RED WING — Goodhue County in southeastern Minnesota has adopted new regulations for the growing frac sand mining industry.

Commissioners approved the rules 3-2 Monday.

The regulations limit mines to 40 acres of exposed or uncovered ground at any one time. Operations are limited to 6 a.m. to 10 p.m., Monday through Saturday. The county gets authority to require air quality monitoring. And mines must be 1,000 feet from any existing dwelling or platted residential subdivision.

The rules take effect later this summer when a countywide moratorium on sand mining expires. If it’s not extended, the county could begin seeing frac sand mining applications this fall.

The silica sand under parts of southern Minnesota and western Wisconsin is used by the oil and natural gas industry for hydraulic fracturing.