Results for Study GW10A: Ground Water Protection List Monitoring for Azoxystrobin, Chlorothalonil, Dichloran, and Iprodione
Abstract
The California Department of Pesticide Regulation’s (DPR) Environmental Monitoring Branch (EMB) collected ground water samples from 184 wells in areas with high use of four agricultural fungicides—azoxystrobin, chlorothalonil, dichloran, and iprodione. None of the fungicide active ingredients were detected in ground water. Ninety-two of the wells sampled were located in high-use areas of azoxystrobin, a systemic fungicide that is primarily applied to rice, grapes, and almonds. Three of the wells located in the rice-growing region of Glenn County had detectable levels of azoxystrobin acid, a degradate of azoxystrobin. In this study, the application of azoxystrobin to rice was not the focus; a majority of the ground water samples collected were located in areas where other crops were grown. Additional studies should be conducted in the rice-growing region of California to determine if azoxystrobin or azoxystrobin acid are migrating to the ground water as a result of use on rice.