Iron King Mine - Humboldt Smelter Project

In 2019 the U.S. Environmental Protection Agency (EPA) applied a dust-control cover called Posi-Shell® over waste material called dross on the north end of the former Humboldt Smelter property. Posi-Shell® forms a thick, crusty layer that prevents dusty materials underneath from blowing. The Arizona Department of Environmental Quality (ADEQ), in cooperation and concurrence with EPA, has now laid down a fresh and thicker application of the Posi-Shell® dust-control cover to extend the life of the cover and reduce further weathering. ADEQ will provide a status update about this activity, as well as some other property-related safety projects, on their webpage 

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Humboldt Smelter Project Updates

  1. April 7, 2020
  2. June 18. 2020
  3. July 22, 2020
  4. September 16, 2020
  5. June 25, 2021
  6. November 23, 2021
  7. February 24, 2022
  8. April  18, 2022

In late 2019, the U.S. Environmental Protection Agency (EPA) placed fencing at the former Humboldt Smelter property to limit public access. EPA continues to work with the owner of the former Iron King Mine property to upgrade and add fencing. We ask the public to follow warning signs and stay away from the mine and smelter properties.

In early 2020, EPA focused on the study of options to clean up the contamination, called a “Feasibility Study.” This study uses the information EPA collected in the remedial investigation, which was a comprehensive evaluation of sampling data and information about the nature and extent of contamination. The Feasibility Study will also use information about approaches to reuse the smelter plateau, collected during the May 2019 community brainstorming workshop.

EPA was planning a trip to Dewey-Humboldt. However, we continue to adjust to the evolving COVID-19 situation. EPA is taking necessary steps to ensure that decisions about ongoing cleanup activities at Superfund sites are made with the health and safety of communities, EPA staff, and contractors as the priority. As a result, we are postponing in-person public meeting events to reflect current COVID-19 guidance from federal, state, tribal and local officials.

In the meantime, we have updated EPA’s Iron King Mine/Humboldt Smelter site webpage. Please contact EPA with any questions using the contacts on our webpage.

Iron King Mine and Smelter Superfund