Long before the authorisation for the construction of the Freudenau power plant was issued on 31 July 1991, an intensive water quality surveillance programme for surface water and groundwater was in operation in the project area.
The area covered by the programme included the entire affected zone by the construction. Roughly 500 groundwater sampling points and 130 surface water sampling sites are currently used in the hydrological monitoring net.
As a result of the construction of the Freudenau power plant and the ensuing need for a sealing system along the right bank of the Danube over a 13 kilometre distance, a groundwater management and monitoring system had to be installed for the second and twentieth districts of the City of Vienna.
The installed on-line water quality control, bio monitoring systems, and regular monitoring in an elaborate network of water quality monitoring wells ensure that no contamination will occur in the aquifer; neither through groundwater management procedures nor by direct infiltration of contaminants from the Danube. Therefore, a supply of safe and clean groundwater in and around the City of Vienna is ensured.
Pöyry has been entrusted to provide design and detailed engineering services, including design and detailed engineering, implementation, operation and training.
Pöyry analyses the relevant hydrological and quality data collected in the second and twentieth districts of Vienna, reports to the Federal Water Authorities, on behalf of the owner of Freudenau Hydropower Plant, and works constantly on improving and specifying the existing monitoring network by extended statistical analysis.