What Is The Urban Wastewater Treatment Directive?

The Urban Wastewater Treatment Directive (UWWTD) is an EU piece of legislation that was formally adopted on May 21^st, 1991. It is concerned with protecting the environment from the potential negative impact of urban wastewater discharge, as well as the effluent of specific industrial sectors. In particular, it focuses on the collection, treatment and discharge of wastewater from domestic, industrial and mixed sources.

While compliance with the UWWTD has been more comprehensive in some member states than others, the UWWTD has been largely effective in achieving its aims of enhancing the health of both the natural world and the human populations which live in the vicinity of urban centres. This was confirmed by a 2019 evaluation of the UWWTD, conducted by the EU, which found that the Directive was fit for purpose, but that there was plenty of room for improvement in its scope and implementation in the modern world.

For that reason, the EU are planning to revise and update the UWWTD in the coming years. At present, there is a public consultation period which is open from the 28^{th of} April to the 21^st of July 2021. Over this 12-week period, the EU will gather insights, suggestions and concerns from citizens, technological companies, stakeholders and industry experts on the subject of urban wastewater. After the consultation period is closed, the EU will then assess and incorporate the comments made by respondents to the consultation and use them to inform their revision of the UWWTD.

What are the main principles of the UWWTD?

The Directive consists of four main principles, which are as follows:

• Planning
• Regulation
• Monitoring
• Information and reporting

In essence, this means that the UWWTD sets out clear guidelines for how member states are expected to approach the planning and construction of new utilities or infrastructure which could affect existing urban wastewater treatment systems. It also sets out how these systems should be regulated and monitored, well as the forms in which the data gathered should be handled and reported.

What does the UWWTD require from member states?

Concerned with minimising the impact of wastewater on urban populations and the surrounding environment, the Directive specifically requires that all agglomerations (or collections of peoples) of 2,000 individuals or more collect and treat their wastewater. It also covers the secondary treatment of wastewater in such areas and the advanced treatment of wastewater in agglomerations of 10,000 individuals or more. There are further provisions and requirements for designated sensitive areas and their catchments, as well.

In addition to requiring pre-authorisation of the discharge of wastewater produced from domestic, commercial and municipal sources, the UWWTD also encompasses that which is associated with certain industrial sectors. Namely, this concerns the food processing industry and other related sectors. Meanwhile, the Directive calls for the wastewater treatment facilities which handle the wastewater to be thoroughly and regularly monitored and for the data amassed thereby to be reported to the relevant authorities. Finally, the Directive specifies strict controls for the reuse of treated wastewater and sewage sludge disposal and reuse which must be followed by all member states.

How and when was the UWWTD most recently evaluated?

In December 2019, the UWWTD was subject to a comprehensive evaluation by the EU. The evaluation was conducted based upon the measurement of five different criteria, which were: effectiveness, efficiency, coherence, relevance and EU-added value.

Performance in each of these criteria was based on a list of 27 questions which were finalised in the evaluation roadmap. The roadmap itself was subject to a feedback mechanism, which discovered 12 issues with the planned evaluation and allowed the EU to amend their approach and define the five aforementioned criteria.

The data used in the evaluation was supplied by an extensive literature review encompassing peer-reviewed scientific studies, national studies, past and present European Commission studies, the databases of the European Environment Agency (EEA) and reports compiled by the Economic Consulting Associates (ECA).

How effective has the UWWTD been since its inception?

The evaluation found that the UWWTD has been effective in achieving its goals of cleaning up water sources and natural environments in EU member states. Specifically, the evaluation found that the UWWTD was instrumental in reducing the emissions of nitrogen and phosphorous into EU aquatic environments by 32% and 44%, respectively. That is significant, since these chemicals can upset the delicate balance of the ecosystems beneath the surface of the water, stimulating rapid growth of some organisms to the detriment of others.

The evaluation also found that while implementing the Directive is an expensive task – with that expense deterring or indeed preventing some member states from complying with it as comprehensively as others – the economic benefits of doing so far outweigh the costs. Those states which have struggled to implement the Directive have received support from the EU in the form of both financial funding and technical assistance. Since the UWWTD was first adopted in 1991, €38.8 billion of funding has been diverted to the wastewater sector throughout the bloc.

Aside from the environmental advantages that the UWWTD has bestowed on those member states which have followed it faithfully, its introduction has also helped to position the EU as a global leader on the issue. As proof, eight of the 15 biggest water companies anywhere in the world are found in Europe.

Are there any areas where the UWWTD could be improved?

Despite acknowledging the progress that the UWWTD has facilitated, the evaluation also uncovered several areas where it must be updated and improved. As a Directive which is now over 30 years old, it was devised and introduced at a time when emerging contaminants such as pharmaceuticals and microplastics were not a concern and as such, requires revision to take into consideration the threat they pose.

Other areas of concern which the evaluation concluded could be improved by a revised version of the UWWTD include:

• Storm water overflows and urban run-off. With climate change increasing the intensity and frequency of extreme weather events, it’s likely that storms are likely to become a more common occurrence. As a consequence, flooding and run-off is expected to become an increasingly pressing issue, which an updated UWWTD must address.
• Individual or other appropriate systems (such as septic tanks). Although septic tanks comprise a small percentage of waste disposal systems in the EU, they were not legislated for in the UWWTD at all. As such, they must be incorporated into any future version of the Directive.
• Small agglomerations. The original version of the UWWTD focused exclusively on agglomerations of 2,000 residents or more. Despite this, 11% of water bodies throughout the EU experience significant pressure from agglomerations smaller than this size or dwellings that are completely isolated altogether.
• Updated monitoring and reporting requirements. The UWWTD in its current format is lacking in its focus on the novel methods for monitoring wastewater from the wastewater network and across the sewage treatment plant to aid optimisation that a modern environment demands. It must be updated to incorporate the latest standards, techniques and technologies.

There is also a desire among EU officials to bring urban wastewater treatment plants (UTTWPs) more closely into alignment with other relevant Directives, Plans and Deals. For example, the Circular Economy Action Plan, the Green Deal and the Zero Pollution Action Plan all contain ambitious targets which concern urban wastewater and both the UTTWD and the UTTWPs which it regulates should be brought into the fold to ensure the objectives are attained.

When will the revision of the UWWTD take place?

The revision of the UWWTD is already in progress and is expected to be finalised in the coming months and years. At present, the UWWTD is subject to a public consultation period which began on the 28^th of April and will run for 12 weeks until the 21^st of July 2021. During this window, industry experts, commercial stakeholders, environmental groups and members of the general public are invited to give their feedback on the issue in the form of an online survey.

The survey is comprised of five distinct parts: the first will focus on personal questions which help to categorise the respondent by their demographics, while the second asks them to voice their opinions on the topic of urban wastewater in general and their experiences on how it has impacted the environment. The third gives a series of different options for addressing the issue and invites insight into the merits and drawbacks for these proposed measures. The fourth, which is reserved exclusively for those with a more in-depth technical knowledge of the issue, asks more complicated questions about the UWWTD and the proposals in the fourth part, while the fifth asks respondents to share any concluding remarks or other information not covered in the preceding sections.

How can I become involved in the proposed revision of the UWWTD?

The public consultation is open to everyone and with the exception of the fourth section, does not require intimate knowledge of any of the issues or the infrastructure behind them. If you would like to make your voice heard and influence the future of the UWWTD, you can visit the European Commission website and follow the relevant links to complete the survey. Your opinion matters! Make sure you share it with the EU.