Distribution System Contamination

It is common for cities to have drinking water treatment plants and yet still have tap water that is considered unsafe or unreliable. This reduction in water quality is often attributed to contamination that occurs within municipal distribution systems. Over the course of the semester, our team will investigate potential mechanisms of distribution system contamination and develop best practices to avoid this contamination in the future. Potential factors that we will investigate include:

• Contaminant intrusion into pipelines: It has been proposed that one mechanism of distribution system contamination is for contaminants to ingress into pipes when the internal pressure of  the pipeline drops below the external pressure of the surrounding area. Over the course of the semester we will conduct experiments to test whether this intrusion is indeed possible and if so whether it constitutes a real threat to drinking water distribution. 
• Effect of Intermittent supply: Due to inadequate infrastructure or water supply, many cities and towns in developing countries are forced to ration water that is delivered to citizens by only supplying water at certain times of the day. The constant cycle of turning on and off the water supply may cause large pressure transients,waves of energy that cause temporary, localized periods of high and low pressure moving through a pipe system. These transients can damage pipe networks and even cause negative pressure within the system that could potentially result in contaminant intrusion.
• Cross Contamination: Backflow from residential storage tanks could result in contaminants moving from those tanks into a municipal distribution system. We will develop a list of best practices to prevent this type of contamination. 
  

Documents   Challenges Tasks Symposium Final Presentation Final Report Fall '14