Thames Water response to the Tidal Pollution incident

Following the Tidal Thames Pollution incident, the Thames Anglers Conservancy have received a letter from Richard Aylard of Thames Water. 
This pollution incident highlights the absolute need for the Tideway Tunnel to be built without delay.
With our climate changing and periods of drought followed by storms, further major incidents will happen causing more damage to our river systems. With the additional growing threat of Hydropower affecting our weirs, the future is very bleak.
A Roach gasping for air after the Pollution
 Letter from Richard Aylard, 7th June 2011
I wanted to give you a bit of background to the major discharges of storm sewage to the tidal River Thames over the weekend and into Monday morning, following heavy rainfall, which I know will have appalled your members and every other angler who cares about the Thames.
The discharges, which we very much regret, clearly led to a significant fish kill and other environmental damage (which is still being assessed). Unfortunately, and although it sounds like a complete cop-out, we had no alternative to making these discharges, which are legal and consented, as this is the way the system was designed in the 1850s, in order to prevent sewage overflowing back up into streets and homes. The problems caused are always particularly bad after a long dry period when the solid matter that has built up in our pipes over several months is discharged into the river by heavy rain. Low flows in the river and the fact that the discharges commenced at around low tide, meaning that the pollution was initially carried upstream, and then down again when the tide turned, added to the severity of the situation.
Incidents like this are clearly totally unsatisfactory in a modern capital city and I know you are aware that we have a major programme of work under way to sort the problem out. In the west London area this includes a 50% increase in treatment capacity at our Mogden sewage treatment works (which you have seen) and the proposed Thames Tunnel.
On this occasion, Mogden STW had to discharge around 200,000 tonnes of screened and settled (but otherwise untreated) sewage once its storm tanks were full to capacity. I do need to assure you that once the extension is completed in March 2013 the works will be able to handle a similar situation without even using its storm tanks, let alone discharging to the river.
The Thames Tunnel is desperately needed to address all the unsatisfactory combined sewer overflows (CSOs) to the river, including Hammersmith, Western and Lots Road Pumping Stations, which between them had to discharge more than 250,000 tonnes on this occasion.
Since the event we have been working with the Environment Agency, using aeration and skimmer vessels and dosing with hydrogen peroxide, to increase oxygen levels in the river and remove debris.
Please let me know if you would like any further information or would like to see the Environment Agency's press release.
Kindest regards
The Thames Anglers Conservancy is a free to join organization and is a consultative member of the Angling Trust for Thames between Staines and Dartford.
As a Thames Angling stakeholder, we are involved with many organizations including the Environment Agency, river user groups and local councils.
We are concerned with many aspects of the Thames including the threat of Hydropower, loss of fishing rights and pollution along with the positive aspects of promoting angling and its benefits.
For more information go to or email
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