Iron King Mine - Humboldt Smelter Project

                           Remediation & Redevelopment Issues

                         Presentation & Soils Clean-up Standards

                                              Comment Letter to EPA

                                          Steven Speyer Presentation

This link is to EPA's Administrative Record for the Iron King Mine-Humboldt Smelter Superfund Site.  EPA's Administrative Record is the agency's collection of documents forming the basis for its selection of a response action at the site.  In posting this link, the Town does not warrant the adequacy of the documentation for EPA's decision-making.

Iron King Mine - Humboldt Smelter Superfund Administrative Records

ADEQ Soils Sampling Report February 5, 2021

ADEQ Presentation and Soils Investigation December 7, 2021

                                                   SUPERFUND SITE PROPOSED PLAN

Proposed plan for Iron King Mine  Humboldt Smelter Superfund Site JPG
Speyer Environmental Expanded Scope of Work
Speyer EPA Public Hearing Statement_03292023-02_public release

Announcements and Key Topics

EPA has proposed a plan to address contamination at the mine site area and soil in the residential area.

Community members are encouraged to review the Proposed Plan and provide input to EPA during the public comments period from March 15 – May 13, 2023. 

For a short summary of the Proposed Plan, view our latest fact sheet. To view the full Proposed Plan, click here (or visit the Site Documents and Data section of this website).

We Want to Hear From You!

EPA will host a community meeting at 6:30 p.m. on March 29 at Humboldt Elementary School. See the meeting announcement in the Dewey-Humboldt Town Newsletter for more information.

Community members are encouraged to attend this meeting to:

  • learn more about the site;
  • the proposed cleanup plan; and
  • submit comments in person.

Community members can also submit comments via email to Remedial Project Manager Jeff Dhont or Community Involvement Coordinator Georgia Thompson.

Comments, postmarked by May 13, 2023, can also be mailed to:

Jeff Dhont
EPA Project Manager
75 Hawthorne Street (Mail Code: SFD-8-1)
San Francisco, CA 94105

Detailed documents on how EPA developed cleanup options are in the site’s Administrative Record, which is a collection of key documents EPA used to create the plan. This record is posted in the Site Document and Data section of this webpage. The Proposed Plan and the Administrative Record are also available at:

Dewey-Humboldt Town Library

2735 S Corral Street
Humboldt, AZ 86329
(928) 632 – 5049
Please call for hours and availability

Superfund Records Center

75 Hawthorne Street
San Francisco, CA 94105
(415) 947 – 8717
Please call for hours and availability

Learn more about the site and cleanup plan by:

  • watching our recorded presentations on YouTube;
  • contacting EPA staff below (in the Site Contacts section of this webpage); or
  • attending our in-person meeting March 29 in Dewey-Humboldt.

After the comment period for the Proposed Plan closes, EPA will:

  • consider and respond to all comments received;
  • select a final cleanup option and publish it in a document called a Record of Decision (ROD);
  • post the Record of Decision to the Cleanup Progress section of this webpage and the Site Documents and Data section of this webpage; and
  • respond to all verbal and written public comments received during the comment period. These responses will be put in EPA’s final cleanup plan for the site once it is done—it is called the Record of Decision.

Public Participation Opportunities

We Want to Hear From You!

EPA will host a community meeting at 6:30 p.m. on March 29 at Humboldt Elementary School on the March 2023 Proposed Plan.

Community members are encouraged to attend this meeting to:

  • learn more about the site;
  • the proposed cleanup plan; and
  • submit comments in person.

EPA recognizes that communities have the right to be involved in the decisions that affect their lives. EPA’s experience has been that when the public is involved in EPA’s work, the cleanup process results in a better outcome and a more robust remedy.

At the IKHS site, EPA’s wants the public to participate throughout the cleanup process, including the investigation phase and the remedy selection phase. EPA and ADEQ have a number of ways for the community to become more knowledgeable about and involved with the IKHS site.

Community Involvement Plan

The Iron King Mine/Humboldt Smelter Superfund Site Community Involvement Plan provides a detailed explanation of how EPA and ADEQ will encourage public participation in the cleanup decision-making process. It is a flexible plan that organizes both EPA’s and ADEQ’s efforts, and it can change based on new community needs.  A hardcopy of the IKHS Community Involvement Plan can be found at the site’s information repository at the Dewey-Humboldt Town Library.

Fact Sheets

EPA periodically issues fact sheets to provide information on a wide variety of topics.  EPA will mail these fact sheets to all mailing addresses within approximately 2 miles of the site. Several fact sheets are available in the documents “factsheet” section of this website and hardcopies can be found in the site’s information repository at the Dewey-Humboldt Town Library.

Copies of the proposed plan are available at Town Hall in the plastic file boxes outside of Town Hall.

EPA Website

Community Resources

Community members might find helpful information at the following resources:

For community members who are looking for resources on managing private water wells, the following resources might be helpful:

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
  9. March 2023

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