Work to clean and clear Olympic Park intensifies

With nearly the entire site investigated and two-thirds of the overall demolition programme complete, work will now accelerate to excavate soil across the Olympic Park, creating the ground levels needed for construction and cleaning it where necessary.

Contamination of the area has built up through a century of neglect and heavy industrial use, making this one of the UK’s most challenging land clean-up jobs.

Two large remediation plants have been created on the Olympic Park with soil washing machines installed to wash, sieve and shake out the contamination which includes petrol, oil, tar and heavy metals such as arsenic and lead. Another soil washing machine has been ordered to help meet the demand and together they will clean approximately 750 tonnes of soil per day.

ODA Director of Infrastructure and Utilities Simon Wright said: 'Now that demolition work is complete on the sites of the ‘Big Five’ Olympic Park venues, over 1.5 million cubic metres of soil – enough to fill 600 Olympic sized swimming pools – needs to be excavated, tested and cleaned where necessary. This soil will then re-used to help create the landscape of the largest new urban park in Europe and form the platforms for the venues for the 2012 Games and the future development.

'We said that by Beijing 2008 the majority of the Olympic Park would be cleared and cleaned. This is a challenging target but we have made strong progress so far and are on track to deliver.'

Ground levels across the site vary greatly and soil will be cut from areas that need to be lowered and used to fill others that need to be raised. For instance, some parts of the Olympic Stadium site will have to be lowered by nine metres while others areas need to be raised by five metres.

In total 600,000 tonnes of soil will be moved to help create the construction platform for Olympic Stadium. This work will intensify over the coming weeks in order for construction to start on the Olympic Stadium two to three months earlier than planned.

Notes to Editors

Download the document ‘Demolish, Dig, Design’, which sets out the ODA’s progress on site at the end of 2007.

Soil washing will be used to treat most of the estimated 800,000 cubic metres of contaminated soil. Machines add water to soil and separate it from contamination by either shaking or leaving it to settle and filtering out clean sand or gravel that is safe to reuse. In some instances chemicals are added to the water to tackle particular types of contamination. The water is reused after being treated. A small amount of concentrated waste from the process is squeezed to reduce its water content and it is then taken to a licensed landfill.

In some instances other treatment methods may be used. If soil contains just petrol related substances (petroleum hydrocarbons) and no other contamination it may be treated by bioremediation. This involves storing the soil in large concrete containers and adding oxygen to help breakdown the contamination naturally, a process similar to composting. Some kinds of contamination will be contained where it is, using a process of chemical stabilization to trap contaminants under the ground and prevent them leaking into the ground water system.

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For further information please contact the Olympic Delivery Authority Press Office on +44 (0)203 2012 700

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