Sewage: Investigation reveals water firms failing to admit how much sewage is being discharged

9 Aug 2023

EMBARGO: 00:01 Thursday 10th August

  • Thames Water refused to hand over data despite saying publicly they do measure the volume of sewage discharged

  • Scottish Water make public how much sewage is discharged into rivers and seas

  • England’s water firms accused of “scandalous cover up”

  • Liberal Democrats demand water firms measure how much sewage they are discharging into waterways

Water firms are failing to disclose how much sewage is being discharged into rivers, lakes and coastlines, Environmental Information Requests by the Liberal Democrats have revealed.

The staggering admission follows public outrage at water companies destroying the environment with sewage discharges. Currently, water firms only provide the length of sewage discharges, broken down by time. However, they refuse to publish the volume and litres of sewage discharged, essential information for understanding the environmental impacts.

The Liberal Democrats have accused England’s water firms of “a scandalous cover up” after the industry denies holding data on the volume of sewage discharged. 

Thames Water said they did not hold the volume data, however, the firm has previously made public that some of its monitors do measure volume. Last year it was reported Thames Water pumped over two billion litres of sewage into the Thames over a 48 hour period. This data was not given when Thames Water responded to the Environmental Information Request.

Meanwhile, Scottish Water does publish the volume of sewage discharged into waterways. Scottish Water’s sewage monitors revealed that 174 million m3 of sewage has been dumped into Scotland’s rivers, lakes and coastal waters since 2018, with 47 million m3in 2022. Unlike England and Wales just a small proportion of Scotland’s storm overflows have monitors installed.  

The Liberal Democrats believe the industry is either not telling the truth on holding the data, or it has installed inadequate sewage monitors. Previous analysis by the party has found one in six sewage monitors were broken last year. 

Liberal Democrat Environment spokesperson Tim Farron MP said:

“These water firms could be guilty of a scandalous cover up. 

“We have no idea how many billions of litres of sewage is being pumped into our precious rivers and lakes. The true extent of environmental damage caused by this scandal is completely unknown.

“We don’t even know how much sewage is being pumped into bathing areas and shellfish water. 

“Either these firms are withholding data from the public, which would be an extremely serious offence, or they just aren’t bothering to fit proper sewage monitors. 

“Ministers need to get tougher on these water firms by demanding they fit proper sewage monitors which are up to the job. The Government is letting water firms get away with faulty and flawed monitors.”



Full responses from water companies following Environmental Information Requests by the Liberal Democrats 

Analysis of faulty sewage monitors

Two billion litres of sewage dumped into River Thames in just two days, report finds





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