A field monitoring protocol was developed to provide comprehensive guidelines for developing pesticide runoff data bases for use in conducting environmental exposure assessments as part of the registration process conducted by EPA's Office of Pesticide Programs. These data bases must be carefully planned to insure that important measurements are made and that both appropriate quality and quantity data are obtained for a representative agronomic location and management scenario. Detailed guidance is provided, therefore, on site selection, experimental design, data requirements, sampling procedures, equipment, quality assurance planning, data base management, data analysis, and exposure assessment modeling.