What is waste? /Understanding Waste

Points for discussion

Put the key figures on a chart or a slide before you begin, and leave them up. You will point back at them.

What waste is, where it comes from, and how much of it there is

• What waste is — anything unwanted or unusable. Something becomes waste either because it has been used once and discarded, or because it is broken, spoilt or of no use to anybody.
• Sources — municipal (homes, shops, construction, schools and offices, treatment plants), agricultural, and industrial.
• Types — solid waste such as plastic, food and building rubble; waste water such as sewage; chemical waste including radioactive waste, e-waste, batteries and pesticides; and biomedical waste.
• How much — India produces 1,70,339 tonnes of solid waste a day and collects 1,56,449 tonnes of it, a collection rate of 92%. Of the total, 54% is treated or processed and 24% is landfilled. The remaining 22% — 37,373 tonnes every day — has no recorded destination. (Central Pollution Control Board, Annual Report on Solid Waste Management 2021-22.) Ask the class where they think that 22% goes. They will be able to point at it on the way home.
• Plastic became an everyday material from the 1950s. Ask the class what a house looked like before it: steel and brass vessels, cloth bags, glass bottles that went back to the shop, newspaper wrapped around everything, leaf plates at a feast. Then ask what has replaced each of those, and what happens to the replacement afterwards.

Where waste goes

Ask students to think about these:

• What do they think happens to the waste from each of those sources — after the handcart, after the truck, after the dhalao?
• What happens if they throw a banana peel, a piece of paper, a sheet of aluminium foil and an empty chips packet onto the soil? Which of the four will still be there next year?
• What do they see when they add one drop, then one mug, then one bucket of ink, oil, muddy water and milk into a bucket of clean water? At what point does each one stop being invisible?
• Use that to introduce “carrying capacity” and “self-recovery” — how much a system can absorb before it loses the ability to clean itself.
• Now repeat it inside a closed container, first one thing at a time, then everything together. What changes once it is mixed?
• Use that to introduce proper disposal. Ask what the best way is to deal with food waste, with metal, and with plastic — and why the three answers are different.
• What happens to the waste that leaves their own home? Do they know who takes it away? Have they watched a kabadiwala weigh newspapers, and do they know where the bundle goes next?
• What is segregation, and why does it have to happen at home rather than later?
• Have they seen a landfill? Do they think anything gets separated once it arrives there? Then go through the three real options: recycling, incineration, landfill.

What waste does

• Waste does not stop being waste at the edge of the city. Rivers carry it to the sea, and the sea does not give it back.
• Land — ground eaten by dump sites, soil poisoned by what leaches out of them, and whole neighbourhoods living beside a hill of rubbish.
• Water — unlined dumps leak into groundwater; waste dumped into a lake builds up a layer that can actually catch fire, as Bengaluru's Bellandur lake has; open defecation contaminates water; dissolved oxygen falls until the water body is effectively dead.
• Air — smell, methane, and fires. A dump catches fire by itself because the gas inside it builds up, and once alight it burns everything in it, plastic included, and the smoke reaches houses for miles.
• People — those who live and work closest to waste are usually the least able to absorb another illness.
• Money — the cost of collection, the cost of the disease, and the cost of land that nobody can use.
• Animals — cattle, dogs and birds eat plastic along with the food it was wrapped in, and die of it.
• Ocean plastic — what it does to fish and turtles, and how it works its way back up the food chain to a plate.

Plastic: the basics

• The world throws away more every year, because each person throws away more than their parents did. Ask the class to test that at home: what does a grandparent remember throwing away in a week, and what did they do with it?
• A great deal of plastic is used exactly once — what gets called single-use plastic. India has banned a list of single-use plastic items since 2022. Ask the class which banned items they still see every day.
• Plastic is made to last and used briefly. That combination is the whole problem: the material outlives its purpose by an enormous margin.
• Recycling catches only a part of it. Plastic that nobody will buy is plastic that nobody recycles — and that is the plastic lying on the street.

What plastic does in the sea

Plastic reaches the ocean mostly by river. Whatever goes into the Yamuna, into the Ganga or into a city storm drain is on its way to the sea.

• Seabirds, turtles and fish swallow it or get tangled in it. A turtle cannot tell a floating polythene bag from a jellyfish.
• Microplastic — plastic ground down small — has been found throughout aquatic life, from plankton upwards, and a good deal of that life is eaten by people.

Plastic waste in India

India's plastic waste is mostly packaging: carry bags, wrappers, film, bottles, sachets, and the plastic inside clothing, toys, household goods and building materials. Packaging is by far the largest single use of plastic.

Not all of it behaves the same way. A PET bottle has resale value and disappears from the street within hours, because somebody will buy it. A shampoo sachet, a gutkha pouch or a chips packet is made of layers bonded together that cannot be pulled apart, so nobody buys it, so it stays exactly where it fell. Send the class to look at what is lying on their own street and sort it by that one test: would the kabadiwala take it?

Plastic waste management starts before the plastic. Refuse, reduce, reuse — in that order, and ahead of recycling, because none of the three uses any energy at all.

What does get collected then goes one of several ways: recycling, incineration, a landfill, a water body, pyrolysis (turning it back into fuel), burning in cement kilns, or shredding into road-building bitumen.

Recycling

• Plastic is a large part of what an Indian city throws out, and India recycles a high share of it — not through a municipal scheme but through the scrap trade.
• The obstacle is non-segregation. Wet waste mixed with dry waste ruins both: the plastic becomes too dirty to sell, and the organic waste too contaminated to compost.
• Waste-pickers — the manual calls them rag pickers — are the backbone of waste collection and recycling in India. They are a tiny sliver of the urban workforce, they recover a substantial share of a city's waste every single day, and almost none of them are on anybody's payroll. Ask the class who employs them, and let the silence sit.
• India's recycling rate for plastic is higher than that of most rich countries, which surprises people. It is high because labour is cheap, because there is a market for lower-grade products, and because thousands of small units do the work. It also means the work is done at a low level of organisation, with poor protective equipment, by people the system does not formally recognise.

Incineration

• Burning waste changes its form and cuts its bulk. It does not destroy what was hazardous in it. Burning mixed waste, especially plastic, releases carbon monoxide, chlorine, dioxins, furans, benzene and a long list of other harmful gases.
• And it creates two new wastes: what goes up the chimney, and what stays behind — bottom ash from the furnace, and fly ash that rises with the gas. India has waste-to-energy plants, and they only work properly when what goes in has been separated first.
• Landfills and water bodies
• Plastic that is not collected reaches drains, then rivers, then the sea. India's rivers and coastline carry a great deal of it.
• Most Indian dump sites are not engineered landfills. A proper landfill has a liner underneath it, a system to collect the leachate, and a plan for the gas. A dump site has a hill, a fire risk, and people living at the bottom of it.