A landfill is a place to dispose of residual waste or rubbish. However, from a zero waste point of view a landfill is a waste of potential resources and consumers should consider all other options before sending waste to landfill.
Environmental effects of landfills
Air pollution: As organic matter breaks down in landfills it releases methane gas, a potent greenhouse gas that traps up to 20 times more heat in the atmosphere than carbon dioxide. To avoid food waste ending up in landfill you can set up a home compost .
Groundwater Pollution: When rainwater flows through landfills it dissolves chemicals producing a toxic liquid called Leachate. This leachate can contaminate groundwater and if it flows into rivers or the sea can kill aquatic life.
Soil Contamination: The chemical substances and decaying organic matter can decrease the soil fertility of the area around the landfill. This then affect the biodiversity in the area.
Social Impacts: Landfills are often unwanted by the surrounding communities due to the eyesore, smell and vermin associated with waste. This lowers land prices and can have detrimental health impacts on communities.
Modern, sanitary landfills are highly engineered sites with layers of storm water collection systems, clay and synthetic landfill liners with leachate collection systems to provide environmental protection from the effects of landfills. Redvale Landfill, owned by Waste Management NZ Ltd, has nine generators to produce electricity from the landfill gas it produces. Enough energy is produced to power the equivalent of 7,500 homes.
To encourage waste reduction, the Waste Minimisation Act 2008 placed a $10 levy on each tonne of waste disposed of at municipal landfills. While this is quite low, discussions to raise it have often been concluded with no change as the adverse effect of a higher fee to responsibly dispose of waste is an increase in illegal dumping.
Shifting away from waste
As we change the way we produce, consume and dispose of products through minimizing waste and implementing circular economic systems, we can reduce the amount of resources destined for landfill and keep products and their constituents in circulation for longer.
The Circular Economy may reduce waste to landfill as material flows are of two types: biological nutrients and technical nutrients. In contrast to a traditional linear economy (of take, make, waste) a circular economy aims to keep resources in use for as long as possible.