The Government is being formally challenged to review its decision on the Thames Tideway Tunnel.

The call comes in a letter sent as a formal request to the three Secretaries of State for DEFRA, Energy & Climate Change and Communities and Local Government for a review of the National Policy Statement for waste water concerning the Thames Tideway Tunnel under s.6 of the Planning Act 2008. Grounds for the review include new supporting evidence.

Co-signatories to the letter are Thamesbank and the Environmental Law Foundation. Sir Ian Byatt, former head of water industry regulator Ofwat, is amongst a number of people who support the request for a review.

Two leading tunnel engineers who were involved in the original studies which examined the feasibility of the project have separately questioned the reliability of evidence used by Thames Water in support of the proposed Tunnel.

The Tunnel was conceived by the Thames Tideway Strategic Study Group (TTSSG) between 2000 and 2005 under the Chairmanship of Professor Chris Binnie. On the basis of the Group’s appraisal at the time the Government in 2007 decided to promote the project as a specific solution. In 2010 Thames Water prepared a Needs Report which included a SuDS Evaluation for Example Areas study - -the only study of alternatives used by Thames to support its choice. 

Emeritus Professor Richard Ashley, lead author of the SuDS study which formed part of the Needs Report, now believes that Thames Water’s terms of reference for the study of alternative solutions to the Tunnel were too narrow, the time and resources dedicated to it were inadequate and blanket assumptions were made for scaling up.

Both Professor Ashley and Professor Binnie have independently called into question the use of outdated data as the main evidence in support of the project.

The co-signatories are separately arguing that the NPS itself has been predicated on the Ashley study prepared in 2010 which was largely based on the now out-dated appraisal by the TTSSG. The study has been included - but is apparently not open to question - in the TTT planning application.

The letter states:

“The case for review is compelling given the inadequacy of the terms of reference given to Professor Ashley which were to only consider reduction of spill volumes and frequencies, to ignore local infiltration measures, to ignore rainwater harvesting (other than rainwater barrels), and not to investigate existing development plans for the area. In addition all the modelling was done by others, and it had been presumed they did it right; however, it now transpires that their modelling exaggerated the impermeable area draining to West Putney CSO by up to 40% within the catchment. Furthermore, SuDS had to be considered as an 'all-or-nothing' option and not a partial option. This information has come to light since publication of the NPS.”

The letter also points out that Government replies to recent questions by Lord Berkeley in the House of Lords about evidence of alternative and SuDS being “disproportionally expensive” to the TTT appear also to be based on Thames Water’ s “too narrow” study.

It also suggests that the scale of discharges into the Thames have been exaggerated in the NPS, particularly when the construction of the Lee tunnel, enhancements to Sewage Treatment Works and better maintenance of existing sewers are taken into account, stating:

“The cost/benefit analysis to date is … flawed because it relies on the figure of 39m cubic metres of raw sewage discharged annually into the Thames… “

“However, on-going improvements to sewage treatment plants, notably Mogden, and the completion of the Lee Tunnel in 2014 will (regardless of the TTT) reduce this to at most 18m cubic metres, - less than half of the NPS figure. The cost of these improvements will have been approximately £1.2bn. £4.3bn to remove the remainder should therefore be considered relatively poor value.”

Government is now “in grave danger of drifting into a solution”

The co-signatories are warning that the Government is now “in grave danger of drifting into a solution to a problem under the Urban Wastewater Treatment Directive which has been misunderstood and highlighting the fact that “alternatives have not been properly investigated.”

The letter also refers to comment by the European Commission that “under the requirements of the EU Directive 2011/92/EU, the UK needs to look at the potential environmental impact of the solution proposed and viable alternatives”. The increasing use of Integrated Water Resource Management which is mandatory across the USA and recommended in Europe is now being put forward as a viable alternative.

Escalating costs should be taken into consideration

The co-signatories have also raised the issue of the potentially escalating cost of the project versus net gain for London, saying that Thames Water’s recent request to Ofwat for an 8% rise in customer bills illustrates costs for the Tunnel are continuing to rise. The letter warns that the outcome will result in a stranded asset of £4.2Bn with a benefit of around £0.3Bn.

The letter also cites Sir Ian Byatt’s report in July 2013 – “Thames Tunnel: A Critique of a Flawed Project” – which concluded that “the tunnel-only” project could be more expensive for both customers and taxpayers than the adoption of a combination of smaller and more flexible solutions. The report said:

“This is a European Union driven project that has snowballed into a Coalition Growth project, gathering costs as it rolls. The proposed solution, chosen by Ministers, is estimated to raise customers’ bills by £70 to £80 a year. Yet the engineering costs seem excessive and, as proposed, it could be both difficult and expensive to finance. The UK is in breach of the EU Urban Waste Water Directive. Ministers have opted for a "tunnel only" solution, having brushed aside cheaper and more flexible solutions.” Sir Ian has described the Government guarantee for the project as “privatising the profits while socialising the risk”.

Last month an Examining Authority of five inspectors appointed under the Planning Act 2008 regime started its consideration of Thames Water’s application to construct the 25 kilometre Tideway Tunnel under the River Thames. The Examining Authority has already separately confirmed that it will not consider the need for alternatives to the TTT as part of the Examination , citing the National Policy Statement on Waste Water published in March 2012 which concluded that the TTT is the “only option to address the problem of discharging unacceptable levels of untreated sewage into the River Thames within a reasonable time at a reasonable cost.”

“Projects of the scale of the TTT require full and open debate”

The letter states:

“We consider that the NPS is both wrong and unlawful in circumstances where alternatives have never been adequately investigated and that the public has, in consequence, never been given the chance to consider any alternative solutions.”

“Projects of the scale of the TTT require full and open debate and scrutiny. However because of the statutory limitations on challenging the development consent order process (DCO) under the Planning Act 2008, there is a real danger that a flawed and expensive Examination will be allowed to continue with strictly limited scrutiny of the most important issues, including the costs, benefits and comparative willingness of the public to pay for the solution finally adopted.”

The letter also refers to the representation by law firm Pinsent Masons LLP on behalf of Southwark Council that the NPS should not have the decisive role it is proposed to have as part of the development consent process and that there should be re-consultation on alternatives as part of the Examination process.

The co-signatories are now calling for the Secretaries of State to start an immediate review of the NPS in accordance with section 6 of the Planning Act 2008. The letter states:

“We believe there is a need to look beyond a monolithic and single problem focused solution such as the TTT. The Secretaries of State are accordingly requested to instigate an independent review of the NPS at the earliest possible opportunity. Thamesbank also invites the Secretaries of State to ensure that there is full and open debate on the NPS in Parliament well ahead of the grant of any development consent for the TTT.”

The Tunnel is due to come under further official scrutiny today – Lord Berkeley will be raising further questions in the House of Lords on the issue, while the London Assembly will be questioning Richard Aylard, Thames Water’s External Affairs and Sustainability Director, about a range of issues, including the Tunnel.

Click here to read the letter in full and access the supporting documentation