Question 2: Are there strong safeguards in place for when things go wrong?
Sulfide mining differs most starkly from iron mining in its duration of pollution, which can continue for hundreds or thousands of years. The generation of acid mine drainage will continue as long as sulfides, water and air mix. No new technologies have emerged that can stop the chemical reaction once it begins. Some hardrock mines in western states need expensive water treatment into perpetuity.
To date, mining companies are unable to point to a sulfide mine that has ever been developed, operated and closed without producing polluted drainage from its operations. Yet studies show that the companies and state agencies reviewing mine plans consistently predict no pollution will occur during the planning and permitting process. Analysis of environmental impact statements for hardrock mines showed that 100 percent of mines predicted compliance with water quality standards before operations began. When researchers examined the track record of these mines after operations began, they found that 76 percent of them were actually discharging pollutants in excess of water quality standards. In addition, “mitigation measures,” or those efforts taken to remedy the discovered pollution problems, failed to do the job 64 percent of the time.
Pollution problems from sulfide mines are not just an issue of old mines using old technologies. Acid mine drainage and toxic metal contamination are problems from modern mines using the latest technology as well. Here are some examples:
- Chino Mine, New Mexico. Operated by Phelps Dodge Corporation (now Freeport-McMoRan). Between 1991 and 1996, almost 250,000 gallons of tailings were released into Whitewater Creek when the mine experienced a series of pipeline ruptures. During a three-month period of time in 2000, at the Chino Mine and two other Phelps Dodge mines in the vicinity, hundreds of bird carcasses were discovered. The birds, some protected by the Migratory Bird Treaty Act, had landed in water in tailings impoundments and in stormwater retention basins. Concentrations of hazardous substances in other birds, small mammals and reptiles showed evidence that wildlife had been exposed to toxic substances at the mine site.
- Pinto Valley Mine, Arizona. Operated by BHP Copper Co. In 1997, a tailings dam failed, and 3.4 million gallons of heavy-metal tainted water were released into Pinto Creek, a water body that flows into Roosevelt Lake, one of the area’s largest sources of drinking water.
- Flambeau Mine, Wisconsin. Operated by the Flambeau Mining Company. The mine began production in 1993 and ceased operations in 1997. It is sometimes cited by industry representatives as an example of a sulfide mine that has not polluted its adjacent waters. Recent studies show this claim to be false. Two areas of contamination have been discovered, one discharge that exceeds water quality standards into a stream that flows into the Flambeau River, and another in a groundwater monitoring well between the mine pit and the River. In July 2012, a federal judge ruled that the mine was the source of the pollution and that the mining company had indeed violated the Clean Water Act.
No mine company sets out with a goal to pollute. Certainly, there are aspects of these projects that represent advancements from the way mining was done a century ago. Nevertheless, a review of the technologies used by modern mines and their resulting track records, indicates industry assurances are overly optimistic, and the portrayals of technological advancements are misrepresented.
Boulanger, A. and Gorman, A. 2004. Hardrock Mining: Risks to Community Health. Women’s Voices for the Earth.
Earthworks. Fact Sheet. Hardrock Mining: Acid Mine Drainage.
Septoff, A. 2006. Predicting Water Quality Problems at Hardrock Mines: A Failure of Science, Oversight, and Good Practice. Earthworks.