Deposition of Heavy Metals From Coal Combustion On Agricultural Lands.

Coal-fired power plants (CFPP) produce over 100 million tons of fly ash per year by nearly 500 power stations in the United States alone. Heavy metals are emitted during coal combustion through the production and release of fly ash particles containing a mixture of unburned carbon and toxic metals including mercury (Hg), arsenic (As), cadmium (Cd), and lead (Pb).  CFPPs are responsible for one third of all human-induced Hg emissions and 60% of As released from point sources. In the current study, we are developing a model that approximates the amount of heavy metals deposited on agricultural lands around CFPPs in the Midwestern United States based on current emission rates with the potential of estimating the possible deposition rates when various emission standards are implemented. To do so, we are creating a GIS-based spatial model composed of multiple modules to input information regarding coal feed composition and grade, power plant capacity and particulate control device implementation, atmospheric transport, soil chemistry, and crop distribution. Ultimately, this tool will aid in assessing the distribution of fly ash on croplands in the vicinity of power plants at a regional scale and estimating the amount of heavy metals in agricultural soils originating from coal-fired plants that can potentially be taken up by crops.