DUGi

Anàlisi de les descàrregues de la xarxa unitària de sanejament de Girona en els seus dos principals sobreeixidors

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@10256@@25984

Many of the sewage networks that carry wastewater in cities operate on a unitary system. In this system, domestic wastewater and stormwater are combined in a single sewerage network. This type of design means that when there is a large volume of rainfall, the systems cannot manage it and overloading occurs, causing excess water and pollutants to be discharged directly into watercourses in the form of unitary system discharges (DSU). DSUs represent a growing environmental concern in many cities around the world by severely affecting the water quality and also the ecosystem functions of watercourses. For this reason, this study aims to estimate the volume of water generated by DSU previous flow measurements made in the sewage network collectors of Girona. These measurements have been made by two flow meters placed just before the spillways where the DSU are produced. With the data from the flow meters and rain gauges available from CATSA, it has been possible to plot the variations in wastewater flow as a function of rainfall. This made it possible to identify a clear relationship between rainfall intensity and overflow volume in different rain episodes. In addition, the rainfall threshold at which the DSU of Hospital Josep Trueta overflows is produced has been determined in this study. This is estimated at 2 mm of rainfall based on data collected. This information is crucial to assess the current state of the sewer network and to plan future interventions to improve this rain threshold. To minimize the adverse effects of overflows, several measures are proposed. These include the implementation of separate sewer systems, the use of computer modelling to monitor the network and the creation of retention basins to jointly manage stormwater and wastewater. These solutions would allow a more efficient management of water resources, reducing environmental impact and improving water quality. In conclusion, this research not only identifies and quantifies DSU, but has also proposed strategies to mitigate their effects, thus contributing to the protection of the environment in Girona specifically the Ter river

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