PARENT SESSION

PT07 Contaminated Harbor and River Sediment
Exhibit Hall
8:00 AM - Tuesday, 11 November 2003

(PT129) Toxicity Identification Evaluation (TIE) Results for Metal Contaminated Sediments.

Norberg-King, T¹, Hockett, J¹, Heinis, L¹, Highland, T¹, Jenson, C¹, Leonard, E¹, Mattson, V¹, Mount, D¹, ¹ USEPA, Mid-Continent Ecology Division, Duluth, MN, USA

ABSTRACT- Identification of contaminants in sediment is necessary for sound management decisions on sediment disposal, remediation, determination of ecological risk, and source identification. We have been developing sediment toxicity identification evaluation (TIE) techniques that allow researchers to characterize and identify chemical causes of acute toxicity in sediments that can be applied using the 10-d solid-phase sediment toxicity tests. In recent experiments, we spiked sediment from West Bearskin Lake (WBS) with several metals. After allowing time for equilibrium, we conducted 10-d solid phase toxicity tests with Cu-, Cd-, Zn-, Pb-, and Ni-spiked sediments and the freshwater invertebrates, Hyalella azteca and Chironomus tentans. We performed the TIE characterization manipulations to remove or detoxify the metals in sediments. These include adding zero-valent Mg, sulfide salt additions to increase acid volatile sulfide (AVS), and adding a cation exchange resin. Toxicity tests were then conducted with the amended sediment samples to determine the efficacy of each addition for removing toxicity using the endpoints of H. aztecaand C. tentans growth and survival. These TIE manipulations are effective at removing the metal toxicity from whole sediment. The relative effectiveness of each manipulation provides information on what to expect during a solid phase TIE on metal contaminated sediments. We will discuss the utility and the limits of the TIE manipulations. This abstract does not necessarily reflect EPA policy.