(187a) Recent Advances in Sensor Technology to Mitigate Terrorist Threats in Potable Water Distribution Systems

The concept of sabotage directed against U.S water supplies is not new. In 1941, Federal Bureau of Investigation (FBI) Director J. Edgar Hoover wrote the following: ?Among public utilities, water supply facilities offer a particularly vulnerable point of attack to the foreign agent, due to the strategic position they occupy in keeping the wheels of industry turning and in preserving the health and morale of the American populace.? [1]

This threat is as important for U.S. military bases as it is for ?iconic' private-sector and government facilities. Researchers have calculated that an attack on drinking water distribution systems could be mounted for between $0.50 and $5.00 per death using rudimentary techniques. With rudimentary pumping equipment, such an attack could yield casualties in the thousands over a period of hours. [2, 3] Long-standing Department of Defense policy encouraging domestic military base reliance upon local utility infrastructures has inadvertently created a significant U.S. civilian/military vulnerability to terrorist attack. The simplicity and inexpensive challenge of mounting a backflow attack through any drinking water distribution network represents an obvious, potentially lethal vulnerability to most U.S. military bases and their neighboring civilian communities. [4]

Before the anthrax attacks of 18 November 2001, owing to the complex chemistries within the drinking water distribution networks and the shortage of effective monitoring technologies, it was conventional scientific wisdom that a threat to the water supply is not economically feasible to detect or mitigate. Several government reports since then have suggested the need to address this challenge. [5,6]

Subsequently, the Engineer Research and Development Center (ERDC), Edgewood Chemical and Biological Center (ECBC), and Hach Homeland Security Technologies have initiated experiments and validation studies to determine the efficacy of a new technology designed to detect and identify the contaminant used in attacks on finished drinking water distribution networks. This sensor data also enables further technology development in reacting to such an attack.

In addition, joint service research lead by ECBC and Defense Threat Reduction Agency (DTRA) has focused on tactical water supplies. The chemistry of these supplies is less dynamic so that detection limits can be set much lower than in water distribution systems. These lower detection limits are summarized in requirements documentation for the Joint Service Agent Water Monitor (JSAWM) written jointly by Center for Health Promotion and Preventive Medicine (CHPPM) and ECBC.

During the process of down-selecting technologies for further study under the JSAWM program, the use of receive operator characteristic (ROC) curves has proved to be a useful discriminator. Although ROC curves are ubiquitous in military technology development, they are less known in the water quality community.

The conference presentation will summarize recent results in three different aspects of water detection systems: recent advances in sensors for water distribution systems, recent advances in sensors for tactical water supplies, and a brief introduction to ROC curves.

NOTES

(1) Hoover, J.E., ?Water Supply Facilities and National Defense,? 1941. Jour. Awwa, 33:11:1861

(2) Kroll, Dan, unpublished study, Mass Casualties on a Budget, 2003, Hach HST. Calculations on threat agents and requirements and logistics for mounting a successful backflow attack.

(3) Allman, Timothy P., Drinking Water Distribution System Modeling for Predicting the Impact and Detection of Intentional Chemical Contamination, Master's Thesis, Department of Civil Engineering, Colorado State University. Summer 2003.

(4) Hickman, D.C., Maj. USAF ?A Chemical and Biological Warfare Threat: USAF Water Systems at Risk,? The Counterproliferation Papers, Future Warfare Series No. 3, USAF Counterproliferation Center, Air War College, Air University, Maxwell Air Force Base, Alabama September 1999.

(5) National Strategy for Physical Protection of Critical Infrastructures and Key Assets, Office of Science and Technology Planning, The White House, 2003

(6) Making the Nation Safer: The Role of Science and Technology in Countering Terrorism, Committee on Science and Technology for Countering Terrorism, National Research Council, National Academies Press 2002.