Environmental concerns fish kills

According to the Illinois Environmental Protection Agency (IEPA), a series of gas blowouts has occurred at two waste injection wells in the state (Brower el al., 1989). In each case, well operators were injecting concentrated hydrochloric acid into a dolomite bed. At its plant near Tuscola, the Cabot Corporation injects acid waste from the production of fumed silica into the Cambrian Eminence and Potosi Formations below 5 000 ft (1 500 m) depth. Allied Chemical Corporation injects acid into the Potosi formation below about 3 600 ft (1 100 m). The acid, which is contaminated with arsenic, is a byproduct of the manufacture of refrigerant gas. Since some of the blowouts have caused damage such as fish kills, there is environmental interest as well as operational concern in preventing such accidents. 

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