Wisconsin Could Face a Mining Disaster
Mining company's proposed tailings dam could cause massive pollution of Lake Michigan.
The same design for storing mine waste, known as the upstream dam construction method, is now being proposed for a large open pit metallic sulfide mine and tailings dam next to the Menominee River on the Wisconsin-Michigan border. While Brazil’s mining agency has already banned this design from further use, Michigan regulators are poised to approve this design and risk a catastrophic dam failure that could send toxic wastes into Lake Michigan and threaten drinking water for millions in the Upper Midwest. A coalition of concerned citizens, environmental groups and the Menominee Indian Tribe of Wisconsin is determined to prevent this from happening.
What are tailings dams?
Tailings dams are some of the largest human-made structures on earth. Tailings are the waste material left over from the crushing, grinding and chemical processing of mineral ores. The chemicals used include cyanide. The tailings often contain residual minerals – including lead, mercury and arsenic that can be toxic if released to the environment. However, unlike water-retaining dams made of concrete and steel, tailings dams are held back by walls of sand and silt.
Contrary to the claims of safety by the mining industry, tailings dams are failing with increasing frequency and severity. When they fail, they can destroy entire communities and livelihoods. The largest mining disaster in Canadian history occurred in August 2014 when the Mount Polley tailings dam failed and released 25 million cubic meters of tailings into the Fraser River watershed in British Columbia. Local emergency response officials warned downstream residents not to drink, cook with, bathe in or come in contact with the effluent.
The Brumadinho dam is owned by the mining giant Vale, the same company responsible for a tailings dam failure four years earlier at the Samarco mine in Mariana that buried three communities and killed 19 people, leaving hundreds homeless and contaminating hundreds of miles of river valleys with toxic sludge. It was one of the worst environmental disasters in Brazil’s history.
The tailings dam failures at Brumadinho and Mariana occurred in a technologically advanced country with a history of mining and with mining companies that had the ability to use state-of-the-art technology to construct and maintain tailings dams. Vale is the largest producer of iron ore and nickel in the world, with massive operations in Brazil. BHP Billiton was a co-owner, with Vale, of the failed tailings dam at Mariana. BHP Billiton, an Anglo-Australian company, is the world’s largest mining company.
This environmental disaster should raise red flags for Michigan regulators who have already been besieged by multiple controversies about the impact of Aquila Resources’ Back Forty project on the communities and environment around this proposed mine.
Aquila Resources’ Proposed “Back Forty” Mine and Tailings Dam
Aquila is a Canadian exploration company that has no experience with mining. It has recently submitted a revised permit application to Michigan’s Department of Environmental Quality (DEQ) for its proposed Back Forty metallic sulfide mine a mere 100 feet from the Menominee River. Although the Menominee River is an interstate waterway (it forms much of the border between Wisconsin and Michigan and empties into the Green Bay, just above the city named for it), the Wisconsin Department of Natural Resources has allowed Michigan to assume exclusive jurisdiction over the permitting process.
The proposed mine would produce 70 million tons of acid-producing waste rock and milled tailings. When sulfide minerals in mines and mining wastes are exposed to air and water, the chemical reaction produces sulfuric acid and metal pollution known as acid mine drainage (AMD). AMD is toxic to fish and wildlife due to dissolved metals and contaminants such as mercury, lead, arsenic, cadmium, zinc, copper and many others. These contaminants would threaten the Menominee River and eventually Lake Michigan, the second largest of the Great Lakes, which are the largest source of fresh water on earth.
Downstream communities oppose the Back Forty project
The main revision to Aquila’s mine permit is the expansion of the tailings dam. Aquila claims that these finely ground chemical-laden wastes, along with millions of gallons of water mixed in a slurry, can be stored safely next to the Menominee River in perpetuity. Downstream communities in Wisconsin that depend upon the river for their drinking water, fishing and tourism doubt the company’s assurances of safety. Seven counties, four towns, three cities, and dozens of tribal governments have passed resolutions against the project.
Mining on sacred lands?
The location of the proposed Back Forty mine has special significance for the Menominee Indian Tribe of Wisconsin because it is their original homeland. The Menominee River is named for the Menominee Indians, who trace their origin back thousands of years to when the Ancestral Bear emerged from the mouth of the Menominee River and was transformed into human form as the first Menominee. They occupied the Menominee River area for millennia, until an 1836 Treaty with the US forced them to cede their original territory in Michigan. However, the Menominee Nation never gave up its right to protect its traditional cultural resources that are essential to their identity. The present-day Menominee reservation is sixty miles southwest of the proposed mine.
The mine site is located on the traditional lands of the Menominee Nation that include prehistoric burial mounds, village sites, raised agricultural beds and dance circles. Similar concerns about harm to water supplies and the destruction of sacred sites have resulted in a massive tribal and environmental protest against the Dakota Access Pipeline next to the Standing Rock Sioux reservation in North Dakota.
Al Gedicks is emeritus professor of environmental sociology at the University of Wisconsin-La Crosse and executive secretary of the Wisconsin Resources Protection Council.