The city of Antwerp in Belgium is closing the loop on wastewater with a €100 million project that will repurpose 20 billion litres of water every year.

The recycled wastewater equates to all the water used and flushed away by 600,000 of the city's residents. From 2025 this treated effluent will instead be transferred to a new high tech treatment plant to produce the huge quantities of cooling water needed by industries based in the Port of Antwerp.

A joint venture called Waterkracht has been set up between Flemish venture capital firm PMV, which is co-financing the project, and Ekopak, which will build and operate the new cooling water treatment plant. Using this alternative water source in an urban water-cycle will reduce the pressure on freshwater resources, say the partners, and will give businesses and households in Antwerp more security of supply, even in times of drought.

Investment for the project is carried out under the Flemish government's Blue Deal programme to mitigate against water scarcity and drought by encouraging water reuse by businesses. Currently, treated sewage in Belgium, and most of the world, is discharged to watercourses where it just flows away or is abstracted and treated again downstream.

To change this, the Flemish government offered €11 million in subsidies for companies willing to invest. Five projects have now been selected for a total of nearly €155 million. Waterkracht is the largest of the five.

Flemish Minister of the Environment, Zuhal Demir, said, "Every drop we can reuse is a drop we do not have to pump from the ground or from surface water. As such, the use of circular water is one of the spearheads in the Blue Deal that aims to better arm Flanders against the more extreme weather conditions we are facing.

"This project not only proves what Flanders can accomplish as an innovative region, it also allows us to guarantee water supply security for industry and our households in periods of prolonged drought."

The Port of Antwerp is one of the biggest in the world, and the second largest in Europe. The advanced cooling water plant will be located in the NextGen district of the port, at the former Vauxhall car manufacturing site.

Municipal utility Water-link is providing the new pipeline distribution network at the port, enabling all industrial customers to use the cooling water, while wastewater utility Aquafin is carrying out initial treatment of the water used by the people of Antwerp and will transport the treated wastewater to the new cooling water processing plant.

Ekopak will use membrane technology to further upcycle the effluent for industrial applications.

TotalEnergies is one of the first companies to sign a long-term agreement with the municipal utility Waterlink for the supply of process water from Waterkracht for its industrial sites in Antwerp. This makes the French energy company the project's largest customer, with annual water use of around 9 billion litres, the equivalent of 280,000 Antverpians - Antwerp residents.

Pieter Loose, chief executive of Ekopak said, “Ekopak’s primary focus is the decentralised supply of water, but with this project we can also make a significant contribution to making the entire port sustainable. We are convinced that our expertise and know-how will help make this project a success.

"We are pleased that the interest is high and many companies want to join this sustainable water story. With TotalEnergies as a new customer there is a good chance that the targeted production volume of 20 billion litres per year will be exceeded.”

These collaborations are seen as a milestone in the transition the Port of Antwerp is making to become more sustainable, and closing the loop on the resources it requires. Waterkracht means valuable drinking water will be retained for the residents of Antwerp so there will be less stress on natural resources, while companies at the Port of Antwerp will be using circular water for their processes.