SER* technical BRIEF BUILDING A SCIENTIFIC FOUNDATION FOR SOUND ENVIRONMENTAL DECISIONS EPA's Water Security Test Bed INTRODUCTION The U.S. Environmental Protection Agency (EPA) is the lead federal agency responsible for working with water utilities to protect water distribution systems from contamination and to clean up systems that become contaminated. Intentional and unintentional contamination of distribution systems can result in large amounts of water and miles of infrastructure that must be cleaned. Advancing the science and engineering of decontaminating pipe systems and of safely disposing of high-volumes of contaminated water are high priorities for EPA. To improve the protection of systems and the effectiveness of cleanups, EPA's homeland security research program has developed a full-scale water security test bed (WSTB) (Figure 1). Figure 1. Water security test bed water storage tank and approximate 445 feet of pipe BACKGROUND Homeland Security Presidential Directives 7 (HSPD-7,12/1/2003) and 9 (HSPD-9, 1/1/2004) tasked EPA with responsibilities for water system security. In accordance with these directives, the EPA's Homeland Security Research Program (HSRP) has been conducting research to help utilities prevent damage from contamination incidents and to enable utilities to rapidly detect and respond to such incidents. April, 2015 1 ------- Early on, HSRP's research was conducted at the laboratory bench or on a pilot scale so that studies could be carried out under carefully controlled conditions. To fuily understand how treatment and decontamination methods and other technologies will function during a real incident, testing must also be conducted at full or near full scale. The WSTB has been constructed to advance such testing. THE TEST BED At the Department of Energy's (DOE) Idaho National Laboratory, the first phase of the test bed was constructed replicating a section of a typical municipal drinking water piping system: roughly 445 feet of pipe laid out in an "L" shape using 40-year-old, eight-inch cement mortar lined, ductile iron pipes and with two fire hydrants (Figure 2). The pipes were excavated after twenty years of use for water conveyance so that testing can be performed in an environment that simulates an operating water distribution system. Researchers built the WSTB above ground for easy access during experiments, and to facilitate fast leak- detection. Figure 2. Cement mortar lined, ductile iron pipes The WSTB is equipped with injection points for the introduction of contaminant simulants and decontamination agents, and sensors to detect contamination. Removable coupons (excised samples) are installed within the piping (Figure 3) and can be analyzed to determine the adherence of contaminants to the pipe walls and to evaluate the efficacy of decontamination efforts. A lined lagoon has been constructed to contain water flushed from the test bed. Figure 3. Coupon sampling at the water security test bed pipe. EXPERIMENTS Several experiments have already been completed at the WSTB including: • A dye (tracer) was injected into the WSTB to evaluate travel times and system flows. 2 ------- • Sodium thiosulfate (Na2S203) was injected to determine if the resulting drop in chlorine would trigger an automated hydrant-based flushing device to remove water from a distribution system when water quality degrades (due to contamination in this case). The device was successfully triggered, which demonstrated that water quality sensors can interact with automated flushing system. • Bacillus atrophaeus subsp. globigii (a surrogate for Bacillus anthracis, the causative agent of anthrax) was injected into the WSTB piping and decontamination with chlorine dioxide was attempted. Chlorine dioxide decontamination in the WSTB was not as effective as would have been expected based on previous pilot-scale experiments. The chlorine dioxide decontamination in the WSTB resulted in spores remaining adhered to the cement-mortar pipe surface. This was likely due to high chlorine dioxide demand from the pipe and inefficient transport of the disinfectant into dead end spaces. • Bacillus spore contaminated water was flushed from the WSTB pipe and was collected in a lagoon. Treatment of the contaminated water was attempted using a mobile free chlorine generator. However, chlorine reacts with all organic matter, not just the targeted contaminants. It was found that chlorine generation could not sufficiently overcome organic load in the effluent lagoon to inactivate spores. FUTURE EXPERIMENTS During 2015 and beyond the following experiments will be conducted in the WSTB: • In the experiments described here, Bacillus spores remain attached to the pipe after decontamination procedures. In future experiments, chemical decontamination will be done with an increased decontaminant contact time with the pipe wall. Also, the dead-end portion of the WSTB will be flushed by adding flow ports to the pipe. • Biofilm growth in the water pipe will be studied to learn how it influences the survival of pathogens and the effectiveness of decontamination procedures in the WSTB. • The effectiveness of the treatment of effluent (see Figure 3) with additional commercially available water treatments (such as Cb, UV, forward osmosis, and/or UV+O3) will be evaluated. • A 1" copper service line will be added between the main line and an adjacent building to conduct experiments on home appliance decontamination and human exposure to household plumbing contamination. • Crude oil contamination simulating a pipeline/transport crude oil accident will be initiated to assess the persistence of crude oil constituents following decontamination procedures. • The threat of cyber-attack on system instrumentation, communications, and computer-based systems for remote monitoring and control (so-called SCADA or supervisory control and data acquisition) will be investigated. 3 ------- Figure 2. Effluent lagoon. OUTREACH EPA is opening up the test bed research capability to additional potential collaborators such as agencies within the DOE, Department of Defense, the Department of Homeland Security, universities, water utilities, and foundations interested in water security research. EPA is also considering partners' needs as they build out the test bed to include service connections and other types of pipe commonly found throughout water distribution systems. CONTACT INFORMATION For more information, visit the EPA Web site at http://www2.epa.gov/homeland-securitv- research Technical Contacts James Goodrich (Goodrich.iames@epa.gov) Jeff Szabo (Szabo.ieff@epa.gov) John Hail (hall.iohn@epa.gov) General Feedback/Questions: Kathv Nickel (nickel.kathv@epa.aov1 If you have difficulty accessing this PDF document, please contact Kathv Nickel (nickel.kathy@epa.gov) or Amelia McCall (mccall.amelia@epa.gov) for assistance. U.S. EPA's Homeland Security Research Program (HSRP) develops products based on scientific research and technology evaluations. Our products and expertise are widely used in preventing, preparing for, and recovering from public health and environmental emergencies that arise from terrorist attacks or natural disasters. Our research and products address biological, radiological, or chemical contaminants that could affect indoor areas, outdoor areas, or water infrastructure. HSRP provides these products, technical assistance, and expertise to support EPA's roles and responsibilities under the National Response Framework, statutory requirements, and Homeland Security Presidential Directives. 4 ------- |