Chongqing, China, 23 Dec., 2003

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Chongqing, China,23 Dec., 2003

• R.A. Hawrelak
• CBE 497
• CBE 317

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The Incident

• Rupture of natural gas well kills scores in
  China.
• A toxic gas cloud of CH4 and H2S covered an area
  roughly 4 km wide by 6 km long.
• The cloud spewed CH4 and H2S 30m high into the
  air.

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Results

• 233 people killed.
• 64,000 forced to flee their homes.
• 9,000 people hospitalized.
• Thousands of dead animals including
• 2,275 rabbits
• 866 pigs
• 241 ducks
• 476 chickens
• 38 dogs

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Reasons for Incident

• A series of missteps by workers and negligence by
  gas field developers triggered a toxic cloud that
  spewed natural gas with a high concentration of
  H2S.
• Gas drilling rigs usually have blow-out
  preventers installed in the drilling pipe.
• It is not known at this time if the well
  developers used this common safety device.

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Mitigation

• 24 hours after the incident started, disaster
  workers ignited the gas streaming from the well
  head to burn away the toxic fumes.
• They attempted to plug the well with 260 cu.m. of
  cement and earth moving equipment. However, there
  are no reports that this was successful.

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H2S Toxicity
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H2S Toxicity
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Typical Dispersion Results
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Typical Dispersion Results
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Typical Dispersion Results
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Lessons Learned

• No Emergency Warning system in place.
• No Emergency Evacuation plan in place.
• Workers were unsure of emergency procedures.
• Hospitals were poorly equipped to handle all the
  injured.

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End of Presentation

• There will be questions on the final exam
  relating to toxic gas incidents.

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