Today I learn that sand is also a necessary component for fracking technology, so immense "sand mines" are being developed, with a variety of local environmental complications:
More at the Wisconsin State Journal.
While the mines bring jobs, they also bring dust, traffic and other problems the state Department of Natural Resources and local governments aren't prepared to deal with... "The state is woefully unprepared for this," said state Sen. Kathleen Vinehout, D-Alma. "We're regulating sand mines like we regulate gravel pits. There is a big difference between a one-acre gravel pit and a 900-acre sand mine."
[The demand for sand results from] the increasing use of a natural gas mining technology called hydraulic fracturing, in which deep wells are sunk in shale and a mixture of water, sand and chemicals is pumped under pressure into the rock, fracturing it and freeing the gas. The sand granules, because they are round and made of hard quartz, then keep the fissures open and the gas flowing.