Jump off Hwy. 169 on an unmarked road between Shakopee and Jordan, and you can peek at what looks like a giant sandbox.

Trucks and cranes nose through sand piles on self-created roadlets, just like the ones every boy used to have at the age of 4 -- and from where you're sitting, they look about that size.

Much closer, though, is an item without the same cozy connotations: monitoring equipment that is helping determine whether all this mining could be endangering peoples' health.

Frac sand mining has drawn little fire in Scott County at a time when other counties in the state and in neighboring Wisconsin seem more wary. Now the state of Minnesota is stepping up its own level of caution.

Two state agencies are asking Winona County to order an in-depth study of environmental and health risks associated with mines and processing.

And a state toxicologist with a Ph.D. from Dartmouth College, when asked whether Scott County figures in those same concerns, responds with a yes.

"Each of the facilities that have been proposed are different, but air concerns are similar for all," said Hillary Carpenter of the Minnesota Department of Health. "We are concerned about potential ambient exposures from silica and from exhausts from trucks and on-site equipment."

But officials in Scott County say they were well aware in green-lighting the mining that the level of concern could rise later on and took steps to safeguard folks nearby.

"One unique thing we did here is to create an open-ended permit regarding public health concerns," said Al Frechette, environmental health manager. "If a new standard arises for silica dust, we can automatically apply it to Great Plains Sand," the company doing the mining.

"Before now, we've normally just issued a permit and the company operated under those standards. But here, because we weren't sure what the state would do, we didn't want to shut down those future options. And Great Plains agreed; they wanted to be a good neighbor and agreed to comply. Moving forward, we think that's the best practice.

"In the meantime, they are sampling for silica dust, and the only time they observed anything, the weather station data on wind direction" -- there's a tower to the north of the site -- "showed a breeze blowing in from farm fields, not from the mining site."

Studying frac sand

Months ago, long before the official expression of concern from the state, news coverage in southeastern Minnesota suggested that key state officials were expressing reservations about the health impacts.

Carpenter told a meeting in Red Wing that sand itself is not the problem -- it's probably 100 times too large and too smooth. "If you can see it, it's not a health problem," the newspaper in Rochester quoted him as saying. It added:

"Wisconsin is trying to study silica dust off-site, but Minnesota isn't doing that," he said. "In order for people to feel comfortable ... there has to be monitoring."

That seemed a broad hint that Minnesota state health officials wanted additional reassurances. Indeed, this month two state agencies, health and pollution control, in what was a first for either, called for an extremely in-depth study of frac sand operations which are producing material used in new drilling techniques that have revitalized the U.S. oil industry.

In response, Winona County Attorney Karin Sonneman noted that while she's wary as well, a full-scale environmental study isn't often done, and when it is, it's expensive and slow.

Great Plains Sand took around a year to get from initial application to approval, Scott County officials say. "Scott County takes no position on these issues other than to review applications as they come and take whatever steps appear necessary to safeguard the public," said Deputy Administrator Lezlie Vermillion.

In a lengthy update on the issue published within recent days in the county's newspaper, Scott Scene, Frechette acknowledges that concerns exist. But he also seeks to reassure residents.

There's a "legitimate concern" about silica sand, he writes, "which has been associated with several human lung diseases, including cancer. Scott County has required additional dust monitoring for Great Plains Sand ...

"I anticipate that state or national standards will eventually be established, [but the firm is] minimizing dust emissions. ... We are comfortable that citizens will not be exposed to dangerous levels of either silica or nuisance dust from this mining or processing operation."

Work underway

On the site itself, huge cables are strung across a lake and a claw is drawn through icy water, dragging sand from below the water table and into piles. Processing isn't taking place there yet, Frechette said.

Potential development of mining on a much larger site to the north of Great Plains' operation, on and around the Renaissance Festival grounds, remains on hold, he said.

"They suspended their [permitting] process last summer," he said, "and we're on standby to get direction from them as to when to restart it. We understand market prices are less favorable now, and they've done some restructuring, with an initial partner departing. They were negotiating with the railroad for a spur and ran into issues there. So I couldn't say what the timeline on that project might turn out to be."

Both projects are located near the Minnesota Valley National Wildlife Refuge, where officials have expressed unease. But they say they're not totally sure what the effects on their property have been.

"We know there's been a lot of work going on," said Jerry Shimek, refuge specialist. "They're blasting on a pretty regular basis. But our only activity there is periodic; we're not out there all the time when they pull the trigger, although we have noticed additional noise, whether it's blasting or just equipment banging around."

David Peterson • 952-746-3285