Preventing mercury emissions from coal-fired power plants using environmentally preferable coal purchasing practices

Electric utilities in the United States will soon be required under the federal Environmental Protection Agency's Clean Air Mercury Rule to significantly reduce mercury emissions. Coal-fired power plants, including the Lower Colorado River Authority's (LCRA) Fayette Power Project (FPP) have demonstrated that the selective purchasing of coal with low mercury content can result in significant reduction of pollution. This selective activity, commonly known as “green purchasing”, has been applied to the procurement of coal. For example, the use of low-sulfur coal from the Powder River Basin deposits of Wyoming results in the prevention of a significant amount of sulfur dioxide (SO2) releases to the atmosphere when compared to other sources of coal in the United States. This same philosophy (selective purchasing of coal) can be employed to prevent mercury emissions and substantially reduce mercury removal costs for electric utilities burning coal. Data analysis confirms that low-mercury coal is available and that selective purchasing of low-mercury coal is possible.LCRA has implemented an extensive pollution prevention program and their green purchasing efforts have been expanded to influence coal purchasing choices. Coal purchasing is limited to the Gillette Coal Field from the Powder River Basin (PRB) of Wyoming. Three sets of coal quality data which include LCRA's Coal Quality Database (CQD), a database created from the Information Collection Request (ICR) conducted by the EPA in 1999, and the U.S. Geological Survey (USGS) Coal Quality (COALQUAL) Database were analyzed. Lab accuracy issues were found to have undermined the reliability of certain records in both the CQD and ICR databases, however, both remain valuable resources. The independent sets of coal quality data and technical reports show measurable differences in mercury concentration in coal in the Gillette Coal Field, both geographically (coal mine) and by depth (coal seam). A preliminary cost benefit analysis indicates that substantial cost savings in operating and maintaining mercury control equipment will be realized with low-mercury coal. Currently, low-mercury coal can be purchased without a significant premium.