In 2003, DOE implemented the first phase of an interim action system at the Moab site to address concerns regarding elevated ammonia levels in ground water discharging to the Colorado River. Uranium is the other main contaminant of concern in ground water. This first phase consisted of 10 extraction wells (called Configuration 1). Four additional configurations of wells have been added since then, for a current total of 42 wells that are designed to reduce the amount of ammonia and uranium that discharges to the river.
Ground water extraction is through Configuration 5 wells, which are located closer to the tailings pile. To date, more than 192 million gallons of ground water has been extracted through the interim action system, preventing more than 765,000 pounds of ammonia and more than 3,700 pounds of uranium from reaching the river. Extracted ground water is pumped via pipeline to a lined evaporation pond or to forced air evaporators. The evaporation pond covers approximately 4 acres and is located on top of the tailings pile.
Freshwater (diverted river water) is injected through wells in Configuration 4 as an additional way of minimizing the discharge of ammonia to the Colorado River. More than 3 million gallons of freshwater has been injected in 2013.
As of May 20, the snowpack was 32 percent of the seasonal average. Because the snowpack has begun to melt, the seasonal average snowpack percentage is respresentative of the runoff potential. According to the Colorado River Basin Forecast Center, the river reached 12,400 cubic feet per second on May 19, as measured at the nearest official gage (in Cisco, Utah). This flow likely represents the peak for the 2013 runoff. No flooding at the Moab site has occurred. The site planned for flooding of low-lying areas to recreate a more natural setting along the river. The project will update this web page as river conditions change.
DOE continues to evaluate the effectiveness of the interim action system, which will likely become part of the final ground water remedy. See Ground Water Interim Remedial Action for project documents associated with the interim action.