Contaminated land is land that contains harmful substances and
is a risk to people's health and the environment.
To be legally defined as ‘Contaminated Land’ land must contain a
contaminant - a Source - and have a
means for the products of that contamination - a
pathway - to reach people or environments which it is
likely to harm - receptors.
The contamination can be a result of:
- Historical industrial use
- The disposal of waste materials
- Accidental spillages
- Illegal activities
- Natural sources
The Government has passed laws requiring councils to look
for sites which could be contaminated. When we find legally defined
contaminated land we can take appropriate action to prevent the
risks to people and the environment.
Sites under investigation
Types of contamination
In the past there were few safeguards to protect people and the
environment from contamination in the ground.
Industry
This type of contamination can vary but some of the more common
contamination problems are from fuels, which can give off gas and
seep into watercourses. This causes harm to life in rivers and
streams and spoils a valuable resource. Others include former
Chemical works where contaminants may produce vapours which may
seep into people’s homes.
Waste
Domestic and industrial waste was often disposed of by burying
it in convenient spaces such as former quarries (landfills). The
decaying waste material produces gases such as methane which can
migrate underground harming vegetation and entering proprieties.
This could cause a risk to people living there.
Nature
Natural processes can also result in contamination. When certain
rock types decay and breakdown due to natural erosion they can
release chemicals into the soil that could be a problem for people
living in the area.
Deciding if land is contaminated
When we investigate contaminated land we follow guidance set out
by
DEFRA using the Source, Pathway and Receptor principle. All
three elements must be present for the site to be legally defined
contaminated land.
- The source is the contaminant which is likely
to cause harm to people or the environment
- A pathway is a way in which the contaminant
can reach a receptor
- The receptor is the person or environment that
could be harmed.
Development and Contamination
It is important that, for any new development or change of use
to a more sensitive development (for example, a former industrial
premises such as a mill being changed to apartments), an
investigation is carried out to assess the site's previous use and
identify any contamination. Any identified contamination must be
dealt with, if the development is to proceed, so that the site is
safe for its intended end use and is not a risk to the
environment.