Urban wastewater: Short-term pain for long-term gain?

Why do we need a revised urban wastewater treatment directive?

First, introduced in 1991, the directive has ensured that towns and cities in member states ‘properly collect and treat wastewater cost-effectively’. And while the quality of European rivers, lakes, and seas has improved since the legislation was first introduced, we have become more aware of other harmful pollutants in wastewater that need to be removed before they re-enter the water system.

When you think of the PFAS chemical family and the science that has emerged in recent years regarding the danger these pose to human health, you can see why the existing directive needed to be revisited. What PFAS has shown is that emerging pollutants, including pharmaceuticals, require additional treatment stages and mechanisms, and these are not cheap.

As the European Commission puts it, wastewater is ‘often contaminated with bacteria, viruses, harmful chemicals, including micropollutants and an overload of nutrients which, when discharged, affect our health and damage our rivers, lakes, and coastal water’.

The revised directive can be seen as an attempt to respond to that reality.

What does the revised directive aim to achieve?

Essentially, the directive protects human health and the environment from the effects of untreated urban wastewater. It requires EU countries to ensure that towns and cities properly collect and treat wastewater cost-effectively. Building on the original legislation, the revised directive aims to:

• Improve water quality through stricter water treatment and the inclusion of new pollutants
• Strengthen the EU’s polluter-pays principle by ensuring that those responsible for pollution bear the costs of remediating it
• Advance circularity through water reuse and the recovery of valuable resources from wastewater
• Address climate change through greenhouse gas (GHG) emission reduction of treatment plants and urban adaptation to heavy rainfall
• Ensure access to sanitation for all, particularly the most vulnerable and marginalised.

To do this, the directive makes it a legal requirement that EU member states:

• Collect and treat wastewater in all urban areas of more than 1,000 inhabitants
• Remove more nutrients that otherwise cause harmful eutrophication with tertiary treatment
• Remove micropollutants with quaternary treatment, financed through extended producer responsibility by the sectors responsible for the pollution
• Make treatment plants energy-neutral and reduce their greenhouse gas emissions by 2045
• Monitor wastewater for health parameters, such as SARS-Covid and antimicrobial resistance.

Re-framing urban wastewater treatment

Is it possible to see the revised directive as not just a piece of updated legislation but a complete re-framing of urban wastewater treatment in Europe?

If you look at the aims above, several themes emerge:

• Quaternary treatment must be used to remove trace chemicals
• Polluters will finance the fourth-stage treatment
• Treatment plants must embrace renewable energy.

Quaternary treatment and chemical removal

With the requirement for a fourth treatment stage, designed to capture trace chemicals that might pass through the traditional treatment stages, the revised legislation confirms that wastewater treatment is no longer just about biological controls.

From 2027, urban wastewater treatment is all about complete pollutant removal, including trace chemicals, such as PFAS and pharmaceuticals. And while this has long been a goal for many wastewater treatment plants, it is now law and introduces the requirement of a quaternary treatment phase.

Primary through to tertiary treatment systems were not designed to capture and remove the pollutants – for example, pharmaceuticals and cosmetics – that now form part of the legislation. Introducing a fourth treatment stage incurs not only equipment costs, but could also change process design expectations. Then there are the additional costs, often overlooked in these discussions, such as staff training and any maintenance that needs to be factored in throughout the year.

However, this fourth stage will only apply to large wastewater treatment plants – 150,000 person equivalent (PE) or above – with phased deadlines:

• 31 December 2033 for discharges from 20 % of these urban wastewater treatment plants
• 31 December 2039 for discharges from 60 % of these urban wastewater treatment plants
• 31 December 2045 for discharges from all these urban wastewater treatment plants.

Decisions will need to be made about which technologies to introduce; much will depend on the pollutant mix present in the local wastewater. Monitoring systems may also need to be upgraded to ensure compliance with the new regulations. Any upgrades will need to be carried out while the plants operate at normal capacity.

‘Polluter pays’ principle becomes law

To finance the additional costs of a fourth treatment stage, the rUWWTD introduces Extended Producer Responsibility (EPR) into law. Under EPR, pharmaceutical and cosmetics producers are required to contribute to the cost of micropollutant removal. This could be as much as 80 per cent of the cost.

EU policy documents highlight that the major source of toxic micro-pollutants detected in wastewater discharges originates from the pharmaceutical and cosmetics industries. Until now, the cost of monitoring and removing them has fallen on utilities, public funding and household bills.

The message here is clear: regulatory focus has shifted upstream, and the industries that produce pollutants effectively become part of the system. From now on, the polluter will pay towards the cost of utilities removing harmful chemicals from water before it returns to the environment. This shift in funding removes the burden of utility customers paying to remove industrial pollution, and shifts wastewater treatment financing to a hybrid model combining public and private contributions.

Pushback on the polluter pays principle

It may come as no surprise that the pharmaceutical and cosmetic industries have not been overly supportive of EPR.

Back in 2024, the European Federation of Pharmaceuticals Industry Association (EFPIA) and the Association of the European Self-Care Industry (AESGP), representing the human pharmaceutical industry in Europe, issued a joint statement, in which they stated:

“While the associations support the overall objectives of the UWWTD and are fully committed to contributing to its effective, efficient and manageable implementation, we are extremely concerned of its negative impact on patient access to medicines and the global competitiveness of our sectors.”

“We strongly believe that the directive fails to comply fully to the EU principles of proportionality, non-discrimination and polluter-paying. The arbitrary decision to pick only two sectors, human pharmaceuticals and cosmetics, to pay for the pollution caused by others fails to incentivise greener product development of all polluters, undermining the European Green Deal.”

It went on to suggest that all industries that produce micro-pollutants should be included in the legislation and asked that the EU consider whether it aligns with its commitment to competitiveness. 

We remain open to collaborating with the pharmaceutical and cosmetics sectors to achieve an effective and efficient EPR system - EurEau

Nathalie Moll, director general, EFPIA, reiterated the point: “The pharmaceutical industry is 100 per cent behind the aims of the directive to reduce water pollution. How Europe decides to do this should be proportionate and fair. Questions remain regarding the legitimacy of a decision which sees just two sectors carrying the financial responsibility for cleaning of the entirety of societal micropollution.”

Medicines for Europe has questioned the validity of the data used to calculate the contribution of pharmaceuticals to the toxic load in urban wastewater. It suggests the figures used were inaccurate, resulting in an overestimation. It also suggests that the EPR fee could result in the production of some medicines becoming economically unfeasible, directly affecting patients and consumers.

Lawsuits filed by pharmaceutical and cosmetics companies and associations were dismissed as inadmissible by the European Court of Justice (ECJ) in February 2026, paving the way for member states to pass the legislation into national law by 2027.

While this ruling has not appeased those industries – Cosmetics Europe stated that it ‘leaves the fundamental questions regarding the legality and fairness of the Urban Wastewater Treatment Directive’s (UWWTD) Extended Producer Responsibility (EPR) scheme unanswered’ – the water sector has welcomed the ECJ’s judgement.

For example, EurEau welcomed the decision and stated that: ‘It’s now time to focus on the implementation of the recast UWWTD, particularly on the EPR. We remain open to collaborating with the pharmaceutical and cosmetics sectors, as well as with other relevant stakeholders, to achieve an effective and efficient EPR system.’

It remains to be seen whether there will be more legal challenges from other entities, but for now, EPR, as part of the rUWWTD, looks set to become enshrined in member state law from 2027.

High-energy treatment versus energy neutrality

Quaternary treatment presents a tension at the heart of the revised directive. Potentially, it introduces an energy-intensive treatment stage at a time when treatment plants are legally required to become energy neutral by 2045. Overcoming these differences will test technical and operational resilience.

Member states will face the challenge of implementing two legal requirements that seem at direct odds with one another. In the mid- to long-term, this could accelerate the move to renewable energy systems and greater resource recovery operations. In the short term, it becomes an engineering challenge that needs to be met.

For old plants, energy neutrality and quaternary treatment present very real challenges, albeit ones that will benefit from EPR payments. For treatment plants yet to be built, the rUWWTD presents a set of guidelines for the wastewater systems of the future: ones that balance water quality, chemical removal, carbon reduction, energy neutrality, and resource recovery in the same footprint.

Energy audits of larger urban wastewater treatment plants and collecting systems must be carried out every four years under the directive, which sets a national energy neutrality target for plants of 10,000 PE and above to produce energy from renewable sources by 2045. This renewable energy can be produced on- or off-site, and up to 35 per cent (of the final target) of non-fossil energy can be purchased from external sources under certain conditions.

What else does the rUWWTD introduce?

EPR and quaternary treatment may have stolen the headlines, but the revised directive introduces several other changes:

Collecting systems

By 31 December 2035, EU member states are required to collect and treat wastewater from agglomeration above 1,000 PE – this figure was previously set at 2,000 PE, thus bringing more wastewater into regulation.

All agglomerations of 2,000 PE or above must be equipped with collecting systems, and all domestic wastewater sources must be connected to these systems.

Integrated urban wastewater management plans are required for agglomerations of 100,000 PE or above by 2033, with a deadline of 2039 for agglomerations at risk with a PE of between 10,000 and 100,000.

Secondary treatment (removing biodegradable organic matter)

By 2035, for agglomerations of 1,000 PE and above, a secondary treatment must be applied before it is discharged into the environment.

Derogations are included for Member States where the coverage of the collecting systems is very low and, therefore, would require additional time to deliver the significant investment required.

Tertiary treatment (removing the nutrients nitrogen and phosphorus)

There will be stricter removal levels for nitrogen and phosphorus:

• Tertiary treatment must be applied in 30 per cent of treatment plants for agglomerations of 150,000 PE or above by the end of 2033, and in 70 per cent of these treatment plants by the end of 2036.
• By 2039, tertiary treatment must be applied in all treatment plants for agglomerations of 150,000 PE and above.
• All treatment plants in agglomerations of 10,000 PE or more should be covered from 2045, with intermediate targets set for 2033, 2036 and 2039.

Water reuse

Although member states are not being directed to ensure treated wastewater is reused, the rUWWTD directs that it is promoted ‘for all purposes and especially in water-stressed areas, while ensuring it does not impact human health or the environment’. This complements the Water Reuse Regulation, with the aim that the two measures combined can reduce freshwater abstractions.

Monitoring wastewater

The directive requires Member States to develop a list of parameters relevant to public health in the monitoring of urban wastewater, which could include SARS-CoV-2 and its variants, poliovirus or influenza virus.

Access to sanitation

Member States must take measures by 2029 to improve access to sanitation for all, and in particular for vulnerable and marginalised people. This complements requirements in the recast Drinking Water Directive for access to water.