The Use of a Multimedia Risk Analysis Approach in Designing Waste Management Strategies

Abstract

A pollution source may release residuals to any of several environmental media, depending on the process design and control strategies. These residuals then are subject to transfer, transport, and transformation within the interconnected compartments of the environmental system. The exposure and susceptibility of people and other receptors to pollutants are different in these various media, and so the risks imposed will vary according to the fate of the pollutants in the system. Because of interactions between compartments in the system, a single-medium approach to environmental management that mitigates problems in one environmental medium at a time independently of risks through other media may not minimize the aggregate risk a receptor receives from all pathways. Alternatively, a multimedia approach advocates focusing on the full environmental system providing pathways for exposure and selecting risk management strategies based on minimization of the aggregate and cumulative risk from all pathways and all compounds. This study combines multimedia risk analysis and an optimization framework to examine a methodology for selecting waste treatment/disposal and pollution control measures, applies the methodology to a sludge management decision problem, and considers the implications for continued use of single-medium analyses. IMPLICATIONSThis study demonstrates that traditional approaches to identifying optimal waste management strategies with respect to risk goals may not only incorrectly identify facilities as posing acceptable risk, but may also fail to locate the optimal strategy within the set of feasible options. Approaches based in aggregate and cumulative risk assessment are, therefore, warranted despite the increased complexity of analysis.