This paper/presentation will introduce a portfolio of research regarding the fate and transport of chemical, biological, and radiological contaminants in urban settings conducted at the US Environmental Protection Agency’s National Homeland Security Research Center. Current research includes laboratory scale experiments to determine washoff coefficients from urban surfaces (e.g., concrete) for B. atrophaeus spores, a surrogate for the causative agent of anthrax. This work is being conducted as preparation for an emergency response to a large-scale release of a persistent chemical, biological, or radiological agent that may result in the contamination of a wide area. The extent of contamination, both on the surface and subsurface, directly impacts the costs related to characterization sampling, decontamination, and clearance sampling (e.g., personnel, consumables, and waste management). Modeling tools that can predict the location and magnitude of contamination may allow a more efficient allocation of key resources since wide area incidents may be very costly and take an extended amount of time to remediate. During this time, the zones of contamination will be impacted by natural and human activities. For example, weather must be considered when developing predictions of the contaminated zones. This paper/presentation will provide an introduction to city managers on the need for prediction capability and the usefulness of fate and transport models for emergency response. It summarizes the applicability and adaptability of 26 existing water models to emergency response applications in terms of original application scale (e.g. agricultural, watershed scale, or urban), data input requirements, unique hydrologic and water quality features, prevalence, mathematical methods, representations of uncertainty, hardware and software requirements, data outputs, and ease of use for public utilities. This paper/presentation will highlight how these features relate to the unique considerations encountered in the homeland security sector and discusses ongoing research needs.