A total of 300,000 cubic yards of uranium mill tailings have been cleaned up in Green River, completing Utah's second big tailings cleanup project.
The first such effort was the disposal of the Vitro Chemical Corp.'s uranium mill tailings. Tons of contaminated dirt were removed from South Salt Lake to Tooele County, where they were stored in a permanent repository.Green River's tailings were stabilized on site in a project that took a year to complete and cost $9 million. Of this, the U.S. Department of Energy is paying nearly 90 percent. The state's bill is 10 percent - plus a bit more because Utah officials took more responsibility than most states do in such projects.
Altogether, the state's cost amounted to between $900,000 and $1 million, said Mark Day, Utah's project manager for uranium mill tailings.
A celebration of the project's completion is scheduled for Tuesday, Dec. 12, at 12:30 p.m. in the Tamarisk Restaurant, Green River. After the ceremony, officials will tour the disposal site.
During the uranium boom of the 1950s and '60s, ore was trucked to Green River from uranium mines in the San Rafael Swell's Temple Mountain and San Rafael Reef. It was processed in the Umetco Mill, built by Union Carbide Corp.
Umetco was an "upgrader" mill where radioactive material was extracted from the ore and enriched. The upgraded material was then sent to a mill in Colorado to be refined.
Meanwhile, somewhat radioactive tailings piled up in Green River from 1958 until the mill was closed in 1961.
Because some of the ore was from a gooey, asphaltlike formation, it had to be heated before it could be processed. This created "kind of a high level of contamination in the buildings" at the Green River mill, Day said.
In addition, 200,000 cubic yards of tailings were left behind, strewn over 48 acres located about half a mile from the built-up part of town. Some of this was used as fill for area building. Ten of these "vicinity properties" had to be cleaned up, with the tailings excavated.
Windblown material had contaminated 64 acres, including 24 acres off the mill site. In the end, 300,000 cubic yards was handled altogether.
"They were picked up with large-wheel tractor scrapers and then they were placed in an embankment that was totally excavated," Day said. The tailings then were covered with a cap of bentonite clay and hard, high-density rock hauled in from Fremont Junction 80 miles to the west.
"That was one of the scariest parts of the project," Day said. "We had to bring over 1,000 loads of rocks from there off that Swell."
Where I-70 begins dipping down off the San Rafael Swell, the grade gets steep. Heavy trucks could lose their brakes there. Once a Deseret News reporter helped a trucker extinguish his brakes as he was driving off the Swell in the winter - the brakes were on fire.
Now that the mill buildings have been decontaminated and the site is safe, Green River officials hope to attract businesses to purchase the property, Day said.
Although old-time miners in the area pooh-pooh the danger posed by the tailings - after all, since the dirt was depleted of much of its radiation in the upgrading, it is less contaminated than the original uranium ore - Day said there was a long-term hazard.
"I look at the danger more as a chronic danger than as an acute danger to the public," Day said. "If the tailings were left exposed to the public generation after generation, they'd pose a danger to the public."