Application of a Heuristic Method to a Water Distribution System For Determining Optimal Water Quality Monitoring Locations

Abstract

Although regulations and requirements for water quality source monitoring have increased, drinking water distribution systems can still be considered vulnerable to purposeful or accidental contamination.This study analyzes the transport of the hypothetical contaminant Cryptosporidium through the distribution system of a city with a population of 30,000 to 50,000 in an attempt to locate the optimal monitoring locations in the distribution system.Cryptosporidium was selected due to its resistance to chlorine and it's conservative properties for vulnerability assessments. The method for selecting the optimal monitoring locations was taken from Chastain (2004) which developed and examined the method for a virtual city. However, Chastain did not apply the method to an actual city. This study looks to use Chastain's method conjunctively with WaterCAD ® and Excel in an attempt to accommodate to the small scale systems which are more vulnerable relatively speaking.The results of the analysis, shown in Appendices A and B, are grouped into zones of significance which contain a cluster of optimal points for placing water quality sensors. These zones of significance are to be taken as a guide for mitigating potential terrorist initiated events on the water distribution system. iv ACKNOWLEDGEMENTS

Locating Optimal Water Quality Monitoring Locations Using Demand Coverage Index Method

“…Laurence (Johnson, 2012) performed an analysis on this same model to determine optimal locations for monitoring stations using a heuristic method. His method involved counting how many times a node detected contamination when the tanks were contaminated during their particular booster schedule (Table 5).…”

“…The method counts the times a node detects a contamination event when a particular source node is injected with contaminant. The previous thesis (Johnson, 2012) used the tanks as injection sites to determine the locations of the monitoring stations.…”

“…This system was modelled and analyzed in a previous Master of Science thesis (Johnson, 2012), where a heuristic method was used to solve for the optimal locations for monitoring stations. The method counted the number of contamination detections a particular node obtained when the storage tanks were contaminated.…”