A methodology for pollution source location in water distribution system

The quality of drinking water is a great concern in many countries and recently many researches have focused their attention to improve drinking water security threatened by deliberate or accidental injection in water distribution systems. A very important aspect is the identification of the point in which the pollutant goes into the network, but this problem has not yet been addressed extensively. The authors propose a methodology able to identify pollution source location in a water distribution network, if consumers or sensor stations detect that a contamination is in act. The methodology is based on a pathway analysis of the network and on the demand coverage concept.!n a first step, a subset of candidate nodes that may be potential source of pollution is individuated. Then, using concentration measurements the source is identified among all candidate nodes solving a linearized optimization problem, which incorporates a hydraulic network simulation model. The analysis is performed on the period during which water quality measurements are available and for which a demand pattern is assigned. Since demand patterns can be estimated only with a high level of uncertainty, only source identification procedures, robust respect to such uncertainty, could be applied to real networks.!n order to demonstrate the practical applicability of the proposed methodology to real situations a Montecarlo analysis is performed for considering nodal demand uncertainty. The uncertainty analysis is performed both in case of constant and time-varying pollutant input concentration. The results show that in both cases the proposed source identification procedure has a good reliability even at high water demand uncertainty levels.