Bed-Sediment Study

Map and Data for This Study

• Objective:
  Determine the occurrence of contaminants in bed sediments deposited in river channels.
• Approach:
  Fine-grained sediments were collected and composited from depositional zones at 23 surface-water sites during low-flow conditions.The composited bed-sediment sample was sieved and processed into several subsamples for analysis.
• Timing:
  Late summer and early fall of 1992 and 1993.
• Targeted Physical and Chemical Data:
  Trace elements, hydrophobic organic chemicals, total organic carbon, and particle size.
• Selected Results:
  Organochlorine pesticides were detected in bed sediments. The occurrence of these compounds in bed sediments was related to land use. Concentrations were small in forested and rangeland areas and were higher in urban, agricultural, and mixed urban/agricultural areas.