How Emergency Response Decision-Makers Utilize the Hazard Estimates from Airborne Contaminant Modeling

The Defense Threat Reduction Agency (DTRA) Technical Reachback provides 24/7 hazards analysis, subject matter expertise advice and decision support for planning, operations, and post event analysis from incidents involving release of chemical, biological, radiological, and nuclear (CBRN) hazardous materials into the air or water. The primary transport and dispersion model used is the Hazard Prediction and Assessment Capability (HPAC). The use of the term Capability instead of Model was intentional because this recognizes that a capability is the integration of subject matter experts (SME)s, data and models to develop relevant decision support information. The CBRN SME is often faced with producing hazard assessments of man-made hazards when information is limited, dynamic and sometimes contradictory. Direct contact with emergency response community (Incident Commanders, First Responders, Local-Regional-State Emergency Managers, plus Federal Agencies) is an important partnership. This paper speaks to this thesis using a case study of a real word train derailment involving the release of acrylonitrile. It is demonstrated that a close collaboration in real time of the science and technology (S&T) and operational communities is able to bring the best science to the situation and affect actionable decisions. Lessons learned are provided for improvements in S&T for situation awareness, risk communication, and supporting infrastructures.