Thames Water began a new water quality trial to safeguard drinking water supplies to millions of households and businesses across London yesterday, 14 October.

The UK's largest water company is now testing the tertiary treatment process that will be used as part of its nationally significant Teddington Direct River Abstraction (TDRA) project.  

Tertiary treatment provides an extra cleaning layer to wastewater during the sewage treatment process, ensuring that water can be safely recycled and transferred back into watercourses to help protect the natural environment.  

However, local campaign group, Save Our Lands and River (SOLAR) opposes this trial.

SOLAR member , Berni O'Dea told Teddington Nub News: "The proposed tertiary treatment plant for Mogden Sewage Works would only meet current standards, which do not include forever chemicals.

"If TDRA goes ahead, the River Thames at Teddington will be flushed with unsafe chemicals, a place where people swim, paddle, row in and walk alongside."

She continued: "Thames Water is admitting it won't meet the highest standards at the proposal stage. This underlines how badly thought out this scheme would be - a cheap, short term proposal with horrific implications for the thousands of riverside users.

"If Thames Water want to spend 5 years building TDRA for the sake of an intermittent drought resilience project, why not improve on the existing abstraction from the River Thames?

"Thames Water still won't share the data about how it concluded TDRA was the "best value option". For a company with the lowest possible credit rating, this already looks like an expensive white elephant."

Thames Water is proposing to use this technology to support its river abstraction and water recycling project in Hounslow, Richmond and Kingston. 

Thames Water forecasts a shortfall of 1 billion litres of water per day by 2050 and expects to supply an additional two million customers in London by that time, up from eight million to ten million. 

 Its TDRA project is designed to protect Greater London's drinking water supplies during periods of drought.

The project proposes to take water from the River Thames and transfer it along an existing pipeline to the Lee Valley Reservoirs, so it can be used for drinking water. 

 To replenish what is taken, and balance water levels and flows, highly treated recycled water would then be transferred via a new tunnel and pipeline from Mogden sewage treatment works, back into the River Thames, upstream from Teddington Weir. 

"If approved, the project will protect water supply for millions of Londoners," said Thames Water.

It is designed to deliver up to 75 million litres of water each day and would spare London's economy from the "catastrophic effects of a severe drought, which could cost as much as £500 million a day".  

 Once operational, the project will also provide immediate protection against the risk of drought ahead of a new reservoir being built for the region.