Climate change and urban wastewater infrastructure: There is more to explore

Climate change is one of the main challenges to the urban wastewater systems in the next decades. In literature, the focus has primarily been on impacts of singular climate changes, such as the impact of more intense storm events in summer or prolonged wet periods in winter. The impact of these expected climate changes on wastewater system performance has been studied extensively by applying the expected climate change as input for urban drainage, sewer or wastewater treatment models. The model-based analysis of the impact of climate change has an important drawback: applied models can only represent the processes incorporated in the model and typically have a limited universality, if at all calibrated, due to the limited information available in the time series used for model calibration. Literature describing possible climate change impacts on performance of the urban wastewater infrastructure based on the analysis of monitoring data is hardly available. Recent developments in continuous monitoring have resulted in an increased availability of high quality data sets. These data sets allow assessment of the impacts of climate change by scrutinizing the data sets searching for meteorological conditions that resemble expected climate changes. The potential of applying data analysis to study climate change effects is illustrated for the case of the Eindhoven wastewater system, for which an extensive database is available. The results of this study show that, due to the limitations of state of the art sewer water quality models as well as WWTP models, model based assessment of climate change impacts does not properly address all possible impacts of climate change. Consequently, the impact of climate change is underestimated. (C) 2012 Elsevier B.V. All rights reserved.