What is a Contaminated Site?

"A site at which hazardous substances occur at concentrations above background levels and where assessment indicates it poses, or is likely to pose an immediate or long-term hazard to human health or the environment."

For an area of land to meet this definition of a contaminated site it must:

Be an identified delineated area of land (a site) such as a landfill or a transport depot;
Have an identified contaminant (a hazardous substance) at a known concentration present in soils on the site, or discharging from the site;
Have the identified contaminant in concentrations that are higher than what would “normally” be expected for a non-contaminated site; and
Because of the contaminant’s location and concentration, pose a threat to people and/or the environment.

This definition, while useful is very broad, and can cover a range of situations and a range of risks and some care needs to be taken in the use of this definition.

Hazardous substances could pose a threat to people or the environment through various physical and chemical properties such as:

Toxicity
Carcinogenicity
Corrosiveness
Combustibility
Explosiveness
Asphyxiation.

It can be seen that the contamination of land and its surrounding areas, can be vary in both its nature and degree of severity. However, in many instances, land contamination can be related to site usage. Establishing a site’s current and historic land use is a worthwhile starting point in any risk assessment as it can provide important clues to the nature of the contamination and the types of contaminants that could be present.

Click here to see a list of sites that, because of their past or current uses, might possibly be contaminated and landuses and associated contaminants (69kb).

Click here to see a description of the responsibilities and roles that individuals, organisations and the government have in respect of contaminated sites.

Page last updated: 01 May 2007