An Analysis of the Wisconsin Regulations to Reduce Mercury Emissions from Coal-Fired Utility Boilers
Andrea K. Martin
Mercury is naturally emitted to the atmosphere, transported, and deposited to the land and water in a global cycle similar to the hydrologic cycle. With humankind’s industrial activities, anthropogenic mercury emissions are substantially adding to this natural cycle and to the natural background mercury deposition levels. Mercury emissions from the combustion of coal has been identified as a significant source of anthropogenic mercury emissions, The resulting increase in mercury deposition has been linked to an increase in mercury concentration in aquatic ecosystems and associated predators.
The EPA is in the process of selecting a federal mercury emission reduction regulation for coal-fired utility boilers. In 2004, Wisconsin finalized state regulations to reduce mercury emissions from coal-fired utility boilers. The effectiveness of any regulation depends on whether pollution reductions within the regulated area will result in an improved environment in that area with fair distribution of the regulatory burden and benefits. The purpose of this thesis is to evaluate the effectiveness of the Wisconsin state mercury regulations by estimating Wisconsin mercury fluxes (emissions and depositions) and predicting the impact of the proposed regulations. This was done by a numerical analysis of an inventory of 1999 mercury point sources. A cost – benefit analysis was performed.
The Wisconsin mercury regulation is negligibly effective in reducing mercury deposition within the state. With assumptions most likely over-predicting the regulation’s effect on mercury concentration in common Wisconsin fish species, the benefit of those mercury regulations on the mercury content of fish was valued at $0. The cost of the state regulation was estimated for years 2005 through 2010, the period the state regulation impacts Wisconsin utilities. The state costs were separated from the costs attributed to the federal regulation. For those scenarios where the state regulation requires mercury emissions reductions from Wisconsin coal-fired utility boilers, the cost of the state regulation is $37,500,000 (2005$). For those scenarios where the state regulation requires only monitoring and reporting, the cost is $940,000 (2005 $) over 2005 through 2010.
Additional mercury emissions data base exploration was performed illustrating the character of national mercury emissions and coal-fired utility boiler mercury emissions.