Subsequent to the catastrophic release of methyl isocyanate in the form of a toxic gas at the
Union Carbide plant in Bhopal, India in December 1984, the factory was closed. The release
killed thousands of people in the vicinity of the plant and left many more thousands suffering
from permanent damage to their health. The cessation of operations at the plant, which was
engaged in the production of a range of pesticides and intermediates was not followed by
remediation of the site. The methyl isocyanate can be presumed to have been dispersed and
degraded in the atmosphere following its release. The same, however, was demonstrably not
the case for other chemicals in the site production and generated wastes portfolio. Moreover,
there is also a legacy of pollution of the site with metals and organic contaminants both inside
and outside the plant.
Within the factory walls the soil is contaminated, in some places very seriously, while some of
the remaining buildings still house stockpiles of unwanted chemicals. Local people, including
children, regularly enter the site, risking exposure to raw chemicals and those contaminating
the soils. Some local residents even graze their cattle there, opening up the possibility of
indirect exposure to contaminants that can be passed on via milk to humans.
The areas adjacent to the factory site, outside the perimeter fence, are also seriously
contaminated. Solvents and other chemicals spilled or leaked into the soil have migrated into
the groundwater. Many thousands of the local inhabitants depend upon the groundwater
resources for cooking washing and drinking purposes. Further threats to groundwater resources
are posed by the former solar evaporation ponds (SEPs) on the site. Union Carbide formerly
discharged much of their liquid industrial effluent into these ponds situated towards the north of
the factory perimeter as a primitive form of waste treatment. The ponds, containing the solid
residues from evaporation were capped with plastic liners and soil in an attempt to prevent the
pollutants being mobilised and moving offsite. The containment, however, has been breached
in at least one location. Leaching of pollutants from them consequently poses an additional
threat to the local population and the groundwater resources.
Accordingly, an urgent need exists to clean the site up and carry out a full post-production
remediation. A site of the size and complexity of the Bhopal plant presents formidable
challenges if remediation is to be carried out to acceptable standards in terms of final
environmental quality achieved and the ongoing hazards posed to human and environmental
health. The remediation process needs to be carried out the highest possible standards. This
report, therefore, is designed to provide some insight into appropriate operational standards and acceptable methods and protocols to be applied in order to achieve these.