The company will utilize the energy to heat 4,000m² of buildings or cool them in summer.
The move will enable the firm to manage completely with gas and decrease its carbon footprint.
Stadtwerke Amstetten director Robert Simmer told AFP "Almost every week we get a visit from a different delegation coming to look. There is a French delegation coming next week, and then a Spanish one. We are starting to lack the resources, we need to beef up our personnel to handle all the tours we have to do."
The company has installed a system along a 42m stretch of sewer where the water temperature can reach 27 degrees Celius.
Water flowing in pipes near the sewer will be warmed by heat exchanger devices.
"The water that is pumped over here is clean, there is no fecal matter. The equipment inside [the sewer] is also self-cleaning," Simmer said.
