An Environmental Protection Agency (EPA) study, conducted by the EPA’s Office of Research and Development National Homeland Security Research Center (NHSRC), examined methods for decontamination of drinking water infrastructure contaminated with anthrax-like spores.

This study, published in Oct 2015, examines the effectiveness of decontaminating corroded iron and cement-mortar coupons that have been contaminated with spores of Bacillus atrophaeus subsp. globigii (B. globigii), which is often used as a surrogate for pathogenic Bacillus anthracis (anthrax) in disinfection studies.

Bacillus spores are persistent on common drinking water material surfaces like corroded iron, requiring physical or chemical methods to decontaminate the infrastructure. In the United States, free chlorine and monochloramine are the primary chemical disinfectants used by the drinking water industry to inactivate microorganisms. Flushing is also a common, easily implemented practice in drinking water distribution systems, although large volumes of contaminated water needing treatment could be generated.

Identifying readily available alternative disinfectant formulations for infrastructure decontamination could give water utilities options for responding to specific types of contamination events. In addition to presenting data on flushing alone, which demonstrated the persistence of spores on water infrastructure in the absence of high levels of disinfectants, data on acidified nitrite, chlorine dioxide, free chlorine, monochloramine, ozone, peracetic acid, and followed by flushing are provided in the study.

The NHSRC will host the EPA’s 2016 International Decontamination R&D Conference November 1-3, 2016 in Durham, North Carolina.