PARENT SESSION
TA6 - Bioavailability Issues in Bioremediation of Contaminated Sediments
Chair: Tabak, Henry1, 1 U.S. EPA, Cincinnati, OH
Co-chair: Lazorchak, Jim2, 2 U.S. EPA, Cincinnati, OH
8:00 AM to 12:00 PM - Tuesday, 19 November 2002
Room Ballroom B
(373) Post-cleanup Monitoring and Fate of Coal Tar in Chattanooga Creek Sediments.
Vulava, V*,1, Menn, F-M1, McKay, L1, Easter, J1, Saylor, G1, 1 The University of Tennessee, Knoxville, TN
ABSTRACT- Coal coking operations at an industrial site (Tennessee Products Site or TP Site) in south Chattanooga, TN resulted in the release of large volumes of coal tar, creosote, and other dense non-aqueous phase liquids (DNAPLs) between 1918 and 1987. This has led to extensive contamination of soils and bedrock at the plant site, as well as in nearby Chattanooga Creek and the surrounding floodplain. Deposits of immiscible coal tar up to 4 feet thick were found in the creek and were apparently caused by runoff from the site through ditches and a storm drain system. Chemicals measured in the creek sediments include coal tar compounds (PAHs, VOCs, SVOCs, NSO-compounds, etc.), PCBs, chlorinated solvents, and heavy metals. The creek and floodplain were placed on the National Priorities List and in 1997, US EPA initiated a remedial action program which included dredging of coal tar and contaminated sediments from a 1.0 mile stretch of the creek. Another 1.5 miles of contaminated creek sediments are scheduled for future cleanup. The main objective of this study is to assess the effectiveness of excavation methods for removal of coal tar compounds from creek bottoms, and the influence of such methods on water quality and the ecology of streams. Initially, we are monitoring chemical concentration in the stream and the sediments, but we also propose to test the applicability of molecular-based microbial ecology monitoring as an indicator of the effectiveness of dredging as a remediation method. We expect this to be a valuable supplement to contaminant concentration monitoring, which can be strongly influenced by dilution and short-term changes in flow rate, and it may prove to be less expensive and more sensitive than other types of ecological monitoring.
Key words: coal tar, Chattanooga Creek, creek sediments