For more than a decade, about 20 gallons of uranium-contaminated groundwater have been pumped per minute into a disposal pond from beneath a tailings site on the eastern edge of the Navajo Nation.
The U.S. Energy Department says the pond is a few years away from the end of its life span, and pumping will have to stop since the pond has almost reached its capacity.
The federal government monitors and pumps groundwater from beneath the Shiprock uranium mill tailings site in northwestern New Mexico as part of a long-term project aimed at cleaning up the area.
Mark Kautsky with the DOE's Office of Legacy Management recently toured the site near the Arizona-New Mexico state line with a group of students from Arizona.
"The water level has come up the point where that pond is just about full," he told the students from Shonto Preparatory School.
Over the next couple of years, the pond will be evaporated and its liner will be replaced, the Gallup Independent reported.
Kautsky said the community of Shiprock should not be affected since its drinking water is piped from miles away and farmers in the area get their irrigation water diverted from the San Juan River about 10 miles (16 kilometers) upstream.
The mill tailings disposal site is located behind a locked fence on a ridge behind the Shiprock Fairgrounds and past the Navajo Engineering Construction Authority.
Families live in mobile homes within several hundred yards (meters) of the site, and yellow signs attached to the fencing display warnings in Navajo not to drink the pond's water.
The disposal site sits on top of a former mill that processed more than 200 tons of uranium ore a day from mines in Cove, Arizona, and other nearby locations.
The mill operated from 1954 through 1968. The buildings and equipment were torn down in the years immediately after the operation ceased and initial cleanup of the site took place from 1975 throughout 1980.
The massive rock covering of the uranium tailings was built in 1986 to prevent the escape of radon gas.
Kautsky said it was safer to leave the tailings in place than to move them.
"If you start picking up all of this material and hauling it out of here through the community there would be a lot of potential for accidents to happen," he told the students.
The Energy Department began long-term oversight of the disposal site in 1991.
Federal officials have said there are over 500 abandoned uranium mines on the Navajo Nation, the largest Native American reservation in the country. Navajo territory spans parts of Arizona, New Mexico and Utah.
The Energy Department has four legacy management locations on the Navajo Nation: the Shiprock site; disposal sites in Mexican Hat, Utah, and Tuba City, Arizona; and a former processing site in Monument Valley, Arizona.
The U.S. Environmental Protection Agency is working with responsible parties and implementing settlements that provide funding to assess and clean up about 40 percent of abandoned uranium mines on Navajo land. Linda Reeves, a regional project manager with the agency, said the EPA is in the early stages of its work.