A good visibility day in Smoky Mountains National Park

The effects of air pollution are apparent in this shot, taken in the same spot as shown above.

The settlement stems from a lawsuit against the agency, brought by Earthjustice on behalf of Environmental Defense, to compel new regulations requiring power plants and factories to install the best available retrofit technology (BART) to control sulfur dioxide and other emissions. These emissions lead to visibility impairment, which is widespread throughout the national park system.

The mean visual range in Eastern “Class I” areas, which include national parks and wilderness areas, was 14.4 miles in 1999; yet without man-made air pollution, visibility would be about 45-90 miles, according to EPA. In the West, the mean visual range was 48 miles for Class I areas, compared to an estimated natural visibility of 120-180 miles.

“Cleaning up the power plants and other industrial sources that pollute our national parks and wilderness areas will protect some of the nation’s most revered scenic vistas,” said Environmental Defense senior attorney Vickie Patton.

EPA previously issued standards requiring power plants and factories to install BART to control emissions as part of a regional haze program established in 1999. In 2001, at the very end of the Clinton administration, the agency also completed proposed standards to help states determine which plants should install BART controls.

In 2002, however, efforts to implement the BART controls stalled when the U.S. Court of Appeals for the D.C. Circuit overturned parts of the 1999 regional haze rule related to BART, saying they improperly infringed on state authority. The court ordered EPA to re-write the BART provisions, yet up until this point, the agency has failed to even issue a proposal.

In settling the lawsuit, EPA agreed to issue proposed rules by April 2004 and adopt final rules one year later. The settlement will be opened for a public comment period and must be approved by the court before it is finalized.