Water firms committing “environmental cover up” as one in seven sewage monitors are faulty

2 Apr 2024

EMBARGO: Immediate Release

  • 15% of sewage monitors found to be faulty meaning one in seven of all monitors don’t work properly 

  • A disgraceful one-fifth of beleaguered firm Thames Water’s sewage monitors are faulty - the worst firm.

  • It means the scale of the sewage scandal could be far higher than originally feared

  • Lib Dems have accused water companies of what amounts to an “environmental cover up” by failing to fix monitors and have called for a national environmental emergency to be declared

Analysis by the Liberal Democrats has found that one in seven of all sewage monitors have been found to be faulty as the party accuses water companies of an “environmental cover up” and calls for a national environmental emergency to be declared.

The number and length of sewage dumps from storm overflows is measured by Event Duration Monitors (EDMs). However, the LibDem analysis has revealed that water companies have installed monitors which do not work for at least 90% of the time, or have not even installed monitors at all.

Across England, there are 2,221 monitors not operating properly. The water company with the worst record on faulty sewage monitors was Thames Water which saw a staggering 20% of its sewage monitors not working properly. The next highest were Southern Water and Yorkshire Water which both recorded 18.5% of their monitors as faulty.

Some monitors have now been broken for two years. In Brancepeth, County Durham, Northumbrian Water’s sewage monitor has been recorded as broken for both years, for apparent issues with an “installation set-up/design issue”. It worked 0% of the time for the past two years. Meanwhile, Southern Water’s monitor for The Solent operated just 30% of the time last year despite being broken the previous year.

The Liberal Democrats are calling for a national environmental emergency to be declared to save ecosystems at risk of collapse and protect our rivers and beaches from filthy sewage dumping.

Liberal Democrat Environment spokesperson, Tim Farron MP said:

“Water companies could be complicit in an environmental cover up. Why on earth would a firm install these monitors if they don’t even work?

“The scale of the sewage scandal could be even larger than originally feared and Conservative Ministers are not interested in understanding the true extent of the damage our rivers and beaches are being put through.  

“They have let water companies off the hook at every turn and are now letting them get away with not even monitoring the amount of filthy sewage that is being dumped. 

“This scandal requires a national environmental emergency to be declared and for this Conservative government to start treating this issue with the focus that it needs. Their inaction has failed our environment and failed communities across the country, now worried about what damage has been done to their waterways.”


Notes to Editors:

First reported by the Times.

Link to Liberal Democrat analysis of Environment Agency sewage discharge data - 2021 and 2022 - Faulty sewage monitors here

Original source is based on 2022 and 2021 data provided by the water companies to the Environment Agency. This reveals the length of sewage discharges, as well as the number of “Event Duration Monitors” which were found to be faulty. 


Water companies have to report the percentage of operating time of the monitors on storm overflows and then if it’s operating less than 90% of the time they have to provide a reason why it is happening and a timeframe for fixing it.




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