Presentation on theme: "Erica Davey, Ellie Hoffman, Lisa Vienckowski R EMEDIATION OF THE 2012 L ONDON O LYMPICS S ITE."— Presentation transcript:
Erica Davey, Ellie Hoffman, Lisa Vienckowski R EMEDIATION OF THE 2012 L ONDON O LYMPICS S ITE
L ONDON O LYMPIC S ITE 2.5km 2 Site in East London’s Lea Valley Over 800,000 cubic metres of contaminated soil Over 20 million gallons of contaminated groundwater
W HAT W AS T HERE ? Oil Lead Petrol Tar Cyanide Arsenic Low Level Radioactive Waste
H OW D ID I T G ET T HERE ? Contaminated through centuries of industrial use, including: Unregulated Landfill Site from the Victorian Era Cosmetics, Soap and Lavender Factory Calico Printers and Porcelain Factory Petrol Factory General Use and Dumping
W HY T HIS S ITE T HEN ? Vision ‘to make a real change in London, across the UK and globally.’ Olympic Park surrounded by ‘some of the most diverse – and most deprived – communities in the country.’ Edge of the Thames Gateway Project – biggest regeneration project in Europe
P OSSIBLE S OLUTIONS Site Flushing Soil Vapor Extraction Thermal Treatment Soil Washing Bioremediation
S ITE F LUSHING Large volume of water and chemicals used to raise water table Removes NAPLs Advantages Relative fast and inexpensive In situ Disadvantages Can be expensive/difficult if many wells/chemicals needed Handling chemicals can be dangerous Chemicals left behind after cleanup may be harmful
S OIL V APOR E XTRACTION Vacuum used to remove volatile and semivolatile organic compounds from the vadose zone Special equipment separates clean air from vapors Advantages In situ Works well when combined with air sparging Air used encourages growth of microbes Safe, relatively quick and simple Cleans both soil and groundwater
T HERMAL T REATMENT Different methods and techniques that apply heat to polluted soil and/or groundwater to destroy or volatilize organic chemicals Used for DNAPLs or LNAPLs Advantages In situ Works in clays where other methods may not Can reach pollution in deep areas Disadvantages Less certainty about uniformity of cleanup Gases may pollute air- use cover
A DOPTED S OLUTIONS Soil washing, bioremediation, soil stabilisation/immobilisation, thermal desorption, and dredging and sediment treatment were all used. Soil washing and bioremediation were the primary methods for cleaning the soil. In an effort to be green, site remediation occurred mainly onsite.
S OIL W ASHING Approximately 500,000 tonnes of soil were treated to remove primarily hydrocarbons and heavy metals. 50-tonne soil washing machines were used to treat the soil onsite. Soil washing separates the soil based on particle size. Separation of soil typesminimisesthe amount of soil that needs to be treated.
On site soil washing machine in action
B IOREMEDIATION 50,000-tonnes of oil and petrol contaminated soil were cleaned using bioremediation. Bioremediation was used to remove contaminants that weren’t removed through soil washing. Microorganisms use natural processes to remove harmful chemicals. Bioremediation is applicable for a wide range of contaminants. Bioremediation was performed above the ground because the soil had already been removed for soil washing.
F ACT F ILE, UP UNTIL S EPTEMBER, 2009 Nearly 3000 site investigations carried out into contamination. More than 200 buildings demolished Approximately six million hours worked Over 80% of 800,000 cubic metres of contaminated soil cleaned and reused.