“We welcome today’s (27/02/23) announcement made by Thames Water that it will be investing £1.6 billion in the next two years on upgrading its sewage treatment works and sewers in a bid to reduce river pollution. We have been calling on Thames Water to boost its investment in sewage treatment works and sewers to help improve our water quality and our waterways for people and for wildlife for many years, so this is very positive step forward.
“This investment will help to reduce storm overflows*. The news that Thames Water is improving its capacity at its sewage sites and reducing discharges is welcome.
“However, tackling storm water overflows are only one aspect of the pollution problem caused by Thames Water’s assets (infrastructure) and in many of our catchments, storm water overflows are not the main problem contributing to poor water quality. Pollution issues arising from sewer asset failures – for example crumbling concrete and leaks that result in cross over between the foul and the rainwater sewer networks – are far more persistent and likely to cause more impact to water quality in rivers than occasional storm overflow discharges. They therefore need to be urgently addressed.
“Pollution at outfalls may be labelled as misconnected plumbing (in which household wastewater ends up in the surface drainage system rather than the foul sewers), however more evidence is needed to discount the premise that a high proportion of pollution in some areas is a consequence of problems associated with aging infrastructure, rather than misconnected plumbing. Sewer asset failures are complex and often require extensive investigation to find and resolve and this is something that Thames Water currently has very little data on and must invest in documenting and fixing.
“We welcome the news that Thames Water will invest in its assets. However, we urgently need clarification on how it will go about fixing its aging infrastructure. This issue needs to be focused on urgently in order improve the health of our rivers and protect our wildlife. The clock is ticking on the health of our waterways and we need Thames Water to act speedily on this issue.”
*The UK’s sewage system relies on a system called combined overflows in which rainwater and sewage drains through the same pipes. When the sewers are overwhelmed, such as in heavy rain, they discharge the excess into rivers to prevent the network from backing up.