U.S. EPA today rolled out the final version of its updated Cross-State Air Pollution Rule, geared to cutting summertime emissions of nitrogen oxides from power plants in 22 states that contribute to downwind ozone problems.
EPA unveiled its initial proposal in November following a ruling by the U.S. Court of Appeals for the District of Columbia Circuit that found the agency's 2014 state budgets for ozone and sulfur dioxide were too strict in some cases and sent them back to EPA for reconsideration (Greenwire, July 28, 2015)
The final version, scheduled to take effect next May, drops North Carolina from the program because air quality modeling showed that the state "is not linked to any downwind or maintenance receptors," according to an agency fact sheet. The remaining states covered by the update are mainly in the eastern half of the United States, although they extend as far west as Kansas and Texas.
The update, when combined with other measures already underway, will cut NOx releases next year by some 80,000 tons in the affected states, or about a 20 percent drop from last year's levels, EPA said. The changes will yield annual benefits valued at up to $880 million, "far outweighing" the $68 million compliance cost, according to the agency's analysis.
To the dismay of environmentalists, however, the update is intended to help downwind states meet the 75-parts-per-billion air quality standard for ozone set in 2008, not the more stringent 70 ppb benchmark put in place last October.
Ozone, the main ingredient in smog, is formed by the reaction of NOx and volatile organic compounds in sunlight. "The common sense actions that power plants can take to quickly and affordably reduce this harmful pollution will help protect the health and lives of millions of Americans," acting EPA air chief Janet McCabe said in a news release today.
The updated regulations will also help improve visibility in national and state parks, according to the agency.