Under Part IIA of the Environmental Protection Act 1990 the statutory definition of contaminated land is;

land which appears to the local authority in whose area it is situated to be in such a condition, by reason of substances in, on or under the land, that -
(a) significant harm is being caused or there is a significant possibility of such harm being caused; or
(b) pollution of controlled waters is being, or is likely to be, caused.

The statutory definition covers land, which poses unacceptable risks to human health or the environment, in its present condition and circumstances.

Under new regulations, which came into force in July 2001, all local authorities in Wales must inspect land in their area for the presence of contamination.

Each local authority must publish an inspection strategy detailing how it plans to undertake this inspection process in a rational, ordered and efficient manner.