Every time it rains in London, the Victorian sewers which contain both sewage and rainwater overflow. In some areas such as at Hammersmimth this can be as little as 2mm of rain. The 19th century system was designed to overflow into the River Thames so that peoples homes and streets are not flooded with untreated sewage. The system does it through Combined Sewage Overflows (CSOs) discharging into the river.
As recreational users of the tidal Thames we are very aware of the pollution; 39 million tonnes of untreated sewage overflowing in an average year! Some of the CSOs discharge sewage into the River Thames on average more than once per week and and after as little as 2mm of rainwater. One of the worst locations is near Chelsea Bridge where 12 metric tonnes of water per second flow into the Thames at peak rainfall. Lovely!
The volume and frequency of untreated sewage overflowing is clearly unacceptable, and also contravenes EC Treatment of Urban Wastewater, which if not fixed will make Thames Water and us the taxpayers liable.
Naturally as paddlers and regular users of the Thames we would prefer to live near and paddle on a river with clean water. So we support the scheme, though not necessarily the Barnes Elms green field site when other brown field sites are available and unused.
Thames Water's solution is a project to upgrade the sewerage system with a tunnel that will run 20miles from Hammersmith to Beckton Sewage Treatment Works in east London. In doing so it will transfer the flows from 34 of the most polluting CSOs.
The route of the tunnel is to follow the River Thames so that it can connect all the sewer outflows along the riverbanks.
The timetable is normally for the project to start in 2013 in order to meet the 2020 target completion date set by the government and the European Union.
Thursday 9th December 2010
Greg Hands (Chelsea and Fulham) (Con): The Secretary of State knows that the Thames tideway tunnel scheme has already seen its costs double from £1.8 billion to £3.6 billion, and that it will cause massive construction disruption along the Thames and add £40 per annum to Thames Water customers’ water bills. Can the Minister assure me that the Government have tried to find the best value-for-money solution to sewage discharge in the Thames?
Residents Site. One of their major concerns is pollution caused by building the Tunnel, but interestingly not that which floats past in the Thames everyday.