Eastern Power Plants Linked to Big Bend’s Haze

EL PASO, Texas -- Part of the blame for the haze increasingly obscuring Big Bend National Park’s wide open vistas may fall to sources as diverse as the Sahara Desert and East Coast power plants.

“I guess the theme that keeps showing up ... is that there isn’t hardly anybody who isn’t responsible for the pollution at Big Bend,” said Mark Scruggs, assistant division chief for the air resources division of the National Park Service.

The findings are from a preliminary analysis of data collected in 1999 as part of a multiagency study. Researchers declined to discuss the study in detail until all parts are completed later this summer.

A significant part of the park’s pollution comes from coal-fired power plants in the eastern United States, including the Ohio River Valley, researchers involved with study said. Nearby power plants in Mexico may have less of an effect than previously thought, they said.

The amount of pollution traveling from the eastern United States “is something we’re surprised about,” said James Yarbrough, a lead researcher with the Environmental Protection Agency.

Pollution appears to be transported from the eastern United States over the Gulf of Mexico and then along the U.S.-Mexican border into the park.

Two Mexican power plants, Carbon I and Carbon II near Piedras Negras in Coahuila, were earlier identified as major sources of sulfates that cause most of the problem. Although the plants meet Mexican air quality standards, they haven’t been equipped with controls for sulfur-dioxide emissions required in the United States.

“We’re not saying Carbon I and Carbon II are exonerated,” Yarbrough said.

Dust from the Sahara Desert may add to the haze, but a fact sheet released earlier indicates that it is not a major contributor.

For the last four years, scientists have used computer models and other methods to analyze air quality data collected between July and October 1999. Scruggs said visibility at the park is worst during those months.

The Big Bend Regional Aerosol and Visibility Observational Study, or BRAVO, is a combined effort of the EPA, National Park Service and Texas Commission on Environmental Quality.

Parks in the eastern United States have worse visibility problems, Scruggs said, but Big Bend “has shown a significant degrading trend.”

So far, the visibility problems don’t seem to hinder visitation, said Vidal Davila, Big Bend chief director of science and resource management.

But people notice.

Jack Lamkin, a former president of Friends of Big Bend National Park, first visited the park in 1956 on his honeymoon.

“We went up on the South Rim and the saying then was you could see three days into Mexico,” Lamkin said. “I don’t know if that was by horseback or by jet plane, but you could see a long way.”

Now, visibility is “tremendously impaired,” said Lamkin, who lives north of the park in Marathon.

“It’s gotten worse, not overnight, but it’s been gradually taken away from us,” Lamkin said. “If it had happened overnight, there would be a tremendous uproar. People would be beating down the doors of government to cure it.”

Davila said the park still has days when you can see for 200 miles, mostly in the winter when air comes from the north. But on a bad day in the summer, visibility can drop to as little as nine miles, he said.

In late June, visibility was holding at slightly more than 40 miles.

“We do get people coming year after year. We hear it in the comment letters,” Davila said. “They bring their families to enjoy Big Bend because they remember the vistas. Then they tell us, ‘We don’t see the vistas.’ ”