GAIA 2: sewerage network under high surveillance

The Hauts-de-Seine are making real time go forward 
Article published in the March-April 2012 issue 209 of Hydroplus magazine.

With the main aim of reducing wastewater discharges into the Seine during rainy weather, the Hauts de Seine General Council (CG 92) commissioned a new tool at the beginning of December to supervise its 625 km of sewerage networks, of which about two-thirds are unitary. On the agenda: real-time context-related alerts, mobility and virtualized servers.
Called Gaia 2, the tool remotely controls 750 measurement sensors, numerous automatons and around twenty automated storm overflow weirs. It incorporates real-time data from the network as well as rainfall measurements and forecasts. 

Context-related alerts

The main originality of Gaia 2 lies in the "synthesis variables" generated in real time. A great deal of work has been carried out by the General Council and the Lyonnaise des Eaux subsidiary operating the network, the Société des eaux de Versailles et de Saint-Cloud (Sevesc), to define these variables. The objective: to automatically issue alerts in the event of anomalies.

"Classic alarms occur when a device such as a pump is not working. With our tool, however, alerts are also issued depending on the context. For example, when a storm overflow spills into the natural environment when it is not raining," explains Bernadette Pister, head of the studies and control department of the delegation to the water department of the CG 92. 

Proof of the importance of this aspect of the project, 60% of the sum invested in the Gaia 2 tool (1 million euros) was devoted to studies and parameterisation. 
 

Virtualized servers

Another innovation is that the supervisor is accessible via the Internet and nomadic tools, which facilitates emergency response. 

Finally, the installation includes innovative virtualized computer servers. "Several (virtual) logical servers run on the same machine. Here, two virtualised servers replace ten conventional physical servers. This reduces hardware and maintenance costs, improves system redundancy and reduces power consumption and space requirements," explains Renaud Ribal, business manager at Ineo, which designed Gaïa 2's IT systems with Ondeo Systems.