Wisconsin is suddenly a player in the national energy game. No, America’s dairyland doesn’t have newly discovered deposits of coal, oil, or natural gas. No, it’s not a leader in wind or solar power. Rather, Wisconsin is a valuable source of….sand. Yes, sand. The specific type of sand needed for hydraulic fracturing, or fracking.
Wisconsin is in the middle of a sand rush because of increased use of the fracking method to extract natural gas. Given the state’s role as a sand supplier, there is a three-part public information series on hydraulic fracturing for Wisconsinites. The Nelson Institute for Environmental Studies is hosting the forums in Madison, they are live-streamed online and archived so that people all over the state and country can tune in. The first session was this evening and it aimed to help Wisconsinites understand what fracking is and why it’s happening and also to address the role western Wisconsin is suddenly playing in this round of the national energy game.
In a sentence, hydraulic fracturing is a process that breaks up shale deep underground in order to access a trapped, dispersed deposits of natural gas. Sand is key to that process and I am going to discuss how Wisconsin came to claim ownership of most the sand frackers want to use, called frac sand. For more on fracking itself, see the Wisconsin Center for Investigative Journalism’s short explainer piece, or, for way more than that, check out Propublica’s fracking series.
Wisconsin State Geologist James Robertson stood before a nearly full lecture hall this evening to answer four basic frac sand questions:
- What is frac sand?
- How does it occur?
- Why does Wisconsin have so much frac sand?
- Where is it found in Wisconsin?
I’ll relay his insight here.
What is frac sand?
Not all sand is created equal. Frac sand is defined by it’s purity, shape, and toughness. It is more than 99% quartz, the grains are highly spherical, and it is hard to crush. Frac sand, Robertson said, has a crush resistance of 4,000-6,000 psi. “You can’t have a bunch of wussy sand that falls apart when you squeeze it,” Robertson told us. That’s because frackers use it to prop open fractures deep underground.
How does this special type of sand occur?
Quartz is one of the toughest minerals to weather. Where sand is almost 100% quartz, as frac sand is, it is because the soil and rock has been wearing away for a long, long time and quartz is the only thing left. Robertson said frac sand deposits are one half to two billion years old.
Why does Wisconsin have so much frac sand?
Twice in Wisconsin’s geologic past quartz-rich sandstones formed. Over time, the patterns of weathering and erosion left those deposits near the modern surface, composed of little else than rounded, quartz sand.
Where is frac sand found in Wisconsin?
For a map with updated frac sand mining activity, go here.
Along with Robertson’s four-part explanation at tonight’s forum of why Wisconsin is a frac sand mecca, UW-Madison Professor of Geoscience Alan Carroll gave a wider perspective on why America is turning to fracking for energy. Kate Prengaman, a fellow journalism grad student and reporter covering frac sand mining for the Wisconsin Center for Investigative Journalism wrote a blog post that accompanies this one, recapping Carroll’s portion of the session.
The Nelson Institute’s next community forum on frac sand mining is on November 13, titled: The Impacts of Frac Sand Mining on Wisconsin. (Kate’s speaking on the panel!)