Environmental woes of mine fires draw attention

Burning coal seam at Centralia, Pa., is part of world problem

January 25, 2002|By Andrew C. Revkin | Andrew C. Revkin,NEW YORK TIMES NEWS SERVICE

Fires are burning in thousands of underground coal seams from Pennsylvania to Mongolia, releasing toxic gases, adding millions of tons of heat-trapping carbon dioxide to the atmosphere and baking the earth until vegetation shrivels and the land sinks.

Scientists and government agencies are starting to use heat-sensing satellites to map the fires and try new ways to extinguish them. But in many instances - particularly in Asia - they are so widespread and stubborn that miners simply work around the flames.

There is geological evidence that grassland and forest fires, lightning and spontaneous combustion of coal have spawned such fires for hundreds of thousands of years. In Wyoming and northern China, broad layers of earth are composed of "clinker," the brittle baked rock left behind when subterranean coal burns.

But the frequency of coal fires appears to have risen, experts say, as mining has exposed more and more deposits around the world to fires, both natural and set by people, and the oxygen that feeds them.

Increasingly, scientists are saying the problem needs to be more carefully assessed, both as a potential contributor to global warming and source of toxic air pollution.

A 1999 report by the Clean Coal Center of the International Energy Agency concluded that the biggest coal fires, in China and India particularly, "make a significant global impact."

Problem unstudied

"These fires are obviously pumping all this noxious material into the air," said Dr. Glenn Stracher, a geologist and expert on mine fires at East Georgia College in Swainsboro, Ga. "That's got to be having some effects, but no one has been studying it."

The coal fires are similar to those that have smoldered for three months beneath the wreckage of the World Trade Center, in that they involve buried fuels and are sustained and intensified by slight drafts of air and heat locked into surrounding rubble or rock. Geologists and engineers who have studied coal fires offered their expertise and specialized equipment - like firefighting foams - to emergency officials in Lower Manhattan. But firefighters at the scene stuck mainly with the simplest method: pouring endless streams of water on the wreckage as work crews slowly removed layers of debris.

Many coal fires start spontaneously, when pyrite and other reactive minerals in coal are exposed to oxygen. They begin to release heat, which, if not dissipated by air currents, builds until the coal itself ignites.

In Indonesia, hundreds of coal fires erupted deep in the rain forests when forest fires spread during an extreme drought in 1997 and scorched exposed coal seams.

Alfred Whitehouse, a fire expert for the federal Office of Surface Mining, now assigned to Indonesia, said there were 700 such fires just in East Kalimantan, on the island of Borneo. Some were extinguished by crews using hand pumps and picks to isolate the hot spots. But many are still burning, he said.

The fires persist as long as there is the right mix of fuel, oxygen and heat.

Sometimes, that can be a very long time. One fire eating deep into an Australian peak called Burning Mountain is believed to have been going strong for 2,000 years. The mountain has often been mistaken for a simmering volcano by passers-by, although Australia has no volcanic activity.

Centralia fire

In the United States, a common cause of such fires has been the burning of trash dumped into abandoned mines.

That is how the coal fire most familiar to many Americans started 40 years ago, in Centralia, a town in the anthracite region of eastern Pennsylvania. Smoldering trash in a dump ignited a coal seam. The fire steadily crept through abandoned mine tunnels, forcing the federal government by 1984 to evict residents and eventually pay $40 million to buy damaged land.

Centralia briefly gained national notoriety, then faded away. Its population shrank from 1,100 to 40. Smoke and steam now rise from overgrown back yards and cracked, sunken streets, marking the path of subterranean fires that continue to consume buried coal. Geologists say it could burn for another hundred years.

But Centralia's is just one of dozens of fires that smolder unchecked in old mines and coal seams around the country. The federal Office of Surface Mining has tallied nearly $1 billion in accumulated costs from coal fires, primarily in Pennsylvania, West Virginia, Utah, Colorado, Kentucky and Wyoming. In Maryland, the coal seam near Vale Summit has been burning for many years.

And the coal fires in the United States are negligible compared with those overseas. In China's rich northern coal belt, hundreds of underground fires are burning upward of 200 million tons of coal each year, about 20 percent of the nation's annual production. The fires produce nearly as much carbon dioxide, the main gas linked to global warming, as is emitted each year by all the cars and small trucks in the United States.

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