Five years into the exploration for natural gas in the Fayetteville Shale, most Arkansans know about the hydraulic fracturing process and its links to environmental havoc, including poisoned wells and radioactive wastewater in various parts of the United States and increased earthquakes here in Arkansas. Now, a mushrooming side industry is beginning to attract national attention to farming communities in Wisconsin and Minnesota. This industry drains waterways and creates hundred-acre gashes where there once was forest, hills and pasture, and it can pollute the air and water with invisible toxic particles. It's called frac sand mining, and on a quieter scale, it's also happening — and on the verge of expanding — in North Arkansas.

The process, which environmentalists have compared to mountain-top removal coal mining, involves scraping or blasting a hole about 50 to 100 feet in width and depth to access high-purity silica. During the fracking process, the silica is added to a mixture of water and chemicals and pumped, at high pressure, into natural gas mines to open cracks in shale plates. This type of silica is only found in a few states. Wisconsin and Minnesota have larger deposits than Arkansas, but Minnesota's regulatory system is complex enough to deter many corporations. Neither state has Arkansas's home field advantage, since frac sand from the Ozarks only has to travel about 100 miles to reach the Fayetteville Shale.