Water-Quality Assessment of the Sacramento River Basin, California: Water-Quality, Sediment and Tissue Chemistry, and Biological Data, 1995-1998 (Open-File Report 2000-391)

Organic Contaminant and Trace Element Surveys of Streambed Sediment and Tissue of Aquatic Organisms

Two types of surveys are completed in NAWQA investigations to obtain information on the occurrence and distribution of hydrophobic organic contaminants and trace metals and other elements in streambed sediment and tissues of aquatic organisms. The Occurrence Survey is designed to provide information throughout the study unit. Sites are chosen on the major rivers and on smaller streams which may be important because of land uses (transport of pesticides or other organic contaminants, or metals) or because of distinctive geological features (geological deposits of specific trace metals, for example). Interpretation of data from the Occurrence Survey leads to the design of a Spatial Distribution Survey. A Spatial Distribution Survey is designed to provide more information on the distribution of specific contaminants within a study unit. The Spatial Distribution Survey for the Sacramento River Basin study was focused on trace elements, specifically mercury.

Occurrence Survey

Spatial Distribution Survey for Metals in Streambed Sediment