Kerné Uhel, a water treatment plant to meet the challenges of the Côtes-d’Armor region

September 9, 2022 saw the inauguration of the new facilities at the Kerné Uhel drinking water production plant in the commune of Lanrivain (Côtes-d’Armor), after two years of work. This is an opportunity to look back at the key elements of this installation, a testament to Stereau’s expertise in designing and building resilient, sustainable facilities. Water is a fragile resource. Ensuring its availability, in terms of both quantity and quality, is a key challenge for the Côtes-d’Armor département, which intends to take long-term action to secure this precious resource. D’une capacité de 900 m³/h et dotée de procédés innovants, la nouvelle usine assure la production d’eau potable de plus de 70 000 habitants du centre-ouest des Côtes-d’Armor. Securing the distribution of drinking water, modernizing the treatment process in anticipation of regulatory changes concerning the treatment of micropollutants, ensuring continuity of service during the works, and maintaining the compactness of the facilities – these were the challenges facing the modernization of this plant, the third largest in the department. Produce water of impeccable quality Thanks to the use of the Carboflux® micropollutant elimination process, complemented by ultraviolet disinfection, the new plant supplies top-quality drinking water to the residents of the 16 communes of the Syndicat Mixte de Kerné Uhel and neighboring syndicates. The Carboflux® process has been developed to meet the operating constraints of water that is difficult to treat, such as water from lakes or reservoirs that is highly eutrophic and chronically polluted with pesticides. The Carboflux® process continuously absorbs all pesticide peaks, without any operating intervention. Its performance comes from bringing water into contact with a large quantity of powdered activated carbon (PAC) in suspension, which is continuously renewed to guarantee its permanent effectiveness. Water savings at the very heart of the plant Doubling the flotation stage using the Aéroflux® clarification process ensures perfect elimination of the algae present in the water coming from the Kerné Uhel dam. This is a particularly acute problem in this region. During the summer months, when reservoirs such as dams are eutrophic, only the flotation stage can effectively retain the algal cells floating on the surface, where photosynthesis is most effective. The use of Aéroflux® technology is particularly effective for algae contents exceeding several million algae cells per liter. It also limits the need for further treatment, helping to reduce water losses from the treatment process.