Mac and Black Jack Mines

The Mac and Black Jack Mines are a set of four mines. EPA is working with the Navajo Nation Environmental Protection Agency (NNEPA) to oversee investigation and cleanup work being done by Homestake Mining Company (HMC).

Background

The four Mac and Black Jack Mines were operated between 1959 and 1971 by United Nuclear-Homestake Partners and its predecessors. In 1981, Homestake Mining Company became the sole owner of the four mines. Mac No. 1 is in the Mariano Lake Chapter and Mac No. 2, Black Jack No. 1, and Black Jack No. 2 are in the Smith Lake Chapter of the Navajo Nation. These mines produced approximately 1.8 million tons of uranium ore with Black Jack No. 1 producing most of the ore with a total of 1.4 million tons.

Cleanup Progress

HMC has worked with the Bureau of Indian Affairs and EPA to access all impacted areas within the mining sites. In 2018, HMC finished scanning the mine sites for radiation and sampling soil to see where contamination is located. These findings are published in a “Removal Site Evaluation,” which is available in hard copy at the Smith Lake and Mariano Lake Chapter Houses and is also found online under Technical Reports. In addition to the report, HMC has removed all physical hazards from the mines, including closing all open vent holes.

Next Steps

In coordination with Navajo Nation Environmental Protection Agency (NNEPA), Western Nuclear, Inc. (the company responsible for the mining operations and cleanup) and the affected community, EPA has evaluated potential options to address the hazards posed by the mine waste. The evaluation is presented in a report called the Engineering Evaluation/Cost Analysis (EE/CA).

Community Involvement

Community members have an opportunity to become involved in the cleanup activities and help shape cleanup decisions. EPA and NNEPA meet regularly, in coordination with chapter officials, with residents and other community members about work at the Mac and Black Jack mines.

Cleanup Progress Timeline

The four Mac and Black Jack Mines are in EPA’s Eastern Abandoned Uranium Mine Region and operated in various years from 1959 to 1971 by Homestake Mining Company (HMC).

2014

HMC signed an Administrative Settlement Agreement and Order on Consent for an Interim Removal Action (short-term work to secure the mines while alternatives for long-term cleanup are being developed.)

2017

HMC completed physical hazard work that is summarized in the Removal Site Evaluation Phase 2 Report.

2018

HMC completed the Removal Site Evaluation for the mines.

• View the Reports »

2019

HMC expected to submit a draft Engineering Evaluation/Cost Analysis by Fall 2019 that will include alternatives for addressing the mines.

2023

EPA published an Engineering Evaluation Cost Analysis that describes potential cleanup options for the site and opened a 60-day public comment period to receive input on the document before selecting a final cleanup option.

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