Mercury Rule Overturned

Congress and EPA are weighing their options now that a federal appeals court has thrown out a rule to reduce mercury emissions from coal-fired power plants.

The Feb. 8 court decision overturned what the Bush Administration emphasizes was the world's only nationwide control on mercury released by electricity generators. But the decision does not leave all coal-fired power plants in the U.S. off the hook. Many states are requiring these facilities to make significantly faster and deeper cuts in emissions of the neurotoxic metal than EPA's rule did.

EPA's regulation, favored by utilities, would reduce the 48 tons of mercury emitted by power plants annually by 69% sometime after 2018, perhaps as late as 2025. Administration officials, however, acknowledged that electricity generators essentially had to do nothing to meet the rule's first round of mercury reductions, which were to lower nationwide emissions to 38 tons per year by 2010. Instead, the coal-burning generators would capture mercury as a side effect of another regulation. That rule would curb emissions of sulfur dioxide and nitrogen oxides—which cause acid rain, particle pollution, and smog—from power plants in 28 eastern states.

Perhaps the most controversial part of the overturned rule was that it would allow power plants to buy and sell allowances to release mercury. Generators that cleaned up their emissions could sell excess allowances to dirtier facilities.

To pave the way for this cap-and-trade program, EPA removed utilities from a list of sources whose emissions must be tightly controlled under the Clean Air Act. It was that action that the U.S. Court of Appeals for the District of Columbia Circuit determined was unlawful.

Now, EPA could take a new regulatory approach on its own, or Congress could give the agency explicit instructions to act. Sources on Capitol Hill say a provision on mercury could end up in climate-change legislation currently working its way through the Senate.

The case against EPA was brought by 17 states and several environmental groups.