AWWA JAW65356

The link between the contamination of distributedwater and the occurrence of operations and maintenance(O) activities in distribution systems (DSs)has mostly been based on specific cases resulting inwaterborne disease outbreaks. It has also been possibleto know the fraction of reported outbreaks, particularlyin the United States, that can be attributed to DS deficiencies.However, without being in a situation of diseaseoutbreak, water utilities can be faced with DSwater quality variations such as the occurrence of coliform-positive samples, occurrences of heterotrophicplate count bacteria, and customer complaints. Nospecific study of the fraction of these water qualityevents originating from DS activities has been compiled.This research, using a data integration approachbased on the simultaneous study of different types ofhistorical databases, is a first step toward verifying andestablishing such a link. The analysis shows that Oactivities can be related to water quality variations invarious proportions, and some of the main causes ofwater quality changes are identified (e.g., pipe replacementand valve and hydrant operation). Water supplierscan apply this concept of data integration to assesstheir own systems. Includes 21 references, tables, figures.



Keywords: Water Quality; Operation and Maintenance; Distribution Systems; Heterotrophic Plate Count; Contamination; Waterborne Diseases; Bacteria