Transport of sediment and associated contaminants in streams is a water-quality issue of national concern. Of the nearly 600 x 107 tons of material eroded annually in the United States only about one tenth of the material reaches the coasts. Much of the sediment is stored on hillslopes, floodplains and other parts of stream valleys causing extensive damage to man's works in the river environment. Toxins sorbed to sediment are not only expensive to remediate but can be a large public heath risk. The determination of contaminant flux is an important step in evaluating remediation priorities and assessing progress in solving water quality problems.