Lukachukai Mountains Mining District: Cove, Lukachukai, and Round Rock Chapters, Navajo Nation, AZ

On March 5, 2024, EPA announced the listing of the Lukachukai Mountains Mining District (LMMD) on the National Priorities List, commonly called the Superfund List. Sites included on the NPL are eligible to receive federal funding for long-term, permanent cleanup.

The documents for EPA’s listing of the site are available at the information repositories on the Navajo Nation and online at EPA's Superfund Site Information website.

• Background
• Community Involvement
• Cleanup Progress Timeline
• Documents

Background

The LMMD site is located primarily in the Cove, Round Rock, and Lukachukai Chapters of the Navajo Nation in northeast Arizona. Past uranium and vanadium mining in the Lukachukai Mountains created more than one hundred piles of mine waste rock. These waste materials are contaminated with radium-226, uranium and other heavy metals. The Lukachukai Mountains are home to the Navajo people, and they use it for hunting, plant gathering, and livestock grazing. The mountains provide habitat for several sensitive species, including the federally threatened Mexican spotted owl (Strix occidentalis lucida).

Waste piles in the Lukachukai Mountains continue to pose a threat to people and the environment. Waste from these piles has migrated downstream in washes and may have impacted groundwater. Past ore hauling activities spread contamination along miles of historical ore haul roads. The wide-spread contamination at the site requires a coordinated effort to ensure cleanup of all former mining areas and to address downstream impacts.

EPA has organized the LMMD site into four Operable Units (OUs) to organize and complete the investigation and cleanup of the site. The Operable Units at the LMMD site are:

• OU1 - Fund Lead Mines Source Control
• OU2 – Sitewide Groundwater and Surface Water
• OU3 – Tronox Mines Source Control
• OU4 – Cyprus Amax Mines Source Control

Community Involvement

Community members have an opportunity to become involved in the cleanup activities and help shape cleanup decisions. EPA and Navajo Nation EPA (NNEPA) meet regularly, in coordination with chapter officials, with residents and other community members about work at the LMMD sites.

Who is the Community?

The community includes people in both rural areas around Cove, Lukachukai, Red Valley, and Round Rock. Many people have seasonal sheep camps and graze livestock near mine site in the Lukachukai Mountains.

EPA and NNEPA Community Involvement Activities

EPA and NNEPA works with community leaders such as the council delegates, chapter, grazing and land board officials, responsible company liaisons, as well as community members for all outreach activities and information sessions which are conducted with cultural sensitivity. In 2025, EPA completed a Community Involvement Plan for the LMMD site. To keep the community informed, EPA and NNEPA has done the following:

• Developed fact sheets and flyers
• Conducted interviews for a Community Involvement Plan
• Attend chapter meetings to share information on cleanup progress
• Held open house meetings and workshops to share and receive input on cleanup alternatives
• Worked with chapter officials and family members to gain access to mine sites
• Conducted a Superfund Job Training Initiative event for the impacted communities to provide job-specific required training and certification to 24 community members

Partnerships

EPA and NNEPA continue to work and strengthen relationships with a number of organizations focused on uranium and radiation, including:

• Navajo Nation Abandoned Mine Lands Program
• Navajo Nation Department of Health Community Health Representatives
• Bureau of Indian Affairs
• Bureau of Indian Education
• Indian Health Service
• Agency for Toxic Substances and Disease Registry
• Nuclear Regulatory Commission
• Department of Energy
• Northern Arizona University
• Diné College
• Others as suggested by community members and local officials

Cleanup Progress Timeline

Prior to the LMMD site being listed on the National Priorities List, EPA was conducting investigation and removal activities under enforcement agreements and the Tronox Settlement. The timeline below starts is specific to the LMMD site.

2025

• EPA developed and completed a Community Involvement Plan for the LMMD site, including conducting interviews and meetings with impacted communities.
• EPA is completing the characterization of 11 mines funded by the NPL listing.
• EPA is completing the cleanup of the Cove Transfer Station 1 and 2 utilizing funding from the Tronox Settlement.
• EPA is completing characterization of 4 mines funded under the Tronox Settlement.
• Conducted a Superfund Job Training Initiative event.
• EPA started planning for a Remedial Investigation for Operable Unit 2, investigation of groundwater and surface water impacts.

2024

• EPA received funding for, and began, the Remedial Investigation of 11 fund lead mines under Operable Unit 1.
• EPA completed an investigation and removal action plan for the Cove Day School.
• Listed the LMMD site on the National Priorities List.
• EPA is completing characterization of 12 mines funded under the Tronox Settlement

Documents

• Lukachukai Mountains Mining District Community Involvement Plan (pdf) (10.6 MB, July 2025)
  This Community Involvement Plan (CIP) outlines opportunities for individual participation and meaningful information sharing regarding EPA’s activities in the Cove, Lukachukai, and Round Rock Chapters of the Navajo Nation and other communities surrounding the Lukachukai Mountains Mining District (LMMD) National Priorities List (NPL). This CIP is also a tool for the public to use to make sure EPA is responsive to their needs and concerns.
• EPA Fact Sheet: Lukachukai Mountain Mining District is Now a Superfund Site (pdf) (2.26 MB, March 2024)
  Fact Sheet describing the placement of the Lukachukai Mountain Mining District on the Superfund National Priorities List on March 7, 2024.