An exposed waste impoundment cell at the Energy Fuels’ White Mesa Mill in southeast Utah is out of compliance with federal Clean Air Act standards, according to the Environmental Protection Agency and Utah Department of Environmental Quality.
The 40-acre Cell 4B permanently stores hazardous wastes from the mill’s uranium milling process and from off-site deliveries. It is supposed to have a water cover over waste solids to reduce radon emissions and prevent hazardous material from blowing away in the wind.
But despite noncompliance notices from state and federal agencies, a flyover April 4 by EcoFlight revealed the waste cell is still mostly uncovered by water.
In an email to The Journal, Curtis Moore, Vice President of Marketing for Energy Fuels, said that water is currently being added to Cell 4B at a rate of 300 gallons per minute, which will take a few months to fill it.
On Oct. 27, the UDEQ issued a compliance advisory to Energy Fuels for suspected violations of the Clean Air Act National Emissions Standards or Hazardous Pollutants.
The compliance advisory noted solids observed above the liquid surface of Cell 4B indicating a failure to maintain liquid levels in accordance with environmental regulations.
In a Dec. 2 letter to Energy Fuels, the EPA ruled the mill facility is unacceptable for the receipt of off-site wastes, as a result of the ongoing alleged violation of the Clean Air Act.
The liquid cover over the impoundment cells is designed to mitigate radon emissions, according to the December EPA notice.
Based on Energy Fuels reports on radon emission rates from another impoundment cell that is covered in water, “EPA estimates that the uncovered material in Cell 4b is emitting approximately 10 times the radon emissions of the covered material in the cell,” the notice states.
As a substitute to milling uranium ore, which has not been cost-effective to mine, the White Mesa Mill has been accepting “alternative feed” material from radioactive cleanups around the U.S. and internationally.
The waste is milled to recover uranium in the form of yellow cake, which is used to create fuel rods for nuclear power plants. It is not used for nuclear weapons.
The alternative feed and uranium milling wastes are permanently stored at the White Mesa Mill site located on U.S. 191 between Blanding and the Ute Mountain Ute reservation community of White Mesa.
In 2017, the company asked the EPA to define solids, and interpreted the EPA’s 2019 response to mean the cell’s waste material did not meet the definition, and therefore was not required to be covered with water in the impoundment cell.
In its response to Utah and federal notices of Clean Air Act violations, Energy Fuels stated there is no “solid material” subject to liquid cover regulation in Cell 4B, and that it contains only “evaporative crystals” not defined by EPA as solids.
In a March 3 letter to Energy Fuels, EPA rejected the company’s interpretation, and reiterated that the Cell 4B must be covered in water because it contains solid waste material as defined by environmental laws.
The Clean Air Act states “the liquid levels in the impoundment shall be maintained so that the solid materials in the impoundment are not visible above the liquid surface.”
Energy Fuels stood by its position that the cell did not have be covered by water during a mill inspection by the EPA and the state of Utah officials Jan. 13, according to the EPA.
Regardless of that position, Energy Fuels is filling the pond, Moore said in an email, and he provided additional comments on the Cell 4B issue.
“We were absolutely stunned to receive that notice from the EPA in December 2021, since we believed we were in full compliance,” he stated. “This all looks like a huge misunderstanding.”
Moore said Cell 4B is an evaporation pond and doesn’t currently have any uranium tailings.
“The 10x (radon) number the EPA made in their original notice to us in December 2021 is not applicable. That applies to uranium tailings in a tailings cell, not the crystals in this evaporation pond.”
Testing of the ponds show radon emissions are below standards, Moore said, and that the EPA gave approval to expose material in the pond because it does not emit much radon.
“The material in the pond today is the same as what was in the pond in March 2019 when they gave us that approval – 97% - 98% evaporite crystals,” Moore stated. “There are no radon emitting uranium tailings in that pond. There is zero risk to public health or the environment from this material being exposed.”
EPA said while it provided the White Mesa mill a variance regarding evaporative crystals not being defined as a solid material specific to them forming above the liquid surface on the freeboard border of the waste cell, the exemption did not go further.
“The Agency’s 2019 interpretation was not intended to apply to all or most of the substances or materials present in the impoundment,” states the EPA in the March 3 notice to Energy Fuels, “and was not intended to permit the unrestricted drawdown of the liquid in a nonconventional impoundment.”
The freeboard exemption on solids was to prevent the cell from being overfilled with water in an attempt to cover evaporative crystals that kept reforming over the water surface.
A call to Energy Fuels for comment on the Cell 4B issue was not immediately returned.
The White Mesa Mill is the only conventional uranium mill operating in the U.S. and has had a mix of supporters and detractors over its lifetime – a divisiveness that continues.
Supporters tout the good-paying jobs and property tax base it provides for San Juan County. They are encouraged by the mill’s plan to enter the rare earth market.
Opponents including environmental groups and the Ute Mountain Ute Tribe, which has a reservation near the mill, have concerns about environmental safety of the plant’s emissions, its older waste containment ponds and risk to water quality.