Sampling Purpose: In 1994, after the 1993 flood, bed-sediment samples were collected from Pools 1 - 26 on the Upper Mississippi River and the St. Croix River, and were analyzed for simultaneously extracted metals, acid-volatile sulfide, polynuclear aromatic hydrocarbons, polychlorinated biphenyls, organochlorines, and fungicides. This data set contains two types of sediment grab samples ("B" and "C" samples). The "B" samples were a composite of 15-20 grabs collected along 1 to 5 transects at the lower end of each pool. Because the "B" samples represent a large spatial area, the coordinates (UTM) for the first sample, collected along the first transect, were entered in the database to provide positional information. We did not enter all of the "B" sample contaminant data in this data set (No. 33) because the majority of the contaminant data was already reported in Data Set No. 26. The "B" samples were split at the time of collection, and were analyzed by two different laboratories. To avoid sample overlap, we only entered contaminant data not reported in Data Set No. 26. The "C" samples were collected at the same time as the "B" samples, but from one station, on one of the transects, and therefore, the river mile and sample coordinates are more accurate than the "B" samples. All of the "C" sample contaminant data was entered in the database. In addition, whole-sediment toxicity tests with amphipods were conducted on the "C" samples and are reported in the database.
Note: This report contains additional contaminant data that is not listed in the database, and therefore, was not entered.