Making European wastewater treatment plants more efficient and circular can help achieve zero pollution targets — European Environment Agency

Most European cities wastewater treatment plants focused on cleaning water and returning it to the environment in a simple, linear approach. However, with the use of new techniques and innovation, these facilities can serve as resource centers provide reclaimed water, energy, nutrients and organic matter for reuse, recycling and recovery, in accordance with the EEA report ‘Beyond water quality Wastewater treatment in a circular economy‘.

This would ensure that these vital facilities respond decisively to the ambitions of the European Green Deal. The report sets out policy considerations for the transition to sustainability as part of the European Green Deal, focusing on opportunities to achieve zero pollution and circularity.

The challenges of wastewater treatment

Manager waste (urine, feces and dirty gray water that we discharge into our sewers) as well as urban runoff from roads and industrial waste water is far from a pollution-free process across Europe. The treatment required to minimize water pollution can result in the production of greenhouse gases and contaminated sludge, which can then pollute air, soil and water. Wastewater treatment plants face additional challenges such as stormwater floods extreme weather conditions due to climate change, and the fact that there are many more pollutants in urban waste water than previously recognized by EU legislation. We have a 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. In addition, the construction, maintenance and operation of wastewater collection and treatment fall under high financial and greenhouse gas emission costs.

Revisions and assessments of key pieces of EU legislation such as the directives on urban waste water treatment and on sewage sludge offer the opportunity to modernize and improve consistency across the sector and help deliver the ambitions of the European Green Deal. The report says action is needed in other related areas to support water treatment to achieve future sustainability and reduce pollution. In particular, efforts are needed upstream to ensure more efficient use of water and pollution control, to minimize both the volume of water to be treated and the level of contamination. Planning legislation should allow for innovation in approaches to water and wastewater management, as large treatment plants can offer considerable economies of scale, while decentralized wastewater treatment can enable circularity at the local level.

Other key findings

  • Wastewater treatment is not “one size fits all”. Local conditions ask local solutions. Financial resources, land availability, population density, nature of receiving waters and types of industrial activities all influence the options available. Ensuring flexible approaches to meet necessary quality standards can enable innovation and locally appropriate solutions.
  • Economic incentives for recycling and legislation that helps to scale up circular approaches to urban waste water treatment, allowing recovered resources to enter the market, while legal barriers limiting the use of these resources – e.g. sewage treated – should be reviewed.
  • Making the transition to more efficient wastewater treatment and a circular economy requires a change not only in regulatory and institutional approaches, but also in the way we, as citizens, value our individual and collective responsibilities towards wastewater management. Nature-based solutions, which provide benefits such as green spaces and reduced flooding – for example reedbeds – can generate local support.