The official opening of London's new multi-million pound super sewer has triggered the installation of high security perimeter protection for its main access points.
Former Mayor of London Boris Johnson opened Thames Water's extension to the Lee Tunnel by flushing a toilet in an underground ceremony, declaring the £678 million project 'an amazing achievement for British engineering'.
The 4.3 mile-long Lee Tunnel extension took four years to build and is designed to stop sewage flushing into the River Thames and River Lee. It will be followed by the construction of an even larger sewer, the Thames Tideway Tunnel, later this year.
Johnson said: "It is expensive and I understand people's concerns about that but in the end the real cost, it seems to me, is the cost to our city, to the environment, of not doing it. The Victorians were very ambitious our generation should be similarly ambitious.
This amazing new super sewer is providing the bold infrastructure needed to support the movements of our rapidly growing city. For years our historic Victorian systems have heaved at the seams, muddling along, battling to cope with the increasing rainfall and waste of a modern population.
Now the River Thames will benefit from vast improvements to its water quality with less pollution and overflow.
The access points are being secured by perimeter security expert Zaun, with its most intruder-resistant product, ArmaWeave, with double leaf gates.
It is being installed by Zaun subsidiary Binns Fencing, who are working with main contractor MVB, a joint venture comprising Morgan Sindall, VINCI Construction Grands Projets and Bachy Soletanche.
ArmaWeaves unique properties add substantial resistance to cutting attacks with hand, powered and non-contact tools. The tight mesh pattern provides no climbing aids, again limiting the potential for intrusion.
On average 39 million tonnes of untreated sewage mixed with rain water gets discharged into the River Thames from overloaded treatment works and combined sewer outfalls every year.
The biggest of these outfalls, at Abbey Mills pumping station, has been discharging 16 million tonnes of sewage per year to the River Lee.
The £678 million Lee Tunnel the largest single project in the history of the privatised water industry in England and Wales, and the deepest ever bored under London at 75 metres deep will capture this sewage to keep it out of the River Lee.
The Lee Tunnel connects the Abbey Mills Water Treatment Centre to Beckton Sewage Treatment Works, Europe's largest such site, both if which are also secured by Zaun perimeter protection.
The Thames Tideway Tunnel will connect to the Lee Tunnel and will capture sewage from the remaining 34 combined sewer overflows, keeping it out of the River Thames.