Decision Model Applied to Groundwater Remediation

Abstract

A decision making methodology was used to design and propose several remediation plans for a former hazardous and radioactive waste burial site. The site, situated on a 1.6 acre property located west of 44th Street in Stillwater, Oklahoma, belongs to Oklahoma State University. It was used by the University as a hazardous/radioactive waste burial area for over two decades before alternative disposal options were initiated. Since its closure, twelve groundwater monitoring wells have been installed on the site, from which periodic groundwater samples have been collected and tested for contamination. Four of the detected contaminants were used as contaminants of concern in this analysis. The contaminants were grouped into three waste categories, chemical, radioactive and mixed, for the purpose of the analysis. A spatial technique was used to estimate the distribution of each contaminant and its probability of occurring at given concentrations around the site. Five remediation technologies were considered for cleaning the site and their expected monetary values were derived based on prevalent 2009 cost data using preset time periods, a fixed interest rate and defined cost components as cost parameters. A decision tree modeling technique was used to compare possible scenarios, based on cost of implementation, to suggest the least expensive path available to achieve remediation goals. The final results from this project are recommended remediation alternatives with their accompanying costs. It was also found that cost elements such as time and waste characterization were critical to the overall remediation cost of the project.