The mission of the Department of Energy's (DOE's) Office of Environmental Management (EM) is to clean up the environmental legacy of nuclear weapons research and production during the Cold War. That mission includes cleaning up nuclear waste, contaminated groundwater and soil, nuclear materials, and contaminated facilities covering two million acres of land in thirty-five states. EM's principal program goals include timely completion of tank waste treatment facilities, reduction of the life-cycle costs and acceleration of the cleanup of the Cold War legacy, and reduction of the EM footprint. The mission of the EM Technology Innovation and Development program is to transform science and innovation into practical solutions to achieve the EM mission. During fiscal year 2010 (October 2009-September 2010), EM focused upon accelerating environmental cleanup by expeditiously filling identified gaps in available knowledge and technology in the EM program areas. This report describes some of the approaches and transformational technologies in tank waste processing, groundwater and soil remediation, nuclear materials disposition, and facility deactivation and decommissioning developed during fiscal year 2010 that will enable EM to meet its most pressing program goals.