Issue Date: November 2023

The CL:AIRE “Professional Guidance:  Comparing Soil Contamination Data with a Critical Concentration” publication (v 1.1 February 2021) emphasised the importance of developing, refining and thoroughly understanding the Conceptual Site Model (CSM) prior to considering whether statistical analysis would be applicable for a soil contaminant data set.

In response to this publication, SoBRA set up a sub-group in 2022 with the intention of providing technical guidance to support risk assessment practitioners to understand the soil contaminant element of the CSM prior to carrying out any generic or detailed quantitative risk assessment (and any associated statistical analysis).  The guidance provides a series of tips on the key data sources that should be considered and the questions that should be answered by risk assessment practitioners, to ensure that the soil contaminant distribution is correctly interpreted, not only in the context of its chemical properties and the environmental setting, but also how the distribution and CSM may change over time through human and environmental influences.