Why build a new wastewater treatment plant?

Ensuring a both economically and environmentally optimised wastewater structure for the future, we need to build a new and bigger Marselisborg Wastewater Treatment Plant. Our goal is simple but ambitious – we want it to be the world’s most resource efficient wastewater treatment plant (WWTP). And a facility that contributes to a more liveable Aarhus.

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 percent.

Meeting the needs from a city in growth

At the same time Aarhus municipality is facing an annual increase in population of 4,000 people. An increase that have to be met by increasing the capacity and performance of the wastewater treatment plants.  

Aarhus Vand and The City of Aarhus has therefore decided to work towards a structure of two future WWTP’s: Egaa and Marselisborg. 

In the consolidation into only two future WWTP’s, Egaa WWTP has already undergone an extensive energy renovation to meet the future needs for capacity and is today producing more electricity than it uses. The existing Marselisborg WWTP on the other hand has proven to be too small to meet the future demands and the current location does not allow the necessary expansion.

At the same time, we need to meet the demands and expectations for a cleaner harbour and bay area creating liveability for plants, animals and people. It will therefore be essential to avoid polluting the receiving waters with the increased phosphorus and nitrogen discharges even as the population grows.

Building a new Marselisborg WWTP

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 draft for a master plan for Tangkrogen therefore suggests that the current Marselisborg WWTP is demolished and a new is built 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 world’s most resource efficient WWTP – Marselisborg ReWater

Building a new Marselisborg WWTP, our ambition is to establish not only a wastewater treatment plant but a ‘resource plant’. By this we mean that the plant, in addition to the purifying of water, will also produce energy and nutrients from the wastewater to an unprecedented extent.

Developing Marselisborg WWTP into a future resource plant, we have chosen to name the new plant Marselisborg ReWater. The “Re” referring 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.

Making room for urban development

The consolidation of our waste water treatment plants serves not only a more efficient and cost-effective operation and reduction of the environmental impact – it also unleashes new possibilities for urban development.

Our goal is to utilize the specific potential of the site and the central location on Tangkrogen – at the foot of the forest, and at the beginning of an attractive coastline – to make sure that the new plant fit into the local surroundings. And at the same time contributes positively to the development of both Tangkrogen locally and in terms of liveability in Aarhus in general by obtaining a multi-functionality in design and land use.