S.Z. Cohen*, T. E. Durborow *, K. Balu†, and J.A. Senita**
*Environmental & Turf Services, Inc., 11141 Georgia Ave., Wheaton, Maryland, 20902 USA;
†Ciba Geigy Corp., P.O. Box 18300, Greensboro, North Carolina, 27419-8300, USA;
**currently with REMCOR, Inc., 701 Alpha Dr., Pittsburgh, Pennsylvania, 15238, USA
One of the biggest challenges facing pesticide scientists and regulatory agencies has been the reliable prediction of the environmental behavior of pesticides. Field studies are useful, but they are also costly in terms of time and money. Thus the principal focus has been on studying the basic mechanisms of persistence and mobility in the laboratory, with limited attempts to conduct the studies in a site-specific context. Yet regulatory decisions frequently require risk assessments on a site-specific basis. This is especially true for ground water concerns. Our recommended approach to ground water risk assessments is to intensively study the pesticide at a limited number of sites, calibrate a computer simulation model to the specific site(s) and study conditions, and use the model to predict subsurface behavior at other sites and under different conditions. This cost-effective but scientifically valid approach was applied successfully to the new herbicide triasulfuron (CGA-131036, the active ingredient in Amber®, a low volume sulfonylurea compound used for post-emergent weed control in wheat and barley.
Thus the purposes of this poster are to briefly summarize the ground water monitoring study and the model calibration of the monitoring results, and demonstrate how the calibrated model can be used to predict leaching patterns in other field scenarios.