Regulatory Process

All industrial projects, including the underground Twin Metals Project, must navigate an extensive, complex regulatory process. The process will span several years and provide many opportunities for public input and comment along the way.

All new mine projects must obtain a series of approvals to begin construction. Before the approval process begins, the company must develop a project design and conduct environmental baseline studies to submit a formal mine plan proposal. Only after the company submits a formal proposal to state and federal agencies, will environmental review and later permitting begin.

Environmental Review

Environmental review is a prescriptive process that has two primary goals:

  • Consider the benefits and impacts of the project to the human and natural environment
  • Inform the public about the benefits and impacts of the project

Environmental review is an interdisciplinary process by which multiple federal and state agencies collaboratively consider the proposed project. They do this by preparing an Environmental Impact Statement (EIS). In Minnesota, an EIS is prepared to demonstrate compliance with both the National Environmental Policy Act (NEPA) and the Minnesota Environmental Policy Act (MEPA). Both NEPA and MEPA have multiple mandated opportunities for public input. In addition, the project must comply with Section 106 of the National Historic Preservation Act of 1966 (NHPA), which requires federal agencies to take into account the effects of their undertakings on historic and cultural resources. Under Section 106 of the NHPA, the responsible federal agency must determine whether the undertaking could affect historic properties, identify the appropriate State Historic Preservation Offices (SHPOs) and Tribal Historic Preservation Offices (THPOs) to consult with, and involve the public and other potential consulting parties.

During environmental review, scientific subject matter specialists with expertise in topics like wetlands, habitat, cultural and historic resources, economics, air quality and soundscapes work with engineers to consider whether alternative project scenarios could reduce potential impacts and still meet project goals. For more information about environmental review, visit these links:


Once the EIS is complete and findings are approved by state and federal regulatory agencies, all permits must be issued before construction commences. Environmental review and permitting are different. Environmental review is a collaborative and multidisciplinary process. Permitting entails one agency focusing on each specific type of permit. For example, the Minnesota Pollution Control Agency issues permits to protect air quality and the Minnesota Department of Natural Resources issues water use permits. Many of these permits have their own legally mandated public input processes. Permits also address financial assurance for closure. Only after all permits are issued can construction begin.

Permits include enforceable requirements about how the facilities are constructed, operated and eventually closed. Permits also have extensive requirements for monitoring and reporting during operations to oversight agencies to ensure the facility is in compliance. For example, permits will outline a schedule for collecting groundwater and surface water quality samples. During operations, these samples will be sent to a state-certified laboratory for water quality testing. Minnesota regulators will review the laboratory results to determine if they meet the stringent surface water and groundwater quality protection standards as specified in operating permits. Air quality permits will have similarly rigorous monitoring and reporting requirements. Noncompliance can result is corrective actions, fines or even permit revocation.

Minnesota’s mines are required by state law to have bankruptcy-proof financial assurance for reclamation and closure performance. Minnesota requires state-managed and annually adjusted financial assurance to cover any possible costs, including post-closure reclamation, before permits can be issued. Minnesota is authorized to deny or revoke a permit if a company does not comply.