Tuesday, July 16, 2013

Mine Waste and Pollution Concerns

Investigative reporter Tony Kennedy recently wrote for the Star Tribune about waste water and pollution concerns involving frac-sand mining in Wisconsin and Minnesota.

Over the past year, holding ponds at mine sites have failed during heavy rains, releasing sandy sediment and processing water. In some cases, the material has contaminated public waters, threatening to suffocate fish eggs, kill aquatic plants, and otherwise harm fish habitats. Kennedy reports that the WI DNR has cited nearly 20 frac-sand mines for alleged violations of water regulations.

Speaking on behalf of the Wisconsin Industrial Sand Association, Rich Budinger blames small, inexperienced sand companies and heavy rains, and says existing storm water regulations are sufficient.

In addition to holding ponds, Kennedy describes how sand mines create waste material consisting of clay and undersized sand, often called "fines." This material is in part generated during the processing or washing of frac sand, which separates fines from the desired product. The murky wash water containing the fines is then treated with flocculants, chemicals "that cause suspended particles to sink so that the water can be reused." Once separated from the water, the fines are piled as waste material, eventually plowed back into the ground during mine reclamation.

At the Preferred Sands site in Blair, WI, waste piles have absorbed rain water and spilled onto adjacent land on at least two occasions, "trashing the interior of a house, flowing into a garage on another property and fouling a wetland."

Kennedy also reports that state officials and some frac-sand companies are concerned about the widespread use of polyacrylamide, a chemical in the flocculants. "Polyacrylamide contains residual amounts of acrylamide, a neurotoxin linked to cancer and infertility." While polyacrylamide is thought to degrade safely when stored above ground, concerns emerge when the chemical is improperly buried with mine waste. Polyacrylamide and another flocculant chemical called polydadmac have recently been added to the Health Department's list of "chemicals of emerging concern."

Source:  Kennedy, Tony. 2013. Pollution worries abound in frac sand waste streams. Star Tribune, July 13.

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