Attempts to open a large-scale ­silica sand mine in Washington County will arouse public concerns of cancer-causing dust clouds and depleted groundwater but also bring a rallying cry for new jobs.

That was the consensus at a ­public forum in Mahtomedi that explored the controversy surrounding ultrafine sand mined for use in hydraulic oil fracking in North Dakota and other states.

About 325 people came to hear five panelists talk about their differing perspectives on an issue that's pitted neighbor against neighbor in other counties.

"This is an industry that's exploded on us all of a sudden," said state Rep. Peter Fischer, DFL-Maplewood, who implored the Legislature to strengthen laws to better protect residents from mine-generated pollution.

No recent proposals for silica sand mines have surfaced in Washington County, although rich deposits of silica sand lie within 50 feet of the ground's surface in the southern portion of the county and along the St. Croix River. A smaller mine that has been operating in Woodbury for years, producing silica sand for glass and other products, recently received City Council approval to operate for another year.

The Mahtomedi forum last week, hosted by the White Bear Lake Area League of Women Voters and several environmental groups, included a former Red Wing, Minn., mayor who now is executive director of the Minnesota Industrial Sand Council. After conflict-of-interest accusations, ­Dennis Egan resigned from the City Council in February to retain his job as an industry lobbyist.

The Unimin frac sand mine and processing facility in Tunnell City, Wis., was placed in an excavated pit to keep noise and visibility as low as possible. But depleted groundwater and health issues are other concerns frac sand miners must address in such cities as Mahtomedi.

At the forum, Egan defended local companies in Minnesota that he said were trying hard to work with residents and city leaders, and comply with laws. One of the companies he mentioned as a responsible community partner was Tiller Corp. of Maple Grove, which has reopened a traditional sand and gravel mine in Scandia after years of applications and reviews. Tiller was fined earlier this year for proceeding with a silica mine in North Branch without necessary air quality permits, and got in trouble last year for failing to prevent a large spill into the St. Croix River from a silica washing site in Grantsburg, Wis.

"I don't necessarily think the system is broken. I know you're going to say that's the industry speaking," said Egan, who read a list of regulations and ­permits that govern mines in Minnesota. "There's a whole bunch of people we listen to and we're in it for the long haul."

Fred Harding, a resident of Maiden Rock, Wis., where a large silica sand mine opened five houses away from him, warned people to beware of industry promises of jobs and environmental protections. No resident of Maiden Rock has been hired at the mine, he said, and the company has a state permit to draw 1.4 million gallons of groundwater a day for sand washing. Microscopic particles of silica sand generated for oil fracking endanger the health of ­residents, he said.

"My experience with ­industrial sand mining, I hope and pray, isn't like yours," said Harding, who's acknowledged he's been "accused of being a job-killing activist."

Panelist Bill Spitzer told of how a frac mine proposal in St. Charles, Minn., divided city residents until the City Council voted in March against an annexation that would have enabled a new mine and a ­shipping plant.

"People lost friendships, they lost their values, and they lost trust," said Spitzer, the town's mayor, who described how the City Council undertook a lengthy "process of caution" before the vote.

The fifth panelist, Commissioner Tom Landwehr of the Minnesota Department of Natural Resources, said the state agency regulates hard rock mining but local ordinances mostly govern silica sand mines. The state should provide more technical assistance to local governments that are feeling overwhelmed with complex frac mine proposals, he said.

"It's challenging with these controversial issues because there's such a diversity of opinions and people feel very strongly," he said.

Retired WCCO news anchor Don Shelby, who moderated the forum, asked panelists whether state regulations are strong enough to protect residents from threats of silicosis and other health and safety concerns.

"We don't have a way to address cumulative impacts," Landwehr responded. Regulators need to better monitor long-term developments that will offer more insight into the industry than looking at mines individually, he said.

Kevin Giles • 651-925-5037