Management of soil contamination with asbestos
Section 7 of the “2011 Code of Practice on Safe Asbestos Removal”, titled “Controls for Specific Asbestos Removal Jobs”, lists the procedure for handling asbestos-contaminated soil. Soil is contaminated when asbestos-containing material (ACM) is dumped into the topsoil, or buried materials are disturbed during activities such as agriculture, road construction, or exposure to the elements.
Guidelines:
1. Evaluation
This step is necessary for the assessor to recommend the best and most relevant steps to follow to decontaminate the site. It is quite short and should only be done by professionals, according to the criteria of the Environmental Protection Heritage Council.
2. Sitemap
The surface, the shape, the areas of greatest contamination and their boundaries must be marked on the plan, which must have a key to serve as a guide.
3. Elimination
After evaluation, samples may need to be taken to an accredited laboratory to determine the type of asbestos present, whether adhering or friable.
The wet method should be used, as wet soil accumulates. No fiber will float in the air in this way.
4. Licenses
A Class B license holder is only required to participate when the asbestos in the soil has been correctly identified as non-friable. A Class A licensee must only work on friable asbestos.
5. Security:
Air monitoring: should be done at suitably spaced intervals as work progresses. The level of fiber in the air should not exceed 0.01 fibers per square milliliter.
Barricade: a fence should be placed around the work area and cordoned off with a 200 micrometer thick plastic sheet.
Personal Protective Equipment (PPE): Full-face respirators with constant air supply are best for protecting the face. Thick disposable coveralls should be worn as fine asbestos particles can float through thin or coarse clothing.
Inside the enclosure, a negative air supply unit must be used.
6. Settlement
A clearance certificate must be issued after friable asbestos removal by a certified inspector, who certifies that the area is safe for use once again. The process involves monitoring the air inside and outside the enclosure immediately before and immediately after removing the enclosure. In addition, the route used to transport the asbestos must be cleared.
A suspect site whose soil is suspected to have been contaminated by asbestos can vary in degree, in terms of description and classification, from contaminated to remediated. In between, it could be contaminated requiring investigation, requiring restricted use, cleaned up but for restricted use and not contaminated. That’s in accordance with the Contaminated Sites Act of 2003. A site whose use is restricted means that it is difficult to establish the full extent of the contamination, and only cleared areas can be used. Most of the time, the usable area is delimited.
When soil is contaminated, it presents a risk when it is agitated and the fibers become airborne, or when edible plants grow in it, they absorb it when it is leached and can end up in the human bloodstream.