The process of hydraulic fracturing, or fracking, uses pressurized fluids to fracture shale formations in order to extract natural gas or petroleum. Fossil fuel pumping using this technique has greatly accelerated since the early 2000’s. It allows fossil fuels that were formerly too difficult and expensive to extract to be mined, and has been an economic boon to places like North Dakota and Pennsylvania. It also has numerous negative environment affects, like groundwater pollution and the creation of greenhouse gases.
While no fracking is taking place in Minnesota, we are a major source of the high quality quartz sand used in fracking. (See here for a map of mine sites in southern Minnesota.) Professor Emeritus of Geography Bob Douglas has written a report on this issue:
“The St. Peter sandstone is classic sedimentary rock deposited in layers during the Ordovician geologic time period. The sand is now in great demand for its use in fracking, where a mixture of sand, water, and chemicals are forced into oil and gas shale deposits. . . [This silica sand is] high strength, chemically inert, spherical in form, and compared to ‘common’ sand, has larger grains. . .It behaves in many ways like a liquid.
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“St. Peter and Jordan Sandstones are riding a wave of unprecedented demand for use in ‘fracking.’ This is the process for mining oil and natural gas whereby a solution of water, chemicals, and sand are forced into shale formations under high pressure. The solution breaks up or fractures the rock. The silica sand also helps keep these fractures open so that the natural gas or oil can flow through the shale deposit into an oil or gas well. The sand is often called a ‘proppant’ as it refers to ‘propping open’ the fractures. Given the raging demand of cheaper oil and natural gas, the silica sands in Minnesota can’t be mined and shipped fast enough.
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“There are, however, a number of serious problems and potential hazards related to silica sand mining. . . These include air pollution and toxic dust from open sand cars and trucks and their possible health affect, increased truck and rail traffic and their impact on small towns, the increased use of groundwater, the disposal of waste water, and the processing and treatment, and storage once the sand is mined.”
For the full report, please contact Dr. Bob Douglas.