Should the Thames Tideway Tunnel Go Ahead?
Executive Summary
Joseph Bazalgette built London’s current sewage system in the 1960’s and, at the time of construction, they stopped the spread of Cholera which was rapidly spreading amongst Londoners at the time. The system also brought an end to the Great Stink of London. (BBC History, 2016)
Introduction to the Thames Tideway Tunnel
The construction of the Thames Tideway Tunnel is an eight-year project starting in 2016 with the projected completion date in 2023. The tunnel is being constructed in order to address the issue of London’s overflowing sewer system. The current 20,000 miles of networked sewage pipes were built in the 1860’s by Joseph Bazalgette and they are failing to meet 21st century demands with London’s growing population and increasing levels of rainwater ending up in the sewers. The sewers were designed so that rare overflows would be flushed into the river, however, at the time of construction this only happened on average once a year and now it happens on a weekly basis resulting in 39 million tonnes of raw sewage ending up in the River Thames every year. (BBC News, 2014) (Super Sewer: An Introduction to the Thames Tideway Tunnel Project in London, 2016) According to Phil Stride from Thames Water, “It is absolutely not consistent for a world-leading city to be using its river as an open sewer”, and it is because of this that the Thames Tideway Tunnel became the proposed solution to London’s sewage problems. (Bateman, 2013)
Primary Objectives
19th Century Design
Although Bazalgette’s sewage network is structurally sound, when the network was but in the 1860’s the population of London was only 2 million, one quarter of the size of the current 8 million people living in London, and so the sewers were not built to handle the volume which it must do now. (Bateman, 2013) (Why Does London Need the Thames Tideway Tunnel? 2012) At the time of construction the sewers would flow on average once a year from one of 57 combined sewer overflow (CSO) sites along the tunnels and now it happens on average once a week, leading to the excessive pollution of the River Thames. (Why Does London Need the Thames Tideway Tunnel? 2012)
The tunnelling network is a combined system where the sewage tunnels were not only built to handle sewage but to manage drain water and as little as 2mm of rainfall can now trigger an overflow in the tunnels. (Why Does London Need the Thames Tideway Tunnel? 2012) Nowadays, because of global warming there is a trend of increasing numbers of storms in recent years and this is likely to continue, and so the sewers must be able to manage this. As well as this, with London becoming a busier city there are many more buildings and concrete paving and roads, with this becomes less green spaces; this means that water which once was soaked into the Earth is now going into the sewage system leading to increased pressure on the network. (BBC News, 2014)
Currently, the overflowing sewers are released into the Thames at a rate of 50 tonnes a second, however the solution to this would be to intercept the drainage at certain points so that the overflows will enter the new tunnel rather than the river. The tunnel would then take the sewage to a treatment works in East London before it is discharged into the river. (Bateman, 2013)
22nd Century Solution
The Thames Tideway Tunnel is a long-term solution to the current problem, and has been described as a 1 in 150 year project. It is a 25km tunnel going as far as 65m below the River Thames. The tunnel will be built to withstand current demands and it is also possible to amend the tunnel in order to withstand greater volumes in future decades due to population growth in London, caused by the growth in urbanisation, and the changes in climate. (Tideway, 2016)
The recently constructed Lee Tunnel and upgrades to current sewage treatment works will help with managing sewage discharges into the Thames, however, 18 million tonnes of sewage will be left in the river and so this sewage must be taken to treatment before this discharge hence the need for the Thames Tideway Tunnel to be built to take this sewage to treatment. The new tunnel will catch the ‘first flush’ from 34 of the most polluting CSOs which will greatly reduce the amount of sewage water entering the river. (Thames Water, 2013)
It is necessary that London find a way to manage their sewage discharge in order to comply with the Urban Wastewater Treatment Directive; this is a directive that requires EU cities to have suitable systems in place to collect and treat sewage in order to protect the environment. The European Commission has made it clear that they will enforce the UWWTD and if Thames Water fails to act very quickly they risk facing large fines. The fines are based upon the duration of pollution and how serious it is; the minimum lump sum that the UK faces is £8,500,000 and incurring this charge would lead to increased taxes. The Thames Tideway Tunnel provides a relatively fast solution to this problem and so helps the UK’s case against the UWWTD should they be issued with fines. (Note that since the UK have now voted to exit the EU this may not be an issue, but it is likely that the UK will want to manage sewage, whether or not it will be as strict as the UWWTD is unknown, but until the separation of the EU and UK we must comply with their laws.) (Creating a River Thames Fit for Our Future, 2015) (Thames Water, 2013)
Issues Facing Society
4 Billion Pound Project
The Thames Tideway Tunnel has been forecasted to cost £4.2 billion to complete; this will inevitably affect Thames Water’s customers’ bills. (Bell, 2015) Although the project is financed and constructed by Bazalgette Tunnel Limited (BTL), who gained a license from OFWAT to become a separate utilities business, and investors, such as Allianz and the Eurpoean Investment Bank, fund them there will still be rises in bills as Thames Water work alongside them. (Tideway, 2106) Thames Water have said that they expect an average annual increase of up to £25 per household which has caused upset with many of their customers. The average cost of the combined service, water and wastewater charges for Thames Water is £374, with the possibility of a rise to £399, which is still a great deal lower than the average cost for South West Water, which is £488 (see Figure 1). (Our Finances Explained, 2016)
Disruption to Residents
Alternatives Considered
Conclusion
Should the Thames tideway tunnel go ahead? What are it primary objectives and what are the issues facing society in its construction?
References
Bateman, T. (2013). Does London need a £4.2bn ‘super-sewer’? – BBC News. [online] BBC News. Available at: http://www.bbc.co.uk/news/uk-england-london-24046324 [Accessed 8 Nov. 2016].
BBC News. (2014). London’s ‘super sewer’ gets the go ahead – BBC News. [online] Available at: http://www.bbc.co.uk/news/uk-england-london-29175607 [Accessed 8 Nov. 2016].
Creating a River Thames Fit for Our Future. (2015). 1st ed. [pdf] Department for Environment, Food and Rural Affairs, pp.3-4. Available at: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/471847/thames-tideway-tunnel-strategic-economic-case.pdf [Accessed 14 Nov. 2016].
Why Does London Need the Thames Tideway Tunnel?. (2012). 1st ed. [pdf] Thames Water. Available at: https://www.thameswater.co.uk/london-tideway-improvements-the-case-for-the-thames-tunnel.pdf [Accessed 14 Nov. 2016].
Tideway. (2016). Our solution – Tideway | Reconnecting London with the River Thames. [online] Available at: https://www.tideway.london/the-tunnel/our-solution/ [Accessed 17 Nov. 2016].
Bell, S. (2015). What Is The Thames Tideway Tunnel?. [online] Londonist. Available at: http://londonist.com/2015/08/what-is-the-thames-tideway-tunnel [Accessed 17 Nov. 2016].
Our Finances Explained. (2016). 1st ed. [pdf] Thames Water, pp.8-9. Available at: https://www.thameswater.co. uk/tw/common/downloads/aboutus-financial/Our_Finances_Explained_2016.pdf [Accessed 17 Nov. 2016].
Tideway. (2016). £700m European Investment Bank backing for Thames Tideway Tunnel – Tideway | Reconnecting London with the River Thames. [online] Available at: https://www.tideway.london/news/media-centre/700m-european-investment-bank-backing-for-thames-tideway-tunnel/ [Accessed 17 Nov. 2016].
BBC (2016). BBC – History – Joseph Bazalgette. [online] Available at: http://www.bbc.co.uk/history/historic_figures/bazalgette_joseph.shtml [Accessed 17 Nov. 2016].
Super Sewer: An Introduction to the Thames Tideway Tunnel Project in London. (2016). 1st ed. [pdf] Institution of Civil Engineers. Available at: http://www.icevirtuallibrary.com/doi/pdf/10.1680/jcien.2016.169.2.51 [Accessed 17 Nov. 2016].
Possible:
https://thameswater.co.uk/cps/rde/xbcr/corp/working-group-report-objectives-vol-1.pdf
http://www.tunneltalk.com/UK-London-26Mar2014-Thames-Tideway-Tunnel-objections.php
https://infrastructure.planninginspectorate.gov.uk/wp-content/ipc/uploads/projects/WW010001/WW010001-001272-8.3_Needs_Report_Appendix_A_Regulatory_Impact_Report.pdf
http://cleanthames.org/wp-content/uploads/Prof-Colin-Green-TTT-environmental-disaster.pdf