Fine soil-like materials (FSLM)

• Context (DTE): Fine soil-like materials (FSLM) recovered from legacy dumpsites may contain contaminants; therefore, they must be tested before being used in any application.
• FSLM is produced during the Biomining (bioremediation technique) of waste dumpsites.
• FSLM is the largest component obtained from landfill mining. It has little or no economic value.
• FSLM, comprises particles smaller than 6 mm. Fine materials in 4-6 millimetres are called ‘bio-earth’ or ‘good earth’ materials.

Application of FSLM

• Soil enricher.
• Filler material for low-lying areas.
• Used in road construction.
• Brick making.

Issues

• As per Central Pollution Control Board guidelines, FSLM must comply with the Fertilizer Control Order standards to be used as a soil enricher. However, in most cases, they do not comply.
• They are not tested for toxic metals before being used as a filler material.
• Heavy metal contamination is a significant risk associated with using untested FSLM.
  • Toxic metals (lead, mercury, cadmium, and arsenic) can harm human health.
  • Additionally, heavy metals have the potential to accumulate in plants and animals. This can lead to bioaccumulation.

Way forward

• The comprehensive “Guidance document for assessment and remediation of contaminated sites in India” by MoEFCC serves as a roadmap for tackling the issue.
• It sets clear boundaries for acceptable levels of heavy metals and toxic contaminants through two key sets of standards (Environmental Quality Standards (EQS) and Threshold Limit Values (TLV)).
• These standards can be utilised to assess the gainful application of FSLM recovered from landfill waste.