PolyMet technicians testing passive water treatment systems at the NorthMet Project site

We are committed to building the NorthMet Project to strict standards, meeting or exceeding all applicable state and federal environmental regulations, ensuring a safe work environment, and protecting Minnesota’s beauty and natural resources.

Below are some examples of the measures we’re taking to protect the environment. More measures and their details are found in the Final Environmental Impact Statement and permit applications.

Cleaning up legacy mining issues. Because of legacy issues created by iron ore processing at the site, long-term water care is needed regardless of whether the PolyMet project moves forward. Operating permits will enable us to implement a comprehensive water treatment program to address those issues. It will lead to a net reduction in levels of mercury and sulfate in the St. Louis River even when the emissions from new mining at the site are factored in.

Treating water for the long term. Typical of most mines today that operate under strict environmental regulations, we will treat water to meet state standards before it is discharged, for as long as is necessary. The plan for doing this is outlined in the Permit to Mine and includes bankruptcy-proof financial protection to ensure the treatment also can be funded for as long as is necessary. Download our fact sheets on long-term treatment, and financial assurance.

Meeting the wild rice standard. We are committed to meeting Minnesota’s strict sulfate standard for wild rice, which is far more stringent than the drinking water standard. We’ll use modern, proven membrane technology to meet the standard, a groundbreaking measure for industrial and municipal facilities in the state. Download our water quality fact sheet.

Using existing facilities to minimize land disturbance. Two of the great advantages of our project is our location in an existing mine district and ownership of the former LTV Steel taconite mine and processing facilities, which we will modernize and reuse. This includes a tailings basin, crushers and mill, and associated infrastructure such as rail lines, transmission lines and substations, pipes and roads. This limits any new land disturbances primarily to the mine site itself where the open pit and waste rock stockpiles will be located and subject to environmental controls and regulations.

Ensuring tailings dams are safe. Dam stability and water management are two key considerations when siting, designing, building and operating tailings impoundments. The existing tailings basin has stood the test of time for more than 40 years. We will add to that structure, applying similar design with enhanced engineering controls. This includes adding rock buttresses to the exterior face of the dam. Download for our fact sheet on tailings dam safety and environmental protections.

Controlling Seepage. Using control technology that has been employed with success at mining and industrial operations globally, we will install a nearly five-mile-long hydraulic barrier or cut-off wall – an underground wall made of bentonite – that will extend from surface to bedrock around a portion of the existing tailings basin to keep untreated water from seeping off site. Water will be collected and pumped to a treatment facility. At closure, a permanent pond will be formed at the tailings basin. The pond bottom and exposed beach areas will be amended with bentonite to minimize future leakage. Download for our fact sheet on tailings dam safety and environmental protections.

Replacing and mitigating wetlands. The NorthMet Project is estimated to directly impact approximately 900 acres of wetlands, which we will be required to mitigate or replace. Based on EPA recommendations, the minimum required amount of replacement wetlands is 900 acres. In other words, for every acre of wetland we disturb, we must replace it with equal or more wetlands. The U.S. Army Corps of Engineers and Minnesota Department of Natural Resources will determine final mitigation requirements as part of their permitting process. The Army Corps of Engineers already has stated that the mitigation sites identified by the company would be acceptable for use in compensating for direct wetland losses. Download a DNR fact sheet on wetlands.

Planning for closure and reclamation. Having detailed plans in place for closing and reclaiming the site after mining ends are pre-requisites to obtaining permits to build and operate the project. These plans include backfilling the East Pit after it is mined out with waste rock that has been stored temporarily on-site on a lined facility, and covering and planting vegetation on permanent waste rock stockpiles. Some of this work will happen concurrently while the mine is still operating. Also, warehouses and other buildings will be removed and water containment and treatment facilities will continue to be maintained. The goal of reclamation is to restore the site to as natural a state as possible. In our case, we will leave it better than we found it. Download the DNR’s fact sheet on reclamation.

Bankruptcy-proof financial assurance. It’s a state law that the company must provide bankruptcy-proof “financial assurance” to the state before starting any construction or mining activity. This ensures the state has the right amount of money available to close and reclaim the site at any given time if the company is unable to do so. It also protects taxpayers from these obligations. The financial assurance amount is re-examined annually by the state to ensure the appropriate level of bankruptcy-proof funding is always available. Download our fact sheet on financial assurance.

Protecting beyond our project. We partner with Ducks Unlimited in support of its Living Lakes Initiative, a program that restores the health and functionality of Minnesota’s degraded shallow lakes and wetlands. Our funding helps DU, a leading conservation group, enhance wild rice in more than 100 shallow lakes and wetlands in northern Minnesota each year.