Wednesday, November 11, 1998

DOE taps into natural flushing, new water supply near old uranium mill

RIVERTON, Wyo. (AP) - Federal energy officials decided to forgo an environmental impact study and rely on natural flushing to dissipate contaminants at the old Susquehanna-Western uranium mill.

Although contamination was never detected in deep groundwater, the shallow depths did contain uranium, sulfate and molybdenum. People concerned about a perceived threat to drinking water relied on bottled water.

In September, a consortium of government officials and water users dedicated a water line that provides clean water to more than 25 homes in the Arapahoe area.

The U.S. Department of Energy, Indian Health Services and the Department of Housing and Urban Development provided $2 million for the project.

In conjunction with the new water supply, natural flushing and monitoring is being used to demonstrate contaminants naturally disappear within 100 years. Officials estimate it will take 50 years to complete the natural flushing process at the Susquehanna site.

The Susquehanna-Western uranium mill operated south of Riverton near St. Stephen's Mission from 1957 to 1962.

More than one million tons of tailings from the plant remained at the site on the Wind River Indian Reservation until 1988, when federal and state governments spent $34 million to move materials to the Gas Hills.

Left behind in shallow waters beneath and around the 140-acre site are elevated levels of molybdenum, radium, selenium, uranium and other elements, according to authorities.

However, much of the plume moved away from the old mill and tailings site, officials said. Some of it harmlessly discharged into the Little Wind River.