A Phase II contaminated land assessment is required where the conceptual model developed during Phase I identifies areas of high risk that cannot be mitigated, or where further information is required (i.e. where a risk of soil or groundwater contamination exists). These investigations involve intrusive sampling of the soil and groundwater and sometimes soil gas.
The purpose of a Phase II assessment is to determine whether any contamination exists and, if so, what the extent and level of contamination is. This information is then used to refine the conceptual model and risk assessment. The risks arising from the contaminants present on the site are assessed for all potential pathways of exposure to determine whether they are acceptable. This is commonly achieved using soil guideline values (SGVs) or by using the Environment Agency’s CLEA model. In instances where the risks cannot be adequately mitigated and are considered unacceptable, remediation will be required prior to development.
Ecospan Environmental Ltd usually undertakes intrusive sampling of contaminated land and in situ groundwater or soil gas using the Geoprobe.