Whole-building airflow and contaminant transport modeling has a potentially important role in the development of contaminant sampling strategies in response to the airborne release of chemical or biological agents . The effectiveness of these strategies relies on the ability of the selected sampling locations to adequately characterize the levels of contamination throughout an exposed facility to a desired level of confidence in the sampled results. The Department of Homeland Security has sponsored a series of multi-agency exercises, during which contamination experiments were performed to gauge the confidence that could be obtained by various sampling strategies as well as the effectiveness of various sampling methods in a real-world setting. These experiments are very resource intensive and time-consuming, limiting the number of experiments that can be reasonably performed. Building simulation can be used to perform virtual experiments that would allow more tests to be performed under a much larger set of building operational and environmental configurations. However, in order for the simulations to be useful, the building models need to provide realistic results with a high level of confidence. The purpose of this report is to describe a simulation validation effort based on measurements of contaminant levels performed during the aforementioned exercises.