The U.S. Environmental Protection Agency recently finalized a plan for Texas to address serious air pollution that is negatively impacting visibility at the Big Bend and Guadalupe Mountains National Parks in Texas. States are required to have plans for reducing haze at national parks and wilderness areas under the federal Clean Air Act.

EPA prepared a plan for Texas after rejecting a plan that the state submitted in 2009 that would not have required new pollution controls at any Texas power plants. The new plan known informally as the Regional Haze rule will mandate cuts in sulfur dioxide emissions at several of Texas' coal-fired power plants.

The clean-air protections put in place as a result of the new rule will probably require pollution reductions from a number of Texas power plants; such as Luminant's Big Brown, Martin Lake, Monticello and Sandow coal plants; NRG's Limestone plant; the GDF Suez Coleto Creek plant; Xcel Energy's Tolk plant; and the San Miguel Electric Co-operative plant.