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Environment: The Yellow Haze of Texas

America and Mexico join forces to answer a perplexing question: Why’s the air so dirty in our nation’s most remote preserve?
By John Shinal

From his seat near the front window of the Terlingua Trading Company, store manager Bill Valentine used to be able to look across the vast west Texas desert on any given day and see the famously rugged peaks of the Chisos Mountains rising up from Big Bend National Park. Watching as a sunset here on the Mexican border paints the crags rust and
orange against the deep blue canvas of the sky, Valentine smiles wistfully. “That’s the kind of view that’s good for the soul.”

Indeed, it’s precisely this sort of hold-your-breath vista that draws more than 300,000 visitors to Big Bend each year. But these days the views are anything but a given, especially with the onset of spring, when smog-filled winds push in and clog up the sky. This month the EPA is releasing a long-awaited field study, conducted with the help of Mexican environmental officials,
that places much of the blame for Big Bend’s air quality problems in the hands of two government-owned, coal-fired power plants 120 miles to the south, in the state of Coahuila. Environmentalists believe the fallout from the study, good or bad, will provide a touchstone for future negotiations between the countries. “This study is significant because it’s the first major effort to
work together with Mexico on air-quality issues,” explains Dave Simon, Southwest Regional Director of the National Parks and Conservation Association. “No matter what the results, at least the Mexicans have finally agreed to a protocol.”

The remote park’s air-quality problems started to gain notice in the mideighties, when the Mexican government built the first of the two power-generating smog spewers, known as Carbon I and II. Together the plants release an estimated 250,000 tons of murky sulfur dioxide per year, enough to frequently cloak the park behind a thick, smoky haze.

And it could get worse. The Park Service estimates that visibility at Big Bend, now the poorest among western national parks, may drop another 60 percent if the plants continue to pollute at current levels. “It’s as bad at Big Bend as in the San Gorgonio Wilderness, and that’s just 50 miles west of the Los Angeles basin,” says Jim Sisler, an air-quality researcher at Colorado
State University. At one point visibility plummeted to an all-time low of nine miles, a startling figure for an isolated park where the horizon used to be the eye’s only limit.

“We would cite computer models to Mexican officials and they’d reject the results,” explains Miguel Flores, a Park Service air resource specialist. “We didn’t have the smoking gun we needed.” Finally, after years of negotiations and — perhaps not coincidentally — a $50 billion bailout of its economy by Uncle Sam in late 1995, Mexico agreed to the study last spring.
“It’s a start, but studies alone won’t be enough to convince the Mexican government to act,” says Simon.

Even as officials on both sides of the border hash out the study’s significance, the air isn’t likely to get clearer soon. The reason? Dinero. “If you were the Mexicans, what would you do?” posits John Forsythe, an air quality technician at the park. “Clean up Mexico City, or clean up some remote area on the frontier so a bunch of hikers can see?”