FOLLOWING the threat of legal proceedings against Thames Water, many residents living around the Mogden Sewage Treatment Works recently received leaflets explaining the company's proposals to improve the plant.
I draw your attention to the first line of the text. 'Much of the waste water treated at Mogden is made up of rainwater'.
This 'rainwater' is in fact foul sewage diluted by stormwater in combined (foul plus rainwater) sewers.
The failure of Thames Water to prevent odour nuisance to local residents and polluted rainwater discharging into the Thames from Mogden is not solely due to poor design of the works.
It has mainly resulted from their continuing failure to separate foul sewage completely from rainwater in their sewer network system.
I should point out that the original 'sin' of installing combined sewers was not Thames Water's. However, they are guilty of not replacing all the existing combined sewers with new foul sewers for foul sewage and stormwater sewers for unpolluted rainwater in their area, even though many of the combined sewers are more than 100 years old.
It is a sad fact that if Mogden was onlyobliged to treat foul sewage and not polluted stormwater, it would cover less than one tenth of the existing site and there would be no smell.
Treatment costs would, of course, be consider-ably less.
Also, in respect of foul sewage, if industrial effluent was discharged and treated separately at Mogden, domestic sewage could be processed safely into useful fertiliser, as already happens in many parts of the world and some parts of the UK.
MIKE LOVELACE Ex-drainage engineer, Rydal Gardens, Hounslow.