ABSTRACT
Nutrients, pesticides, and metals are three major categories of chemical compounds that can pollute streams in forested, agricultural, urban, and mixed land use watersheds. In this chapter we examine the chemical interactions and physical processes that influence the movement of these pollutants from the land to waterways, regardless of local land use. Atmospheric deposition of pollutants and eutrophication are also defined and discussed in this chapter. Atmospheric deposition is a regional phenomenon that is partly or completely independent of local land cover or use. Eutrophic conditions, particularly in coastal estuaries, are the result of nutrient loading from large areas, including loading from atmospheric deposition, and often cannot be attributed to a particular local land use.
