CL:AIRE is pleased to announce that "Professional Guidance: Comparing Soil Contamination Data with a Critical Concentration" has been published and is now available to download for free from the CL:AIRE website.

The new guidance was written by statistician Nigel Marriott, supported by a steering group comprising representatives from Environment Agency, Nuclear Decommissioning Authority (NDA), RSK, Soil and Groundwater Technology Association (SAGTA), Society of Brownfield Risk Assessment (SoBRA), and Yorkshire and Lincolnshire Pollution Advisory Group (YALPAG).

The guidance updates a 2008 document of a similar name that was published by CL:AIRE and the Chartered Institute of Environmental Health, supported by SAGTA. As the guidance adopts an entirely different approach to the previous guidance, it completely supersedes it and the 2008 document has now been withdrawn.

The 2020 revision addresses the problem of potentially erroneous conclusions by dropping the reliance on a single scientific test and emphasises the importance of a comprehensive understanding of the datasets in the context of the conceptual site model.

SAGTA, NDA, Environment Agency and RSK are gratefully acknowledged for their funding of this project.