Remediation of legacy waste dumpsites

Remediation of legacy waste dumpsites

Subject: Environment

Section: Pollution

Context: The recent past has seen a paradigm shift in waste management policy in India, focussing extensively on the remediation of legacy waste dumpsites in the country.

More on the News:

• A proper roadmap to divert the combustibles (plastics, paper, textiles, leather, wood, etc) recovered during the biomining process would be extremely critical to dumpsite remediation.
• The combustible fraction constitutes about 8-20 per cent of the legacy waste in an old dumpsite. That means India has to deal with nearly 13 million-32 million tonnes of combustible materials lying in around 3,159 dumpsites in the country.
• These combustible materials (typically referred to as segregated combustible fraction or SCF) are excavated as an end-product of the legacy waste dumpsite remediation process.
• SCF are typically contaminated with inert material and high moisture content (more than 30 per cent), making it not so desirable for the cement factories.
• As a result, many urban local bodies are struggling to find economically viable options for the disposal of recovered material, including combustibles.
• Currently, the only available option is co-processing in the cement industry. Co-processing refers to the use of waste materials having high calorific value as alternative fuels or raw materials (AFR) to recover energy and material from them.
• Due to the high temperature in cement kilns, different types of waste can be effectively disposed of without harmful emissions.
• A variety of wastes, including industrial wastes and plastics, can be disposed of in an environmentally safe and sound manner through the technology of co-processing in cement kilns, according to the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal.
• In cement kilns, different kinds of hazardous and non-hazardous wastes, including plastic wastes, get utilised as AFRs.
• During the usage of plastic wastes in cement kilns as AFRs, the material and energy value present in them get fully utilised in the cement kiln. In this manner, plastic waste can replace the raw materials and fossil fuels that are conventionally utilised in kilns.

Challenges in Co-processing:

• Expensive additional critical infrastructure required for co-processing the SCF recovered from biomining.
• Quality of RDF (recovered from biomining of legacy waste dumpsites): compromised due to high moisture and ash content.
• High cost of transportation

Recommendations:

• These are the recommendations to amend the Solid Waste Management Rules 2016 as suggested by MoHUA:
• The cement plants located within 400 km of a solid waste-based RDF plant shall make necessary arrangements to utilise RDF in the following phase-wise manner at a price fixed by the state government. Such units should:
  • Replace at least 6 per cent of fuel intake within one year from the date of amendment of these rules (equivalent calorific value/thermal substitution rate) by municipal solid waste-based SCF and/or RDF, subject to the availability of RDF.
  • Replace at least 10 per cent of fuel intake within two years from the date of amendment of these rules (equivalent calorific value/thermal substitution rate) by Municipal Solid Waste based SCF and/or RDF, subject to the availability of RDF.
  • Replace at least 15 per cent of its fuel intake within three years from the date of amendment of these rules (equivalent calorific value/Thermal Substitution Rate) by Municipal Solid Waste based SCF and/or RDF, subject to the availability of RDF.
  • The transport cost for SCF/RDF up to 100 km from the cement plant shall be borne by the cement plant; however, beyond 100 km cement plant can transport at its own cost or by ULBs as mutually agreed upon by the parties.