More than 90% of our existing mercury emissions into the Great Lakes can be eliminated using current technology

The Natural Resources Defense Council states the following:
Poisoning the Great Lakes

Mercury Emissions from Coal-Fired Power Plants In the Great Lakes Region

Mercury emitted into the air from coal-fired power plants is by far the leading man-made source of mercury in the Great Lakes and the rivers and streams of the region. This new NRDC report analyzed pollution data to determine the top 25 mercury emitting power plants in the Great Lakes states, and the top three in each state. The U.S. Environmental Protection Agency (EPA) recently issued nationwide standards to limit airborne mercury emissions and other toxic air pollutants from coal-fired power plants by 2015. Currently, not all states require that pollution controls be installed, including the report's top three culprit's: Indiana, Ohio and Pennsylvania. The report also highlights how a significant fraction of mercury and other air toxics emitted by the worst plants can be removed by air pollution controls already or soon to be installed at many power plants. Other technology that would achieve an overall reduction in mercury of 90 percent or more is readily available.
http://www.nrdc.org/air/mercury-in-the-great-lakes.asp
http://thinkprogress.org/climate/2012/06/08/496598/power-plant-mercury-emissions-poisoning-the-great-lakes/

and for more general info,  http://www.cleanwateraction.org/press/coal-plant-water-pollution-threatens-great-lakes

Thanks, Janice