Minnesota's Environmental Quality Board (EQB) on Wednesday adopted a "toolbox" of frac sand standards designed to help local governments regulate an industry whose explosive growth in the last 18 months has brought the region riches as well as controversy.

Environmentalists quickly derided the optional standards as too soft, and mining interests faulted them as overreaching.

Will Seuffert, the agency's executive director, said that while the board wasn't able to address every concern raised by advocates, the model standards will help communities that have sometimes been overwhelmed by a frac sand boom that led to more than 100 new facilities worth hundreds of millions of dollars in western Wisconsin and a frenzy of activity in southern Minnesota.

"It's one piece of a bigger puzzle," Seuffert said. "Our involvement is ongoing."

The criteria, which passed by a unanimous vote of the board, suggest protections for air and water, as well as ways to regulate sand hauling, blasting, lighting of mine sites and the creation of buffer zones from residential areas.

The suggested standards, created at the direction of the 2013 Legislature, augment legislation passed last year that now requires special permits from the Department of Natural Resources for mines proposed within a mile of any trout stream in southeastern Minnesota. In addition, the state Pollution Control Agency is continuing to refine air quality regulations for silica sand, and the EQB has assembled technical-assistance teams for use by local governments.

"I think we are in a good spot right now," said Sen. Matt Schmit, DFL-Red Wing, who spearheaded the passage of Minnesota's first frac sand laws in 2013. "I think the EQB has done an admirable job."

Although frac sand activity has slowed in recent months, activists continue to watch it closely, and Schmit said local units of government have come a long way in understanding how to regulate the industry. In mid-2012, a burst of land deals and new mining proposals circulated throughout southeastern Minnesota. As environmentalists protested and some mining concerns threatened to bring lawsuits, many counties, townships and cities adopted temporary mining bans to buy time and brace themselves.

A handful of Minnesota frac sand operations have started up in that time, but the mining boom seems to have cooled, and a spokesman for the Minnesota Industrial Sand Council said Wednesday that there are currently no newly proposed mines in the state.

Fred Corrigan said southeastern Minnesota still has potential to be a hotbed of activity, but today's operators are scrutinizing market conditions and railroad access before proposing any new sites.

Harder line?

Seuffert said the only substantive change to the model standards during Wednesday's four-hour hearing in Rochester was for the board to back off slightly from a recommendation that all frac sand processing activities be enclosed for dust control. Now the report suggests to local governments that other dust-control measures could be considered.

Bobby King, policy program organizer for the Land Stewardship Project, a Minnesota nonprofit, said the final standards were an improvement over a weaker set floated in September. But she described them, overall, as a disappointment to local officials who want to take a hard line against the industry.

"There's nothing in there that stands out to me as great," King said.

Environmentalists pressed the board to adopt guidelines for counties and other local governments that want to ban the industry outright, King said. But the document offers no such options.

Schmit said some environmentalists also wanted more rigorous standards to protect water resources. "More could be said about impacts on water," he said. "But I think we are giving our local units of government something beneficial."

Tony Kennedy • 612-673-4213