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A group of seven "coasteerers" swimming around a rocky section of a coastline, all wearing red helmets and yellow lifejackets
Coasteerers enjoying the water at Baggy Point National Trust headland in Croyde, North Devon, UK © Coasteering / Unsplash

Our wastewater infrastructure must improve to protect public health

News of contaminated waterways increasingly hits the headlines as more people take to the UK’s open water for recreation. Now, the National Engineering Policy Centre has published the first report looking at how to mitigate health risks posed to the public from human faecal pathogens. Professor David Butler FREng, chair of the report’s working group, sets out the role that engineering interventions can play in a much-needed upgrade of our wastewater infrastructure, alongside collaborative action with other stakeholders to bolster a robust and efficient wastewater system.

Our sewage system has long helped keep us safe from major diseases. It has been remarkably successful in interrupting the transmission of major epidemics and protecting the environment by treating wastewater before it is returned to our rivers and seas. But with ageing wastewater infrastructure, growing urbanisation, and the increased intensity and frequency of rainfall expected due to climate change, the strain on this system is mounting. At the same time, the popularity of activities such as swimming and boating in our rivers, lakes, and coastal areas has increased. These recreational activities can be great for mental and physical health and wellbeing, but also increase exposure of the public to sewage pollution.

Recent reports of people falling ill after spending time in our waters serve as a stark reminder of the public health risks associated with sewage pollution. Now more than ever we have greater public awareness of water pollution and greater availability of water quality data. All of which contributes to changing public expectations of water quality. 

Heightened awareness of pollution incidents in rivers and beaches, particularly from storm overflows, has resulted in calls for action. But storm overflows aren’t the only source of sewage pollution. Sewage passed through treatment works will have a substantially reduced concentration of faecal organisms, but this treated sewage can still contain harmful organisms, and is discharged into our waterways all year round. While we may not always find causal links to specific disease outbreaks, the public’s increased interaction with natural water sources highlights the urgent need to ensure they are clean and safe.

With ageing wastewater infrastructure, growing urbanisation, and the increased intensity and frequency of rainfall expected due to climate change, the strain on this system is mounting.

Professor David Butler FREng

In creating our latest National Engineering Policy Centre report, Testing the waters: Priorities for mitigating health risks from wastewater pollution, we consulted more than 100 engineers, wastewater experts, the water industry, campaign organisations, and policymakers. 

This is the first thorough assessment of interventions to reduce public health risks associated with the use of sewage contaminated public waters. We quickly learned that addressing these challenges requires a comprehensive approach that combines immediate actions to reduce public health risks with long-term transformational strategies to upgrade our sewage infrastructure for future generations.

We have identified three priorities. Firstly, water companies must prioritise maintenance and rehabilitation of our existing infrastructure to resolve some of the causes of overflows. Secondly, we need a much better understanding of the impact of faecal pollution on microbiological water quality and the associated public health risks, and ways to monitor it in real time. And thirdly, this evidence must inform bathing water regulations. 

Alongside these in the immediate term, investment in monitoring the flow through our wastewater system and modelling at a local level will deepen our understanding of infrastructure health and enable proactive management of the system. Encouraging sustainable drainage solutions and promoting better management of surface water are key steps to reducing overflows and contamination. We need more innovation and technology pilots in the water sector to develop treatments that effectively remove organisms, microplastics and metals that harm public health and ecology. 

Of course, engineering solutions alone cannot reduce risk to public health. Communicating risk effectively to the public through educational campaigns and community involvement will be essential for raising awareness and promoting responsible behaviour. Improved signage and information available at recreational sites will mean people can make informed decisions about whether they choose to swim or kayak that day. A comprehensive review of bathing water standards is also essential to ensure our assessments of water quality keep pace with our ever-evolving public health needs. 

Looking further ahead, there is real opportunity for transformative change. We need an ambitious vision for a future sewage system. One that preserves our environment, promotes societal wellbeing, and places public health at its heart. This vision must be supported by measurable targets to ensure accountability, track progress, and enable engineering and innovation to identify the ‘win-win’ solutions.

To deliver on this vision, we need a collaborative and collective effort by governments, the engineering industry, regulators, water companies, and the public. By embracing evidence-led, risk-based approaches and engaging stakeholders, we can set foundations that are essential to inform regulations, standards, and policies. 

It is a sad fact, but as more people make use of the UK’s wonderful rivers, lakes, and coastal waters, our ageing sewage system is increasingly unable to protect their health. Despite treatment, harmful organisms still contaminate our waters, but our report highlights what can be done. We’re not suggesting these solutions are deployed at all sites across the UK, instead a risk-based approach is required. This means local decisions about how to best protect the waters people want to use – and putting public health back at the centre of our sewage system. 


💧 Read Testing the waters: reducing health risks from water pollution and its recommendations in full


Professor David Butler FREng is Co-Director of the Centre for Water Systems and Professor of Water Engineering at the University of Exeter where he is an internationally leading researcher, teacher, manager, and consultant in the water sector.  He is a chartered civil engineer and a Fellow of the Royal Academy of Engineering, the Institution of Civil Engineers, the Chartered Institution of Water and Environmental Management, and the International Water Association.

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