The water treatment plant in Laichingen, Germany, which is designed for a population of 35,000, is one of the country’s pioneers in the treatment of wastewater. It recently became one of the first plants to institute the fourth treatment stage, a process that removes micropollutants, such as medication residues, hormones or residues from personal hygiene products, from the water. To date these trace materials, which pose a danger to aquatic organisms, have made their way unchecked into the ecological system. As a final step that follows the mechanical, biological and chemical treatment processes, the fourth stage eliminates these contaminants by means of, for example, an active charcoal filter. Serving as partner for the entire measurement technology was Endress+Hauser. The operator of the plant was persuaded by the complete offering for all standard liquid analysis parameters, as well as the Liquiline transmitter platform and Memosens sensor technology. This allows the plant to continuously monitor and optimize the processes that remove the trace materials. Because the Memosens sensors significantly reduce the maintenance effort, cost efficiency is improved at the same time.