On 3 June 2026, the Ministry for the Ecological Transition and the Demographic Challenge (MITECO) opened the preliminary public consultation on the transposition of Directive (EU) 2024/3019 on urban wastewater treatment — known in the sector as the TARU Directive (urban wastewater treatment). It is the deepest reform of the Spanish regulatory framework on sanitation and wastewater treatment in the last three decades: it will repeal legislation in force since 1995 and impose new technical, energy and transparency thresholds across the whole sector.
The public consultation closes on 26 June 2026, and the final deadline for transposition ends on 31 July 2027, with mandatory application from 1 August 2027. It may look far off, but experience tells us that investments in water infrastructure require planning horizons of three to five years. Public administrations, industries and operators that wait until 2027 to start planning will arrive late.
Five structural changes the new law will bring
1. Drastic reduction of the threshold for agglomerations covered
Current rules only require wastewater treatment in agglomerations of more than 2,000 population equivalent. The new law lowers that threshold to 1,000 population equivalent. The consequence is immediate for hundreds of small municipalities, especially in Catalonia, where the territorial structure consists of numerous rural settlements that until now fell outside the obligation to have their own treatment plant.
2. Mandatory treatment of micropollutants
This is one of the most technically demanding changes. Treatment plants will have to incorporate quaternary treatment to remove micropollutants such as pharmaceuticals, personal care products and other chemical molecules that conventional treatment does not retain. That means investment in ozonation, activated carbon or advanced membranes in practically every large treatment plant in the country.
3. Extended producer responsibility: pharmaceutical and cosmetics industry
This is the change with the greatest economic impact for the private sector. The pharmaceutical and cosmetics industries will have to fund a substantial share of the costs of quaternary treatment, in application of the polluter pays principle. It is the first time in Europe that the cost of advanced treatment is passed directly to the sectors that produce the micropollutants.
4. Energy neutrality for the sector by 2045
The Directive sets a target of energy neutrality for the wastewater treatment sector by the year 2045. Treatment plants will have to produce as much renewable energy as they consume — mainly through sludge biogas, integrated photovoltaics and heat recovery. This requirement opens an enormous strategic window for hybridisation between the water cycle and the energy transition, two fields that until now have been handled separately.
5. Management of storm overflows and public transparency
New obligations are introduced for monitoring combined sewer overflows during heavy rainfall episodes, and public disclosure of effluent quality data is established. Local authorities will have to modernise telemetry and reporting systems to meet these requirements.
Practical implications for each actor
For local authorities, especially municipal and county councils with medium-sized or small treatment plants, the EPBD opens two fronts at once: the need to extend coverage (settlements not previously covered) and the need to invest in quaternary treatment at existing plants. These investments will have to be budgeted for from now on, because public investment cycles are long and the European funding available (the water cycle digitalisation PERTE, NextGen funds) has time windows that are closing.
For the agri-food, chemical and pharmaceutical industries, the impact is direct and runs two ways: on the one hand, as producers of industrial wastewater subject to new discharge thresholds; on the other, in the specific case of pharmaceuticals and cosmetics, as funders of part of the municipal advanced treatment. The recommendation is to bring forward a complete water audit and to review the existing agreements with the municipal treatment plants receiving their indirect discharges.
For integrated water cycle operators, the challenges are technical but also a matter of business model. Energy neutrality forces a rethink of the treatment plant as hybrid water-energy infrastructure, not as a passive plant. Those who can integrate the water cycle with renewable generation, sludge valorisation and heat recovery will be far better positioned in 2045.
Recommendations
Given this scenario, we recommend three immediate actions:
Take part in the public consultation before 26 June. This is the moment to influence the technical aspects affecting each sector. Sector organisations are submitting contributions; individual companies and public administrations can do so too.
Exposure diagnosis and a 2027-2045 roadmap. An inventory of discharge points, the technical distance from the new thresholds, identification of the investments needed and a prioritised sequence.
Integration of the water-energy pairing. Start designing investments with hydraulic compliance and energy neutrality in mind at the same time. Doing the works twice is not a profitable option.
At auma auma we support industries, public administrations and integrated water cycle operators through this transition: from water audits and regulatory exposure diagnosis through to technical planning integrated with the energy dimension. The new wastewater law is not just a regulatory update: it is the redesign of Spanish sanitation for the next twenty years.