Influence of remediation on sediment toxicity within the Grand Calumet River, Indiana

Session: Chemical Contaminants (3)

Rebecca Dorman, U.S. Geological Survey, [email protected]
Jeffery Steevens, U.S. Geological Survey, [email protected]
John Besser, U.S. Geological Survey, [email protected]
Daniel Sparks, US Fish and Wildlife Service, [email protected]

Abstract

The Grand Calumet River, located in northern Indiana, is a historically contaminated system due to a wide range of industrial activities. This study was conducted to determine the influence of sediment remediation within the Grand Calumet River on the level of contamination and toxicity on sediment dwelling organisms.  Sediments with high concentrations of metals and organic compounds were remediated between 2005 and 2016.  A combination of acute and chronic sediment toxicity tests were conducted over a span of 7 years using the amphipod Hyalella azteca, the midge Chironomus dilutus, and the mussel Lampsilis siliquoidea, in sediments from 29 sites that included remediated and non-remediated sites. Previous studies focused on short-term exposures to evaluate the severity of sediment contamination at the site, with results of longer-term exposures conducted to determine if sediments remaining in the GCR with lower concentrations of contaminants after remediation may still be toxic. The chemistry and bioassay lines-of-evidence were evaluated across three regions of remediated sites and compared to non-remediated locations.  Temporal trends indicate there is a wide range of toxicity in both reference and non-remediated sites that may be due to year-to-year variation that is not related to remediation or other confounding factors associated with the