Contaminant intrusion in water distribution systems : advanced modelling approaches

• Main Author: Mansour Rezaei Fumani, Saheb
• Language: English
• Published: University of British Columbia 2013
• Online Access: http://hdl.handle.net/2429/44042

Since exposure to contaminants may have direct adverse impacts on public health, contaminant intrusion has been recognized as one of the top priority in drinking water supply research. Three components must exist to cause contaminant intrusion into a water distribution system. These include the availability of source(s) of contaminant(s) around a water distribution system, the existence of driving forces (low/negative pressure) to make a contaminant enter into a water distribution system, and the presence of pathway(s) through which contaminant(s) intrude into a water distribution system (WDS). Exposure assessment is the most challenging part as location of contaminant intrusion, rate of intrusion, and the fate of contaminants within WDS need to be estimated accurately. In this dissertation, first, common uncertainty analysis techniques are discussed in the context of conservativeness, execution time, ease of formulation, and complexity. Second, a fuzzyrule based model has been developed to identify contaminant intrusion potential in a WDS. The potential of contaminant intrusion has been determined by integrating the potentials for contaminant sources existence, driving forces, and pathways. Third, a novel ingress model has been developed for more realistic estimation of intrusion rate by taking into account the effects of surrounding soil on intrusion rate. Coupled with an Eulerian-based transient hydraulic model, a Lagrangian transient water quality model is developed to predict the fate of the contaminant throughout a WDS. The proposed models are applied to case studies available in the literature to investigate the applicability of the models. The proposed models enhance the reliability and safety of WDSs by improving the prediction ability of the existing modelling tools.