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Control of Water Terrorism Agents

Charles D. Riley, Jr., P.E.

Course Outline

This 2-hour course is an assessment of the potential threat of chemical and biological terrorism against public water supplies. The EPA web site will be visited to study the current National Primary Drinking Water Regulations. The listed contaminants and their established maximum contaminant levels (MCLs) will be examined. Many of these contaminants are highly toxic and are potential threats to water supplies. The course examines a number of biological agents including bacteria, viruses, and toxins. A review of radioactivity and potential radionuclide contaminants is presented. The course examines the applicability of current technology for the control and mitigation of water terrorism agents. In addition, the course examines the EPA Environmental Technology Verification Program and assesses future research needs.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

At the conclusion of the course, the student will have a better understanding of the threat of water terrorism. The course addresses some of the following questions:

Intended Audience

The intended audience for the course includes public works engineers, consulting engineers, environmental engineers, chemical engineers, and any other engineer with an interest in the subject of water terrorism. The course is designed to provide 2 PDH credits toward the continuing education requirements for registered professional engineers.

Course Introduction

With the ongoing war on terrorism comes a heightened sense of concern and anxiety about the threat of water terrorism. While the threat is a real concern, incidents of intentional contamination of a water supply with the intent to harm or kill people are extremely rare.

On the other hand, news of illness and even deaths caused by water contaminated by natural or man made pollutants is common. There are many news accounts of sickness resulting from water supplies contaminated by E. coli bacteria or other pathogenic microorganisms. In 1993, more than 400,000 Milwaukee residents became seriously sick from Cryptosporidium cysts in the municipal drinking water and many deaths were reported. High incidents of cancer and other health problems have been reported from drinking contaminated well water in or near toxic waste dump sites. Outbreaks of typhoid, dysentery and other water borne diseases were common before the introduction of chlorination for disinfection of water supplies. Now, there is strong evidence that even the practice of chlorination is resulting in the formation of carcinogenic byproducts such as trihalomethanes.

The EPA citing such factors as large water dilution ratios, the barrier of water treatment facilities, and stepped-up security measures has stated that it would be very difficult for terrorists to introduce the quantities of contaminants necessary to contaminate an entire water system. In fact, it seems more likely that terrorists would choose to destroy critical water infrastructure such as pump stations, storage facilities, or treatment plants to disrupt supply. Such actions could have a catastrophic effect on the economy in critical areas.

However, there are historical examples of water based terrorism that indicate the vulnerability of water to chemical and biological attack. For example, the Japanese used anthrax as a weapon to contaminate water and food supplies during World War II.

A search on the internet and a minimal amount of money is all that is necessary to build a simple biological fermentation facility capable of producing trillions of deadly bacteria. While most biological warfare agents are more effective when dispersed as aerosols, they can also be deadly in a water supply. Potential biological warfare agents include a number of bacteria, viruses, biological toxins, and cysts.

In fact, there are many sources of cheap and deadly organic and inorganic chemicals on the worldwide market that could be used to poison water supplies. Tanker trucks containing industrial wastes, fertilizers, and chemicals drive on our highways every day providing an easy target for terrorists seeking a supply of deadly chemicals. An abandoned factory or warehouse with a water hydrant or water connection provides a convenient point of entry for such chemicals to be pumped into a water distribution system.

There are some naturally occurring radioactive elements such as radium and uranium that can be found in water. These are primarily found in ground water supplies and are generally present in low concentrations. Contamination of a water supply with man-made radioactive matter would more likely occur from the fallout of the detonation of a nuclear device such as a strategically placed nuclear dirty bomb.

Drinking water standards for the U.S. are established by the Environmental Protection Agency (EPA) under the authority of the Safe Drinking Water Act. The National Primary Drinking Water Regulations are established for contaminants that can adversely affect public health and are known or anticipated to occur in public water supplies. Obviously not all of the agents available to water terrorists will be found in the EPA regulations, but many of these listed contaminants are highly toxic agents that could be used by water terrorists. Go to the EPA web site to find the current maximum contaminant levels (MCLs) for the listed contaminants. (

Course Content

The course content is in a PDF file (152 KB) Control of Water Terrorism Agents. You need to open or download this document to study this course.


Course Summary

Historical examples show the vulnerability of water supplies to chemical and biological contamination. Terrorists can choose from a variety of chemical and biological agents to contaminate a water supply. There are many sources of cheap and deadly organic and inorganic chemicals. Potential biological warfare agents include a number of bacteria, viruses, and toxins. Some agents are effectively removed by conventional water treatment practice; other agents are not effectively removed and can be a serious threat to public health.

A number of advanced water treatment technologies are available such as activated carbon, reverse osmosis, ion exchange, sub-micron filtration, and ultraviolet that have proven to be effective in removing some of these potential contaminants. Point-of-use systems that integrate these technologies can effectively remove the broad spectrum of potential contaminants. While we can never be absolutely safe from potential threats, these systems can serve as a final barrier of protection.


Once you finish studying the above course content you need to take a quiz to obtain the PDH credits.

Take a Quiz

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.