In November 2019, the Danish government established 13 so-called ‘climate partnerships’ with the private sector, covering the entire Danish business community and its emissions of greenhouse gases (GHG). Each of the 13 climate partnerships was asked to provide their respective sectors’ recommendations on how to achieve the ambition of the Danish government, namely to reduce the country’s greenhouse gas emissions by 70 percent in 2030. Among these partnerships were the Climate Partnership on Waste, Water and Circular Economy, where I had the honour of being appointed as Vice Chair with a special focus on the climate effects of the water sector.

The water sector’s climate impact

The water sector today is a significant contributor to climate effects. Partly because both water and wastewater treatment and distribution require a lot of energy and partly because of the significant emissions of nitrous oxide (N2O) and methane (CH4) related to wastewater treatment – both of which are highly potent high greenhouse gases.

The climate effect of discharging untreated wastewater, which will be generated in the recipient, is estimated to be roughly 3 times greater than emissions. So to avoid treating wastewater is not a sustainable solution to the GHG footprint of our sector, either. Therefore to fulfill the UN Sustainable Development Goals, we must focus on extending and building wastewater treatment facilities in every part of the world, not only as a means to minimise the climate impact but equally important to create a healthy and environmentally sound water environment as well as livable cities.

To me, the conclusion is obvious; we need to improve what we are doing inside the fences of our own waterworks, wastewater treatment plants and distribution systems. We have a wide variety of solutions available to reduce and diminish our share of the world’s greenhouse gas emissions.

In the Climate Partnership for Waste, Water and Circular Economy, we decided to set high ambitions for all of our focus areas and for the water sector, our evaluation showed that an energy and climate neutral water sector by 2030 is an ambitious, yet realistic and achievable goal.

We presented the main GHG emissions and their sources from our sector and we presented the tools and possible solutions to eliminate these emissions. The figures show the total emission from the water sector in 1990, today and what it would look like in 2030, if we use the tools available.

My personal experience from our utility, Aarhus Vand, is that we can be both energy and climate-neutral throughout our entire water cycle – all the way from groundwater abstraction to drinking water supply and the discharge of treated wastewater. We have worked intensively on reducing our climate impact over the past years. I am proud that we have succeeded in doing this as part of our general reinvestment strategy, focusing mainly on three initiatives:

1. Shift to the most energy efficient equipment combined with online process control
2. Introduce measures to increase energy production (biogas, electricity and heat)
3. Reduce our GHG emissions (especially N2O) through sensor metering and process control

The lessons learned from our experience is that it is in fact possible – and not necessarily more expensive – to move towards energy and climate neutrality.

For many water and wastewater utilities, it is generally the question of acknowledging the importance of GHG emissions from the utility and then focusing on every small step to reduce the utility’s GHG footprint.

In June this year, a vast majority of the Danish Parliament decided to move forward and set a national target of achieving an energy and climate-neutral water sector in Denmark by 2030. This will contribute to the Danish ambition of reducing the country’s GHG emissions by 70 percent (compared to 1990 levels) by 2030 and to showcase to the rest of the world that high environmental standards and climate neutrality are both possible and achievable.

The good news is that the solutions are already available – and they work. I am sure you can learn much more about the Danish goal of an energy and climate-neutral water sector at the IWA Conference in May next year in Copenhagen. – I hope to see you there.

Figure 1

Figure 2