What is longwall mining?

 

One reason longwall mining succeeds in being the scourge of southwestern Pennsylvania is that the general public doesn’t have a clear notion of what longwall mining is.
If you visualize a long wall, you probably have the wrong idea.

 

Longwall is a form of underground mining that differs from traditional “room and pillar” mining in that no pillars or posts are left behind after the coal has been extracted. A longwall mining machine cuts along a 1000 foot-long coal face, going back and forth along the face, taking out all the coal.

 

The machine has a protective shield that keeps the roof from falling on it. But as the machine advances, the roof – a layer of rock, frequently slate, sometimes sandstone or limestone – subsides more or less instantly. The machine will cut a swath 1000 feet wide and a mile or more long. As the rock immediately above the coal seam subsides, so do successive layers above that layer, until soon the subsidence reaches the surface, and the surface and contents subside. When an eight foot thick seam is mined, surface will subside from one foot to five or six feet.

The hidden cost of longwall mining

 

By Phil Coleman

In recent years, West Virginia has been the poster child for coal. In a state that has always been celebrated for its mountains, the coal industry’s practice of mountain top removal is so overtly damaging that one or two pictures are all that is needed to persuade. Cutting away a mountain top of stone and clay to retrieve the narrow veins of coal beneath is such an obviously destructive practice that you don’t even have to know about the miles of streams that are destroyed in the process to be outraged.

Pennsylvania is not a poster child. Most mining damage is hidden away, out of sight. But it is damage nevertheless.

Pennsylvania’s heritage over the past century and a half is one of bad mining practices. Scars rule the landscape in the eastern anthracite regions where miles of spoil stand barren and unreclaimed. Gob piles loom like barren mountains in southwestern Pennsylvania, reminders of the history of bituminous room and pillar mining. Thousands of miles of streams run acid because of bad surface and deep mining practices.

Throughout the state the coal industry now proclaims itself “Green and Clean,” but it is not. It claims that it no longer damages the landscape, that it doesn’t destroy streams, that it repairs any damage to houses to the satisfaction of the owners. Its claim is that longwall mining will cause subsidence so quickly and evenly that nothing is harmed.

But the truth is that longwall mining is destructive in many ways. It cracks houses, sometimes irreparably. It damages roads and highways. It breaks gas and water lines. It dries springs and wetlands and destroys streams.

Consider Roy and Diane Brendels’ historic home in Greene County. After six years of torturous attempts to shore it up and stop the cracks, the mining company, Consol Energy, finally paid a settlement to the Brendels and tore down their 12-room stone and stucco Spanish Revival home which had been listed in the National Historic Register. The Brendels, worn out by litigation and unable to live in their beautiful old home, had to sign an agreement with Consol not to discuss the settlement in order to receive any recompense. Many believe that Mrs. Brendel’s death at 61 was hastened by the strain and grief she experienced during their ordeal.

Consider the dam at Duke Lake, in Ryerson Station State Park. This dam was cracked by by geologic stress from nearby longwall mining. However, Consol Energy claims that it is not to blame. The state of Pennsylvania is now suing Consol for $50 million.

Consider South Fork, a stream that the Fish Commission stocked with trout each spring. After it was undermined, it went dry and made a subsequent pond downstream.

When damage is done, the mining company begins by denying the damage. Then it claims the damage is only temporary. Finally, it insists that it won’t pay for damage unless the home or farm owner agrees not to discuss the settlement. The industry knows that most damage is out of sight and therefore, out of mind. It knows that in another decade or two, it will have exhausted the available coal and will have left the area, taking its trainloads of wealth with it.

Longwall mining is the new mythology. Decades from now, it will be the old horror story. The industry will say, “We used to damage homes and streams, but we don’t do that any more; we have a new technology that is better than the old.”

Don’t believe it.

Phil Coleman is a member of the Allegheny Group and has twice served as Chapter chair.

Published April 2008