WA’s Department of Mines, Industry Regulation and Safety (DMIRS) recently released an information sheet explaining how to deal with soils at a workplace which are contaminated with asbestos-containing material (ACM).
Asbestos in soils only poses a risk to the health of workers if the fibres become airborne and are then inhaled.
The likelihood of exposure depends on the nature, quantity and distribution, condition (that is, whether it is non-friable (bonded) or friable (crumbles under hand pressure, non-bonded)), level of disturbance, and systems of work and controls used to limit the release and inhalation of asbestos fibres.
Non-friable asbestos is asbestos that is bound tightly in a matrix (e.g. asbestos cement fencing, eaves), while non-friable asbestos may become friable after severe degradation, such as during a fire or as a result of a chemical ‘attack’.
Friable asbestos refers to asbestos that can be broken up using hand pressure. Examples include asbestos pipe lagging, asbestos fibres spread by high-pressure cleaning of asbestos cement, or fire damaged asbestos cement sheeting that has spalled. Friable asbestos presents a greater health risk than non-friable due to the increased chance of fibre release.
Asbestos contaminated soils must be inspected by a competent person such as a consultant who has the relevant training, knowledge and experience to undertake the task. The detail of inspection required depends on a number of factors including:
The information sheet said residential sites with contamination can be reported to the Local Government Authorised Officer (Environmental Health Officer) who has powers to regulate asbestos contamination under the Health (Asbestos) Regulations 1992.
Recent or minor, small scale soil contamination at workplaces can be removed using safe systems of work under the Occupational Safety and Health Regulations 1996.
Removal of non-friable asbestos in soil contamination of 10 square metres or more (total asbestos surface area) may be conducted by a restricted or unrestricted asbestos licence holder.
However, if the asbestos contamination is friable or mixed friable/non-friable, an unrestricted asbestos licence holder should be engaged. An independent consultant may also be required to assess and manage the site to address the client’s compliance with environmental legislation.
“It is important to note that soil remediation work is a specialised activity and may require additional competency, skills and resources. As such, the selection of a restricted or unrestricted licence holder should consider the resources, skills and experience required for soil remediation work. Controls and safe systems of work must be used during the removal of asbestos in soils,” the DMIRS said.
Following removal, the adequacy of the work will need to be assessed, and the soil validation will depend on the remediation approach adopted and the form of asbestos. Sampling should be conducted to check that the decontamination is complete. Air monitoring based on risk should be conducted to ensure exposure controls are effective.
Contaminated soils must be contained using an appropriate method and accompanied by a warning label or sign prior to transport to a licenced waste facility. Appropriate systems of work must be used to decontaminate the vehicles used after transport of the asbestos-contaminated soils.