Michigan TU’s New Mining Policy

by Al Woody and Robb Smith, MITU Conservation Committee

Almost two years ago, the Back Forty Mine Project (BFMP) became a concern to Michigan Trout Unlimited. Since it would be affecting a warm water stream, Michigan TU did not give the matter a high priority. However, Michigan TU recognized that a policy/procedure regarding mining activities should be adopted for moving forward on these types of threats to our coldwater resources. As a result, Michigan TU started the development of a policy regarding mining. This article will introduce this new mining policy and update the status of the BFMP.

The BFMP would be located in Michigan’s Upper Peninsula adjacent to a warm water segment of the Menominee River near the city of Stephenson. The open pit mine would extract sulfide rock containing significant amounts of zinc, copper, and other valuable metals. The major process steps are: • The metal ore laden sulfide rock is extracted from the mining site, loaded into trucks, and transported to the mill for processing. • The rock is crushed in the mill and then moved to ball-milling machines where water is added to create slurry. This operation creates very small rock particles with some chemicals. • The slurry is then sent to a flotation process where the chemical rock particle mixture is agitated with air to create bubbles. The bubbles that rise to the top of this bath contain the ore minerals of interest, which are skimmed off and collected to be sent to another facility for further purifying processing. The waste material from the flotation process is sent to a tailing pond.

To evaluate a mine’s threat to coldwater resources, location is the critical issue – the opportunity to harm nearby bodies of water by one or more of the following: • Acid mine drainage – sulfide rock, when exposed to water and air, creates sulfuric acid. • Spill potential – slurry waste deposited in a tailing pond using an earthen dam is often over 100 feet high. • Groundwater depletion – the floatation process needs large quantities of water. • Likelihood of erosion – large, heavy trucks and other earth-moving equipment transport ore to the mill.

Keeping these threats in mind, the Michigan TU Council’s Conservation Committee began preparing a mining policy statement. The Pennsylvania Council of TU has a similar document that identified concerns and offered guidance for action. TU is not opposed to mining, but sometimes the wrong mine is proposed in the wrong location. Michigan TU must fully consider the impacts of mining and mine-related activities on our coldwater habitats before the development of mining projects. Our mineral resources’ economically-desirable development should not come at the cost of coldwater fisheries and their habitats.

The purpose of the mining policy statement is to guide Michigan TU in conserving our salmonid populations and their habitat in areas where they may be affected by mining activities, including storage, transportation, processing, and tailings. The policy covers four mining activities; underground mines, open pit mines, rock quarries, and sandpits. It deals with the three phases of a mine’s life; the permit process, mine operation, and land reclamation after the mine has ceased operations. The policy provides a rationale for evaluating the potential effects of any proposed mining activity on coldwater habitats and identifies the most valuable time and means to get involved with the proposed mining activity.

The threats to coldwater habitats from mining come from the mining operations and the failure to provide adequate environmental site conditions after mining has stopped. The establishment of what will be done during these periods is defined and agreed upon during the permitting process. Thus, reviewing the documents generated during the permitting process and voicing our concerns at that time is very important to achieving TU goals.

Typically, a permit request to mine includes assessments of the mining operations on the environment, how they will be minimized, any needed monitoring, and plans of corrective actions if the need arises. The permit application is submitted to the state or other governmental organizations for review and approval. It is reviewed, commented on, public hearings take place, and a conclusion is made to approve or deny the permit. For Michigan TU to have its concerns heard, we must be involved in this process. Gaining insight into a potential new mining operation is essential so that our involvement in the permit review is effective. This requires watchfulness by our

members and chapters to communicate to Michigan TU any potential new mining activity.

The BFMP is a good example of this watchfulness. The concerns regarding the BFMP are being brought to Michigan TU by several groups, including the Mining and Great Lakes Work Groups of the TU National Leadership Council, Wisconsin Trout Unlimited and some of their chapters, and the Coalition to Save the Menominee River. They and others are concerned and oppose this project because any detrimental incidents caused by the mining process will potentially affect the Menominee River and the upper Green Bay of Lake Michigan, which provide seasonal coldwater trout and “trophy water” bass fishing downstream from the proposed mine site. Any significant leakage or spill from the process tailings, pond slurry, contact water ponds, refining chemicals, or acid mine drainage could be catastrophic.

The Menominee River was recently placed on the 2020 “America’s Most Endangered Rivers” list because of the potential threat posed by sulfide mining activities at the BFMP. Ironically, after many years of extensive restoration efforts to clean up the lower Menominee River, it had previously been delisted as a Great Lakes Area of Concern.

Aquila Resources Inc, a Canadian company, is the owner of the BFMP with local offices located in Menominee, Michigan. In the jargon of the Canadian mining business, Aquila is a “junior” miner; a small venture capital company focused on exploration, not mine ownership. Aquila has very limited capital resources and is probably developing this mine with the intent of reselling it to a more financially capable mining company.

The mine’s target is an ore deposit known as a “volcanogenic massive sulfide” deposit, formed at deep seafloor locations when seawater interacts with the metal and sulfide-rich magma produced by undersea volcanoes. The magma, potentially containing copper, zinc, lead, silver, gold, tin, antimony, and bismuth, heats water that has entered fractures and faults in the rock. The heated water then dissolves some of the sulfide minerals. When the mineral-rich heated water mixes with cold seawater at a seafloor vent or fissure, the various minerals precipitate out of the solution and form the mineral sulfide ore body.

According to information provided on the BFMP website, the proposed open pit mine will produce an estimated 512 million pounds of zinc, 468 thousand ounces of gold, 51 million pounds of copper, 4.5 million ounces of silver, and 24 million pounds of lead over an estimated seven years of mining with the potential of future expansion. The ore is proposed to be processed on the mine site, where both mechanical and chemical extraction methods are to be employed. The chemical extraction processes require sodium cyanide as a leaching agent to separate the target minerals from the ore. The floatation portion of processing uses mercury compounds.

According to the Michigan TU Mining Policy, “sulfide rock mining can have a very harmful effect on the surrounding Back Forty Mine. environment.” The chemical composition of the ore itself and the methods utilized to separate the minerals from the waste rock are potential sources of pollution to the environment. The open pit mining process and the risks it produces are described in the new policy.

The policy states, “The location of the mine and its supporting facilities is a key issue in the degree of environmental concerns because of the opportunity to harm nearby bodies of water.”

The site plan of the proposed BFMP speaks for itself as to the risk to the Menominee River and the downstream environs. The BFMP would border approximately 2800 feet of the Menominee River and be as close as 150 feet from the river. The open pit will measure 2000 feet by 2500 feet and be 750 feet deep.

Other major risk areas are the tailings dam, contact water basins, and the two waste rock storage areas. Considering the “stone’s throw” proximity of the mine pit and the various mine holding ponds, common sense raises the ominous threat to the Menominee River that any spill, overflow, open pit collapse, or dam failure could have. It is also probable that, due to the mine’s proximity to the Menominee River, acid mine drainage will eventually occur and pollute the river and the Great Lakes.

Consideration should be given to the surface geology around the BFMP. It is comprised primarily of sandy glacial moraine and outwash plain deposits along with alluvial deposits. The underlying rock mechanics, which must support the open pit mine walls near the river’s edge, must also be considered.

The permitting process for the BFMP is well underway and addresses most of the concerns listed above. However, the permitting process is not intended to prohibit a mining project. It is designed only to create an agreed promise to do something within identified limits in straightforward terms. The permitting process is a tool for organizations and individuals to learn the details of a project publicly and make appropriate comments about construction, operation, ...continued on page 25