Characterization and cleanup of a site are critical challenges that the United States and the Environmental Protection Agency (EPA) would face in rapidly recovering from a major chemical, biological, or radiological (CBR) hazard incident. This conference is designed to facilitate presentation, discussion, and further collaboration of EPA's Homeland Security Research Program (HSRP), which focuses on an all-hazards approach to cleaning up contaminated buildings (both interior and exterior) and infrastructure. The conference continues to focus strongly on matters involving CBR threat agents but also include "all hazards" elements.