Home Remediation Case Studies Case Study C6: Asbestos - Asbestos Screening and Picking (Exeter)
Case Study C6: Asbestos - Asbestos Screening and Picking (Exeter)

Client

Harris and Harris Construction Ltd

Location

Exeter

Contaminant

Asbestos

Remediation Value

Circa £600,000

 

Project

The remediation strategy was designed to remove asbestos in an excavated soil stockpile to levels below 0.001%, and produce suitable materials for disposal in landfill.

 

Challenges

The site was situated within close proximity to residential areas. This required strict control of emissions and vibrations. The material contained within the stockpile had a very high moisture content, hindering the use of a screener and picking line.

 

Solution

The remediation works were undertaken under Churngold’s Mobile Treatment Licence.

All site operatives were thoroughly inducted on the work to be carried out on the site with particular emphasis of the hazards associated with asbestos. Additional specialist asbestos training (certified asbestos awareness course) was given to operatives specifically involved with the asbestos clearance activities.

Works comprised of screening asbestos containing materials (ACM) contained within a stockpile. Soil screening and hand picking in treatment beds was undertaken to remove asbestos.

 

Solution

Ten rounds of air testing (personal and environmental) were undertaken during the works by an experienced analyst.

Initially a three-belt screener was deployed to undertake particle size separation.

• Fines (<12mm)

• Oversize (>70mm)

• Main Fraction (12-70mm)

Screener output belts were observed for asbestos content during screening. The material contained within the stockpile was to wet to separate the fines, therefore only two belts were used. It was determined that a picking line would be ineffective, thus the use of picking beds was employed. Screened material was spread out in beds 150mm thick, the picking operatives worked their way through these beds to remove all visible ACM. The picking beds were periodically raked through by excavators using their bucket teeth, ensuring all material was revealed to the operatives for inspection. Picking operatives were fitted with an FFP3 half-face respirator and issued with particle tight and splash proof disposable overalls (Type 5 & 6) and disposable gloves.

Approximately 6000m3 of soil was excavated, processed and remediated. All materials passed the clean-up criteria of 0.01%.

 

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