Modernization as the basis for the efficient operational management of a wastewater treatment plant


Screw feeders in the intake pumping station  

The screw feeders transport up to 846 m3 of wastewater per hour to the wastewater treatment plant

  • The Monsheim wastewater treatment plant is to be thoroughly modernized without disrupting operation.
  • The new concepts are designed to ensure the optimum use of available resources and support measures to reduce energy consumption.
  • The powerful modular control technology enables field devices to be easily connected to the control system. Additional automation components complete the plant concept and control system.
  • The consistent concept provides the basis for the efficient operation of the wastewater treatment plant.

Customer profile

Overview of the Monsheim wastewater treatment plant  

The wastewater treatment plant processes the wastewater from three municipalities in the German state of Rheinland-Pfalz

The Monsheim wastewater treatment plant has a treatment capacity for a population equivalent of 46,500, which can rise to 120,000 during the grape harvesting season. The entire district is served by a sewer system covering several kilometers and comprising over ten rain overflow basins and tank sewers, as well as three pumping stations.


Plant manager Ralf Schmidt  

Plant manager Ralf Schmidt set his sights on a comprehensive solution.

Back in the 1970s and 1980s when the Monsheim wastewater treatment plant was built, the focus was on water conservation. In 2014, in the face of ever-growing energy consumption, the operator (ABZ Mittleres Pfrimmtal municipal wastewater association) decided it was time to thoroughly modernize the plant. Modernization was to be completed by 2017, without disrupting operation. Around 6.3 million euros were invested in the project, which aimed to make work more process-oriented and to conserve resources in the long term. Above all, the new concepts were intended to help reduce energy consumption. Furthermore, the plan was for the plant to generate 100% of its auxiliary power consumption. In order to meet these requirements, the entire automation technology used in the wastewater treatment plant needed to be modernized and the individual process steps optimized.


AXC 3050 Axioline controller  

AXC 3050 Axioline controller with mounted digital and analog modules

Those responsible for the modernization project set their sights on powerful modular control technology that made it easy to connect field devices to the control system. After the retrofit, ten PLCs distributed throughout the entire plant control all processes within the sewage treatment plant. Besides the controllers, the entire electrical installation has been housed in new control cabinets. The measured values from the intake to the blowers through to the combined heat and power plants are now recorded via analog and digital interfaces and processed in the distributed PLCs. These control the treatment process based on recorded or available measured values.

To ensure the defined objective is achieved with maximum efficiency, additional automation components complete the plant concept and control system. For example, a redundant FO-based network ring has been implemented throughout the plant using intelligent switches. This ensures a high degree of availability. Staff are able to determine the current status of the individual processes and components via the control panels distributed throughout the plant and, where necessary, influence the relevant process.

Another objective of the project was to save costs during the engineering process. One way to improve processes is to link the automation and visualization levels efficiently. The staff at the wastewater treatment plant therefore used the Waterworx library to program and create applications. The different field devices can be easily integrated into the application using the various blocks included in the library. The integrated visualization interface of Waterworx enables easy connection of the process parameters to the control system. Furthermore, the programmer and operator are assisted by other industry-specific functions when implementing the application. This concept enables a variety of field devices to be integrated into the automation solution with the aid of ready-to-use blocks and objects.


“Modernizing the individual treatment steps combined with the new automation technology and intelligent field devices now provides us with a consistent concept that forms the foundation for the efficient operation of our wastewater treatment plant,” explains plant manager Ralf Schmidt. A modern control system and reliable components alone are not enough to achieve the highest possible degree of efficiency after the modernization program. Rather, the focus needs to be on the solution as a whole. If the user employs the preconfigured blocks to connect complex field devices to the control system, the components can be integrated easily and the availability of the application increased during overall operation.


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