An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Preparing for Potential Attacks

Published September 20, 2017.

After a wide-area attack with a biological agent, like anthrax, rapid response is essential. Safe and effective clean-up methods based on sound science are crucial. That’s why EPA researchers are looking for ways to speed up and simplify the decontamination process to rapidly and effectively respond to environmental catastrophes.

Low-tech Decontamination Methods

EPA researchers are creating low-tech decontamination solutions for a wide-area anthrax incident. These methods rely on products often available in drugstores and could be used by homeowners and business owners.

The researchers studied the effectiveness of a method creating hydrogen peroxide vapor using a standard humidifier. Pilot-scale tests show that off-the-shelf humidifiers using 3% or 8% aqueous hydrogen peroxide vapor solutions for one week are effective for decontaminating most materials contaminated with an anthrax surrogate (meaning it acts like anthrax in the study, but doesn’t present the same level of danger). Some materials are more difficult than others to decontaminate with this method, such as wood and concrete.

Based on these results, EPA conducted a field study that successfully demonstrated that this process could be used for larger structures such as a house. EPA’s test house facility in North Carolina was used to transition the lab work to the field test by determining conditions for the field test. Several experiments were conducted in the house to confirm pilot results, and to determine factors affecting decontamination efficacy, such as determining how much hydrogen peroxide is needed, where to place the humidifiers, and required contact times. Again, the process of generating low concentrations of hydrogen peroxide vapor throughout an (semi-)enclosed area was proven to be effective for the inactivation of the surrogate spores. 

EPA also collaborated with the Department of Defense to confirm these results against infectious B. anthracis spores on typical building materials via bench scale testing through an interagency agreement with the Edgewood Chemical Biological Center.  Additional full-scale experiments are being planned to transition this research to field-ready capabilities and determine the most promising solutions for home and business owners.

“We work very closely with EPA to develop capabilities that can be used in the event of an incident involving Bacillus anthracis, the organism that causes anthrax, or another hazardous biological agent. It’s important that we work in partnership so that we help the nation to prepare for a biological incident.” Don Bansleben, Program manager, Department of Homeland Security, Science and Technology Directorate 

Decontaminating the Subway

In large cities, underground transportation systems are a part of everyday life. In the event of a biological incident, a rapid return to service of these critical infrastructure systems is necessary. Even a slight disruption in service can severely impact people’s lives, businesses, and result in large economic losses. To help communities and individuals return to normal after a biological event, the Department of Homeland Security and EPA are collaborating to improve the recovery capabilities for a subway system.

Researchers started in the lab by evaluating the efficacy of various decontaminants, such as methyl bromide fumigation, chlorine dioxide fumigation, and bleach dispersed as a fog. They also tested different sampling methods and took an inventory of commercially-available equipment that could be used for rapid decontamination.

During the second phase of the project, EPA and its partners demonstrated several cleaning methods using a mock subway station and tunnel. This allowed researchers to transition the methods used in the lab to the field. Some aspects of the demonstration included using a robotic cleaner for surface sampling, which allowed researchers to cover a larger area than traditional sampling methods like swabbing. They also used a technique called aggressive air sampling, which tests numerous building interiors with fewer personnel. Traditional sampling is expensive, requires personal protective equipment, and is very time intensive, so these innovative techniques can shorten cleanup time by reducing the traditional sampling burden.

The research and evaluation will ultimately result in national guidance that will streamline the process and help the response community, other federal agencies, and international governments rapidly respond and recover underground transit systems from a biological incident.

Helping New York City Plan for a Biological Incident

Responding to and cleaning up after a wide-area biological incident is difficult anywhere. But in a city as unique and complex as New York City, it’s incredibly challenging. That’s why researchers from EPA and the Sandia National Lab (with support from the CDC Public Health Emergency Preparedness grant) provided research and scientific expertise to assist the New York City Department of Health and Mental Hygiene develop an “Environmental Response and Remediation Plan for Biological Incidents.”

This plan specifically addressed the release of anthrax spores in NYC and will make sure the city is prepared to protect the city’s 8.4 million residents in the event of a biological incident. In addition to improving NYC’s preparedness, the plan also provides a response and remediation framework for other metropolitan areas across the country.

“This is the first plan of its kind. Over 50 EPA subject matter experts from seven different EPA offices and three EPA Regions contributed to developing the Plan. The first version of the Plan was completed in July 2015 and since then the EPA has continued to offer subject matter expertise and guidance to operationalize the Plan.” Marisa Raphael, Deputy Commissioner of Emergency Preparedness and Response, New York City Department of Health and Mental Hygiene.

Water Security Test Bed in Idaho

Our nation’s drinking water distribution systems can be vulnerable to contamination-causing events such as industrial accidents, natural disasters, or terrorist attacks. EPA researchers work with water utilities to protect these distribution systems and clean up systems that do become contaminated. Whether purposeful or accidental, contamination of these systems can threaten people’s health and result in large economic impacts. To better protect—and if necessary, decontaminate—our nation’s drinking water, EPA researchers have partnered with Department of Energy’s Idaho National Laboratory to build the Water Security Test Bed: the nation’s first fullscale, above-ground drinking water distribution system.

The test bed is a replica of a portion of a drinking water pipe system and is 445 feet of above-ground, cementlined pipes plus fire hydrants. Since most of the nation’s water systems are not brand new, the test bed uses 30- year old weathered pipes that were exhumed from the ground nearby. The test bed is above ground, which allows researchers to easily tailor the system to address a wide variety of applied science questions.

Over the next several years, EPA and partner researchers will conduct experiments using various biological, chemical, and radioactive simulants that replicate highly-toxic materials. Approaches to contamination detection, infrastructure decontamination, and water treatment developed at lab and pilot scale will be demonstrated at this full-sized system. Results from this work will be easily transitioned for use by utilities because the tests have been conducted in a real distribution system.