated through a series of case studies. Sacrifice zones are shown to be sites that are purposefully isolated to prevent human access onto the property. An alternative approach is illustrated at controlled reuse sites, where access is limited to specific use. Both of these management 75Managing Residual Contaminants-Reuse and Isolation Case Studies approaches employ a series of engineered and institutional controls to minimize potential exposure and associated risk. APPLICABLE U.S. REGULATIONSThe United States is addressing radioactive and hazardous waste problems by enforcing a variety of environmental regulations (the Comprehensive Environmental Response, Compensation, and Liability Act [CERCLA]; the Resource Conservation and Recovery Act [RCRA]; the Uranium Mill Tailings Radiation Control Act [UMTRCA]; and the Small Business Liability Relief and Brownfields Revitalization Act). Of particular significance is CERCLA, as amended, which establishes the framework for the federal response to the release of hazardous substances that endanger public health or the environment.The US EPA has the primary authority for implementing the provisions of CERCLA. It does so via the Superfund program that has two primary areas of focus: the long-term cleanup of contaminated sites and an emergency response program (US EPA, 2004c). As a way of prioritizing the program's work, the US EPA establishe...