Improvements of wastewater treatment for groundwater protection in the Haertsfeld.

Wastewater treatment in rural water protection zones is crucial for sustainable source water protection. Specific problems arise where wastewater from decentral treatment plants infiltrates towards vulnerable aquifers. Within the water protection zone of the Egau Waterworks sited on the Swabian highlands with a karstic aquifer, a concept for a central sewer system and wastewater plant went into operation in 1993 in order to solve the conflict between drinking water demands and wastewater treatment. Since then, water quality of the Buchbrunnen karst spring which is used for drinking water supply for about 400,000 inhabitants has shown improvements. The paper describes the development of typical parameters including groundwater flow time and corresponding concentration levels. The concept implemented here may serve as a model for a successful water protection initiative.