The Minnesota Environmental Quality Board has produced a report on silica sand mining.
The EQB is a multi-agency oversight body that received a petition to do an in-depth study of the possible environmental effects of frac sand mining. The industry is growing because silica sand is used in hydraulic fracturing to produce oil and gas.
That kind of study would take several years and cost a lot of money. In the meantime, the agency has produced a 90-page report that summarizes the issues.
So far the questions outnumber the answers regarding possible impacts on the environment, the economy and local communities, said EQB planner Jeff Smyser.
"There are an awful lot of unanswered questions that would need to be researched," Smyser said.
The report includes transportation systems, habitats and native plant communities, as well as maps of southeastern Minnesota's unusual geology, known as karst geology, where rich deposits of silica sand are found. That makes it tricky to predict underground water flows, Smyser said. The limestone bedrock easily creates sinkholes and causes unpredictable groundwater flows.
"It's kind of difficult to know where the water's going to go, just what effects use of groundwater, discharge of processing water is going to have because of that karst geology out there," he said. "So that's a real tricky question that's real hard to answer at this point."
The report is available on the EQB website.