Did you know that one of the biggest labs in London is actually on the London 2012 Olympics site? Over 60 researchers work from a massive Portakabin near the main stadium. For some of them, the Sisyphian and somewhat incongruous task is to clean the mud.

I was there a few days back. The New Media team promoting the Olympics invited London’s bloggers on a bus tour of the Stratford site to mark one year since construction began. The progress is staggering. Both the main stadium and the Aquatics Centre are already at an advanced stage, while the power plant and Olympic Village are also starting to rise. You can see some videos and photos from the tour over on my other blog, but here I’d like to sketch out some of the science taking place in this most unlikely of locations.

It’s yucky out there. The Olympic lands near Stratford were a centre of industry for many centuries. The very dirt has become dirty, laced with the noisome hand-me-downs of successive industrial revolutions. Before the crowds descend in 2012, someone’s got to clear up this heady brew of hydrocarbons, heavy metals, sewerage, possible nuclear contaminants and Europe’s largest fridge mountain. All well and good, but now we’ll never know what super powers our athletes might have developed if they’d been left to wallow in such a mutagenous mixture.

But how do you turn 2.5 square kilometres of benighted, fetid land into a suitable venue for the world’s most honed physiologies? You dig it all up and feed it through giant washing machines like this one:

Image by Duncan Young

That’s right. Over 1.3 million tonnes of earth must be scrubbed at an estimated cost of nearly £1 billion. A team of scientists are on hand to monitor pollution levels and oversee its removal. For simple hydrocarbon waste, the soil is mixed with water, which separates off any hydrophobic contaminants. Clean sand and gravel is then sieved, shaken and filtered out at a rate of 750 tonnes of soil per day. Other nasties are treated by bioremediation (biological breakdown of contaminants in a high-oxygen environment) in large concrete containers. Tougher pollutants are left in situ, fixed in place with chemical stabilisers that prevent leakage into ground water.

As well as efforts to clean up the park, other scientists are working on conservation and biodiversity projects. Fish, amphibians and reptiles have been temporarily evicted to a nearby nature reserve while construction takes place. I was told by the tour guide that fish in the River Lea were stunned with ‘mild electrocution’, allowing their easy capture. Once construction is complete, the site will be decorated with hundreds of bird and bat boxes. It is hoped that otters and voles will colonise the many cleaned up waterways. Invasive species such as the notorious Japanese knotweed will be eliminated and the site replanted with diverse local species, chosen for their ability to tolerate hotter climates and thereby ‘future-proofing’ against global warming.

That’s but a brief overview of a very complex and lengthy operation. More details about sustainability and biodiversity on the Olympic site and project can be found in this document, and I hope to return to the subject in more detail when I get chance to interview one of the scientists working on-site.