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The Environment and Modern Landfills

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A modern landfill needs to meet strict environmental rules.

Modern landfills are carefully managed to make sure they are environmentally friendly and are good neighbours to the land owners next door. This includes assessing all the environmental impacts. Here are some of them:


Making sure that rubbish is kept under control at all times is important. This means locating landfills away from populated areas, and making sure rubbish doesn’t fly away in the wind. 


Landfills use heavy machinery to transport and compact the rubbish.


Rubbish usually contains rotting organic material and other materials that smell. Moving and compacting the rubbish must be done to stop the smells being released.

There are also spray units that stop bad odour leaving the landfill.

Wind-blown rubbish

When rubbish is dumped at the landfill there is a risk that the wind will pick it up and blow it away. This problem needs to be managed carefully.


A modern landfill is designed to be a long term solution for storing waste. That means it needs to be in a place where there are no active earthquake faults that might crack the ground and release liquid (also called leachate) into the groundwater.


Rubbish is often light weight and easily blown away. A modern landfill needs to be protected from very strong winds. Kate Valley landfill operations must be shut down when the wind blows above a certain speed.


Rain water seeps down through waste, making leachate. Leachate contains poisons and must be collected and managed. At Kate Valley, leachate is collected and treated. A special landfill liner acts as a barrier between the waste and the ground. This stops leachate seeping into the ground. The liner also channels the leachate to a collection point before being treated. 

At Kate Valley, the landfill is covered with a thick layer of soil to reduce the amount of rain going into the rubbish. Rain that runs off the top of this soil layer is collected and treated.

Landfill gas (LFG)

LFG is produced as organic waste breaks down inside the landfill. LFG has up to 60 percent methane, a dangerous greenhouse gas. At Kate Valley, a system of wells within the landfill collects LFG. The gas is piped to a treatment plant. The LFG is then used as fuel to run 4 generators. 

Monitoring and testing

Devices are used to monitor water in nearby ponds and streams. LFG and dust is also monitored. Kate Valley even has as an on-site weather station. Information from the monitoring devices is sent by coded signals on a computer based wireless system called telemetry.


Projects that disrupt the land need a rehabilitation plan. This plan will show how the land will be in the same or better condition when the landfill comes to the end of its life.

Audio Māori keywords: 

Challenge: Choose one environmental impact and describe how, in an older rubbish dump, it might affect the environment.

Why do Landfills Exist?

The Journey: Lollipop to Landfill


Making sure rubbish is kept under control at all times is important. Image: Andrew Penny, LEARNZ.

Landfills use heavy machinery to transport and compact the rubbish. Image: Andrew Penny, LEARNZ.

Wind-blown rubbish is a problem that needs to be carefully managed. Image: Andrew Penny, LEARNZ.

Rainfall that runs off the top of the landfill soil layer is collected and the clean rainwater is diverted into streams. Image: Andrew Penny, LEARNZ.