Assessing the impact of the 1985 farm bill on sediment-related nonpoint source pollution

Abstract

In the United States patterns of suspended sediment concentration in rivers reflect the influence of factors such as climate (e.g., precipitation intensity and duration) and the properties of the rocks and soils that are exposed to erosion (Meade and Parker). There are approximately 6 million hectares of highly erodible land 1 in the conterminous United States (accounting for about 33% of the total cropland acreage [CTIC]). Thus, it is estimated that nonpoint sources make the dominant contribution to surface water pollution, that agriculture is the predominant primary source of nonpoint pollution, and that sediment is the most pervasive nonpoint pollutant (EPA 1987; USDA 1991).