AGS has recently published updated guidance for intrusive investigations of contaminated sites. This version replaces the 2012 version of the same name. 

The guidance states that prior to any investigation a desk study should be completed to identify potential contaminants associated with historical and current activities on the land. Hazards associated with these contaminants should then be used to inform a risk assessment for the investigation and sampling activities. It should be noted that the desk study information may be incomplete and should be treated as a guide only.

The British Drilling Association’s site categorisation scheme (green, yellow or red) should be determined based on the desk study (BDA 2008). Notes on the application of these categories are provided by AGS and the category indicates the type of controls, PPE and safety equipment needed for the investigation.

The guidance can be accessed here