As environmental controls become more costly to implement and the penalties of judgment errors become more severe, environmental quality management requires more efficient management tools based on greater knowledge of the environmental phenomena to be managed. As part of this Laboratory's research on the occurrence, movement, transformation, impact and control of environmental contaminants, the Technology Development and Applications Branch develops management and engineering tools to help pollution control officials achieve water quality goals through watershed management. Agricultural sources contribute significantly to water pollution problems in many areas of the United States. This report describes part of a 2-year study in which the social, economic, legal and institutional issues involved in the management and control of pollutants from agricultural nonpoint sources were examined.