Evaluation of vadose zone fate and transport of pesticides using numerical models can be an effective tool in managing pesticide environmental risks in regions experiencing water quality impairment such as the High Plains aquifer. The Environmental Protection Agency (EPA), under the 1947 Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and amendments, maintains responsibility for balancing "adverse environmental effects" against the economic benefits of pesticide use in approving chemical registration and applicator certification. Until recently, evaluations of aquifer vulnerability have historically been more empirical rather than quantitative, limiting assessment of various agricultural scenarios. Using measured data from [...]
