Persistence of Biological and Radiological Contaminants on Wastewater Collection System Infrastructure
Citation:
Szabo, J. Persistence of Biological and Radiological Contaminants on Wastewater Collection System Infrastructure. U.S. Environmental Protection Agency, Washington, DC, EPA/600/S-21/092, 2021.
Impact/Purpose:
The U.S. Environmental Protection Agency’s (EPA’s) Homeland Security Research Program (HSRP) conducts research to detect, respond to, and recover from terrorist attacks on the nation's dinking water and wastewater infrastructure. The studies summarized in this technical brief were meant to be the first step in understanding biological and radiological contaminant persistence in sewer systems. In the event of contamination of a drinking water distribution system with a biological agent, flushing the system to remove the contaminant could result in contamination of the sewer system. In addition, contamination of an outdoor area or a building exterior with a biological agent could result in contamination of the sewer system from wash down activities or rain events. Similarly, contamination from a radiological dispersal device, improvised nuclear device or nuclear power plant accident could result in radioactive contamination entering a wastewater or stormwater collection system, also from wash down activities or rain events. There are open questions regarding environmental contamination by biological agents like pathogenic Bacillus anthracis spores, which cause the disease anthrax, and which are hardy and resistant to inactivation in the environment. First, would spores persist on wastewater infrastructure? Second, if they persist, can spores be removed from the infrastructure via the normal flow in a sewer system or via disinfection? The same questions arise with radionuclides such as cesium, strontium and cobalt, which are used in products that people use every day. To determine the adherence of biological and radiological agents on wastewater infrastructure, samples of materials (i.e., coupons) commonly used in the composition of wastewater systems were exposed to flowing wastewater containing contaminants. The contaminants tested were non-radioactive simulants or a nonpathogenic surrogate for B.anthracis. After determining the amount of adhered contaminant, the coupons were exposed to flowing uncontaminated wastewater to determine if it would remove the contaminant that had adhered to the coupons.
Description:
This tech brief will summaize the available information on the persistence of biological and radiological agents on wastewater (collection system) infrastructure and decontamination information (if available). It will also summarize data on the fate of radionulcides in wastewater treatment plants, particularly in activated sludge. This output will address Partner and WSD needs, but will also align with needs in the National Radiological Preparedness Group (NRPG) ESF-10 Wide Area Radiological Response Strategy Summary Document.