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Chemical Agents of Opportunity for Terrorism: TICs & TIMs

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<strong>Chemical</strong> <strong>Agents</strong> <strong>of</strong> <strong>Opportunity</strong> <strong>for</strong> <strong>Terrorism</strong><br />

Training Support Package<br />

Participant Guide<br />

Slide 19<br />

<strong>Chemical</strong> <strong>Agents</strong> <strong>of</strong> <strong>Opportunity</strong> <strong>for</strong> <strong>Terrorism</strong>:<br />

<strong>TICs</strong> & <strong>TIMs</strong><br />

Cross-Connections<br />

• Mix <strong>of</strong> non potable with potable water<br />

• Distribution system pressure ≥ 20 psi<br />

• Backpressure: external>system pressure<br />

• 1970-01: 459 events, 12,093 illnesses<br />

– Avg 1 line break/yr 1,000 person system<br />

(Potential Contamination Due to Cross -connections and Backflow and Associated Health Risks.<br />

Issue Paper US EPA OGW & DW Aug 2002)<br />

Module One - <strong>Chemical</strong> Contamination <strong>of</strong> Food, Water, and Medication<br />

19<br />

Let’s turn our attention to another potential vulnerability in the drinking water system.<br />

This vulnerability occurs during water distribution, namely cross-connections. These<br />

represent opportunities to introduce contaminants into the potable water system by<br />

exceeding the pressure within the system (minimum <strong>of</strong> 20 psi, usually 2-3 x that<br />

pressure).<br />

A survey <strong>of</strong> 30 years <strong>of</strong> reporting to the EPA identified 459 events with over 12,000<br />

associated illnesses. These were predominantly infectious diseases from contaminated<br />

water leaking into water systems from old water pipes, valves or other connections.<br />

Nonetheless, these numbers point out the potential vulnerability <strong>of</strong> an aging water<br />

distribution system and the ease with which someone could intentionally contaminate a<br />

water supply.<br />

Unintentional water main breaks are reported to occur at a rate <strong>of</strong> approximately one<br />

incident per year <strong>for</strong> every 1000 persons served..<br />

Over 50% <strong>of</strong> the drinking water pipes in the U.S. are over 30 years old and some<br />

systems use pipes that are more than 150 years old. Cross-connections can lead to<br />

contamination <strong>of</strong> the drinking water supply as pressures within the system fluctuate.<br />

Intentional cross-connections can occur by applying backpressure to a water system,<br />

introducing a toxin by tapping into the distribution line. Backsiphoning, another <strong>for</strong>m <strong>of</strong><br />

backflow, can occur when the water pressure in the system drops because <strong>of</strong> lowered<br />

input or excessive use at some point in the system.<br />

December 2008 Version 2.0 Page 275

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