Preliminary Scoping and Assessment Study of the Potential Impacts of Community-wide Radiological Events and Subsequent Decontamination Activities on Drinking Water and Wastewater Systems

Since the terrorist attacks of September 11, 2001, there has been a great deal of concern about further attacks within the United States, particularly attacks using weapons of mass destruction (WMD) or other unconventional weapons, such as a radiological dispersal device (RDD) or “dirty bomb,” which is a type of RDD. During all phases of an RDD event, secondary impacts on drinking water and wastewater systems would be possible. Secondary impacts refer to those impacts that would occur when the water systems were not the direct or intended target of the specific event. Secondary impacts would include (1) fallout from an event occurring elsewhere on water supply reservoirs and (2) runoff into storm water and sewer systems during precipitation events or as a result of cleanup and decontamination activities. To help address potential secondary impacts, a scoping and assessment study was conducted for the U.S. Environmental Protection Agency’s National Homeland Security Research Center to support its water security program. The study addresses the potential impacts on water resources and infrastructure that could result from the use of an RDD, including potential impacts from the initial attack as well as from subsequent cleanup efforts. Eight radionuclides are considered in the assessment: Am-241, Cf-252, Cs-137, Co-60, Ir-192, Pu-238, Ra-226, and Sr-90.