Risk assessment for contaminated land – 2014 update (P2963)

For almost 20 years, risk assessment has been the core principle for the management of contaminated land in the UK.

However, the level of exposure to contaminants at which the receptors are at significant harm or significant possibility of significant harm (SPOSH) has been at the centre of debate for many years.

CIRIA report Contaminated land risk assessment - A guide to good practice (C552) was published over 10 years ago and there is now significant scope to update the publication. 

The subject has attracted a lot of attention, particularly since the revised Part 2A Statutory Guidance published in 2012. This guidance introduced 4 new categories in determining sites where risk may poses a significant possibility of significant harm (SPOSH): 'Category 1 is land where risk is clearly unacceptable; to Category 4 where the risk is acceptably low.'

In March 2014, DEFRA published a series of reports (which include the policy companion document) and ‘Category 4’ values for 6 contaminants, including arsenic, benzene, benzo(a)pyrene, cadmium, chromium (VI) and lead. These are highly complex documents and is why in several places, it a stated that there is a need for a ‘suitably’ qualified person with good understanding of toxicology.

This project will bring together current understanding and experience in assessing technical risk in contaminated sites. It will also develop good practice to further help practitioner and regulators with the process in light of the publication of guidance, such as those related to C4SL in different brownfield scenarios.

Project status

CIRIA is currently undertaking scoping of the proposed project and approaching potential funders.

Further information

For more information and to get involved in the project, please contact Joanne Kwan.