A hydrological model to estimate pollution from combined sewer overflows at the regional scale. Application to Europe

Study Region. We developed a hydrological model to estimate Combined Sewer Overflows (CSO) throughout the European Union + UK (EU), using data of population density and precipitation of 671 Functional Urban Areas (FUAs), representing almost half of the EU population. Study Focus. CSO loads can be quantified at the local scale through measurements, or with calibrated hydrological models. However, they are difficult to quantify at a large scale (e.g. regional or national), due to a lack of data, and the models used at local scale cannot be applied in the absence of knowledge of the combined sewer (CS) network. This paper presents a 6-parameter lumped hydrological model to simulate a CS network and its overflows. New Hydrological Insights for the Region When properly calibrated, the model can reasonably predict the CSO hydrographs as well as aggregated CSO descriptors (annual CSO volumes and duration) of a catchment with known impervious surface area connected to a CS. When model calibration is not possible, using default values of the parameters enables a first approximation estimate of CSOs, accurate within one order of magnitude, that can be used to support scenario analysis for regional and continental CSO management. At the EU scale, the estimated total CSO volume is 5,739 Mm3/y, with a dry weather flow content in CSOs of 460 Mm3/y (assuming a dry weather flow of 200 l/population equivalent (PE)/day including sanitary discharges, industrial discharge and infiltration).

QUARANTA Emanuele;  FUCHS Stephan;  LIEFTING Hendrik Jan;  SCHELLART Alma;  PISTOCCHI Alberto; 

2022-04-27

ELSEVIER

JRC128154

2214-5818 (online),   

https://www.sciencedirect.com/science/article/pii/S2214581822000933,    https://publications.jrc.ec.europa.eu/repository/handle/JRC128154,   

10.1016/j.ejrh.2022.101080 (online),