way. This tunnel, running down to deep from Abbey Mills to Beckton is forecast to capture , or 16 million tonnes annually from the greatest-polluting CSO point in London. Thames Water awarded the £635 million construction contract to the MVB joint venture of Morgan Sindall, VINCI Construction Grands Projets and Bachy Soletanche, in January 2010. Construction began in 2010 and on 28 January 2016 the Mayor of London, Boris Johnson, confirmed the tunnel open. Sewage treatment works modernisation The second part was the £675 million project to modernise and extend London's five major sewage treatment works to treat more sewage, thus greatly reducing the need for storm discharges to the river: Mogden Sewage Treatment Works – a £140 million upgrade to extend treatment capacity by 50% Crossness Sewage Treatment Works – a £220 million upgrade to extend treatment capacity by 44%; Beckton Sewage Treatment Works – a £190 million upgrade to extend treatment capacity by 60%; Riverside Sewage Treatment Works – an £85 million upgrade to improve water quality and produce renewable energy on site; Long Reach Sewage Treatment Works – a £40 million upgrade in Dartford; These intend to improve the standard to which the sewage is treated, thus improving the Tideway's water quality. Acton to Stratford The final part is the Thames Tideway Tunnel. When built, it intercepts the outflows from London's most polluting CSOs, stores them and directs (conveys) them to sewage treatment works for processing. Thames Tideway Tunnel planning and consultation Initial design and phase 1 consultation Following the Thames Tideway Strategic Study, Thames Water consulted with relevant authorities to get feedback from stakeholders who would potentially be affected by the construction of the Thames Tideway Tunnel. Thames Water sought feedback on the proposed tunnel routes and potential locations of construction sites. Three tunnel routes were considered: River Thames Routesuch an alignment, broadly, would followed the river from west London to Beckton STW and would cut across the Greenwich Peninsula, reducing the length of the tunnel where there are no CSOs to be intercepted. Rotherhithe Routea similar alignment, but this would have cut additionally across the Rotherhithe Peninsula, reducing the length of the main tunnel by approximately but requiring longer connection tunnels from some CSOs. Abbey Mills Routethis route would connect the Thames Tunnel to the head of the Stratford to East Ham part at Abbey Mills Pumping Station. This would follow the same route but