The following description was provided by the Science and Technology Directorate of the U.S. Department of Homeland Security.
The National Response Plan designates the IMAAC as the single federal source of airborne hazards predictions during an Incident of National Significance (INS). IMAAC is responsible for producing and disseminating predictions of the effects from hazardous chemical, biological, radiological releases. Knowing the downwind impact from such releases is a key component of developing a common operational picture for response decision making from the local through the federal levels. In the interest of providing decision makers with immediate information to protect public health and safety, IMAAC also supports responses to major atmospheric releases leading up to an INS.
The IMAAC goal is to draw upon and coordinate the best available capabilities of participating agencies. The current IMAAC agency federal partners are the Department of Homeland Security, the Department of Defense, the Department of Energy, the Environmental Protection Agency, the National Oceanic and Atmospheric Administration (Department of Commerce), the Nuclear Regulatory Commission, and the National Aeronautics and Space Administration. IMAAC is not intended to replace or supplant dispersion modeling capabilities that federal agencies currently have in place to meet agency-specific mission requirements. Rather, it provides for the coordination to use the most appropriate model for a particular incident and for delivery of a single prediction to all responders.
Responders need a single, unambiguous, accurate prediction for immediate decision making in the event of a major hazardous atmospheric release. IMAAC provides access to complex modeling tools, which incorporate real-time location-specific meteorological data, demographic and geographic data, and first-hand observations about the release from the incident site. IMAAC provides 24/7 experts to run the modeling system, quality assure results, and assist decision makers in the interpretation of model predictions.
The IMAAC can be activated by designated emergency managers and decision makers in local, state and federal agencies for significant hazardous material releases. The IMAAC supports the Homeland Security Operations Center (HSOC), the primary hub for domestic incident management. After activation, the IMAAC coordinates with the agencies involved in the response and the HSOC.
Once activated, the IMAAC will: