HIAS is an inter-municipal water treatment company owned by 4 municipal authorities in the Hamar region on the eastern side of Norway's largest lake, Lake Mjøsa. Lake Mjøsa is both a source of drinking water and a recipient of wastewater. Strong eutrophication of the lake that was the basis for founding HIAS in 1974 and the establishment of a common three stage sewage treatment plant. The plant is now treating about 65,000 PE (phosphorus). Industry connected to the plant is mainly food-related.
Anticipated future demand for disinfection and stabilisation of sludge made HIAS enter into co-operation with Cambi A/S in 1990 with thermal hydrolysis of sludge as a goal. Trials and reports resulted in the implementation of a Government research and development programme that in addition to the thermal hydrolysis also dealt with the possibility of recovering precipitation chemicals by way of chemical extraction. The price of the Cambi plant was comparable with more traditional alternatives and opened up new opportunities for HIAS.
The first sludge was treated at the new plant in November 1995. As usual there were some start up problems, but since September 1996 all the sludge has been treated in the thermal hydrolysis plant.