Indirect water reuse in a partly closed water cycle (Hessisches Ried)

The Hessian Ried is of great importance for the production of drinking water in the Frankfurt Rhine-Main and Rhine-Neckar metropolitan regions. Although the Ried only covers around 5 % of the state's surface area, almost 25 % of the drinking water in Hessen is extracted from the groundwater there due to the hydrogeological conditions. These are characterised by cover layers with a high permeability and by low-runoff and heavily polluted watercourses. Trace substances such as pharmaceuticals, and pesticides enter the flowing waters via the wastewater. These trace substances are only partially retained by the cover layers and thus enter the groundwater. Due to the use of the groundwater for drinking water production and agricultural irrigation, the water management situation can be described as a regional water cycle closure. For this reason, the state government has initiated a strategy to reduce the material pollution of the flowing waters in the fen by means of suitable measures and thus, in accordance with the Water Resources Act (WHG), to ensure both the manifold functions and uses of the water bodies in the future and to protect the groundwater resources in the fen in the long term. Central elements are the system-wide optimisation of the sewer networks as well as the equipment of selected sewage treatment plants with more extensive wastewater treatment in order to minimise the input of trace substances via the watercourse - groundwater path in a targeted manner.