Any physical, chemical, biological, or radiological substance
or matter that is in, on or under the land and that has the potential
to cause harm to human health or the environment.
In the UK, a contaminant is 'a substance that is in, on
or under the land and that has the potential to cause harm
or to cause pollution of controlled waters' as defined
in 'CLR11 Model procedures for the management of land contamination'
published by Defra and the Environment Agency.
Contaminants could be chemical, biological, or radiological
material and may be in the form of solids, leachable material
dissolved in water, non-aqueous phase liquids (eg chlorinated
solvents), gases or vapours. Contaminants are often associated
with human activities at or near to the site, such as industrial
processes or waste treatment, but they may also come from
natural sources, such as radon for volcanic rocks etc.
The presence of contaminants does not mean that harm is
occuring, this depends on many factors including the concentration
and properties of each contaminant.
Policy and regulatory information
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