Reclaiming Coal Mines a Painstaking Process, Particularly in Hard Times

Glance at a satellite image of northeast Wyoming, and you can’t miss the coal mines. Even zoomed out, the square-cornered grey blotches stand out—stretching north to south over more than 70 miles. But if all goes according to plan, someday, when the mining is done, those scars will disappear, erased from the landscape by intensive reclamation efforts.

Coal companies are on the hook for that cleanup, but the industry’s recent collapse has raised questions about whether they will actually be able to meet those obligations. Cleaning up the legacy of mining is complex and expensive, as illustrated on a recent morning at Cloud Peak Energy’s Antelope coal mine, near Douglas.

Standing on a platform looking down into one of the three active pits at the mine, engineering manager Blake Jones struggled to describe the scale of the mining operation. Pointing to the far rim of the mine pit, he estimated the distance at 4 miles. In between stretched a giant void.

In the Powder River Basin, the coal seams are buried underneath hundreds of feet of overlying dirt. In order to access them, colossal shovels remove the dirt and a fleet of enormous trucks cart it away.

Staring down into the enormous pit, it was hard to imagine it ever looking like it did before. But turning away from the pit, Jones pointed to a grassy hill behind us, and explained that Cloud Peak had mined through it just a few years before. Then, using that same fleet of trucks and shovels, they rebuilt the hill, more or less to what it was before.

Cloud Peak literally moved a mountain.

After mining through it, Cloud Peak Energy rebuilt this hill at the company's Antelope coal mine.

Stephanie Joyce/Inside Energy

After mining through it, Cloud Peak Energy rebuilt this hill at the company’s Antelope coal mine.

In fact, they are constantly moving mountains. As the mine progresses, the dirt scraped off the coal goes back into the part of the pit that has already been mined. One truck load at a time, the gaping void is filled.

But moving mountains back into place is just the beginning of the reclamation process. The rest? Rebuilding an entire ecosystem, starting with the plants.

“Before we mine, the vegetation studies go through and document what are the native species and what density, how much sagebrush per square meter, literally to that level of detail,” Jones said. “And then we go back and redo that.”

Most of the of the native vegetation used in reclamation originates at a handful of plant materials centers run by the U.S. Department of Agriculture. One of the main ones for the Rocky Mountain region is the Bridger Plant Materials Center, in south central Montana. On the surface, the center looks like just about any other farm, with guys riding around on tractors in fields. But the crops they’re farming are things like antelope slender white prairie clover, critana thickspike wheatgrass and Indian blanket flower.

The center is the first link in the reclamation process—the seed from its fields is sold to commercial growers, who then grow their own seed to sell to the mines, for reclamation.

Inside the main office, I met Mark Majerus, a former director of the center who still volunteers. When he started working in the mid-1970s, no one was growing native plants for reclamation.

“Companies would go out and find a spot and if it was a good seed year they would collect it and make that available to reclamation,” he said.

Hand-picking enough wild seeds to reclaim hundreds of square miles of mine lands wasn’t practical though. So over the last 40 years, the center has worked to develop farmable native grasses and flowers for reclamation.

“It’s problem-solving, trying to figure out what species will work, what species the economics is there so that commercial growers can actually make a living at it,” Majerus said.

Having the right seed is critical, but it’s also just part of the equation. Mining companies also had to figure out the right way to replace topsoil, and how to plant the seeds so they don’t blow away.

“You know there is the timing, the surface manipulation. If it’s really dry, you might want to do some pitting and stuff to create little microclimates,” Majerus said. “And the mining companies have learned this process over the years—strictly trial and error.”

Today, mine reclamation is much more scientific than it was in the past, and as a result, it fails less frequently.  But even with all that attention to detail, the resulting ecosystem is nowhere close to as complex as what was there before.

“You’re not going to put it back exactly as it was,” Majerus said.

Federal mining regulations don’t require companies to recreate exactly what was there before mining, but they do require 10 years of successful vegetation growth and the restoration of groundwater aquifers, among other things.

By that measure, the “reclaimed” hillsides at the Antelope mine, like more than 90 percent of the land that has been mined in the Powder River Basin, are not there yet. In Wyoming alone, the work that is left to be done will likely cost upwards of $2 billion.

A tractor cultivates the fields at Bridger Plant Materials Center in Bridger, Mont.

Stephanie Joyce/Inside Energy

A tractor cultivates the fields at Bridger Plant Materials Center in Bridger, Mont., a sort of nursery for native vegetation used in reclaiming coal mines. Most of the centers are operated by the U.S. Department of Agriculture.

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