There are six main things a society can do with its rubbish, and not one of them is clean. Two bury or burn it, one ships the problem abroad, and three send the material back into use. Knowing the trade-offs of each is what an exam question on disposal is really testing.
📘 What you need to know
The six disposal methods: landfill, incineration, waste-to-energy, exporting, recycling and composting.
Every method has advantages and disadvantages that affect both ecosystems and societies.
Landfill is cheap and flexible, but produces methane and risks leachate contaminating groundwater.
Incineration cuts waste volume sharply, but causes air pollution and leaves toxic ash.
Waste-to-energy recovers usable energy, but is expensive and can still encourage waste generation.
Exporting relieves domestic pressure, but raises environmental injustice and transport emissions.
Recycling conserves resources and saves energy, but needs facilities and clean, uncontaminated material.
Composting turns organic waste into fertiliser and keeps it out of landfill, but only works for biodegradable material.
1. Landfill sites
Landfills bury waste in designated areas, in large holes dug into the ground. A modern engineered landfill is more than a hole, though, and the engineering is what separates a reasonably safe site from a dangerous one.
Leachate is the liquid that trickles through buried waste, picking up chemicals as it goes. The liner and collection pipes exist entirely to stop it reaching the water table.
Advantages
Disadvantages
Centralised — one location manages large volumes of waste
Methane generation from decomposing waste, a potent greenhouse gas
Flexible — handles a wide range of materials, including non-recyclables
Land requirements are significant, and suitable land is hard to find
Lower operational costs than most other disposal methods
Risk of contamination of groundwater and soil from leachate
Reduced impact when engineered with liners and leachate collection
Long-term monitoring is needed for years after the site closes
Gas capture — some sites collect methane and use it as an energy source
Environmental injustice — noise and smell pollution usually fall on less affluent urban outskirts
2. Incineration
Incineration burns waste at high temperatures to reduce its volume.
Advantages
Disadvantages
Reduces waste volume drastically
Air pollution — emits harmful gases and pollutants, including greenhouse gases
Less reliance on landfill, so less waste is buried
High operational costs for the technology and maintenance
Handles hazardous waste that can be processed safely at high temperature
Public concern — communities often oppose incinerators on health grounds
3. Waste-to-energy (WtE)
Waste-to-energy plants, also called energy-from-waste (EfW), burn waste specifically to generate electricity or heat. It is incineration with the energy captured rather than wasted.
Advantages
Disadvantages
Energy recovery — converts waste into usable energy, reducing reliance on fossil fuels
High capital investment to build, operate and maintain
Significant volume reduction
Limited by composition — not all waste converts efficiently to energy
Provides a predictable, controllable energy supply
Not a perfect solution — a plant needs feeding, so it encourages waste generation rather than reduction
That last disadvantage is the one worth remembering. Once a city has spent a fortune on a waste-to-energy plant, it needs a steady stream of rubbish to keep it running. That creates a quiet incentive against reducing and recycling, which is exactly the opposite of what the waste hierarchy asks for.
4. Exporting waste
Exporting means sending waste materials to other countries for treatment, recycling or disposal.
Advantages
Disadvantages
Offloads responsibility for countries struggling to manage their own waste
Environmental injustice — may cause environmental and social harm in low-income countries
Reduces domestic pressure on local waste systems
Transport emissions — shipping waste long distances increases carbon emissions
Access to advanced facilities that the exporting country may not have
Legal risks between exporting and importing nations
Economic benefit — may be cheaper than processing locally
Long-term effects — does nothing about the root cause of excessive waste generation
5. Recycling
Recycling converts waste materials into new, usable products.
Advantages
Disadvantages
Resource conservation — saves raw materials and reduces damaging new extraction
Energy use in processing — collecting, sorting and processing can be energy-intensive
Energy savings — usually uses less energy than making materials from scratch
Limited facilities — access varies between countries and regions
Economic cost may be lower than other disposal options
Contamination — dirty recyclables reduce the efficiency of the whole process
Reduces landfill and incineration by keeping materials out of them
Limited market — not everything is recyclable, and demand for recycled products can be weak
6. Composting
Composting breaks organic waste down into nutrient-rich soil.
Advantages
Disadvantages
Environmentally friendly — produces natural fertiliser, reducing the need for chemical alternatives
Limited to organic waste — only handles biodegradable materials
Reduces landfill waste, keeping organic matter out and lowering methane emissions
Space and time — needs room for compost piles and takes time to break down
Enriches soil, improving soil health and crop growth
Odour — unpleasant smells if not properly managed
Low cost — can be done at home or in local communities
Requires households to separate waste correctly
Where each method sends the material
One useful way to compare the six is to ask a single question: after this method, where has the material gone? Some methods close the loop and return material to use. Others just move it.
Waste-to-energy sits awkwardly between the two. The material is gone, but at least some of the energy in it is captured rather than lost.
Worked examples
WE 1
Evaluate the use of landfill for solid domestic waste
Evaluate the use of landfill sites for the disposal of solid domestic waste. (4 marks)
For: practicality
Landfill is centralised, cheap to operate and flexible enough to take materials that cannot be recycled.
For: engineering
Modern sites use liners and leachate collection to limit contamination, and some capture methane for use as an energy source.
Against: environmental
Decomposing waste still produces methane, leachate risks polluting groundwater and soil, and large areas of land are taken up.
Against: social
Sites are usually placed near less affluent areas, causing noise and smell pollution and harming residents’ quality of life.
Workable as a last resort, poor as a main strategybring in the social dimension — most candidates write only about methane and leachate
WE 2
Compare incineration with waste-to-energy
Compare and contrast incineration and waste-to-energy as methods of waste disposal. (3 marks)
Similarity
Both burn waste at high temperature, sharply reducing its volume and cutting the amount sent to landfill, and both risk releasing harmful emissions.
Difference
Waste-to-energy captures the heat to generate electricity or heat, so energy is recovered rather than lost, reducing fossil fuel use.
Shared drawback
Both are expensive to build and run, leave residues needing disposal, and neither reduces the amount of waste a society produces.
Same process, but one gets something back from it“compare and contrast” needs similarities as well as differences — give at least one of each
WE 3
Suggest a disposal strategy for a coastal city
A coastal city produces large amounts of solid domestic waste, of which nearly half is organic. Suggest a disposal strategy and justify it. (3 marks)
Step 1: deal with the organic half
Introduce composting of kitchen and garden waste, which removes about half the waste stream and stops it producing methane in landfill.
Step 2: recover the rest
Expand recycling for glass, metals, paper and plastics, conserving raw materials and using less energy than making new material.
Step 3: handle what remains
Send only the non-recyclable residue to engineered landfill or waste-to-energy, with liners, leachate collection and emissions control.
Divert the organics first, then recycle, then dispose of the remainderuse the composition figure given in the question — a strategy that ignores the data scores poorly
💡 Exam tips
Learn two advantages and two disadvantages for each of the six methods.
Use the technical terms: leachate, methane, toxic ash, contamination, energy recovery.
Always include a social impact alongside environmental ones — smells, noise, health, property values.
Note that engineered landfill is very different from an open dump.
Point out that exporting and waste-to-energy do not reduce waste generation.
Where data is given about composition, use it to justify your chosen strategy.
⚠ Common mix-ups
Calling recycling a perfect solution. It uses energy and needs clean, sorted material.
Confusing incineration with waste-to-energy. The difference is whether energy is captured.
Forgetting the ash. Burning waste does not make it disappear; toxic ash remains.
Saying landfill always contaminates groundwater. Liners and leachate collection are designed to prevent it.
Treating composting as universal. It only works on biodegradable waste.
Ignoring who lives near the site. Disposal decisions are social decisions.
Up next: Managing and Reducing Waste. Everything on this page happens after the waste exists. The final page deals with the far more effective approach — stopping it being made in the first place.
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