Multi-Criteria Decision Analysis and the Tar Creek Superfund Site

Abstract

The Tri-State Mining District was formed to encompass areas of Oklahoma, Kansas, and Missouri where lead, zinc, and other metals were mined from the 1900s until the 1960s. Tar Creek in Ottowa County, Oklahoma was the recipient of much of the mining waste generated during this period. The Tar Creek watershed is an approximately 53.3-square-mile area, where 19,566 people reside. It is characterized by high heavy metal soil concentrations, contaminated surface and ground waters, air transport of contaminants, and exposed mining wastes. There are human health and ecological exposure hazards from these media. A need for evaluations of long-term solutions that could be constructed or implemented to improve the ecosystems is apparent. There has been a movement toward a more ‘holistic’ response to human health and wildlife risks at and adjacent to Tar Creek, including determining problems affecting residents and identifying appropriate remedial actions. In 1983, the area along Tar Creek was listed on the National Priority List (NPL) as a Superfund Site. The Environmental Protection Agency signed a Memorandum of Understanding with United States Army Corps of Engineers and the Department of Interior in 2003 to collaborate on assessment and remediation efforts with multiple stakeholders, which include tribal authorities, local interest parties, and other entities. Multi-Criteria Decision Analysis (MCDA) is a systematic and structured process beneficial to users during the pre- and postphase of decision making. MCDA could prove an asset to the Tar Creek project, particularly when dealing with multiple stakeholders coupled with numerous remediation objectives and risk remedies, by applying decision processes such as Analytical Hierarchy Process (AHP) and Multi-Attribute Utility Theory (MAUT). Commercial software packages use decision processes as engines; for example, Expert Choice® utilizes AHP while Criterium DecisionPlus® exercises MAUT. MCDA, paired with decision-making tools, provides the results of modeling/-monitoring studies, risk analysis, cost, and stakeholder preferences so that risk managers are able to systematically evaluate and compare alternatives and actions supporting risk management and thus credibly prioritize resources. The following sections will discuss the background and history of the Tar Creek Superfund Site, the MCDA framework/structure, commonly used MCDA tools in conjunction with theories, and a methodology for how MCDA can be effectively used at the site.