Wassergewinnung Essen (WGE) was founded in 2002 as a co-operative group between Essen Public Services and GELSENWASSER. At the Ruhr in Essen, the company is focused on procurement, extraction, treatment and supply of drinking water and then delivering to its partners. The formerly autonomously operating water plants in Essen-Überruhr and Steele-Horst are among the WGE’s water treatment sites. 60 million m³ of drinking water per year is produced from these to supply Essen, with the towns of Bochum, Gelsenkirchen, Hattingen, Sprockhövel, Velbert-Langenberg and Herne also each receiving a boost to their water supply from this. The plants were merged into a united water plant with two pumping plants. The water extraction plant in Burgaltendorf is spread over an area of 172 hectares. Here, enriched groundwater and bank filtrate are extracted and then conveyed to Überruhr for the next stages of treatment.
The linking system between the two water plants guarantees the quality of the drinking water in the long term. To achieve this, the plants are linked by a 2.8 kilometer long double circuit line and new treatment phases have been installed. The already present water treatment system (WAA I), which comprised the treatment phases of ozonation, flocculation and rapid filtration, was improved by adding the following treatment phases: activated carbon filtration, physical deacidification and UV light disinfection. These treatment phases were installed in the new water treatment system (WAA II), which also comprises a pure water storage tank with a capacity of 15,000 m³ as well as the UV systems.
Ten Barrier® M 3800 systems are currently in operation in WAA II for treatment of drinking water for the Essen-Horst pumping plant. A maximum of 6,000 m³/h is treated there. Ten further systems have been installed to supply the Bergerhausen pumping plant with a maximum of 8,600 m³/h of water. The systems are DVGW (German Association for Gas and Water) certified, which is compulsory for the treatment of drinking water in Germany. They contain medium-pressure lamps and their compact system design sets them apart from the crowd.
For this project, a specific control concept has been created that fits the operator’s requirements exactly and has also been approved by the DGVW. Each control cabinet is linked to the central control system via a high-speed fiber-optic link. Every element can be monitored in the disinfection process, and every line and conduit is also constantly controlled. Every section of conduit or line that contains an integrated UV system contains a flow meter. This details the exact amount of water that each UV system must treat. Based on this figure, the UV radiation adjusts automatically. This ensures that a UV fluence of 400 J/ m², as required by the DVGW, is always achieved. Thus the system works with ultimate precision, ensuring not only that it is definitely effective but also that it saves energy.
The WAA II now contains the largest activated carbon system in Germany. The UV systems, which are the final stage of the treatment process, disinfect 14,600 m³/h of drinking water, which provides enough water for around a million people. The decision makers chose Wallace & Tiernan® UV Disinfection systems, as this UV technology has already been successfully integrated into other GELSENWASSER sites. 47 of this type of Wallace & Tiernan UV systems have already been installed in six water plants altogether, including GELSENWASSER. Together, they disinfect over 36,000 m³/h of water in total.