A methodology developed by the U.S. Environmental Protection Agency (U.S. EPA) for evaluating the mass transport potential of hazardous organic compounds through environmental pathways is used to determine the potential mobility of eight chlorinated and organophosphorus pesticides in soil systems. Soil treatability studies are conducted to determine first‐order degradation constants. Partition coefficients among water, soil, and air phases are calculated. Results of the treatability study along with calculated partition coefficients are used as input to a finite difference mathematical model to evaluate mass transport potential, including amount and extent of movement, through environmental pathways to groundwater and to the atmosphere. Application of the model using results of the treatability studies provides a methodology for predicting the behavior of hazardous constituents in soil systems, and for ranking chemicals with regard to the need for management and control for protection of public health and the environment.