01/10/2011 05:12 am ET | Updated May 25, 2011

Radioactive Material Leaks Into Upstate NY River

Several hundred gallons of water contaminated with radioactive materials from a 1950s nuclear research site spilled into the Mohawk River near Schenectady on Oct. 25, prompting an investigation by the United States Energy Department.

The site, part of the Knolls Atomic Power Laboratory, in Niskayuna, was used to develop the technology for purifying plutonium for nuclear bombs. A rainstorm washed 600 to 800 gallons of water containing plutonium, uranium and trace amounts of two other radioactive substances, strontium and cesium, into the river, according to a letter sent by the New York State Department of Environmental Conservation to the Energy Department and to a contractor working to clean up the site.