AWWA JAW56636

The last barrier of a water supply system is the distribution system. To ensure the quality of water that is delivered to the customer, utilities take precautions to prevent intrusions, both accidental and deliberate, from occurring. Many waterborne illnesses can be traced to similar breakdowns in the distribution system. Intrusions may occur during backflow at a connection or where a water main is broken. Other conditions such as low pressure can also cause an intrusion. In addition, systems can be vulnerable to intentional sabotage. Although this article focuses on accidental intrusions, its findings can provide a basis for assessing susceptibility because of intentional attacks on distribution systems. This article provides a framework to identify locations in the distribution system that are susceptible to contaminant intrusion. The framework integrates infrastructure information, hydraulic modeling, and demographic data. These elements are managed within a geographic information system. Susceptibility is based on the joint spatial occurrence of three critical conditions: system pressure, intrusion pathway, and contaminant or pollutant source. Locations found to be susceptible to intrusions are prioritized for attention based on proximity to sensitive populations, such as children and the elderly. This active management approach will perhaps allow utilities to avoid more heavy-handed regulatory requirements. If a utility is able to demonstrate that it is in tune with the day-to-day operations of the system, regulators are perhaps less inclined to require numerous regulations and expensive sampling protocols. Includes 29 references, tables, figures.

Product Details

Edition:

Vol. 94 - No. 6

Published:

06/01/2002

Number of Pages:

14

File Size:

1 file , 840 KB