Modeling Approach for Regulatory Assessment of Turf and Golf Course Pesticide Runoff

The U.S. Environmental Protection Agency (EPA) uses the models PRZM (Pesticide Root Zone Model) and EXAMS (Exposure Analysis Modeling System) to estimate environmental concentrations (EEC) of pesticides for aquatic exposure assessments and the estimated drinking water concentrations (EDWC) of pesticides for human exposure assessments. To address turf chemicals, EPA has developed specific scenarios for PRZM-EXAMS that estimate runoff of pesticides from managed turf grass. This paper discusses these turf scenarios and associated adjustment factors that are applied to model outputs specifically for golf courses.