In the dyeing process 80.000 m³ water are needed annually. The biggest part comes from the river of fulda, which flows directly under the building. The river water is cleaned intensely with gravel filters, before it can be used.
In summer the demand could be not always covered, because of a low water level in the river. A rainwater harvesting system was installed as a supplement.
The rainwater is filtered by a WISY vortex-fine-filter and is led into a small intermediate tank to allow additional sedimentation to happen. Then it is pumped into a 30 m³ storage tank, which is 50 m away from the filters. From there it is constantly used in the dyeing process, along with the river water.