GEOCHEMICAL SIGNATURES OF POWER PLANT EMISSIONS AS REVEALED IN SEDIMENT CORES FROM WEST VIRGINIA RESERVOIRS

Only recently have electric utility power plant emissions been included on EPA’s Toxic Release Inventory which reported that electric utilities ranked highest for industrial toxic air emissions in 1998. These emissions were likely an important component of toxic air releases in the past, particularly prior to the Clean Air Act of 1970.

Sediment cores were taken from two reservoirs located in the northern part of West Virginia for the purpose of identifying particulate signatures of coal-fired power plant emissions from the Ohio River Valley region. Sediments were analyzed for major-minor-trace elements, magnetic properties, Cesium-137, and PAH’s. The temporal distributions of sedimentary As, Pb, Zn, and magnetite show pronounced peaks dated about 1969. Spherical magnetite with internal metallographic texture, indicative of combustion rather than detrital origin, dominates the magnetic properties of the sediment. The trace element peaks and the excellent correlation between elements and magnetite suggest that the amount of power plant particulate emissions in the Mid-Atlantic Region has decreased dramatically in the 1970s.

Regional distributions of sedimentary Pb and Zn commonly reflect vehicle-related influences (e.g., leaded gasoline and rubber-tire emissions). However, the proximity of the West Virginia cores to major power plants, rural nature of the study site, correlation with As, which is enriched in Appalachian Basin coal, and the timing of Pb peaks (1969 versus 1975 for leaded gasoline) suggest that these metal distributions are dominantly controlled by power plant emissions. Furthermore, reanalysis of stream sediments collected in this region during the NURE program shows elevated As along the Ohio River Valley, indicating a regional impact on the geochemical landscape.