Published: March 09, 2009 03:32 pm      

Ground-breaking businesses

Driving past the Unimin plant on Le Sueur County Road 23 near Ottawa, the enormity of the mining operations going on is not apparent.

But take a ride with plant manager Grey Lusty around an earthen berm and down a bumpy gravel road, and the scene that opens up is similar to the gold mines of Lead, S.D., or the coal fields of Wyoming. Giant 100-ton trucks, loaders and other heavy equipment scuttle around a broad, deep terraced mine.

At the lower portions of the 170-foot deep pit is the prize — fine white silica sand.

The largely unnoticed local company is indicative of an industry that draws natural resources from the ground in and along the Minnesota River Valley. Often operating in out-of-the way areas, the plants — and their significant economic impact — are often overlooked.

“I’m still a little surprised when I tell people who I work for and they don’t know who we are or what we do,” Lusty said.

The geology of the valley makes it prime for mineral extraction. Some of the oldest granite in the world is upstream. Hard dolomite, sandstone, clays, gravel and other minerals are all along the valley. But it was a horrendous natural event 10,000 years ago that made the area’s mining industry what it is today.

Glacial lake Agassiz, which covered a large part of northern North America, broke open sending torrents of water, over hundreds of years, digging out the deep Minnesota River Valley.

That event makes it economically feasible to get to the minerals that would otherwise be too far underground to access.

The oldest industries

Some of the very first businesses started in the area were mining related. There were several limestone quarries, whose stones were used to build railroad bridges, government buildings, businesses and homes.

What is now commonly referred to as Mankato/Kasota stone, is prized by architects and builders around the world for its hues and quality.

Increasingly hard-to-find gravel has always been the backbone of the construction industry, used for everything from building roads to making concrete.

Clay was used by Native Americans and sought after by European explorers coming up the Minnesota River. Today, locally mined kaolin clay is used for everything from medicine to brick-making and artists’ clay.

The Acme-Ochs Brick Co. at Springfield, with a 60-million annual brick capacity, is the only brick manufacturer in the state.

And the pure, white silica has been mined from Kasota to Ottawa for more than 100 years.

Unimin: Modern face of mining

The various grades of Unimin sand are used in four industries: glass making, the back dusting on shingles to keep them from sticking together in the pack, the making of molds in foundries, and extraction of oil and natural gas.

Lusty, who’s been with the international mining company for 15 years and at the local Unimin mine since 2000, said the entire Kasota operation is geared toward sand for the oil and natural gas industries.

“The pure, hard grain and because it is round is what makes our sand so desirable.”

Companies use the sand to extract oil and natural gas from wells that no longer produce well with normal pumping. The sand is pumped down the wells and forced into the veins, fracturing them. That expands them and the sand remains in the veins, holding them open while oil flows out.

That’s where the strength and roundness of the sand is vital, Lusty says. It’s strong enough to hold the veins open and the oil can flow through the round grains of sand because they don’t compact.

Recent high oil prices sent oil companies back to less productive wells, boosting the demand for the silica. The Kasota plant is operating seven days a week, 24 hours a day.

Unimin has 75 employees and has a broad indirect economic impact in the area.

“All the contractors and vendors who we work with in the area produce a lot of economic activity. We have a big impact on a lot of people around the area,” said Lusty, a Montana native whose father was in the gold mining industry.

At Ottawa, Unimin is mining about 170 acres. The company has reclaimed about 165 acres of former mines at Ottawa and another 70 acres is in the process of reclamation.

At Kasota, Unimin is mining about 340 acres. About 225 acres have been reclaimed with 70 acres more in the process of reclamation.

The company is in the midst of seeking permits for the next phases of mining. At Kasota they are seeking permits for 1,134 acres — which would provide sand for some 25 years, depending on demand.

In Ottawa, they are working on permits for a 1,000-acre site on the north edge of town, which could provide silica for as long as 100 years.

Unimin’s relationship with the small historic village of Ottawa has been at times uneasy. Blasting, use of water and other concerns have long been raised by some residents in the town of fewer than 300.

Many of the Kasota-stone buildings in Ottawa are among the oldest in the state, dating to the 1850s and 1860s. Potential vibration damage to those buildings from blasting in the quarry has been a concern of conservationists.

But Unimin, which pays a sand tax to Le Sueur County, is the largest property taxpayer and provides jobs, has many defenders in the area.

Relations have improved dramatically between Unimin and environmentalists who in the 1970s called for protection of the Kasota prairies.

Through a series of agreements and negotiations, Unimin has done more work at reclaiming exhausted mines and making them wildlife habitats, as well as providing funding and working with local conservation groups. Many of those involved with the early Save the Kasota Prairie campaign praise Unimin for the strides it has made.

“We try to prove ourselves as good corporate neighbors and citizens,” Lusty said. “I think we’ve shown you can return (the land) to a state that is even better than we found it in.”

Stones for the world

While most area mining operations go largely unnoticed, the limestone quarried between Mankato and Kasota is well known, not just locally but across the nation and around the world.

The local stone is being used on the new Twins stadium, was used to cover the dramatic curved architecture of the Smithsonian’s American Indian Museum in Washington, D.C., used on the American embassy in Moscow, and in numerous government buildings, including the Mankato post office.

“Limestone occurs almost every place in the world,” said Howard Vetter, of Vetter Stone. “But in very few places does it have the quality and the strength and freedom from cracks and defects that allows large pieces to be cut from it.”

As it turns out, the shelf of limestone between Mankato and Kasota is of extremely high quality and a variety of colors. And because the glacial waters carved the river valley down to the limestone, it’s accessible to Vetter and his children, who are the third generation to operate the quarry.

Vetter Stone also owns and operates an Alabama quarry that provides limestone with charcoal-colored veins over a light colored background.

While access to gravel deposits and silica sand in the area will become more and more limited in the coming century, Vetter has a 500-year supply of good limestone locally. The Alabama quarry has a 2,000-year supply.

Vetter, who has 80 employees in Minnesota and 45 in Alabama, said the family works hard to keep up with technology. “We have a very modern facility and always look to upgrade. It’s changed a lot. My father died in 1975 and there are no machines from that era we still use.”

The recession and housing slump have hurt the residential side of the stone business, but construction in higher education, public buildings and health care are still strong. “We are bidding a tremendous amount of work, which surprises me.”

The Twins ballpark exterior will utilize 100,000 square feet of stone cut into 4-inch-thick panels — 100 truckloads in all. The work is about 80 percent done.

The local stone is sought after, in part, because of a variety of colors available, from pinks and earth tones to creams and tans.

“The color varies by depth and by location. Some of our quarries, the same strata will change color in a relatively short space.”

After spending the past 50 years traveling to worksites across the country and overseas, Vetter takes pride in the results.

“It is a good feeling to drive around Minneapolis and look at the 57-story Wells Fargo building, or go to Los Angeles Museum of Art, or the National Museum of the American Indian. It really gives one a sense of accomplishment.”

Gravel tougher to get

When it comes to mining, there is nothing more common, widely used and necessary than gravel and crushed rock.

But accessing aggregates is becoming increasingly difficult and expensive, adding to the cost of everything from road projects to building a driveway.

“It’s getting a lot harder to get permitted. The requirements are a lot more stringent with the air and water regulations,” said Eric Leverson, general manager of construction at Southern Minnesota Construction.

“In a lot of places, usually near urban areas, it’s impossible to get permitted at all.”

The regulations came about in large part, he said, because the complete lack of regulations in the past led to problems.

“Years ago you opened a gravel pit and did whatever you wanted. So it’s not a bad thing that there are more regulations.”

SMC is the largest aggregate miner in southern Minnesota with pits up and down the river valley and stretching from Owatonna to Windom. They mine gravel, crushed limestone, crushed quartzite and sand.

SMC uses it in construction projects they are doing as well as supplying other construction firms.

The difficulty in getting aggregate has produced one benefit.

“It’s the reason we need to be recycling products. When you take up concrete roads and asphalt roads, it needs to be reused. It doesn’t create waste and it conserves our resources we haven’t tapped already,” Leverson said.

State’s only brick-maker

Acme-Ochs Brick near Springfield is more than a century old and Minnesota’s only brick manufacturer.

The company began in 1891 when Adolph Casimir Ochs literally stumbled on an outcropping of red clay along the banks of the Cottonwood River. He started making brick and, at the time, Ochs Brick Company was one of 50 brick-makers in the state.

The process was grueling as workers shoveled clay, mixed it with water in horse-driven mixers and pressed the clay by hand into maple molds. The bricks were air-dried, then fired in wood-fueled beehive kilns, one of which still stands today at the brickyard in Springfield.

Modernization in the 1960s included a 258-foot-long kiln that expanded manufacturing to more than 30 million bricks per year.

A 1999 expansion by Ochs Brick doubled production to 60 million bricks.

In the winter of 2007-2008 the plant was idled and in February 2008, Acme Brick Co. — a major national brick manufacturer — purchased and reopened the business.

Acme says the Acme-Ochs Springfield plant is one of its most technologically advanced and efficient in the nation.