Year in Review: UMore mining project advanced

Dakota Aggregates to start 40-year operation in 2013

Scores of meetings in 2012 led to the Rosemount City Council to approve on Dec. 18 a mining permit for Dakota Aggregates to start in 2013 its projected 40-year operation to mine hundreds of acres on the University of Minnesota-owned UMore Park property.

The council unanimously approved the measure, which includes provisions to help ensure that groundwater flowing from the 900-acre area is suitable for drinking water and that concerns about dust, noise and traffic are addressed.

Since there is possible contamination in some of the soils, five new groundwater monitors are expected to alert the city to unsuitable groundwater conditions prior to water reaching three possible future well locations.

Eventually, the mining operation will create of a large pond in the southwest corner of the mining area. This pond will be created as part of a wet mining operation, for which Dakota Aggregates, a cooperative between Cemstone and Ames Construction, will mine into the water table and extract sand and gravel using a barge as the center for its operation.

The monitoring wells are placed in locations that would capture the slow groundwater flow about five years after it exits the pond. City officials say groundwater from the pond wouldn’t reach the possible future water wells until about 20 years.

If a problem would be detected, it would be long before it could meet a well.

City Planner Eric Zweber said those future wells could be built, but the city could continue to supply drinking water without them.

While the area projected for the first phase of the mining operation is not located on previously identified contaminated sites included in a Superfund review area as a result of the World War II-era ammunition plant Gopher Ordnance Works, the city, Dakota County and the Minnesota Department of Health have advocated for precaution.

Current tests are not enough to ensure contaminated soils won’t be unearthed during the operation, which will include a dry- and wet-mining phase that will dig as close to an edge of the Prairie du Chien aquifer – the underground body of water that supplies drinking water to a host of communities.

The monitoring is focused on high levels of concentrations of bacteria, pH, chloride, iron and manganese, according to Zweber.

The city says a water treatment plant would not be needed as a result of the mining operation as has been rumored.

Council Member Jeff Weisensel brought up that issue since he had heard some residents were told a $100 million plant would be needed.

That the city of Rosemount would need a treatment plant as a result of the mining is a complete absurdity, Weisensel said.

Dakota County reiterated in its comments that it will enforce its ordinances with regard to the treatment of contaminated soils. Dakota Aggregates said it will follow all applicable rules in managing soils.

During the December approval, the company applied for not only a permit for a 40-year mining operation, but will have annual operation permits considered.

The first permit is for Sub-phase 1A, which will occur in the southern edge of the property where aggregate processing machines will be located.

No more than 80 acres can be mined at one time in two of the four zones on the property, which Zweber said is far fewer acres than have been mined in other Dakota County mining operations.

The city also has the ability to have the operation shut down the mining when high wind advisories are posted.
Bigger picture

The big picture of the approval is that the mining operation is the first step toward the University of Minnesota’s plan to build a sustainable community of housing, public spaces and commercial properties.

The ultimate vision is for the property to be a place where 20,000 to 30,000 residents could live.

Because the property has what has been called very high quality material for aggregate processing, the university is working with Dakota Aggregates to raise some revenue for its planning process.

“This is really a means to an end,” said Community Development Director Kim Lindquist.

She said this is setting the framework for future development, and the city will realize the economic benefits of the project.

Council Member Mark DeBettignies called the project a win-win for all those involved.

Council Member Kim Shoe-Corrigan said the council realizes the weight of the decision as it would affect future councils and shape the future of the city.

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