By Rob Collins

The European Commission’s recent revision of the Urban Wastewater Treatment Directive [1] provides a roadmap for an innovative, resource-efficient and sustainable management of wastewater. Not only are the treatment requirements now extended to smaller plants serving smaller populations, but the producers of pharmaceuticals and cosmetics – one of the main sources of micropollutants in urban wastewater – will need to contribute to the costs of treatment in alignment with the ‘polluter pays’ principle. Moreover, targets for the use of energy from renewable sources and the promotion of reuse of treated wastewater, particularly in water stressed areas, are now included.

So, where does this leave wastewater treatment in the UK? Despite the intensive and long overdue attention on sewer overflows, a substantial proportion of the UK’s wastewater treatment plants still deploy no more than secondary treatment, whereby many pollutants are discharged to rivers and coasts in partially treated effluent. And implementation of the polluter pays principle here in the UK remains a very distant goal.

But the contrast with developments across the EU may soon also extend to acceptable levels of chemicals in the aquatic environment. The European Commission is proposing to extend the number of ‘Priority Substances’, i.e. those pollutants of greatest concern, from the current 45, to 70 and, moreover, is proposing stricter standards for several of them, including PFAS forever chemicals. Alarmingly, analysis of PFAS levels in English rivers [2], shows that at least 77% of them would fail these new standards, more than half of them by 5 times or more.

What is our government’s thinking here? After all, many of these chemicals are persistent, bioacccumulative and toxic, and their presence means that not a single English river meets good chemical status – a classification based on just a handful of the hundreds of chemicals that are found. They also raise implications for public health[3].

Unfortunately, the UK is also falling behind when it comes to tackling chemicals ‘at source’. For example, analysis by the Pesticide Action Network UK[4] has shown that, since Brexit, there are 36 pesticides that can still be used in the UK but which are no longer allowed in EU countries. Of those, thirteen are considered Highly Hazardous as defined by the United Nations. The European Commission has also been proactive in restricting the use of some PFAS chemicals[5] and developing a strategy to tackle endocrine disrupting chemicals[6] - whilst in the UK the Chemicals Strategy long-promised by the previous government has apparently been quietly shelved.

There is now plenty of clear evidence of a divergence between the UK and EU chemical regulatory regimes and worryingly, it would appear that the UK lacks the capacity, expertise and capability to keep pace with its EU counterparts[7]. Moreover, we certainly lack the resources to properly monitor and clean up chemical pollution[8].

Unless these challenges are urgently addressed, chemical contamination of our environment will continue to grow and require staggering sums of money to address.

Further reading

[1] Council confirms new wastewater directive • Water News Europe

[2] UK falling behind in the fight against toxic ‘forever chemical’ cocktail in our rivers

[3] Forever Chemicals found in bottled and tap water from around the world - University of Birmingham

[4] UK falling behind EU pesticide standards - Pesticide Action Network UK

[5] Commission restricts use of a sub-group of PFAS chemicals

[6] Overview - European Commission

[7] REACHing for divergence?—UK chemical regulation post‐Brexit - Jones - 2024 - Integrated Environmental Assessment and Management - Wiley Online Library

[8] Cost of dealing with PFAS problem sites ‘frightening’, says Environment Agency | PFAS | The Guardian

[9] Estimated scale of costs to remove PFAS from the environment at current emission rates - PubMed