Revised guidance on contaminated land

Revised guidance on contaminated land


Author: Sophie Wilkinson

Revised statutory guidance in relation to the contaminated land regime has been laid before Parliament, along with regulations amending the definition of when land will be determined as contaminated

The revisions are intended to focus regulator resource on high risk sites but some have argued that the effect may be to make development of some sites easier at a cost to health protection. The changes are expected to become effective on or soon after 6 April 2012.

Amended definition of contamination

Currently, land will meet the definition of contaminated if:

  • significant harm is being caused, or there is a significant possibility of significant harm being caused, to human health or the environment or
  • pollution of controlled waters is being, or is likely to be caused

The definition will be amended by introducing a higher threshold test in the case of water pollution. The regulators will need to show there is significant water pollution or a significant risk of significant water pollution.

The amendment will rectify the anomaly that significant harm to the environment or human health (or a significant possibility of the same) is needed for land to be contaminated but that any water pollution achieves the same result.

Revised Statutory Guidance

The revised guidance is shorter and simpler. Authorities must also use their powers to designate land as contaminated only where no appropriate alternative exists.

Other useful amendments and clarifications include:

  • acknowledgment that background levels of contamination, arising as a result of natural processes or diffuse human pollution, are unlikely to cause land to be contaminated
  • mandatory risk summaries where the regulator has determined that a site is likely to be contaminated. The risk summaries will be publicly available if the site is designated as contaminated land
  • a four category test for determining if significant possibility of significant harm exists for human health:

- this will make it easier for regulators to dismiss low risk (or category 4) sites and focus resources on higher risk (category 1) sites

- for moderate risk sites consideration must first be given to health effects but if a decision cannot be made as to whether a site is category 2 (contaminated) or category 3 (not contaminated), then consideration can also be given to socio-economic factors

  • a similar four category test for determining significant water pollution or a significant possibility of the same
  • local authorities can decide if a site is or is not contaminated on the basis of information provided to it by the landowner or another interested party
  • designation of a site as contaminated can be postponed if the landowner or some other person undertakes to deal with the problem


The revisions emphasise that resources should be focussed on the highest risk sites and give regulators more confidence to determine these sites as contaminated.

There is also some clarity around when sites will be considered to be lower risk and a focus on being pragmatic. However some argue that this is at a cost to health protection.

Time will tell how the revisions will operate in practice and if the result is an increase or a decrease in the number of contaminated land designations.