Building the World’s Most Efficient Wastewater and Resource Plant

State of Green
By State of Green , March 29, 2017

A strategy has been launched to build the world’s most resource-efficient wastewater treatment plant (WWTP) by transforming the existing Marselisborg facility in Aarhus, Denmark into a resource plant of the future: Marselisborg Rewater in 2026. It is an open call for companies, manufacturers, research institutions, entrepreneurs, and alike to take part in developing it.

In 2005, the Aarhus City Council decided to optimise the wastewater structure in the Aarhus municipality by reducing the operation costs of the wastewater treatment plants. As a result, it was decided to consolidate the wastewater treatment operation into two large-scale and much more efficient plants equipped with the most environment-friendly and efficient technologies. A consolidation estimated to reduce operating costs by 40%.

In the consolidation into two future WWTP’s, Egaa WWTP underwent an extensive energy renovation to meet the future needs for capacity and is today the first WWTP in the world to produce 50% more electricity than it uses.

– Related news: First Water Treatment Plant in the World to Generate 50% Electricity Surplus

On the other hand, the existing Marselisborg WWTP proved to be too small to meet the future demands, and the current location did not allow the necessary expansion. Today Marselisborg WWTP is located at Tangkrogen – an area of 12 hectares near the Marselisborg Forest in the south-eastern part of midtown Aarhus – bordering on the harbour, a nearby residential area, a marina and a space for cultural events.

The existing Marselisborg WWTP

Rebuilding Marselisborg WWTP into the world’s most efficient facility

The draft for a master plan for Tangkrogen therefore suggests that the current Marselisborg WWTP is demolished and rebuilt onto a site approx. 500 meters west of the current site by including a territory of the bay and extending the existing harbour front. The total construction cost is estimated to be DKK 1.6 billion (approx. EUR 215 million).

The ambition to build a new Marselisborg WWTP is to establish not only a wastewater treatment plant but a ‘resource plant’. This means that the facility, in addition to the purifying of water, will also produce energy and nutrients from the wastewater to an unprecedented extent. Renamed into Marselisborg ReWater, the “Re” referres to the words “resources”, “recycle”, “reuse” and “rethink”, allowing for a broader mind-set on how to manage wastewater treatment and water supply in the future.

– Read more about: Aarhus Vand 

The goal is to make Marselisborg ReWater the world’s most resource efficient WWTP, not only meeting the current and future requirements within water purification, but to be a leading player in securing an optimal aquatic environment in the Aarhus Bay, benefitting both humans and nature.

CEO of Aarhus Vand Lars Schrøder presents the new strategy for Marselisborg Rewater

Open call for contributions

What the new plant will look like when build in 2026 is yet unknown. However, it is certain that making it the world’s most efficient WWTP cannot be achieved using today’s technologies and solutions. Therefore, an open call has been made to attract companies, knowledge institutions, and citizens to develop the future Marselisborg ReWater in collaboration with Aarhus Vand. Marselisborg ReWater will therefore serve as a ”test-bed” where development and test of new or optimised treatment processes can take place.

In order to manage the innovation process of assessing new technologies, an innovation strategy for Marselisborg ReWater states 15 innovation challenges that have to be solved in the development of building the new facility.

Sign up for “speed dating” meetings

The starting point for the Marselisborg Rewater journey is a series of 1:1 meetings in Denmark where all interested parties can ask for meeting where we discuss the potential for collaboration. It is called “speed dating” to state that this is an opportunity to mutually look for “the right match”.

Representatives from Danfoss, Insero and Aarhus University took the stage to discuss
future solutions for Marselisborg Rewater during the launch of the innovation


Speed dating meetings will take place at Aarhus Vand in Aarhus (Viby J) on the following days: April 19th, April 26th, April 27th, May 5th and May 10th.

The meetings will be held in Danish or English based on preference and it is possible to sign up through the website.

Source: Aarhus Vand 

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