Contaminants modeling with TOXI5

Control of toxics pollution in surface waters requires an adequate knowledge of transport and transformation phenomena which address these substances to their final fate; thus, the application of models could provide a quantitative assessment of their effects on the aquatic ecosystem. The Water Quality Analysis Simulation Program (WASP), which has been developed by US EPA, is one of the more widely applied modeling systems to study water quality problems in streams, lakes and estuaries. In this paper, TOXI5, which is the part of WASP addressed to toxics pollution problem, has been applied to a case study in a flooded limestone quarry located in Bedford County, Indiana, which has been previously polluted with equal quantities of the insecticides DDE and Lindane. The results obtained show a good agreement with field observations; particularly, model results point out the different removal mechanism for DDE and Lindane