THE ORGE RIVER
polluted during wet weather
02/2005
Vallee Aurelie
European class
Situation of the basin
• The basin of the Orge river belongs to the
parisian basin.
• The river is above Paris and it’s a tributary
of the Seine river.
• It flows out for 52 km and goes through
urbanized areas.
• The basin is a 950 km² area.
02/2005
Vallee Aurelie
European class
Sources of pollution in this river
during wet weather
Overloaded of purification stations
 Wrong connections in the treatment plant
Saturation of the waste water’s pipes
Urbanized running water carries away metals,
hydrocarbons, weedkillers and others pollutants
02/2005
Vallee Aurelie
European class
Impacts on the environment
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Gas exchanged inhibited by hydrocarbons
Destruction of ecosystems caused by toxicity
Increase of the turbidity of water,
flora cannot do photosynthesis any more
Stop of oxygenation of the water
Decrease of the biodiversity
Evapotranspiration restricted by urbanization
02/2005
Vallee Aurelie
European class
Solutions against the pollution of
the Orge river
• Installation of decant stations
• 10 desanding pools and deoilers
• Surveillance in continue to monitor the quality of the
water
All the data is sent to a central database management.
• Each year hydrobiologists make a report
• In the case of accidental pollutions:
 Samples taken to be analyzed in labs
 Floating waterblocks to stop and absorb pollution
 Pumping trucks can be used in specific case
02/2005
Vallee Aurelie
European class
Example of machine to clean the
water
02/2005
Vallee Aurelie
European class
http://step.ouvaton.org/tech3.htm
Evolution of Orge water quality
• Improvement until the beginning of the
80’s
• Then stagnation of the quality for 10 years
• About flora & fauna: status quo
Poor biological quality water
But the downstream section where the
deterioration has been curbed, shows the
improvements in cleaning up rainwater
and restoring the vegetation of riversides.
02/2005
Vallee Aurelie
European class
Evolution of the basin
02/2005
Vallee Aurelie
European class
• http://www.sivoa.fr
• http://step.ouvaton.org/tech3.htm
02/2005
Vallee Aurelie
European class