Plans to make the River Thames swimmable have sparked confusion after London Mayor Sadiq Khan announced a 10-year strategy to clean up the river.

The initiative aims to reduce pollution and promote safe public swimming in areas such as Teddington in southwest London. However, a recent decision by the environment secretary, Steve Reed, has cast doubt on the success of these plans.

Reed’s approval of a controversial water recycling scheme by Thames Water is raising concerns, especially as it involves discharging treated sewage into the very spot targeted for cleanup.

Thames Water’s proposal would allow 75 million liters of treated sewage to be pumped into the Thames daily at Teddington, a plan intended to manage water shortages during droughts.

This decision has alarmed environmental activists, swimmers, and local politicians, who argue that the project conflicts with efforts to restore the river’s ecosystem and make it safe for swimming.

Conflicting Priorities

Environmental campaigners are particularly worried about the effects of pumping treated sewage into the river, which could lead to increased water temperatures, alterations in salinity, and harmful consequences for fish and other wildlife.

They argue that these changes could be detrimental to biodiversity and the overall health of the river system. Despite these concerns, Reed gave the green light to the plan, which aims to replace the river water abstracted for drinking purposes during droughts with treated sewage.

Marlene Lawrence, a member of the Teddington Bluetits, a local wild swimming group, expressed her disappointment.

“I welcome Sadiq Khan’s plans to make more wild swim spots safe for public use. However, I cannot see how Thames Water’s planned abstraction plan can be approved when it involves them pumping treated effluent full of chemicals back into the river to replace river water taken out in times of drought.”
Marlene Lawrence

Lawrence added that the river upstream of Teddington Lock is a popular spot for swimmers, kayakers, and families, making the decision to approve the treated sewage project even more perplexing. “The river would not be safe to swim in, and there could be devastating effects on river life,” she said.

Concerns Over Water Quality

Local MP for Twickenham, Munira Wilson, who has campaigned against the Thames Water project, shared similar concerns.

While she supports efforts to clean up the river, she questioned the mixed messaging from authorities. “I’m pleased to hear that Teddington has been identified as a priority area for cleanup because of high pollution levels, but I’m also surprised by the mixed messages,” she said.

“Concerns about water quality are exactly why I and local campaigners are fighting Thames Water’s proposals to pump treated effluent into the river at Teddington. Yet the environment secretary recently gave the green light to the water resources management plan, which includes these proposals. Which is it? Teddington residents want answers from a minister who has promised to protect our precious river.”
Munira Wilson

Despite this pushback, Thames Water’s £250 million scheme is moving forward. In addition to the Teddington project, the plan includes a new reservoir in Oxfordshire as part of the company’s long-term water resource management efforts.

Potential Environmental Impact

Environmentalists are particularly concerned about the presence of so-called forever chemicals, such as per- and polyfluoroalkyl substances (PFAS), in the treated sewage set to be pumped into the river.

These chemicals, which do not break down easily, could pose long-term risks to water quality and the health of river ecosystems.

The controversy surrounding Thames Water’s scheme is not new. In 2019, the Environment Agency rejected a similar proposal due to the projected environmental impact of releasing millions of liters of treated sewage into the river.

However, with water shortages looming, authorities now seem more inclined to consider drastic measures, despite the potential ecological costs.

As the debate continues, residents and environmental groups are left questioning whether the River Thames can ever be both a clean, safe space for swimmers and a reliable source of drinking water during times of drought.