&EPA Northeast Church Rock Mine
Design Update
U.S. Environmental Protection Agency • Region 9 • San Francisco, CA • January 2020
Design Overview
Background
The United Nuclear Corporation (UNC) Mill Site and the
Northeast Church Rock (NECR) Mine Site are located
at the end of Route 566, about 17 miles northeast of
Gallup, N.M. The U.S. Environmental Protection Agency
(USEPA) has decided to clean up the NECR Mine Site by
placing the mine waste in a repository at the nearby UNC
Mill Site. USEPA is currently overseeing a design for this
repository and this fact sheet describes the main activities
included in the design.
What is a repository?
A repository is a place for holding waste. The UNC Mill Si
engineered cell with a top (cover) and bottom (liner) to ke
United Nuclear Corporation Mill Site.
(Photo courtesy of UNC.)
repository for the NECR mine waste will consist of an
> contamination from further polluting the environment.
What is the repository design process?
The design is developed in two main phases. The first phase is to provide a general overview of how the repository
will be constructed. The second phase is to provide a final design that includes detailed construction and technical
specifications. USEPA approved the completed design for submission to the Nuclear Regulatory Commission
(NRC) for a license amendment in 2018. This fact sheet provides an overview of this EPA approved design
submitted to the NRC.
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Figure 1: Overview of UNC Mill Site repository
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Figure 2: Work Areas at the NECR Mine Site and UNC Mill Site,
Work Summary
Step 1: Digging and Hauling
NECR mine waste would be dug up from the purple work areas
shown in Figure 2 (labeled as "NECR Mine Site" in legend).
Covered trucks would haul the waste to the UNC Mill Site. The
trucks would use new roads to stay off public roads as much as
possible. The trucks would cross Route 566 at a stoplight just south
of the Pipeline Road turnoff (see Figure 2). Each truck carries 30
cubic yards (about 42 tons) of waste.
Step 2: Placing Mine Waste and Covering
The mine waste would go in the repository shown with black diagonal lines in Figure 2 (labeled as "Extent of Final
Repository" in legend). The clay cover layer for the existing mill tailings cells (labeled as "Existing Cover/New Liner")
would stay in place and serve as a liner for the mine waste. After placement of the mine waste on the liner, soil from
the borrow areas would be mixed with rock to create an evapotranspiration cover (known as an "ET cover") that
would cover the mine waste and prevent exposure to people and the environment. The cover also prevents wind
and water erosion, and keeps rainwater and snow melt out of the mine waste. Figure 3 shows how an ET cover
works. While most water runs off the cover, water that goes into the cover comes back out by evaporation or by plant
roots taking up the water from the clean cover (transpiration). The rock in the cover minimizes erosion from
wind or water. The cover is designed to last at least 1,000 years.
The mine waste would be transported in haul
trucks similar to the one shown.
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Figure 3: Conceptual Dra wing of an ET Cover
Step 3: Installing Stormwater Controls
Stormwater management, or "stormwater controls," is
an important part of designing the waste repository.
Stormwater controls keep soil from running off the work
areas and stop water from eroding the repository or
nearby areas. Figure 2 shows stormwater controls at the
site in orange (labeled as "Stormwater Controls" in legend).
The Pipeline Arroyo, that runs along the West side of the
repository, would have major stormwater controls. A large
engineered structure, would direct water flow away from
the repository, preventing erosion.
Step 4: Restoration at the NECR Mine Site
After removal of contaminated soil from the NECR Mine
Site, USEPA would then conduct "verification surveys" to
ensure all mine waste has been properly removed and the
area is safe. Once the area has been certified as safe, the
site would be regraded and revegetated.
Examples of previous revegetation on the NECR mine site
at six and eighteen months after reseeding.
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Additional Information
Timeline
In September of 2018, the company responsible for cleaning up the mine, UNC, which is owned by
General Electric (GE), submitted a request for a license amendment (which includes the completed
design) to the U.S. Nuclear Regulatory Commission (NRC) for construction. The NRC must approve the
license amendment before construction can begin. The NRC estimates that the license amendment
process will be complete in January of 2020. If NRC approves the request, USEPA would then negotiate a
legal agreement with UNC/GE to construct the repository. Construction will take about four years.
Involved Parties
UNC will conduct the NECR cleanup under the oversight of USEPA and a design review team.
The design review team includes staff from USEPA, Navajo Nation EPA, the New Mexico Environmental
Department, the NRC and the U.S. Department of Energy. A local resident appointed by the Red Water
Pond Road Community Association (whose members live close to the mine) is also part of the team.
The resident receives technical assistance services through USEPAs Technical Assistance Services for
Communities program.
More Resources
For more information on the NECR repository design and construction plan, visit the technical document
section of the NECR website found at: https://www.epa.gov/navaio-nation-uranium-cleanup/eastern-
regi on-abandoned-uranium-mines
Contacts
Sara Jacobs
Priscilla Tom
USEPA Remedial Project Manager
USEPA Community Involvement Coordinator
(415) 972-3564
(505) 240-0093
jacobs.sara@epa.gov
tom.priscilla@epa.gov
Dariel Yazzie
Navajo Nation EPA
(928)871-7601
darielyazzie@navajo-nsn.gov
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