Wastewater Reuse: What Will the New European Regulation Change?

Reusing wastewater to conserve freshwater is one of the benefits of what is known as “reuse.” This approach is a key strategy in a context where global warming is increasing pressure on water resources.

Julie Mendret, University of Montpellier

© mat stock.adobe.com

Yet this potential is hardly being tapped in France, where only 0.6% of wastewater is reused. This is negligible compared to other European neighbors, such as Italy, which reuses 8% of its wastewater, or Spain, which reuses 14%. Why is our country lagging behind? This situation in France can be explained mainly by a lack of public awareness and very strict regulations.

The reprocessing and reuse of treated wastewater are governed in France by two ministerial decrees from 2010 and 2014. These regulations define four levels—A, B, C, and D, from best to worst—each with specific water quality requirements and a list of permitted and prohibited uses. For example, crops consumed raw may only be irrigated with water of quality level A.

In addition, there are operational constraints depending on the irrigation method, such as wind speed, minimum safety distances from residential areas or waterways, and public outreach…

Regulatory barriers

While these strict regulations may be necessary for public health and environmental reasons, the constraints involved in implementing them complicate the preparation of applications and may even jeopardize projects.

Several of these projects were therefore abandoned due to constraints related to implementation (preparing the application, land-type restrictions, specific requirements for sprinkler irrigation, etc.) and execution (traceability requirements, water quality monitoring, irrigation schedule management, etc.).

Sanitary quality levels of treated wastewater according to French regulations.
Example of the minimum distance requirement (in meters) that must be maintained between plots irrigated with treated wastewater and activities that must be protected under French regulations.

A new European regulation

How can we prevent these projects from falling apart due to regulatory obstacles? This is the focus of the new European regulation of June 5, 2020, on the reuse of wastewater, which aims to promote reuse by harmonizing the rules for its implementation across Europe.

The European Parliament thus reiterates that these new rules:

“aim to ensure that treated wastewater is reused more widely in order to limit the use of surface water bodies and groundwater. The decline in groundwater levels—due in particular to agricultural irrigation, but also to industrial use and urban development—is one of the main threats to the EU’s aquatic environment.”

The stated goal is to increase water reuse from 1.7 billion cubic meters per year to 6.6 billion, which would reduce water stress across the EU by 5% by 2025.

The European regulation applies only to agricultural irrigation—other uses remain the responsibility of the Member State; Member States have three years to bring their facilities into compliance.

More flexible than the French framework

This new regulation is more flexible than the current French framework: the four water quality classes are retained—with stricter microbiological thresholds (for the Escherichia coli criterion, French Class A corresponds to Class C in the new regulation)—but performance targets are no longer required, except for Class A. To compensate, the frequency of health inspections—which varies depending on the water quality class—has been increased.

Another major advance: the mandatory usage restrictions related to distance, soil type, and wind speed have been eliminated. In their place, “barriers” have been introduced—such as an additional treatment—that allow quality criteria to be adapted based on the risks involved.

The operator of the wastewater treatment plant must submit a risk management plan that identifies the risks and the measures implemented to manage them (replacing the mandatory French guidelines that have been in effect until now). Once approved, this plan will enable the operator to obtain an operating permit that specifies, among other things, the quality class of the treated water and the authorized agricultural use.

The risk management plan, developed by the wastewater treatment plant operator, is therefore one of the cornerstones of these new regulations.

It allows for a case-by-case assessment of each project and provides greater flexibility in the development of water reuse projects. It also includes a public awareness component by encouraging the publication of certain data (reclaimed water quality, test results, etc.) to reassure consumers and improve public acceptance of water reuse, which is already growing rapidly. Today, 83% of French people say they are willing to drink potable water produced from wastewater.

Quality requirements for reclaimed water intended for agricultural irrigation under European regulations.
EUR-Lex

Harmonization and Questions

In some respects, the European regulation of June 5, 2020, represents a real step forward. Practices and quality standards will be uniform across all member states, with usage restrictions tailored to actual risks and greater transparency for consumers.

However, this new regulation considers only one use: irrigation; it is to be hoped that, over time, this will provide an opportunity to expand the use of this technology in France to other areas, such as the irrigation of golf courses and parks, firefighting, and groundwater recharge.

However, very stringent quality requirements can lead to additional costs for upgrading facilities, particularly if an additional treatment step must be added. In some cases, this obstacle cannot be overcome without public funding.

Finally, these regulations do not address certain categories of pollutants that are of great concern (such as microplastics and pharmaceutical micropollutants), which are a source of anxiety for consumers and for which advanced treatments must generally be implemented.The Conversation

Julie Mendret, Associate Professor, HDR, University of Montpellier

This article is republished from The Conversation under a Creative Commons license. Readthe original article.