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 6,000 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 have 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 the resource plant of the future - Aarhus ReWater
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 new wastewater treatment plant, Aarhus ReWater, will be located nearby the current Marselisborg WWTP.
Making room for urban development
The consolidation of our wastewater 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.
The world’s most resource efficient WWTP – Aarhus ReWater
Aarhus ReWater will become the world’s most resource efficient wastewater treatment plant (WWTP). And set new standards both nationally and internationally using state-of-the-art technology to enhance its performance.
Our ambition is to not only meet the current and future requirements within purifying of water, but to be a leading player in securing an optimal aquatic environment in Aarhus Bay benefitting both humans and nature.
Building a new 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 the new WWTP into a future resource plant, we have chosen to name the new plant Aarhus 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.
From wastewater treatment plant to resource plant
By using the term resource plant, we want to state that Aarhus ReWater will not only be treating wastewater, but also produce energy and nutrients from the wastewater to an unprecedented extent. The ambition is to have an energy neutral supply of drinking water and wastewater treatment.
Aarhus ReWater will be extracting and utilizing valuable resources from the wastewater. Resources that are today classified as waste matter and needs disposal, but can be used for ‘green’ power and heating or fertiliser. By utilising the resources, we can reduce the costs of wastewater treatment by sale of electricity, heat and biogas, extraction of resources such as heavy metals, phosphorus and plastic, or cultivation of crops that both cleans and can be used for fuel or industrial production.
Building a learning plant for the future
How the new plant will look like when build in 2028 we don’t yet know. But what we do know is that our ambition on making it the world’s most efficient WWTP cannot be achieved by today’s technologies and solutions. Therefore, we strive to make room for flexibility so that we can meet the future needs that we do not yet know of. Therefore, the ambition is not to build a plant that stands unchanged for the next hundred years. On the contrary we’re building a plant that will constantly help us expand our knowledge and therefore constantly can be improved.
Technology and requirements are constantly changing. What we are thinking today does not apply tomorrow. Therefore, our job is not to build a finished plant, but to build a “learning” plant that will be able to meet the existing demands while at the same time being adaptable and making us wiser. Aarhus ReWater will therefore serve as a ”test-bed” where development and test of new or optimised treatment processes can take place.
Making use of tomorrows solutions
While a lot of the technologies acquired to build a WWTP is already known to us – and in use on our current plants – other technologies are yet to be developed. This is why we in our innovation strategy for Aarhus ReWater has formulated 15 innovation challenges, that is to be addressed – and solved – in the forthcoming years.
We cannot solve all the challenges ourselves. Therefore, we invite companies, knowledge institutions, and citizens to develop the future Aarhus ReWater with us.