The greatest challenge that the sanitation system of the greater Paris region had to face in the final decades of the twentieth century was the quality recovery of the Seine and Marne rivers. The pollution of the receiving water was caused by a lack of treatment capacity and technical performance as well as by combined sewer overflows during rain events. After decades of investments, huge improvements in the water quality of receiving waters were obtained and the objectives of the European Water Framework Directive (WFD) are close to being achieved thanks to the development of wastewater treatment plants and a sewage transport system. At the same time Syndicat Interdépartemental pour l’Assainissement de l’Agglomération Parisienne (SIAAP), the public utility in charge of the transport and treatment of wastewater for the Greater Paris region, has also invested in a real-time control following a 1997 sanitation masterplan study that recommended the implementation of real-time control for better control of stormwater pollution caused by combined sewer overflows, allowing a reduced need for storage facilities. Building upon existing systems and the experience acquired since the mid-1980s at SIAAP as well as each of the its constitutive départements: Paris, Hauts-de-Seine, Seine-Saint-Denis and Val-de-Marne, this real-time control system called MAGES (Modèle d’Aide à la Gestion des Emissaires du SIAAP) began operation in 2008. The new system (as described in section 3.2) integrates all the data from each departement system, and is powered by a hydraulic deterministic model fed in real-time by 2000 sensors. It provides flow forecasts for a trend scenario in each part of SIAAP’s networks and at each treatment plant on different time scales depending on the weather conditions. This trend scenario is used by the operators to adjust the management of the system. This smart system takes advantage of the capacity within the coverage area to transfer sewage from one wastewater treatment plant (WWTP) to another. Such transfers enhance system wide security in case of shutdown due to any reason such as planned works or incidents. MAGES has been the driver of several changes in the way to see and operate the sanitation system. First, each operating site has the knowledge in real-time of what has happened elsewhere on the sanitation system, resulting in a shared and global view of the system. At the same time, the SIAAP department that operates MAGES has a global overview of the hydraulic running condition of the whole system. Ten years after the commissioning of MAGES, it is still difficult to assess its benefits in terms of savings either on investment or operation costs. Nonetheless, smart management is here to stay. Projected constraints on the operation of Paris’s regional sanitation system from tighter regulations, population growth and effects of climate change on the Seine hydrology are impelling SIAAP to develop smarter tools aimed at reducing pollutant loads discharged into the rivers without entailing excessive costs. This case study details the development of a real-time control system (MAGES) in the Paris region designed to better control stormwater pollution caused by combined sewer overflows and to optimize the need for additional storage or treatment facilities. The case study is structured to outline the challenges facing the Greater Paris region water and sanitation networks, and the solutions provided by SIAAP, the public utility in charge of the treatment and transport of wastewater, over the past 20 years. After a brief overview of the geographical characteristics of the region of concern, it introduces SIAAP and the challenges facing it in ensuring improved quality of the Seine. This is followed by a description of the evolution and features of the MAGES system, links to the Sustainable Development Goals, and challenges and opportunities that lie ahead.
Integrated Smart Water Management of Sanitation System in the Greater Paris Region
UNESCO – IWRA – K-Water
2018
