The Liberal Democrat MP for Kingston and Surbiton, Ed Davey, has hit out at the Government and water companies for "purposefully muddying" the truth regarding the scale of water pollution in Kingston.

New statistics from the Government reveal that in 2025, sewage was dumped into Hogsmill River by Thames Water for a total of 138 hours in 2025. 

However, the Liberal Democrats have warned that these figures - which only show the duration and number of spills - fail to convey the environmental damage being caused. 

Under current regulations, water firms are only required to monitor the number and duration of sewage spills, but not the volume of sewage discharged. 

Thus, the Liberal Democrats are calling "for water companies to be required to monitor and report the volume of sewage dumped to ensure water companies cannot get away with deliberately obscuring how much they are polluting our waterways with sewage".

Responding to the figures, the Lib Dem Leader said: "These shocking statistics are only the tip of the iceberg for the Royal Borough of Kingston.

"With the Government still failing to require water companies to measure the volume of spills, the truth is being purposefully muddied.

"It is impossible for the public to get a clear picture of the extent of the pollution in our local rivers and beaches.

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"You wouldn't go into a pub and ask for 'three and a half seconds of Guinness', so why are we measuring sewage spills in this way?"

He added: "The people of Kingston and Surbiton deserve to know the true extent of the damage.

"That's why I'm calling on the Government to end the Great Sewage Cover-up, and force Thames Water to record the volume of sewage spilling into our local waterways."

A Thames Water spokesperson told Nub News: "We are committed to reducing discharges to improve the health of the environment. Over the next five years, we are delivering the biggest upgrade to our wastewater network in 150 years, including increased treatment capacity, reduced storm discharges and new nutrient‑reduction schemes.

"The Event Duration Monitor returns that were released last week show discharge events were around three times lower than the previous year with shorter spill durations. Although this is in part due to reduced rainfall in 2025, we are encouraged that we are seeing early signs of progress from the operational and capital investment we have been making.

"Taking action to improve the health of rivers is a key focus and transparent data is central to that effort. Across the water industry, current monitoring equipment does not measure the volume of sewage released, except at a small number of sites where this is required by a permit.

"We do have volume monitors at Mogden, Didcot, and several large, combined sewer overflows in London to support engineering work for the Tideway Tunnel. Where volume data is available we publish it."