For decades, millions of tons of uranium mill tailings sat beside the Colorado River near Moab, Utah, leaving behind a major environmental cleanup challenge in a landscape known for its red rock scenery and tourism. The waste came from a uranium processing site that operated during the Cold War era, and concerns grew over contamination near the river. According to the U.S. Department of Energy, crews began transporting the tailings by rail in 2009 to an engineered disposal cell about 30 miles away in Crescent Junction. In September 2026, the Moab Uranium Mill Tailings Remedial Action Project marked a major milestone: 17 million tons had been removed from the riverbanks.
How the waste reached the riverbank
The material left near Moab was uranium mill tailings, the sand-like waste produced after uranium-bearing ore is processed. Although the tailings do not resemble the bright yellow uranium compounds often shown in popular culture, they can contain radioactive materials and other contaminants that require long-term management. The former Moab uranium mill operated near the Colorado River, an important waterway that supplies communities, supports agriculture and carries water through some of the American Southwest’s most environmentally sensitive landscapes.When the mill closed, the tailings remained at the site. For many years, the waste was stored in a large pile close to the river. Its location created concern because wind, erosion, flooding and groundwater movement could potentially carry contaminants away from the original site. The material was not treated like ordinary construction debris. It required a carefully planned removal process that could protect workers, nearby communities, transportation routes and the river corridor.
Rail transport began in 2009
The Department of Energy began moving the tailings by rail in 2009. Rather than carrying the waste by truck through surrounding communities and roads, the project used specially managed rail shipments to transport it from the Moab Site to Crescent Junction. The disposal cell is located approximately 30 miles away. It was engineered specifically to contain the material and reduce the possibility that water, wind or erosion could spread contamination. Moving 17 million tons is a logistical operation on a massive scale. Crews have had to excavate the tailings, load the material into rail containers, transport it to the disposal location and place it inside the engineered cell.Each stage involves monitoring and safety controls. The work must also account for changing weather, equipment maintenance, rail scheduling and the need to prevent dust or contaminated material from escaping during handling.
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Why the location matters
The proximity of the tailings pile to the Colorado River made the Moab cleanup especially important. The river is not only a major regional water source, but also a defining feature of the surrounding environment. Moab is known for its national parks, desert landscapes and outdoor recreation. The river corridor supports wildlife and provides a route through a region where water is already limited. Protecting the area requires attention to both visible pollution and contamination that may move through soil or groundwater.The Department of Energy’s project is intended to remove the large surface pile and address contamination beneath and next to it. Removing the material reduces the risk associated with leaving a radioactive waste pile in place beside the river. However, the completion of the main removal milestone does not mean every part of the cleanup is finished. The site still requires monitoring, construction and restoration work.
What remains to be done
According to the Department of Energy, crews will continue developing and implementing a final groundwater compliance action plan. This work will determine how groundwater conditions are monitored and managed over the long term. The project also includes removing contaminated soil beneath and adjacent to the original surface tailings pile. Even after the visible waste has been transported away, material beneath the pile may require excavation or other treatment.Officials must also demonstrate compliance with radiological standards. That process involves testing and documentation to confirm that the site meets the requirements established for cleanup and long-term management. Other remaining tasks include disposing of equipment and infrastructure used during the project, completing the cover over the Crescent Junction disposal cell and stabilising the Moab site. Final stabilisation is expected to involve regrading the surface and revegetating the area so that it is less vulnerable to erosion.
Building a long-term disposal cell
The Crescent Junction site is designed to contain the tailings for the long term. Its cover will play an important role in managing moisture and protecting the disposal cell’s integrity. Water is a major concern in the management of radioactive waste. If rain or melting snow enters a waste pile, it can move contaminants through the soil and potentially into groundwater. A properly designed cover helps limit infiltration and reduces exposure to weather and erosion.The cover also needs to remain effective over many years. That means engineers must consider settlement, drainage, vegetation, surface runoff and the effects of extreme weather. Long-term disposal is therefore more than placing the tailings in a hole and covering them. It requires a stable design, monitoring systems and a plan for maintaining the site after active cleanup crews have left.
A milestone, not the final chapter
The removal of 17 million tons is a major achievement for the Moab Uranium Mill Tailings Remedial Action Project. It marks the movement of an enormous amount of radioactive waste away from the banks of the Colorado River and into a purpose-built disposal facility. The milestone also shows why environmental cleanup projects can take decades. The mill closed long ago, but the waste remained a complex responsibility for government agencies, engineers, workers and surrounding communities.For people living near the Colorado River, the project offers the possibility of a safer and more stable landscape. For officials responsible for the cleanup, the next phase will be focused on groundwater, remaining contaminated soil, the disposal cell cover and final restoration.The pile that once dominated the riverbank is gradually disappearing from the Moab landscape. Yet the project’s success will ultimately be measured not only by the amount of waste removed, but by whether the disposal site remains secure and the former mill property can be stabilised for generations to come.
