WASHINGTON—The key to the Bush administration's mercury rule for power plants is trading pollution credits, a system that proved wildly successful in reducing acid rain under a 1990 rule.
Power plants get "allowances" to spew a certain number of pounds of mercury pollution based on a certain number of credits for each state.
If a power plant—usually a newer one—can reduce pollution more than required, it can then sell allowances to another power plant.
Power plants that are having trouble cleaning up can then buy allowances instead of reducing pollution.
Limits on pollution go into effect in 2010 and are tightened again in 2018.
The Environmental Protection Agency expects mercury pollution to have a value of about $76 million a ton in 2020. Each year, plants emit 48 tons of mercury into the air over the United States.
Because of the way allowances are distributed, some states will have to cut emissions faster than others. Nineteen states—including California, Missouri, Minnesota, New Jersey, South Carolina, North Dakota and South Dakota—can even increase emissions of mercury from power plants by 2010.
And states that burn western coal, which has lower heat output but from which it is harder to remove mercury, will benefit more. Texas will only have to reduce its mercury emissions by 7 percent by 2010. Pennsylvania, Ohio, North Carolina, Georgia and Michigan—all of which produce less mercury pollution than Texas—have to cut by 64 percent, 42 percent, 26 percent, 18 percent and 15 percent, respectively.
(c) 2005, Knight Ridder/Tribune Information Services.
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