In Haute-Savoie wastewater produces energy!

Posted on 01 September 2016.

A pioneering complex has been born in Haute-Savoie. Designed using some of Veolia’s most innovative technologies, it is a combined wastewater treatment plant, waste treatment center, and energy and agricultural recovery plant.

All the residues produced by the complex are re-used

Somewhere between Lake Geneva and Mont Blanc in the Haute-Savoie lies the "Grand Massif" - a huge natural protected area and a busy ski destination in winter. Between the summer and the tourist season, the number of residents increases from 4000 to more than 35,000. For the communities on the Grand Massif, this increase brings with it certain responsibilities in relation to sustainable development, particularly as regards waste and wastewater management.

In order to meet these challenges, in 2009 the SIVOM, a union bringing together Morillon, Samoëns, Sixt-Fer-à-Cheval and Verchaix, commissioned a complex that was to say the least progressive. Designed with Veolia’s latest technology, it has been designed to treat wastewater, manage organic and vegetable waste, and produce energy. Explanations.

It all begins with the wastewater. Transported to a treatment plant, it is filtered and processed so as to eliminate any pollution and impurities. The treated water is decontaminated and returned to the natural environment. But the story doesn’t end there: the Morillon complex has also incorporated the principle of circularity into its operations. In other words, all the waste from the plant is re-used.

Sewage sludge from the water treatment process is collected and then goes into a digester where it is mixed with the organic waste (food grease, the leftovers from our plates) collected by SIVOM from restaurants, canteens and homes. As it ferments the mixture produces methane, which is then used to fuel a cogeneration unit to produce energy. The system allows flexibility in relation to the changes in the nature and quantity of the treated residues while also efficiently operating under all circumstances. This system has already been set up by Veolia in other treatment plants, in particular in Hungary.

But that's not all! Once it has gone through the methanation process, the remaining sludge is dehydrated in a centrifuge. Mixed with plant waste – which is also collected from local businesses and people’s homes – it produces compost. And is used either to re-vegetate the slopes after the snow has melted or to fertilize agricultural grassland.

Finally, the complex also includes 420 m2 of photovoltaic panels installed on the roofs. They produce up to 63,000 kWh per year. With the energy produced by the combustion of methane, there is enough electricity to make the entire complex self-sufficient.

Much more than just a wastewater treatment plant, the state-of-the-art Morillon complex is a real sustainable development platform. It helps to preserve the Grand Massif ecosystem, but most importantly opens the door to the treatment plants of tomorrow. They will need to meet the challenge of treating our waste while also producing energy.