To monitor the dynamics in water quality in drinking water distribution networks, and to facilitate a quick and timely response to quality incidents and pro-active network operations, real-time water quality information is vital.The use of sensors for these traditional water quality parameters has serious limitations, both in terms of detection capabilities as well as operational aspects.Each of these sensors measures only a limited sub-set of all possible constituents of the water matrix, and therefore a multitude of sensors is required to obtain substantial coverage.Nevertheless, even using a combination of the traditional sensors, there remains a significant gap in detection capabilities, with a blind spot that includes most non-aromatic organic molecules.Optiqua has developed a generic optical sensor concept, EventLab, that can be deployed online throughout a distribution network, and that meets the four key operational requirements of such an water quality event monitoring system: (i) continuous real-time detection, (ii) generic: one sensor covering the full spectrum of possible chemical contaminants, (iii) high sensitivity, and (iv) low cost and low maintenance.EventLab measures minute refractive index (RI) changes in water.RI is a useful generic indicator of water quality as any substance, when dissolved in water, will change the refractive index of the water matrix.Intrinsic advantages include consistent sensitivity for all substances, response linear with concentration and high resistance to matrix interference.Results from installations have confirmed the added value of the system as EventLab picks up water quality variations that remain invisible to traditional sensors.EventLab can be used as a stand-alone water quality monitoring solution, providing consistent coverage to detect any water quality variation due to dissolved substances.Alternatively, EventLab can be used as the basis for a multi-sensor monitoring strategy.