While the state has made some progress with the backlog in the past two decades, a “startling” number of plant closings during the recent recession has created “an entirely new generation of brownfields,” according to the Wisconsin Department of Natural Resources.

Frac sand fever has hit much of west-central Wisconsin, catching residents and local governments by surprise when demand for sand suddenly soared and permit applications began to pour in. The number of Wisconsin frac sand mining operations has more than doubled in the past year.

Overview of permits required to operate a frac-sand mine.

Resources to learn more.

There’s a new wrinkle in Wisconsin’s fast-growing frac sand mining: It turns out that an endangered butterfly, the Karner blue, lives in the same region. And some companies may be failing to check for the butterfly as they move ahead with mining operations.

Over the past six months, Gogebic Taconite LLC spent $114,883 lobbying state officials in support of its proposal to open an iron ore mine in northern Wisconsin. State Sen. Bob Jauch, D-Poplar, who represents the district where the mine would be located, says this was “a complete waste of money.”

This western Wisconsin community is in the midst of a land rush — call it a sand rush — fueled by exploding nationwide demand for fine silica sand used in hydraulic fracturing of oil and natural gas. At least 16 frac sand mines and processing facilities are operating, and an additional 25 sites are proposed, in a diagonal swath stretching across 15 Wisconsin counties from Burnett to Columbia, the Center has found.

A state program helped Didion Milling win $5.6 million in stimulus funding to expand its Cambria milling and ethanol plant, which has a history of environmental violations.