Diapositive 1

1
Stade de France
Built on an industrial waste land
H. Gregory C. Denis
2
Introduction
1912-1966 (54 years) Cornillon gas
factory Produced gas for heating and lighting
60kg of tar 150l of ammoniacal water
1 ton of coal
Waste stocked on site
3
Background
Geological bassin of sedimentary rocks
Soil composition
Successive marine deposits
More than 50 000m³ must be treated
First idea incineration
Impossible for economical reasons too much soil
4
3 types of contaminated soil

• 1st pitch, tar, bitumen and soil containing
  polycyclic aromatic hydrocarbons (PAHs)

• 2nd soil with PAHs concentration, c

• 3rd soil with PAHs concentration, c

PAHs concentration gt 50,000 ppm
500ppmltclt50,000ppm
30ppmltclt500ppm
Soil with hydrocarbons concentration lt 30 ppm are
considered inert
Solution incineration
Solution Biological treatment in situ
biological mound
Not dangerous to health or stadium construction
Rocks which cannot be cleaned up that way were
washed with special machinery
left in place but laid out in layers separated
from the surface and the water table
(ppm parts per millions1 milligram per kilogram
of soil (mg/kg) )
5
Possible solutions

• Physical methods
• Soil washing
• Incineration
• Soil vapour extraction systems - PVC pipes are
  used to collect gases
• Barrier a vinyl sheet protects upper layer
  (including playing field)
• Solidifaction / Stabilisation - Excavated and
  cement / bitumen added in a cold stabilisation
  plant.

• Biological methods
• Bio-remediation
• Aeration inject air into / puncture the soil,
  enabling a phase transfer of hydrocarbons from
  dissolved to a vapour phase

6
Bioremediation

• 530,000 cubic feet of earth cleaned in this way.
• Soil moved into a biological mound
• Decontaminated by adding micro-organisms and
  nutrients into the soil
• Activates the naturally occurring microbes in the
  soil, degrading the contaminants.
• Reduces the degradation time to a few months
  (usually take 100s of years)

7
Soil washing

• Inexpensive
• Soil washing separates soil by particle size.
• Most organic and inorganic contaminants tend to
  bind and sorb to clay, silt, and organic soil
  particles. Most silt and clay sticks to larger
  particles like sand and gravel.
• Surfactants or similar mild solvents helps remove
  petroleum hydrocarbons and other organic
  contaminants.
• The separated material is smaller in volume and
  is more easily disposed of or further treated.

8
Conclusions
The contamination was actually cleared rather
than prevented from travelling further with a
barrier Maintenance and inspection not
necessary Very expensive Time consuming (2
years) It was successful!