Both agricultural runoff and the release of untreated sewage are leading causes of river pollution in the UK. In 2021, untreated sewage was discharged into English waterways for more than 2.5 million hours.

The discharge of sewage has happened for several different reasons.

A lack of investment in dated infrastructure means the capacity of many sewage pipes is regularly exceeded. So, to avoid sewage backing up and flooding public spaces and people’s homes, water companies often release sewage elsewhere through the combined sewer overflow network.

The situation has not been helped by disruption to wastewater treatment chemical supplies following Brexit and the COVID-19 pandemic. The Environment Agency responded to these shortages by introducing temporary waivers in 2021, allowing water companies to temporarily release not-fully-treated effluents into the environment.

Raw sewage can affect human health and is a threat to wildlife. Not only does it contain harmful bacteria and viruses, sewage discharge floods rivers with nutrients that aid the development of algal blooms. These blooms prevent light from reaching deeper layers of water, so do not allow some plants to photosynthesise. They can even reduce the oxygen content of water, which worsens habitat quality.

Within Europe, the UK’s polluted waterways are largely an anomaly. Many other countries have reported significant improvements in bathing water quality in recent decades – indeed, bathing is now possible in some capital cities including Amsterdam, Berlin, Copenhagen and Vienna.

Between 1991 and 2019, the percentage of Europe’s bathing waters with “excellent” water quality increased from 53% to 85%. In several countries, including Austria, Greece and Malta, more than 95% of bathing sites are now classified as excellent.

So, what lessons can the UK learn from European countries that have cleaned up their act?

Continued…

For the full article by Dr Tanja Radu visit the Conversation.

ENDS