Encountering asbestos containing materials during a site investigation or redevelopment

5 Encountering asbestos containing materials during a site investigation or redevelopment 

If a site has a history of previous buildings being abandoned, demolished or any industrial processes that may have used asbestos, or led to waste materials being deposited on the site, then it is very likely that asbestos debris or materials will be present within the soil or fill material. 

The potential presence of these materials can usually be identified by a desktop study, which typically would search through the documented history of the site and determine the previous usages and changes that it may have undergone. Additionally, a site investigation may determine the presence of building rubble or made ground that is obviously not natural and may contain unknown contaminants such as ACMs. 

Prior to any works on site, a risk assessment should be carried out and possible control or preventative measures put in place to minimise any release of asbestos fibres and subsequent exposure of the operatives working on the site, or members of the public who may live, work or have right of way near the site boundary. If there is a strong possibility of ACMs being disturbed then it may be considered prudent to carry out reassurance air monitoring during the works to determine the airborne fibre levels and hopefully prove that no increase in the background fibre levels has occurred. 

As with any work involving the disturbance of ACMs, the important fact to remember is that the airborne fibre release must be kept to an absolute minimum (as low as is reasonably possible) and that reliance upon RPE/PPE must not take precedence over the ability to reduce or minimise fibre release. 

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