News Release issued by
the COI News Distribution Service on 07 September 2010
157/10 Environment
Secretary Caroline Spelman today gave her support to Thames
Water’s plans for a tunnel to reduce the amount of raw sewage
discharged into the River Thames.
The core of London’s sewage network was designed in the late 19
th Century and was designed to overflow at times of heavy
rainfall to ensure that sewage did not back up into houses and
streets. Combined Sewer Overflows (CSOs) were intended to
discharge the raw sewage into the Thames in the event of extremely
heavy rain.
Increasing populations and changes to land use in London have
lead to this occurring around 50 times per year. With further
population growth and projected climate change, this figure is
expected to increase in coming decades and spills could occur when
there is very little rain. This also creates problems for the UK’s
continued compliance with EU waste water treatment regulations.
On 22 March 2007, the then Minister for Climate Change and the
Environment announced his support for a tunnel based solution to
the problems in the Thames and asked Thames Water to take forward
the design process for the Thames Tideway Project. This included
the Lee Tunnel (a smaller tunnel on which construction work has
begun), upgrades to sewage treatment works and the larger Thames
Tunnel. In the intervening years Thames Water, the Environment
Agency and Ofwat have worked together researching and analysing
different options. Thames Water estimates that the proposed Tunnel
will cost £3.6bn which could result in bill increases of around
£60-65 per year for Thames Water customers.
Caroline Spelman said:
‘A tunnel continues to offer by far the most cost effective
solution to the unacceptable problem of raw sewage being regularly
discharged into the Thames. This is a large and complex project
and I recognise that it comes at a significant cost. I will ensure
that Defra and Ofwat continue to scrutinise the costs and options
to ensure that Thames Water’s proposals represent proper value for money.’
Thames Water will shortly launch a consultation exercise on the
need for the tunnel, the route and the sites needed to construct
and operate the project. Defra carried out an Impact Assessment in
2007 and will update this before publishing the revised version of
the document on the Defra website.
Notes to editors
1. A Written Ministerial Statement can be found on the Defra
website here:
ww2.defra.gov.uk/2010/09/07/tunnel-sewers/
2. Sewage collection and treatment in the UK is largely
determined by the requirements of the Urban Waste Water Treatment
Directive (91/271/EEC) transposed into domestic law by the Urban
Waste Water Treatment (England and Wales) Regulations 1994.
3. The controlled use of CSOs is a necessary part of combined
sewer systems that collect both rainwater and sewage. Without
them, sewer flooding of premises and roads and overloading of
sewage treatment works could occur following heavy rainfall.
4. Recent investigations have shown that around 39 million cubic
metres of storm water are discharged annually from the tideway
CSOs with six of those 57 CSOs discharging on a weekly basis (50 –
60 times annually).
5. Currently under construction is the Lee Tunnel which runs from
Abbey Mills pumping station to Beckton STW and will be completed
in 2014. The Lee Tunnel and Beckton STW upgrade will reduce the
total volume of discharges to the tideway by around two thirds.
The Thames Tunnel is expected to be completed in 2020.
6. A separate consultation on the route of the Thames Tunnel is
being carried out by Thames Water during September 2010.
7. Further information on the Tunnel can be found on the Defra
website at:
http://www.defra.gov.uk/environment/quality/water/waterquality/sewage/overflows/index.htm .
Contacts:
Defra Press Office
Phone: 020 7238 6600
NDS.DEFRA@coi.gsi.gov.uk
Sarah Saxton
Phone: 020 7238 5456
sarah.saxton@defra.gsi.gov.uk