On Feb. 19, Minnesota lawmakers heard testimony on the state’s silica sand mining in what may be the first phase of a potential fight over what the state’s role may be, the  Associated Press reports.

Although permitting decisions are typically left to local jurisdiction, busloads of critics flooded the Capitol and asked for a statewide study of health and environmental impacts; a temporary moratorium on new mines and processing facilities; and improved statewide oversight and regulation.

“We feel (local governments) are best suited to decide the local land use issues,” Mike Carson, director of land use affairs for Tiller Corp., told an AP reporter. “They are each unique, and each of them should be studied on their own so that all the local issues and concerns can be dealt with.”