Dams that hold back huge amounts of uranium mine waste above the fertile Ferghana Valley in Central Asia is unstable, threatening if they collapse with possible nuclear disaster on the same scale as Chernobylwhich would render the area uninhabitableas studies have revealed.

Dams holding back about 700,000 cubic meters of uranium mine waste in Kyrgyzstan have become unreliable after a landslide in 2017. Another landslide, or an earthquake, could send the waste into a system of rivers used to irrigate farmland in Kyrgyzstan, Uzbekistan and Tajikistan, studies of Soviet-era radioactive waste disposal facilities showed. This will probably force millions of people in these three countries to relocate.

These studies, which are part of a program by the European Commission and the European Bank for Reconstruction and Development to upgrade the facilities, show that the type of waste cannot be safely stored in the current facilities and will need to be moved away from the banks of the Maili-Su river.

The Fergana Valley, where the contaminated water will end up, is the most densely populated region in Central Asia with 16 million people, many of whom are engaged in the cultivation of cotton, rice, grains, fruit and vegetables.

“If a landslide causes the river to overflow, the waste from the two mine dams will enter the water,” said Gulsher Abdulayeva, director of Maili-Su’s radioactive elements laboratory. “The environmental disaster would be almost comparable to Chernobyl.”

Studies have shown that the waste in these dams is in liquid form, and therefore more dangerous and can end up in the river in the event of a strong earthquake, said Sebastian Hess, an engineer working for the German company GEOS that has signed a contract with the government of Kyrgyzstan.

“This could be a terrible disaster,” he said, adding that “this water is used to irrigate farmland, which means agricultural products could be contaminated.”

The foundations of the dams were eroded by water during the 2017 landslide which caused the water level in the river to rise, bringing the river closer to the waste.

The Bishkek government and the GEOS company estimate that 22-25 million euros will be needed to move the waste from the two unsafe sites to another one far enough away from the river.

The area near the town of Maili-Su, one of the world’s largest uranium ore dumps, was developed by the Soviet Union between the 1940s and 1960s. A factory in the town also processed uranium ore from other nearby mines.