Cost-Benefit Analysis of Cosolvent Flushing to Treat Groundwater Contamination Source Areas

Dense non-aqueous phase liquids (DNAPLs) in the zone beneath the water table can be a virtually permanent source of groundwater contamination that cannot be remediated by currently available technologies. Cosolvent flushing is a new technology that has the potential to remediate these sites and could pose a solution to the problem of DNAPL source areas.A computer model was developed to determine the cost and time to remediate an aquifer using cosolvent flushing. Included in the model is a module to calculate costs of recycling the alcohol that is used as the cosolvent. The model was validated using site conditions to a prior study. It was determined that recycling the cosolvent allows cosolvent flushing to be a cost effective alternative to surfactant flushing, another new technology being considered for DNAPL source area remediation.