THE EFFECT OF COAL-FIRED POWER PLANT EMISSIONS AND FLY ASH ON A REGIONAL WATERSHED

The use of coal as a source for power generation is amplified, as global energy demands continue to increase. Extensive coal reserves in localized regions of the U.S. have attracted large scale power plants; these areas often remain riddled with abandoned and unreclaimed mines from previous mining. The combination of nearby coal reserves and accessible low-cost abandoned mines provides an ideal location for power generation and fly ash disposal. Fly ash, the waste product of coal combustion, concentrates inorganic non-combustibles such as heavy and trace metals. This increases the potential for localized environmental damage if emissions and fly ash reach the environment in appreciable amounts. In order to assess the impact of coal power production on local watersheds, we determined the major element, trace metal and isotopic chemistry of a regional reservoir located in the anthracite coal fields of eastern PA. The focus of the study involved quantifying the effects of wet and dry deposition of fly ash and inorganic aerosols from power plant emissions and mine reclamation by observing spatial variations in precipitation, surface sediments and water chemistry. Major cations (Ca, Mg, Na, K) and anions (Cl-, NO3-, SO42-) were determined by ion chromatography while trace metal analysis (Cr, Mo, Zn, Cd, Se, Hg, Pb, Th, U, etc.) was completed using standard ICP-MS techniques for waters and sediments. Because of the high distribution coefficients of heavy metals (KD), sediments provide more information about metal deposition resulting from natural and anthropogenic sources. The role of each source was investigated using the spatial distributions of metals relative to the power plants, highways and other pollution sources. A sediment core from within the reservoir was analyzed to observe whether any changes in metal chemistry have occurred in recent decades as coal-fired power production and fly ash mine reclamation commenced. Sampling and analysis is ongoing. Initial results indicate that reservoir water meets EPA standards because of the high KD for metals. Some sediments do show a measurable (but relatively low) anthropogenic input of trace metals with a combination of sources, vehicular and coal combustion. In the sediment core, younger sediments show higher levels of many trace metals and an attempt to isolate the source and timing of additional trace metal input continues.