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Infrastructure: Getting the dirty work done fast

The Olympic Park's much-publicised trophy buildings will take the plaudits when 2012 rolls around. But the unsung heroes will be the team that has prepared the massive site before construction starts.

As the Olympic Stadium and Aquatics Centre begin to emerge out of the ground this summer, one could be forgiven for thinking that this is where London 2012 construction begins.

However, over the past 12 months there has been a mass of activity that has transformed the Olympic Park from a polluted post-industrial wasteland into a clean, clear site ready for construction.

Just how much has been done becomes clear when listening to ODA infrastructure and utilities director Simon Wright rattle off a very long list: "In the enabling works, on the environmental side we have seen the translocation of species - 200 common lizards and 50 smooth newts among others.

"In clearing the park we have seen 190 buildings demolished and 92% of all that material recycled, slightly over our 90% target.

"We have relocated three steel-framed buildings in their entirety and are about to do a fourth. In our reuse of materials we have saved a large amount of London stock brick and kept granite, concrete paving slabs and concrete kerbs from the old highways.

"The site investigation involved 2,700 separate intrusions in the Park, comprising boreholes, trial pits and window samples."

Add 600,000 tonnes of contaminated soil being treated by soil washing, a further 50,000 tonnes being cleaned through bioremediation, and 120,000 tonnes of waste from a 100-year tip, and the extraordinary nature of what has been achieved already on the 246ha site becomes clearer. And the clean up is set to continue for at least another year.

The vast quantities of land treated and high levels of recycling sets an example and create a legacy for sustainable construction, showing what can be achieved when everyone on a project is committed to common goals.

"I think that one of the things that's been really good on the enabling works is the whole team ethos," says Wright. "Demolition and remediation contractors Nuttall and Morrison have really bought into the targets, they've mobilised the optimum resources and have demonstrated a real commitment to deliver, which they've successfully done.

"They've gone beyond the call: where there's been a necessity to hit the targets, people have got together Đ CLM as programme manager, Atkins as project manager and designer and the contractors Morrison and Nuttall - they've got together and found ways of solving problems and that's the key: jointly solving problems and not simply passing the buck and saying 'it's not my fault, I'm not to blame."

As the project moves out of the remediation phase and into the main construction period from now until 2011, Wright's focus shifts towards the installation of utilities, bridges, highways and other associated infrastructure such as culverts and underpasses.

Contracts awarded include those to Skanska, Nuttall and Balfour Beatty who will be building 8km of roads through the Olympic Park and nearly 20 road and foot bridges, Barhale Construction building a tunnelled primary sewer and pumping station, McNicholas providing water, gas, electrical and telecoms networks, and Elyo Suez is building an Energy Centre.

What has been a key theme in the design stages of all of the Park's infrastructure has been the focus on legacy: designing something that will last not just for a few weeks in the summer of 2012, but for generations.

"We're really focused on the legacy, that's the whole essence of the project," says Wright. "We looked at the legacy and then asked 'how can we backfit the Games to work?'. An example of this is the fact that we have a trunk gravity sewer capacity designed for legacy. This would be very expensive to enlarge in the future."

Barhale will build a new 1.2m-diameter tunnel running from north to south, to a primary pumping station that pumps the flow up into the Northern Outfall Sewer. This prevents additional flow being put into the already struggling Abbey Mills pumping station.

When asked which of the projects excites him the most, Wright is unequivocal. "It's the Energy Centre," he says. This design, build, finance and operate project is being run by Elyo and designed by architect John McAdams and Parsons Brinckerhoff.

"It's the largest private sector concession for an integrated energy centre, with district heating, providing fantastic legacy which will really help future developers to achieve low-carbon development. We have the ability to convert to alternative fuels in the future, so
this could become a zero-carbon facility if it were to be fuelled by biogas, or other kinds of renewable energy if there is a source, which is being talked about as a possibility in east London.

"It's a pretty innovative deal.

It is not only the scale and complexity but the fact you're putting the primary network in now at the outset.

"You've got the entire energy network Đ the heating and cooling pipework is all going in the ground now and it's only really the Games that could have triggered that.

"Projects like the Energy Centre are the real legacy of the Games, because normally you would have to build this in incrementally."

Wright sees the Energy Centre and the Olympic Park's focus on sustainability as creating a legacy that reaches beyond east London.

"It's part of a much wider agenda for Britain," he says.

Targeting recycling

Morrison construction manager Lee Humphries is at the heart of the team helping the ODA to achieve its target of recycling or reusing 90% of all demolition material on the Olympic Park.

"The key to being successful in recycling such a high percentage is planning," says Humphries.

"Before we took possession of the buildings we were going to demolish, we surveyed them and assessed what materials could be reused. We carefully took out and segregated materials -
it was more of a deconstruction than a demolition."

Recycled materials include plasterboard, glass and timber from door and window frames, which were taken offsite to be turned into chipboard and MDF. Steel reinforcing bars were taken away for smelting, but bricks and concrete were crushed to be reused as aggregate onsite.

Morrison has also worked in the north of the Olympic Park and had the unenviable task of cleaning up the former site of the West Ham tip, with everything from Victorian household waste to debris from the Blitz.

"To sort through this we used a complex sorting system," says Humphries. "The first stage is a mechanical screen. All the fine soil falls through screen then heavy materials are handpicked and dropped into skips."

The fine soils are reused onsite, while the heavy materials are sorted into those that can be recycled or reused and those that must be taken offsite to landfill.

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