Altheim is a municipality in the Upper Austrian “Innregion“ with 5000 inhabitants and encloses an area of about 22 km2. The budget on a yearly base is about 6,300,000 Euro (5,670,000 US$). The decision to construct a geothermal heat supply, for environmental reasons, was made by the municipal council in January 1989. The district heating system is fed by 106 C geothermal fluid flowing from an aquifer about 2300 m deep. Since 1989, efforts were undertaken by the municipality to supply 10 MWe of thermal heat to a district heating network