Strategic Action Plan - International Environmental Technology Centre

Strategic Action Plan Report
industry, as well as in construction and other solid waste management operations. The following are the
major steps followed for landfill mining:
• Excavation - The contents of the landfill cell are excavated and bulky material is separated out. The
excavated waste is then organized into manageable stockpiles.
• Soil Separation (Screening): Screening is done using a trommel or vibrating screens to separate out
soil in the excavated material. The size and type of screen used depends on the end use of the
recovered material. Generally smaller mesh screen is used to remove small pieces of metal, plastic,
glass, and paper.
• Processing for Reclamation of Recyclable Material or Disposal: Depending on conditions, either
the soil or the waste could be reclaimed. The separated soil could be used as fill material or as daily
cover in a SLF. The excavated waste can be processed at a materials recovery facility to remove
valuable components (e.g., steel and aluminum) or converted to RDF which then can be used for
producing energy.
For landfill mining program there are several benefits as well drawbacks which need to be looked into. Some
of these are given below:
Potential Benefits
• Landfill mining extends the life of the current facility by removing recoverable materials and reducing
waste volume through combustion and compaction.
• Recovered materials, such as ferrous metals, aluminum, plastic, and glass, can be sold.
• Generation of revenues from the sale of reclaimed soil:
• Combustible reclaimed waste can be mixed with fresh waste and converted to RDF which then can be
burned to produce energy.
• Reducing Landfill Closure Costs and Reclaiming Land for Other Uses:
• Liners and leachate collection systems can be installed at older landfills, once the mining of major
portionof the dumped MSW is done. Also, hazardous waste can be removed and managed in a more
secure way.
Box 5.1: Feasibility Studies on Landfill Mining
The dumpsites at Kodungaiyur and Perungudi, near Chennai were taken up for feasibility studies on
mining of decomposed material.
The study indicated that about 65% of the samples recovered from the dumpsites of about 10 year old
was fine particles. The fill at these dump sites were shallow with a depth of about 3 m and no
significant variation in waste characteristics was noticed with depth of the fill. This fine fraction of the
samples can be used as compost for non-edible crops or as cover material to future landfills after
determining the geotechnical suitability. In dumpsites with uncontrolled dumping, the degradation
process is not uniform and the recovery of fine fractions is not possible. A few heavy metals in the
recovered material exceed the Indian standard for compost but well within the USEPA limits for
compost. There is significant difference in the concentration of heavy metals such as Cu, Cr, Ni, Pb
ISWM Plan for Pune 108