The Commission has also seriously criticised both Thames Water and the Environment Agency for their failures to provide a robust evidence base to support the case for the tunnel.
The Commission is now calling for the Government to reconsider a Ministerial request in 2007 for Thames Water to pursue a full-length storage tunnel solution.
In April 2007, the Minister of State for Climate Change and the Environment told Thames Water, that “A full-length storage tunnel with additional secondary treatment at Beckton sewage treatment works…is needed.”
In March 2010, the then Secretary of State for Environment, Food and Rural Affairs, Hilary Benn, set out the case for the Thames Tunnel as a project of national significance, which, if not implemented, could cause reputational risk to the UK.
The succeeding Secretary of State, Caroline Spelman, issued a written ministerial statement in September 2010 confirming the Coalition Government’s support for the construction and wrote that: “I am also minded that development consent for the project should be dealt with under the regime for nationally significant infrastructure projects established by the Planning Act 2009. I consider that this project with its unique scale and complexity, is of national significance and, therefore, appropriate for this regime.”
Alternative options have never been adequately tested
The Commission says that the alternative options to a full length tunnel have never been adequately tested - including reducing flows by separation, green infrastructure, construction of local detached sewage treatment works, construction of distributed storage and enhancement of the existing sewerage network. In the Commission’s view these would allow a partial tunnel solution at a lower cost or even a non-tunnel solution.
While the Commission agrees that the scale of sewage discharges into the Thames Tideway is unacceptable, it believes that building individual treatment works at the ten worst Combined Sewer Overflows (CSOs) which are responsible for nearly 80% of the total load would be a better solution, rather than the proposed 22km long tunnel. The Commission is calling for the benefits of connecting the proposed number of CSOs to a full-length tunnel compared with the costs to be re-assessed.
The report recommends that a wide ranging cost-benefit study, including the full range of potential benefits, should be undertaken to investigate the potential and feasibility of connecting certain less frequent discharging CSOs to green infrastructure source control measures as an alternative to connection to the full length tunnel.
Thames Water and Environment Agency evidence base under fire
The Commssion has also called into serious question the Environment Agency’s methodology for determining whether a CSO has unacceptable adverse environmental impacts. The report says it is crucially important that this should be supported by a scientifically robust evidence base informed by adequate monitoring, validated computer models and measures which can be precisely calculated.
The quality and accuracy of the EA and TW monitoring of individual CSO discharges were among issues raised with the Commssion. The Commission expressed surprise at the fact that decisions on such a significant investment as the construction of the Thames Tunnel were based on computer modeling results that had a weak scientific base and could not be verified due to the lack of knowledge and monitoring data.
Environment Agency and Thames Water failure to provide evidence
The Commission said the efficacy of the modelling could not be assessed in detail by the Commission as modeling reports and results were not provided in evidence, despite repeated requests. It also said that although the Environment Agency (EA) has 20 years of monitoring data on dissolved oxygen levels in the Thames, this was not provided in evidence – despite being better water quality data than anywhere else in the country.
The Commission was also disappointed at Thames Water’s failure to provide access to computational models used in the most recent analyses of the sewer network, despite numerous requests. The report states:
“The justification for overriding the evidence has been given to us as ‘based on visual observation made by Thames Water, Environment Agency and due to public complaints received’. This calls into question the scientific rigour and validity of the whole assessment exercise conducted by the Environment Agency which scores and ranks each CSO on accepted criteria, only for visual observations and public complaints ultimately to determine if a CSO is assessed to be satisfactory or unsatisfactory.”
Current planning and funding produces “costly and inflexible” water infrastructure
Among the Commission’s key recommendations is the need for the Government to address current planning and funding arrangements for water and wastewater systems. The Commission believes these make it easier to construct “large, costly, inflexible and environmentally impacting infrastructure systems, like the tunnel” than to provide green infrastructure alternatives.
The Commission now wants Defra, the Environment Agency and Thames Water to give careful consideration to alternative solutions proposed by Professor Chris Binnie, chair of the Thames Tideway Strategic Study Group which examined storm sewage into the Thames Tideway in 2000, which “appear to offer much better value for money than the single tunnel solution.”
Tunnel costs will push Thames Water customers into water poverty
The Commission also expressed serious concerns about the escalating costs of the Thames Tunnel and its impact on customers which they say will push a significant proportion of Thames Water bill payers into water poverty.
In June this year Martin Baggs, Thames Water’s Chief Executive Officer, revealed that the current £3.6 billion price tag is an indicative 2008 price, used to benchmark options, and that it will inevitably increase at outturn once the project risk and financing cost is added in.
water industry regulator Ofwat has already recognised that the impact on customer bills based on the £3.6billion price tag will be large – a £60 to £65 increase in annual bills, which currently average £319.
National Policy Statement and energy and carbon impacts among concerns
Other concerns include how the Thames Tunnel project is currently being addressed under the forthcoming National Policy Statement (NPS) on Waste Water. The Commission says this should not pre-empt the role of the planning process to determine whether the Thames Tunnel meets the criteria for major waste water developments.
There has been no public information made available about the energy and carbon impact of the tunnel. According to evidence from Defra, Ofwat is expected to require this only at the next asset management planning 5 year review in 2014. The Commission believes an assessment should made of the environmental impact of the tunnel, in comparison with alternative solutions, before any decision is taken on its construction.
During its three month examination the Commission has reviewed the findings of previous studies and reassessed the assumptions made in those studies in the light of subsequent research and more up-to-date scientific knowledge. It has also taken written and oral evidence from a range of stakeholders and experts in the field, including Thames Water.
Thames Water’s phase one consultation process for its plans was conducted from September 2010 to January 2011. The phase two consultation process is due to begin in November 2011. Thames Water expect to submit planning applications in the summer of 2012.