Superfund Site to Reservoir?
Berkeley Pit, located near Butte, Mont., is the world's second largest open mine and the nation's largest Superfund site. According to the Environmental News Network (ENN), for 17 years, hundreds of corporations and study groups have studied ways to contain the pit's 26 billion gallons of contaminated ground water before it seeps into neighboring aquifers and water surfaces. Now one group in particular is hoping to put its research to work in the Pit.
Previously, the Montana Standard reported that a small, privately funded group announced it successfully has treated Berkeley Pit acid mine wastewater to potable standards. The paper said representatives from Ion Resolutions, Virginia City, Mont., claimed that they have been able to treat the water, which is full of heavy metals, to drinkable standards. To illustrate the point, Ion employees showed fish thriving in the treated water and even drank a glass the water themselves.
ENN said Ion's plan involves oxidation-reduction, a mining process that is unlike most acid mine removal treatment processes that are unable to recapture metals. Literature from Ion Resolutions claims the process is designed to accomplish four goals: 1) Selectively precipitate and recover as saleable products the copper and zinc contained in the acid mine water; 2) Produce a final sludge that settles rapidly, filters readily, and is insoluble in sulfuric acid, allowing disposal in the Berkeley Pit or other similar waste water reservoirs; 3) Produce an acceptable water that meets high standards; and 4) Essentially pay processing costs with the value of copper, zinc and clean water produced. Lead Ion scientist Rick Shafsky told the Standard that the group could treat the water at a cost of $1.70 per 1,000 gallons.
However, according to ENN, whether or not Ion Resolutions' plan is implemented is up to owners of the abandoned copper mine site who are responsible for treating the water - Atlantic Richfield Co. (ARCO) and Montana Resources. They currently continue to press ahead with plans to use hydroxide precipitation to treat the water, a treatment method that is proven to remove metals from water by adding lime to distill acid content in metals, the news service reported. This plan, however, also generates about 500 tons to 1,000 tons of heavy metal sludge per day, which would be stored in toxic waste ponds.
Ion's Shafsky said that by using the proper technology, metals can be recovered and the pit can be cleaned, without having to spend millions more dollars on creating toxic disposal ponds, ENN reported. "Sludge is sludge. Once it exists, you've got maintenance costs for the waste ponds. The sludge still leaves the water pH at 10. No human on the planet can drink that. Why produce sludge when you can have drinking water?" Shafsky argued.
Montana Resources' environmental manager John Burke holds a different opinion, claiming that there is no alternative to the lime plan, ENN reported. He said, "Ion Resolutions' method can remove metals, and they can drink the water; but I wouldn't go near it with all the traces of sulfate in it," Burke said. "Ion's system works theoretically, but it's different when you have to operate 50,000 gallons of water per minute."
If Ion is to convince ARCO and Montana Resources of its plan's validity, it must do so soon. ENN reported that construction of a lime hydroxide plant is set to begin this spring.