Globally, it is important to act responsibly to protect people and the environment from intensive, untreated wastewater streams. We need efficient treatment of our wastewater to protect our health and natural environment. With the right technologies, wastewater can become a valuable resource, turning sludge from treated wastewater into energy and transferring heat from the treatment process to the district heating networks.

Severe environmental degradation of many inland and coastal waters around the world is the outcome of decades of uncontrolled discharge of wastewater. Globally, about 80 percent of wastewater is discharged untreated to the surrounding environment, which has major consequences for human health, biodiversity and the environment.

Denmark realised the severe effects of a growing population and a blooming industry at a very early stage. Today, as a result of progressive efforts, more than 95 percent of all wastewater is treated.

In Denmark, wastewater is considered a valuable resource.

The Danish water sector has a goal of becoming energy and climate-neutral by 2030 – and perhaps even net producers of energy. That is an ambitious goal which requires cooperation between Danish authorities, water utilities, companies and organisations if we are to create more innovative solutions, adding value for both water consumers and the society as a whole.

Today, wastewater is a resource for reuse, extraction of nutrients, energy production and soil improvement. And this is an example of how Denmark contributes to finding solutions to some of the world’s major water and climate challenges, in accordance with a number of the United Nations’ Sustainable Development Goals.

If properly treated, wastewater may for example be reused as technical water in some industries, as irrigation water for crops and for recreational purposes. The number of available solutions is plenty but to harvest the full potential of investments in wastewater treatment, it is crucial to look ahead and think long-term. Wastewater should no longer be thought of as a problem but as a resource. We must make the most of the water we have, including wastewater.

This white paper features a series of best practice examples of wastewater treatment – both centralised and decentralised. Although many of these solutions have been created within a Danish context, they are scalable and applicable for a global audience.