EVALUATION OF A CAPTURE ZONE OVERLAY METHOD FOR DESIGNING GROUNDWATERREMEDIATION SYSTEMS

Simplified approaches are often used to model the removal of groundwat er contamination. These approaches can yield poor remediation schemes because they incorrectly portray the effects of multiple pumping wells . In this study, a pumping configuration designed by graphically overl aying capture zones having an identical, quasi-elliptical shape was ev aluated with a numerical mass transport model. After a 3-year period ( within which the hypothetical aquifer was to be remediated) the contam inant mass had been reduced by 77%. Due to stagnation zones which deve loped between extraction wells, approximately 15 years of pumping was required to remediate the aquifer with the overlay configuration. An a lternative design, consisting of an extraction well between two inject ion wells along the long axis of the plume, removed the contaminant wi thin the 3-year design period.