The French Water Industry publishes a groundbreaking study on the benefits of the revised Urban Wastewater Treatment Directive (UWWTD 2)
As the revised European Urban Wastewater Treatment Directive (UWWTD 2, known in France as "DERU 2") must be transposed into French law by 31 July 2027, the Strategic Committee for the Water Industry (CSF Eau) is publishing a groundbreaking impact study on the French sanitation system.
Conducted between 2025 and 2026, this study assesses the technical and financial impacts of UWWTD 2 while demonstrating the benefits it brings at the national level. On this basis, the industry puts forward concrete recommendations to support public authorities and ensure the directive is successfully implemented.
A directive whose benefits far outweigh its costs
The study estimates that two-thirds of the costs will be related to reducing wastewater discharges during rainfall events. The overall cost of compliance with UWWTD 2 over the 2028-2045 period will reach €2 billion per year — mainly for the roll-out of Integrated Management Plans (IMPs), reducing wastewater discharges during rainfall events, new treatment for nitrogen, phosphorus and micropollutants, and investments in the energy neutrality of treatment plants.
Against this cost, the expected benefits are estimated at more than €3 billion per year, or an investment that returns to France one and a half times the value invested: safer drinking water, preserved ecosystems, protected coastlines, and improved bathing water quality.
"The UWWTD 2 (Urban Wastewater Treatment Directive 2) represents a unique opportunity to improve the quality of our sanitation services. By prioritizing wet-weather wastewater collection and pollution prevention, it calls on us to take action further upstream to better protect natural environments, public health, and water uses. The French water sector welcomes the directive's ambitious scope and calls for a transposition that is clear, transparent, and commensurate with the stakes involved. Local authorities need clarity to plan their investments, and water sector stakeholders stand ready to support them in this vital undertaking for their communities. The UWWTD 2 is a long-term endeavor, given the investments and infrastructure required and the benefits it will yield for future generations. Yet, it is also a matter of urgency: the decisions made in the coming months will have a lasting impact on the quality of our water resources, the resilience of our communities, and the protection of our health.."
Xavier Girre, Chairman of CSF Eau
The urgency of acting before the 2027 transposition deadline
For CSF Eau, the success of UWWTD 2 will depend above all on the visibility given to local authorities from the transposition stage onwards. The industry is calling for all zones subject to the strictest requirements to be published simultaneously, to avoid an "investment wall" in the mid-2030s — especially as the first regulatory deadlines start as early as 2033, while major sanitation projects require several years of studies and delivery.
Today, only 42% of local authorities comply with current regulations on rainfall discharges. Under the previous directive (UWWTD 1), France is still behind for 3% of its urban areas: 78 are subject to European litigation and 610 are in breach.
Beyond regulatory compliance, UWWTD 2 is also an opportunity to strengthen the resilience of French territories, accelerate the ecological transition, and reinforce France's industrial excellence in the water sector.
Key figures
- +€3bn/year in environmental and socio-economic benefits
- €2bn/year in investment over the 2028-2045 period
- 2/3 of the costs will be related to reducing wastewater discharges during rainfall events
- 31 July 2027: deadline for transposing UWWTD 2 into French law
- 2045: target date for full compliance
- 125,000 jobs and 5,000 companies across the French water industry
Downloads
Download the executive summary (PDF)
Download the detailed summary (PDF)
Download the full study (PDF)
Download kit press (PDF)
About CSF Eau
Created in 2018 within the French National Industry Council, the Strategic Committee for the Water Industry (CSF Eau) brings together the State, companies and employee representatives to support the development of the French water industry and strengthen its competitiveness. The industry today represents more than 5,000 companies, 125,000 jobs and €22 billion in revenue.
