Sampling Purpose: The U.S. Geological Survey (USGS) collected sediment samples after the flood of 1993 from 24 of the 29 navigation pools on the Upper Mississippi River (UMR). Composite sediment grab and core samples were collected from the lower one-third of each pool. These were the same locations sampled in 1991-1992 by the USGS (Data Set 25). Samples were analyzed for total, organic, and carbonate carbon, total nitrogen, particle size, metals, polynuclear aromatic hydrocarbons, organochlorines, polychlorinated biphenyls, herbicides, fungicides, and sterols. Because each sample represents a large spatial area, the coordinates (UTM) for the first sample, collected along the first transect, were entered into the database to provide positional information.
Note: Supplementary contaminant and toxicity data pertaining to this data set can be found in Data Set 33. Sediment samples were split with another division of the USGS, and analyzed for additional contaminants that are not already reported in this study.