Frac Sand: more coverage

Mapped: More than 20 proposed frac sand facilities

Produced by MPR News intern Frank Bi

May 1, 2013

Click on the dots to explore the map

MPR News has created this map to illustrate the current level of frac sand mining in Minnesota, based on data from the Minnesota Pollution Control Agency, the Minnesota Department of Natural Resources, and several counties in the affected areas. It's the most comprehensive map to date showing frac sand mining activity in Minnesota.

Currently, no state agency oversees silica sand mining, but the MPCA and the DNR often review permits that most mines need for things like using groundwater or discharging wastewater. Any other review or permitting of mining activities is left to authorities on the county or municipal level.

We collected information from multiple government agencies that oversee the regulation process to determine how many companies are mining for silica sand in Minnesota, or planning to do so.

The data show there are 17 active silica sand mining facilities in Minnesota, with at least 21 more in the planning stages. The frac sand facilities on the map are classified by their current operational status.

• Active: means the facility is currently mining, processing or transporting frac sand.

• Proposed: means the facility has submitted paperwork to be approved for frac sand operations.

• Prospect: indicates that either the facility is on hold due to a local moratorium or that no paperwork has been submitted, although intent has been indicated.

Frac sand mining tends to be concentrated in southeastern Minnesota, with clusters of proposed or prospect facilities in Fillmore and Houston counties.

The highest concentration of active frac sand facilities is in and around the city of Winona.

The areas of silica sand indicated on the map have been identified by the Minnesota Geological Survey as the best locations for mining, based on the high level of quartz present in the layers of sandstone in those areas, and the deposits' proximity to the surface (50 feet deep or less). Some proposed mines fall outside of these areas.

Silica sand is made from small, hard, round quartz rock. It's perfect for hydraulic fracturing, a process where pressurized water and chemicals are used to break open shale rock to free the oil and natural gas deposits within. The sand is shot in to keep the fractures propped open so that the oil and gas can be removed. The boom in frac sand mining has occurred as hydraulic fracturing has become a more common method of producing energy.

Map last updated: May 1, 2013