Steve Garske, UPEC Mining Action Group, 

Kathleen Heideman, UPEC Mining Action Group, 

Ron Henriksen, Front 40 Environmental Group, 

Gregg Bruff, Upper Peninsula Environmental Coalition Coordinator, , (906) 201-1949

New Report Finds Fault with Sulfide Mine’s Plans

MARQUETTE, MI — A new technical report from the Center for Science in Public Participation (CSP2) identifies serious faults with Aquila Resources’ Back Forty Mine Permit Amendment application, now under review by the Michigan Department of Environmental Quality.

The technical review of the Back Forty permit was conducted by Dr. Kendra Zamzow, an environmental geochemist, and Dr. David Chambers, an internationally-known expert on tailings dam safety. CSP2 analyzes mining applications in order to “provide objective research and technical advice to people impacted by mining.”

The Back Forty project proposes to excavate an 800-foot deep open-pit sulfide mine on the banks of the Menominee River, 100 feet from the water. Milling will also take place on-site, using cyanide leaching, mercury recovery, and flotation. Aquila claims to be “minimizing impacts” but the footprint of the facility has ballooned to 440 hectares (1087 acres), largely due to a larger tailings management facility. Most of the mine site would be covered by waste rock, ore storage, milling facilities, and tailings storage. Environmental groups claim that the Back Forty’s environmental impacts could be significantly reduced by using feasible, common-sense alternatives — but Aquila has rejected these options.

Nearly all of the Back Forty rock is reactive – capable of producing Acid Mine Drainage (AMD) when exposed to air and water. AMD pollution devastates watersheds and lasts hundreds of years. Tailings and waste rock will be stored on-site during mining, and the tailings will remain on the surface forever. Aquila has told their investors they will pursue underground mining as a “second phase” of operations, but this is not acknowledged in any permit. Underground mining could extend the mine’s life from 7 years to 16 years, greatly magnifying the risks. During the closure, the open pit will be backfilled with waste and tailings. Once this takes place, groundwater contaminated with AMD is predicted to seep into the river.

CSP2’s technical report evaluated the Back Forty mining permit, including updated environmental impacts, feasible alternative designs, financial assurances, and Aquila’s proposed use of an “upstream” tailings design, the same risky construction method that has resulted in catastrophic tailings dam failures around the world.

Key Findings of CSP2’s Technical Report

  • The Tailings Management Facility (TMF) is to be constructed using the upstream dam construction method, which is the least safe design. It also applies an underestimated seismic event to the construction design.
  • There are no details for the wastewater treatment plant (WWTP).
  • There is no information on how mercury from the retort will be stored or transported, or whether there is a facility to receive it. Mercury emissions from the retort did not go into air deposition modeling.
  • Air deposition modeling suggests that Spring Lake currently meets mercury water quality standards, but will exceed (violate) them after mining begins. By using old data, Aquila Resources may be biasing the baseline high, underestimating the impact of emissions.
  • There are significant unexplained inconsistencies with the volume of chemical reagents, and the storage capacity for lime.
  • Recent data suggests upper groundwater layers flow faster than the data used in the groundwater model. The groundwater model was not updated and may underestimate the volume of dewatering and impacts to wetlands.
  • Biological monitoring should include mussels, but currently, that is not scheduled.
  • There are no plans to monitor surface water for metal concentrations, although sediment and mine discharge will be monitored for metals. Surface water metal analysis should be added.
  • Financial assurance is underestimated.

“This report only underscores the fact that the original Mining Permit should not have been granted,” said Ron Henriksen, spokesperson for the Front 40. “Aquila continues to provide inadequate applications with missing information. The DEQ should rescind this entire permit, have the applicant revise their mistakes, and refile it, properly formatted, with all material in one complete, organized application package.”

“These flawed permits and their environmental impacts are deeply interconnected. We urge the State of Michigan to hold a consolidated hearing on the Mine Permit Amendment, the Air Permit application, and the Dam Safety Permit application – an option allowed under Part 632 in cases where an applicant applies for multiple permits,” said Kathleen Heideman, a member of the UPEC Mining Action Group.

“We need a thoughtful, consolidated hearing to discuss these permits,” said Heideman. “Nothing less than the future of the Menominee River is at stake.”

“The mine permitting process generates thousands of pages of data and arguments and choices. What is a grassroots environmental organization to make of it? Our logical minds can see where the loose ends are dangling. By hiring mining experts ourselves, we can identify those loose ends as areas of serious concern about this mining permit.  We can enter the discussion that would otherwise be dominated by agency staff, lawyers, and mining company engineers. The expert commentary gives us a louder and more credible voice,” said Jon Saari, a board member of the Upper Peninsula Environmental Coalition.

“CSP2’s expert review of Aquila Resources’ latest Back Forty mining permit application has exposed serious flaws in their mining layout and operational design. This includes their insistence on using the risky upstream dam construction for their tailings facility,” said Steve Garske, a member of the Mining Action Group of the Upper Peninsula Environmental Coalition. “If constructed as planned, this mine will literally be an accident waiting to happen.”

Technical review of the Back Forty Mine Permit Amendment was made possible by a collaborative effort of the Mining Action Group, the Front 40 Environmental Fight, the Coalition to Save the Menominee River, a 2019 grant from Freshwater Future’s Great Lakes Network, and a 2019 emergency mini-grant from the Western Mining Action Network.

Public Participation

The deadline for submitting written comments on the Aquila Back Forty Mine Permit Amendment has been extended until February 15, 2019, at 5 pm (EST). Mail comments to Back Forty Mining Permit Amendment, MDEQ-OGMD, 1504 West Washington Street, Marquette, MI 49855, or email comments to DEQ-Mining-Comments@michigan.gov with “Back Forty Mining Permit Amendment” as the subject.

Learn More


The mission of the Mining Action Group
The UPEC Mining Action Group (MAG), formerly known as Save the Wild U.P.,  is a grassroots effort to defend the clean water and wild places of Michigan’s Upper Peninsula from the dangers of sulfide mining. Contact the Mining Action Group at  or call (906) 662-9987. Learn more about the Mining Action Group at miningactiongroup.org

The mission of the Front 40 Environmental Group
The Front 40 is a grassroots organization that was formed in early 2003 in response to the threat of a metallic mineral mine potentially being developed on the shores of the Menominee River in Lake Township, Michigan. It is the principal objective of the Front 40 Environmental Group to ensure that metallic sulfide mining operations are not allowed to adversely impact our rivers, lakes, groundwater, and lands. Learn more about the work of the Front 40 Environmental Group at menomineeriver.com