A viewpoint from Veronica Edmonds-Brown, Senior Lecturer in Aquatic Ecology, University of Hertfordshire. An extract from a piece first published in The Conversation:

As a child swimming off the coast of south Devon in the 1960s, I believed the warm water passing through my legs was the Gulf Stream current. Now, as an adult, I realise it was actually raw sewage being discharged into the ocean.

In those days, it was not unusual for coastal towns to pump sewage out to sea where it was believed to be safely diluted. These pollution problems are now resurfacing because of poor management rather than ignorance six decades on.

Victorian infrastructure and dwindling investment

The UK’s wastewater network comprises both sewage and surface water pipes. Homes flush sewage to treatment works, where solids, bacteria and other contaminants are removed. The treated water is then discharged to rivers or the sea.

Sewage and surface water occupy separate systems, but the pipe network is interconnected and combined in parts, the idea being that during heavy rain, the surface water will flow into sewage pipes and dilute it. Today, the opposite is often likely to happen, and it’s partly due to the country’s ancient and overburdened system for managing wastewater.

The network was designed by Joseph Bazalgette. Construction began in 1858 and was completed in the mid-1870s. There has been little investment to update the pipes or expand the treatment facilities in the intervening 150 years.

The UK has a sewage system built to serve half the population it must cope with today. Every new development, from small groups of houses to entire estates, increases the burden of sewage and expands the area covered by concrete and tarmac, which can add between 8% and 18% of additional surface water – the main reason for London’s flash floods in July 2021.

To begin tackling these problems would require policy reform in the water industry and beyond. But legislation in recent years has only made the problem worse.

Privatisation and feeble fines

England is the only country with a completely privatised water industry. Any pollution arising from these private water companies is monitored by the Environment Agency.

Routine monitoring of rivers and coastal waters is essential to ensure they’re in good condition. Because of funding cuts since 2010, water sampling by the Environment Agency halved between 2013 and 2019. The agency also lost its independence that year when it was absorbed into the Department for Environment, Farming and Rural Affairs.

Water companies may need to be forced to invest in infrastructure if fines are not proving sufficient motivation. Failing that, revoking licences may become the government’s only way forward.

Liz Truss has many challenges ahead. The cost of making the UK’s sewage and surface water network fit for purpose has been estimated at a minimum of £150 billion, and perhaps as much as £500 billion.

This may be too much for water companies to absorb. Nevertheless, something as fundamental as sewage treatment and drainage infrastructure should be a national priority, and high on the to-do list of the new prime minister.

The full piece in The Conversation can be read here.