Waste Reduction Methods (College Board AP® Environmental Science): Study Guide

What is waste reduction?

• Instead of controlling trash, waste reduction approaches reduce its production.

• Effective management is essential to reduce the environmental impact of municipal solid waste (MSW)

• Preventative strategies focus on reducing waste generation and controlling pollution before it happens

• These strategies are generally more sustainable than restorative approaches, which focus on:

  • Cleaning up waste

  • Repairing environmental damage caused by waste mismanagement

• Designing products and packaging to use less material and be more effective all contribute to decreasing waste

• Buying goods and services that have a minimal environmental impact (green procurement), such as products made from recycled materials or can be recycled easily

• The most effective preventative strategy is to consume fewer products, leading to less waste

Recycling

• The most recognisable method of waste management are the 3Rs of reduce, reuse and recycle

  • This encompasses the principle of reducing the consumption of products—not using single-use plastics, buying only what is needed

  • Repurposing items—using plastic carrier bags as bin liners or cola bottles as cloches to protect new seedlings 

  • Recycling items such as paper, glass, etc. Recycling focuses on converting waste materials into reusable materials

• It conserves natural resources, reduces energy consumption, and minimises greenhouse gas emissions associated with the production of new materials

• The benefit is that waste is reprocessed into new products, which reduces demand for raw materials and decreases the environmental impact

• Also, less energy is used, reducing CO₂ emissions

• However, recycling requires new infrastructure of collecting and processing facilities, which do add to greenhouse emissions and air pollution

• But it does create job opportunities in the recycling industry

• Some materials can be difficult or costly to recycle, whilst others need energy and resources to collect, sort and process

Composting

• Composting is the process of breaking down organic waste into nutrient-rich soil

Advantages

• Composting produces natural fertilisers, reducing the need for chemical alternatives

• Organic matter is kept out of landfills, lowering methane emissions

• Compost improves soil health and can enhance crop growth

• Can be done on a small scale at home or in local communities

• Municipal composting facilities can provide jobs

• Tipping fees and trash removal costs can be reduced due to removal of dense compostable materials

• Landfills may emit less foul odor as organic material is composted

Disadvantages

• Composting can only handle biodegradable materials

• Compost piles need space and can take time to break down waste

• If not properly managed, composting can create foul odors

• Compost may attract vermin

• Compost may spontaneously combust due to the heat build up during decomposition

• Compost can release methane

• Nutrients released during decomposition can run off into surface waters

• Composting takes time, investment and labor

Reducing e-waste

• Dumping electronics in landfills can release toxic substances like lead or mercury into the soil and water 

• E-waste increased by 21% in the five years to 2019 due to higher demand, shorter product lifecycles, and limited repair options 

• In some countries, the plastic covering is burnt to recover the metal; this releases pollutants into the air, causing respiratory issues

• To reduce e-waste, the 3R principle of reduce, reuse, and recycle should be used 

• Reduce by postponing upgrades of electronics as long as possible

• Consider the product's lifecycle and repair options before buying

• Reuse the products by returning the items to the manufacturer for repurposing

• Recycle the electronics by taking them to a dedicated e-waste recycling facility

Reducing landfill

• Landfill mitigation strategies help reduce the environmental impact of waste disposal

• These strategies range from waste-to-energy solutions to rehabilitating landfills for recreational and ecological purposes

• Waste-to-energy (WTE ) incineration

  • Waste in landfill is burnt to generate electricity or heat

  • This reduces landfill volume and methane gas emissions, along with providing an alternative energy source

  • This helps extend landfill lifespan and reduces pressure on limited disposal space

  • It also produces usable electricity or heat, making it a dual-purpose waste management strategy

  • A disadvantage is that WTE incinerators emit

    • air pollutants

    • dioxins

    • heavy metals

    • fine particulate matter

  • These contribute poor air quality and serious health risks

  • There are additional costs in removing the toxic ash that remains after incineration

  • Example: The Hennepin Energy Recovery Center (HERC) in Minnesota burns waste to generate electricity for the local power grid

• Landfill diversion

  • Waste is diverted from landfills by increasing recycling and composting, which reduces the need for landfill expansion

  • This extends the lifespan of the landfill

  • Reduces pollution from waste decomposition

  • Increases production of compost for agriculture

  • San Francisco’s Zero Waste Initiative aims to send zero waste to landfills by promoting strict recycling and composting rules

• Landfill capping and sealing

  • Once a landfill is full, it can be capped with layers of soil, clay, and plastic liners to prevent leaks and groundwater contamination

  • This reduces the risk of leachate contaminating groundwater

  • Ensures the land is safer for use at a later date

  • Example: The Los Angeles Lopez Canyon Landfill was capped and later turned into a wildlife habitat and recreational area

• Habitat restoration and park development

  • This is where former landfills are transformed into green spaces, parks, and wildlife reserves

  • It increases biodiversity in urban areas

  • Provides more recreational spaces for communities

  • Improves air quality from tree planting

  • Example: Freshkills Park in New York, once the world’s largest landfill, is now a 2,200-acre public park with hiking trails and wetlands

• Waste reduction and public awareness campaigns

  • In order to reduce landfill, there needs to be a change in human behavior to encourage people to reduce their own consumption and recycle more effectively

  • This will reduce the environmental footprint from excessive consumption

  • Encourage sustainable habits for long-term benefit

  • Example: The 'Love Food, Hate Waste' campaign in the UK educates people on reducing food waste

• Sell or donate clothing:

  • Unwanted clothing is one of the largest contributors to landfills

  • With the boom of the fast fashion industry, clothes are treated as disposable

  • Most clothing does not biodegrade and emits CO₂ and CH₄ when decomposing, emitting more CO₂ than coal-fired energy

Combustion of gases

• Landfills produce methane as decomposition begins

• This gas can either flared off or captured and used to generate electricity (gas-to-energy process)

• This lowers greenhouse gas emissions

• Provides a renewable energy source that powers homes and industries

• Reduces the volume within landfills

• Example: The Freshkills Park (formerly Fresh Kills Landfill) in New York captures landfill gas and converts it into natural gas for heating homes

Waste policies

• Government waste policies control and decrease trash and its environmental impact

• Policies include regulations on waste disposal and management, recycling, and waste reduction education

• Landfill regulations: To preserve the environment and public health, governments may regulate landfill placement, design, and operation

• EPR: Extended producer responsibility regulation holds manufacturers and producers responsible for product waste from raw material extraction to disposal

• Pay-as-you-throw (PAYT): Households are charged on the amount of waste generated, encouraging recycling and reduction

• Recycling mandates: To reduce landfill waste, governments may require paper, plastic, and glass recycling

• Waste-to-energy policies: Governments may encourage incineration to turn waste into energy

• Zero waste policies aim to reduce the amount of waste sent to landfills to zero, by reducing, reusing and recycling waste

• Waste policies are necessary for human and environmental health, as well as conserving resources, creating jobs, and lowering greenhouse gas emissions