26/09/2019 - Environment | Mainstorming

IAS Parliament 5 years

KEY POINTS

· The first rule of waste management all over the world is that households must segregate their waste before it is collected from the doorstep. The Solid Waste Management Rules 2016 prescribe the same.

· If we do not mix wet waste with dry waste, the burden of solid waste management on our municipalities reduces significantly. The wet waste can be composted locally; the dry recyclable waste can go for recycling and what remains can be safely disposed.

· Waste collection is organised daily for wet waste and once a week for dry waste. This is important because the unmixed transportation and processing of wet and dry waste encourages citizens to keep their waste unmixed too.

· Wet waste, more than half the total waste, is used for composting or bio methanation in a decentralised manner. It reduces, at one stroke, the need for long-distance transportation of waste by half.

· The perils of waste to energy plants which rely on the incineration of mixed waste. Such plants in India have been either non-starters or highly polluting failures. Even so, several cities are actively promoting incineration of mixed waste.

Avoiding Compactors

· Compactors are expensive machines that squeeze and compress the volume of waste.

· They enable more waste to be carried per trip and, thus, reduce transportation costs. The central message was that garbage was now going to be out of sight, and there will be no stench and vector-borne diseases in the vicinity.

· Use of compactors on mixed waste makes it almost impossible to extract the recyclable dry waste such as plastics, metal, paper and cardboard from the mixture. The compression of wet waste in the mixture releases leachate (a black foul-smelling liquid) that is difficult to dispose.

· Leachate percolates into the soil and contaminates groundwater. When it drains off into the sewer system, it overloads the sewage treatment plants.

· After the compacted waste is transported and dumped, the lack of aeration at the site results in the decomposing wet waste generating methane, a potent greenhouse gas that causes global warming.

· As waste pickers routinely light fires at landfill sites to extract scrap metal, the presence of methane gas stokes the fire further, and the presence of PVC plastic in the compacted waste means that the burning of plastics would release carcinogenic dioxins and furans.

· A much smarter alternative for municipalities under Smart Cities Mission would be to promote decentralised composting of wet waste, tie-up with local kabadiwalas or NGOs for recyclable dry waste, and work on safe disposal of the rest. for more sustainable methods of waste management.