To predict the potential environmental or human health risk posed by agricultural pesticides, exposure assessments require the estimation of chemical concentrations in field runoff and in associated streams. In the report, a methodology is described for estimating the mean, maximum, frequency, and duration of pesticide concentrations, and the maximum daily pesticide runoff and its frequency for various agricultural crops and regions across the country. The Stream Transport and Agricultural Runoff of Pesticides for Exposure Assessment Methodology (called STREAM) is designed for screening level analyses to provide the order-of-magnitude accuracy appropriate for exposure assessment with minimal investment in time and resources. The specific crops included in STREAM are corn, soybeans, cotton, wheat, and sorghum.