It has attracted its fair share of criticism over the past few years, but the Millennium Dome, built originally as a temporary structure for the millennium celebrations in Greenwich, London, UK, has developed into an amazing permanent venue.

The Millennium Dome was intended initially to have a one-year lifespan, but was quickly considered for a long-term purpose and ultimately renamed The O2. Although it sat idle for six and a half years, it was given a multi-million-pounds injection by its new owners and now ranks among the world’s most exciting sports and entertainment precincts.

The O2 has an overall diameter of 365m (400 yards), an internal diameter of 320m (350 yards), a circumference of 1km (.6 mile) and is 50m (54 yards) high at its central point.

Apart from the huge music and sports arena with a seating capacity of 23,000 (which has already hosted some of the biggest rock bands from around the world), The O2 includes a massive 667,000 sq ft of restaurants, bars, retail outlets, night clubs, even a skating rink and exhibition space. There is also an 11-screen cinema complex, an indoor beach, two concert halls and an exhibition space that is currently home to Tutankhamun’s treasures - all housed under the huge tented roof.

When at full capacity, the entire building will be able to hold 60,000 patrons.

The O2’s owners, AEG Europe, claim to have alleviated the ‘50-minute queue for the loo’ by installing 548 toilets; and there lies part of the problem faced by some of the UK’s best plumbing engineers.

For the massive redevelopment, the local Greenwich Council dismissed the use of open stacks within the tented area because of perceived threats of SARS and other airborne viruses.

Enter Studor - a global manufacturer of a range of products which offer solutions for venting buildings’ drainage systems, eliminating the need for roof penetrations.

“Basically, the entire structure underwent a complete rebuild," says Studor technical manager Steven White, “and this introduced a drainage design problem. Originally it was designed as a temporary structure for the millennium celebrations, having open stacks terminating within the structure."

With the new design, there weren’t many options left to the developers but to run ventilation to the outside – which happens to be around 180m (196 yards) away – the equivalent in height of a 60-story building. With the Studor System we were able to offer a solution which avoided the need to penetrate the clean lines of the building’s exterior with vent pipes to the atmosphere, providing the sealed drainage system required.”

Normally, vent stacks stabilize the air pressures within the soil stack to maintain it at near atmospheric pressure and help to reduce the incidence of negative and positive transient pressures which have the potential to cause induced siphonage of trap seals within the system – the only barrier between the drainage system and the living space. In extreme cases positive transient pressures can lead to trap water-seals blowing out of or bubbling within the fixture and leaking sewer gases into the building’s interior.

The solution to this has been to use AAVs (Air Admittance Valves) and P.A.P.A.s (Positive Air Pressure Attenuators). Originally developed for high-rise buildings and comprising a large bladder within a cylinder, the P.A.P.A. unit acts like a shock absorber, attenuating pressure waves and stopping them affecting the plumbing system, hence eliminating the need for vent piping and, in the case of The O2, roof penetrations.

Studor, together with the Drainage Research Group at Heriot-Watt University in Edinburgh, Scotland, led by Prof. John A. Swaffield, worked together to develop a suitable system for The O2 and to prove to building control that the system would work.