By Sara Jerome,
A global hot spot for mining frac sand; Wisconsin could have its groundwater contaminated by this process, critics say.
Frac sand is "quartz sand of a specific grain size and shape" that is suspended in the fluid that gets injected into oil and gas wells, according to a report by the Wisconsin Geological and Natural History Survey, a University of Wisconsin program.
"The type of sand used in this process must be nearly pure quartz, very well rounded, extremely hard, and of uniform size," the report said.
Wisconsin has "some of the best frac sand in the country because several of our geologic formations meet these specifications and are found near the surface," according to the report.
The concerning part comes in when frac sand is washed. This step is necessary to ensure uniformity. Chemicals are used to clean the sand.
Those chemicals are a threat to the water supply, opponents argue.
"The chemical people are most concerned about is called polyacrylamide, which is used to get mud and fine silt out of the water used to wash the sand," Wisconsin Public Radio reported.
University of Wisconsin Geology Professor Kent Syverson told Wisconsin Public radio that polyacrylamide is harmless, but "it's made from a toxic chemical called acrylamide."
“There will always be trace amounts or residual amounts that are present in that acrylamide that are present in that polyacrylamide as well. It could get into the groundwater and that’s why this is an issue," he said.
If the acrylamide is found in the water, that will raise some important questions, he said. "How much of it is in there, what concentration is in the water, the direction it’s moving, how fast it’s moving and how far before it might encounter a private well?”
Not much is known about the potential threat. "While Syverson says such a chain of events is possible, there haven't been any studies to prove this happens," public radio report said.
Nevertheless, the Department of Natural Resources has regulations to protect groundwater from these chemicals.
"Silica sand mines must follow the same requirements as other nonmetallic mining operations in Wisconsin, including getting necessary air and water permits and following state reclamation laws," the rules say.
Frac sand mines are unpopular with many residents in Wisconsin. Locals are already taking precautions about potential threats.
"With four sand mines in operation within a few miles of New Auburn public schools, district officials have taken extra precautions to keep silica sand out of the building's air system," the Associated Press reported this week.
For more on fracking and its effects on groundwater, check out previous coverage on Water Online.
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