Texas Tries to Clear the Air at Two National Parks

To comply with federal air quality requirements for national parks, the Texas Commission on Environmental Quality is revising the State Implementation Plan, SIP, to address visibility at both Big Bend and Guadalupe Mountains parks and at protected areas in neighboring states. The federal rule calls for visibility improvements at national parks on the haziest days and no additional visibility impairment on the clearest days. It also requires states to take into account their impact on such areas in other states when determining their own reductions. The U.S. Environmental Protection Agency, EPA, has set a long-term goal to eliminate the effects of human activity on visibility by 2064, but for now states are concentrating on improvements for the next 10 years.