Applications of three completely mixed compartment models to the long-term fate of dieldrin in a reservoir

Three chemical fate models (SLSA, TOXIC and EXAMS II) were applied to a flood control/recreational reservoir in Iowa to assess the long-term fate of a persistent chemical, dieldrin. These models were validated via calibration, verification and sensitivity analysis based on 16 years of field data sets. The three models were calibrated interactively to supplement the shortcomings of an individual model and minimize differences between them. The results indicated that these models can serve as useful tools for assessing the long-term fate of persistent chemicals, as long as the user is fully aware of the model assumptions and limitations. The models were discussed in terms of differences, assumptions and limitations to aid model users in their understanding and in the proper choice of the models for their applications.