Iowa grain company digs into silica sand

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June 19, 2011 - 7:00pm

In northeast Iowa, where the undulating farm fields spill into tall cliffs on the Mississippi River, the Pattison family is unearthing a new-age treasure: silica sand.

For decades, the Pattisons' grain shipping business was tucked into the 300-foot bluffs. They stored grain in old mine tunnels drilled into cliffs and loaded it onto barges to ship down river. And they pretty much ignored the sand all around them.

But then one day Kyle Pattison got a phone call from a fracking company. "They asked us to supply sand, for frack. And that's how we started with the idea," Kyle Pattison said.

The Pattison Bros. grain company turned into Pattison Sand Co. Magical sand

Fracking refers to a method of fracturing shale rock to extract natural gas. And the process has taken off in the United States, spurring a seven-fold increase in natural gas production since 2000.

And that has spurred demand for silica sand, a key ingredient in the fracking process. Much of the sand is found in the Midwest. Wisconsin alone has hundreds of mines, and even with new mines opening, some have sold out their sand well into the future.

The natural gas industry just can't get enough of it.

"For magical reasons probably, this sand actually has a lot of the properties that they covet. So they're descending upon all these areas to provide this particular sand unit for their shale gas fracking operations," said Iowa State University geologist Bill Simpkins.

While the sandstone deposit stretches under 12 states, it's really only accessible in some places where it's near the surface -- parts of Wisconsin, southern Minnesota, Illinois and Missouri. And in Iowa, there's only a small area with accessible sandstone, in the northeast along the Mississippi River. The rest is nestled some 1,200 feet underground, under farmland.

Simpkins said this quartz sand is incredibly tough and durable, and it's naturally breaks into fairly uniform spherical crystals. When energy companies are drilling for the natural gas that's bound up in shale (sedimentary rock) they drill down, oftentimes thousands of feet, and then they blast pressurized water and chemicals into the shale -- to fracture it.

"And the role of the sand is to keep the fractures open," Simpkins said. These uniform tiny sand spheres hold the cracks open much better than other materials, and even with shipping across the country they're cheaper, too. And as shale fracking has been rapidly expanding across the nation, so has the demand for frack sand.

And that's why Kyle Pattison got into the business. Pattison is a trim, middle-aged man. He's is awfully hard to get in touch with, and when you do, he doesn't string many words together. But as an employee describes him:

"He's quite the visionary, and is always looking ahead at what's the next step, or two steps even beyond that," said Beth Regan, Pattison Sand Co.'s permit and environmental coordinator.

In 2008, Pattison jumped on the opportunity to re-open the mine, which had closed in 1982 -- and sold off the family grain business to Consolidated Grain and Barge.

"Yeah, there is plenty of demand for the frack sand," Pattison said. "As far as the employees, we've grown in the last six months from a little bit over 100 to a little over 150 employees.

Pattison Sand is developing fast. Now it's extracting and shipping about 30 to 45 rail cars full of sand a day -- that's about 5,000 tons of sand leaving the mines daily. And according to the natural gas industry--each ton of frack sand fetches about $100, which is roughly 60 percent more than when it is sold to glass and construction companies.

One petroleum consultant firm estimated the natural gas industry uses about 10 million tons of frack sand a year.

Changes to the land

Pattison Sand is mining what's called the St. Peter Sandstone, and this ancient rock deposit stretches from Missouri up to Wisconsin. The rock formed some 450 million years ago when this land was under the sea.

The sandstone deposit is tucked in the middle of the cliff, about 200 feet under from the top of the bluffs. Vaulted, crypt-like ceilings stretch between massive pillars. The company leaves 55-foot wide square pillars of rock to hold up the ceiling as it mines. The pattern of carving out square chunks leaves the spent mines like honeycombed chambers.

There are open pit mines on top of the bluffs, where bulldozers peel off layers of topsoil and limestone to reach the sandstone.

"Here you can see where the St. Peter Sandstone now has all been exposed," said Regan. "And then when they quarry this off, they'll load it into big dump trucks, and they'll take it into the mine, and into the crusher where it goes through its first process. "

Some view this kind of top-land removal mining as fairly destructive, though Pattison Sand is working to keep from leaving scars on the landscape. Regan pointed out about 5,000 saplingsthat were planted in this area.

Filling the pits back in with soil and planting vegetation helps to restore the environment, and it also means the company has less active mines to insure. Some of those filled-in pits will eventually be farmed.

Pattison Sand also has worked out an agreement to mine underneath nearby farmland where there is an extensive deposit of sandstone. One engineer estimated there is enough sandstone here to mine here for 10 years -- and that's a lot considering the mines run 24-hours a day, 365 days a year.

The company operates in the Upper Mississippi River National Wildlife & Fish Refuge, and has had the land surveyed for endangered species as well and native burial mounds. The team did find two endangered flower species in the area, but not near enough to the mine operation to of concern, Regan said.

Air quality

Pattison Sand is working to minimize its impact on the land, and also has taken steps to minimize silica dust. These tiny particles, about 1/20th of the width of a human hair, are listed as a carcinogen in occupational exposure by the U.S. National Toxicology Program.

"Basically, the particles for some reason -- maybe their shape, maybe their electronic structure, no one really knows for sure -- but that elicits a response that causes the cells in lungs that clean up particles (to fail)," said

Jeff Myers, an environmental toxicologist with the Department of Natural Resources Bureau of Air Management. "For some reason those particles are toxic to that cell."

"If there's enough damage, it causes an inflammatory response. And subsequent to that you can get things like silicosis --and possibly cancer." The risk of cancer depends largely on the amount, duration and concentration of exposure to the silica dust.

Myers said health officials don't consider ambient exposure to be a risk for the general public, however, data from some states shows emissions from some industrial facilities could result in levels of concern for people living near the sources.

States like Texas and California have regulations to minimize dust from getting airborne, which include requirements about using water to keep down dust and containing areas where sand is transferred. Iowa doesn't yet have any such regulations, but Pattison employees do use respirators in the mines. And with only one mine in the state, the concern of the dust traveling outside the mine is likely minimal.

In Wisconsin, however, there's been a rush of new mines opening to meet the sand demand. The Department of Natural Resources there reports that some of the mines have already sold all the sand they won't extract for several years. This rapid uptick in industrial production has led the state to begin exploring whether it should regulate the dust. For more from Harvest Public Media visit its website



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