Mariagerfjord Wastewater Treatment plant on Islandsvej 5 in Hadsund was built from June 2012 to November 2013. The wastewater treatment plant has been in operation since the autumn 2013.

The new wastewater treatment plant should replace the 11 existing plants in the Municipality step by step. Within a period of seven years from 2011 to 2017 Mariagerfjord Vand a|s has closed 10 wastewater treatment plants in Mariagerfjord Municipality. The last of the existing wastewater treatment plant closed in the beginning of 2017.

More than 100 km of new pipes have been established and several new pumping stations have been built in order to transport approximately 5 to 6 million cubic meters of wastewater per year to the plant. Mariagerfjord Wastewater Treatment plant handles and treats the wastewater with in the whole of Mariagerfjord Municipality.

Mariagerfjord Wastewater Treatment plant is designed to handle 75,000 person equivalents. The process tanks at the plant are divided into three sections - an anaerobic, an anoxic and an aerobic section.

When the wastewater has been handled, the sludge from the wastewater is converted into biogas. The process breaks down the organic matter in the sludge and convert it into biogas, which then can be used for electricity, heat and warm water.

The treated water is discharged to the ocean (Kattegat) through a sixteen-kilometre-long pipe. Four kilometres of the pipe was established in the seabed whereas the remaining 12 km are on land.

Mariagerfjord Vand a|s also built a new joint operation and administration building at Islandsvej 7, where staff moved in in June 2013. Both the plant as well as the operation and administration building is situated in beautiful surroundings north of Hadsund, surround by corn fields and forests.