Curtailing A Clean Air Rule

Because a federal court recently overturned a key Clean Air Act regulation, two powerful Senate Democrats are asking EPA not to issue a pending related rule that would relax some emission controls on power plants.

The pending rule, which the Bush Administration has indicated it will finalize in coming weeks, is expected to boost air pollution from coal-fired power plants. This in turn is likely to pressure state environmental regulators to impose more stringent emission controls on other industries, possibly including chemical plants, to maintain air quality.

Proposed in 2005, the pending rule would allow utilities to renovate and expand the operating capacity of older power plants without having to install modern air pollution controls. This would be the case as long as a plant's hourly average emissions did not increase—even if its annual emissions rose because the upgraded facility could operate for more hours than before.

In the proposal, EPA said any increase in annual pollution from power plants due to these proposed changes would be offset by another regulation called the Clean Air Interstate Rule (CAIR). Issued in 2005, CAIR called for cuts in emissions of sulfur dioxide, which contributes to particle pollution, and nitrogen oxides, which are precursors to ground-level ozone, from power plants in 28 eastern states.

But a federal appeals court threw out CAIR in July, saying the regulation was flawed and unsalvageable (C&EN, July 21, page 12).

EPA needs to withdraw the pending rule because CAIR no longer exists, say Sens. Barbara Boxer (D-Calif.), who chairs the Senate Environment & Public Works Committee, and Thomas R. Carper (D-Del.), who chairs the panel's Subcommittee on Clean Air & Nuclear Safety.

"At a minimum, the agency must repropose" the pending rule and justify it in the absence of CAIR, Boxer and Carper say in an Oct. 24 letter to EPA Administrator Stephen L. Johnson. For its part, EPA spokesman Jonathan Schradar says, "Work continues on the rule, and our goal is to finish it before the end of the Administration."