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Sewage… what’s the problem?

3 May 2024

4 mins

Credit for this blog content: ‘Barbour Consolidated legislative update services’

Not the most fun topic but an important one…this article is about the impact sewage is having on waterways in the UK.

According to the Environment Agency, there were 3.6 million hours of sewage spills in 2023 compared to 1.75 million hours in 2022. On average, in 2023 there were 1,271 spills a day across England, compared to 825 a day in 2022… this is difficult to put into context, but the fact that the spills have more than doubled in just one year is enough to cause concern. But what caused this and what has this got to do with climate change?

These record levels are due to heavy rain – this is one of the extreme weather impacts caused by climate change. You can read more about the predicted rainfall patterns on the Met Office website .

The industry body for sewage companies, Water UK, have described the levels of sewage spills as ‘unacceptable’. Environmentalists say that, although these spills are not ‘illegal’ as such, they should only happen in ‘exceptional weather’. The Environment Agency commented: “It is important to note that heavy rainfall does not affect water companies’ responsibility to manage storm overflows in line with legal requirements”.

Source: Greenpeace

Why is this happening?

  • The way the UK sewage system works is that rain and sewage share the same pipes.
  • If there is too much rain, sewage treatment works can become overwhelmed.
  • Sewage is spilled into waterways to prevent the system backing up.

Why is the sewage a problem?

  • The spills include human waste, wet wipes, and sanitary products.
  • These can pose a serious risk to local wildlife, as well as swimmers and others who use the UK waterways.
  • This can also cause blockages of the sewage system, which can lead to further spills.
  • Although rain can help to dilute the sewage, academics warn that there is still a risk to the local environment and anyone swimming in these bodies of water.

Dr Dania Albini, Research Fellow in Biosciences at University of Exeter, said: “Sewage pollution in the UK severely impacts waterways, with not a single river in England rated as healthy according to the latest Rivers Trust Rivers report”.

How is sewage affecting living organisms?

Albini went on to explain that sewage being present in rivers can reduce the oxygen levels in the water, which harms aquatic life. This also “causes sickness [in humans] due to the presence of harmful microorganisms and parasites”.

The data…

  • Recent data revealed by the Environment Agency was taken from monitoring stations installed at combined sewer overflows (CSOs).
  • CSOs were developed as overflow valves – these reduce the risk of sewage backing up into people’s homes during heavy rainfall when sewer pipes become overloaded.

The dilemma…

  • Due to higher rainfall in 2023 (20% above average), the overall number of spills was expected to be higher.
  • In 2023, all 14,580 CSOs were fitted with monitors, compared to 2019 when only 57% were fitted with monitors, meaning only half of spills were recorded.

James Wallace, CEO of charity River Action, told BBC News: “Water companies are not being made to invest in fixing their leaky pipes – as long as we have an Environment Agency and Ofwat that are incapable of doing their jobs then we are not in a position to expect water companies to behave”.Ofwat and the Environment Agency are conducting separate investigations into England’s nine sewerage companies; the outcome of these is expected this year (2024). However, these two agencies are also under investigation by the independent Office for Environmental Protection who are concerned they have interpreted the law incorrectly on sewage discharging, by allowing spills whenever it rains rather than only when there is “exceptional” rainfall.

So, we will see what happens over the upcoming year. The best thing you can do is stay informed, and take action to reduce your impact on the environment.

If you would like to read more about this subject, please visit the below link: Event Duration Monitoring, Storm Overflows: Annual Returns.

This article is in support of United Nations Sustainable Development Goal 14: Life Below Water. To read more click here.

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