WALLAND, TN (Times Free Press) - The mountains of East Tennessee are getting back to being more smoky and less smoggy because the Tennessee Valley Authority has spent a combined $5.3 billion since the 1970s curtailing air pollutants created at its 11 coal-burning power plants, TVA officials say.

Two big ozone-producing culprits -- sulfur dioxide and nitrogen oxide -- have been reduced by more than 90 percent from peak levels. And with more planned coal plant closures -- and another $2.2 billion slated for emission control -- those levels are expected to continue to decline, said Duncan Mansfield, a spokesman for TVA.

By 2017, nearly 30 units at its coal-burning power plants will be closed, converted or cleaned up with emission-reducing "scrubbers" as part of an agreement with the Environment Protection Agency, Mansfield said.

That's good news to Jim Renfro, air quality specialist for the national park. His office has been studying ozone in the Smokies from the Look Rock monitoring station for 30 years.

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