European Environment Agency recommends rethinking water treatment to aid circularity

Although the plant treatment process restores and reuses water, it is itself guilty of pollution

Cleaning up waste water is itself a polluting process. This is the main takeaway from a report, which the European Environment Agency released earlier this week. Titled ‘Beyond water quality – Sewage treatment in a circular economy’ it shines the light on the pollution impact of water treatment processes and the missed opportunities in the context of the green transition.

According to experts from the Agency, with the use of new techniques and innovation, the water treatment facilities can act as resource hubs providing reclaimed water, energy, nutrients and organic materials for reuse, recycling and recovery. In essence, they can become critical nodes for circularity.

The challenge and the chance for water treatment

Managing sewage (the toilet and grey waters that we send down our drains), as well as urban run-off from roads and industrial waste water, is far from a pollution-free process across Europe. The treatment required to minimise pollution of water can lead to the production of greenhouse gases and contaminated sludges, which can go on to pollute air, soils and water.

Treatment plants are facing additional challenges such as stormwater surges from extreme weather due to climate change, and the reality that there are many more pollutants in urban waste water than were previously recognized under EU legislation.

There is also limited understanding of the risks to aquatic life presented by mixtures of chemicals in surface waters, and many of these chemicals come from products used in our own homes. Further, the construction, maintenance and operation of wastewater collection and treatment come at high financial and greenhouse gas emission costs.

Reviews and evaluations of key parts of European legislation such as the Urban Waste Water Treatment and Sewage Sludge Directives present the opportunity to modernise and improve coherence across the sector and help deliver on the ambitions of the European Green Deal.

The report says action is needed in other related areas to support water treatment in achieving future sustainability and in reducing pollution. In particular, efforts are needed upstream to ensure more efficient water use and pollution control, to minimise both the volume of water to be treated and the level of contamination.

Planning legislation should enable innovation in approaches to water and sewage management since large treatment plants can deliver considerable efficiencies of scale, while decentralised sewage treatment can enable circularity at the local level.

Thinking about other parts of the value chain, the report also recommends paying attention to providing economic incentives for products of waste water treatment. In addition, lifting legislative barriers can stimulate the promotion of these resources (for example, using treated sewage sludge as fertilizer) on the market.