Thames Tideway Tunnel
[4] Built between 1859 and 1875, Sir Joseph Bazalgette's original London sewerage system was designed to capture both rainwater and the sewage produced by four million people.
[11][12] In the 2011 census returns Greater London hosted just over 8.1 million residents[13] and Thames Water in a leaflet of that year explained how its works and how sewers needed expansion.
[11] As London continued to grow the new developments and suburbs were equipped with separated foul water and rainwater drainage pipe work.
[14] These discharges, a mixture of raw sewage and rainwater, needed to be cut to comply with the EU's Waste Water Treatment Directive (UWWTD).
The remainder were found to be either impractical or insufficient to provide a solution, although the evidence from the outer London Boroughs is that separated storm drainage can sustainably prevent all pollution.
[citation needed] They argued that rainwater from roads should be sent directly to canals, rivers or the estuary, and that landowners could install soakaways for their roof run off, making them eligible for discounted water treatment bills.
In November 2010 the draft National Policy Statement for Waste Water (NPSWW) was issued, and eventually published largely unaltered, despite Parliamentary objections that it promoted the Tideway Tunnel as the only solution.
This 6.9 km (4.3 mi) tunnel, running down to 75 m (246 ft) deep from Abbey Mills to Beckton is forecast to capture 16,000,000 m3 (1.6×1010 L), or 16 million tonnes annually from the greatest-polluting CSO point in London.
When built, it intercepts the outflows from London's most polluting CSOs, stores them and directs (conveys) them to sewage treatment works for processing.
[26] Three tunnel routes were considered: A long list of 373 potential sites was created using a desktop survey of the land on either side of the 34 most polluting CSOs (as identified in the Thames Tideway Strategic Report).
On 3 June 2013, it was announced that the Secretary of State for Communities and Local Government had appointed inspectors Jan Bessell, Libby Gawith, Emrys Parry, Andrew Phillipson and David Prentis as the examining authority to consider any matters arising.
[60] Chaired by the Planning Inspectorate, this determined how the examination would be carried out, including consideration of more detailed hearings on site-specific matters, as well as project-wide issues.
Government legislation and the NPSWW required that all efforts be made to reduce carbon emissions in new projects, but the examiners did not manage to study this issue.
Once the Inspectorate concluded its examination of the application, a recommendation on whether or not to issue a development consent order would be submitted to ministers to make the final decision.
[68] Following detailed analysis it was decided that the best means to deliver the project would be through a regulated infrastructure provider (IP)[69] as this would maximise value for money.
The IP, originally to be formed through a competitive process starting in the spring of 2013, would hold its own license from the industry regulator, Ofwat, and would build, manage and maintain the tunnel.
[11] In a letter to the Financial Times in November 2012, Sir Ian Byatt (former Director General of Ofwat) and politician Simon Hughes MP stated: If Thames is unwilling to make a rights issue, the owners, Macquarie, should be expected to return funds to the utility.
[71] On 29 July, Thames Water announced that a contract notice for work on the tunnel had been published in the Official Journal of the European Union (OJEU).
[72] The successful contractors for the three main tunnelling contracts were announced in February 2015:[73][74] In August 2015, the independent investors to finance and deliver the scheme were confirmed.
Bazalgette Tunnel Limited, a new special-purpose company appointed to take the project forward, received its licence from Ofwat as a new regulated utilities business, separate from Thames Water.
[75][76] The special-purpose company is backed by pension funds and other long-term investors represented by Allianz, Amber Infrastructure Group, Dalmore Capital and DIF.
[82] Since the initial proposal, questions focussed on the cost, the location of construction sites, duration, disruption, and whether a tunnel was the correct solution for London and for Thames Water customers.
Ofwat confirmed the extent of leveraging on the balance sheet, reducing tax due and allowing annual payouts of dividends – money which some feel should have cut the cost of the scheme.
[83] Thames Water maintains that it has done nothing unusual by making tax-deductible investments in the natural and proper domain of its business which reduces tax; this is conventional practice.
[75][85] Some people who live alongside proposed sites were concerned about the noise, disruption and potential loss of public space resulting from construction.
[11] This is a sustainable urban drainage system (SUDS) under Central London streets and open spaces with small pumping stations in places of low gradient.
[11] They outline the added benefits of building green infrastructure, particularly uncovering streams and rivers in some places in inner London Boroughs where they were culverted in the past.
Their most progressive arguments are for replacing paved, impermeable surfaces in London with permeable options and implementing green roofs, swales and water butts to promote the infiltration of rain-water, preventing it from reaching the combined sewer system, thus reducing peak flows and limiting the number of CSO overflows.
[88][89] Green infrastructure would have further benefits for London in addition to addressing the rainwater overflow problem, such as: The number of CSO discharges is set to fall from an average of 60 a year to less than five.
