Skip to content. | Skip to navigation

Landfill

Why?

Landfill is monitored by the Landfill Directive and provides a safe disposal option for wastes that can’t be recycled, composted or used to generate energy.

Fact:

Landfill produces energy too!

Site preparation

Site preparation

A new landfill is prepared with essential containment systems and structures. These include liner systems, gas pipes, leachate collection control and monitoring boreholes. These containment, control and processing systems stay in operation for up to approx. 50 years after the landfill is closed, ensuring the landfill’s stability and the protection of the environment.

Waste arrival

Waste arrival

Waste arriving at the landfill is weighed and its’ contents checked to ensure it complies with the landfill operating licence. This waste is then tipped into the ‘tipping face’ of the landfill. The tipping face is the active / operational part of the landfill.

Compacting

Compacting

Tipped waste is compacted in the landfill by specialist machinery. Throughout the day the landfill is progressively compacted and covered with layers of cover material, such as soil. This layer helps to reduce odour produced by the waste and deter scavengers, like rodents, flies and birds. At the end of each day the operational area of the landfill is completely covered with a layer of cover material.

Decomposition

Decomposition

Waste in landfills is naturally broken down by microbes under anaerobic (absence of oxygen) conditions. This decomposition, combined with rainwater filtering through the landfill, results in the production of liquid, called leachate, and gas.

Gas

Gas

The gas produced by the landfill is collected in storage tanks and is predominantly a mixture of carbon dioxide and methane. This gas is extracted through a series of pipes (gas wells and collection pipes) and is either:

  • burned off in landfill gas flare stacks, or
  • directed to an on-site energy generation plant, where it is converted into electricity, which is most commonly exported to the National Grid. Electricity production from the landfill gas may also continue for years after the landfill has been completed.

Leachate

Leachate

This liquid is contained by the lining system of the landfill and extracted through pipes which deposit it into large storage tanks. From these tanks it is either:

  • pumped into tankers and taken off site to be treated, or
  • pumped into an on-site treatment plant where it is cleaned and discharged either to sewer or to a nearby water course. This system is typically installed within the restoration soils to allow for management of ongoing leachate production following closure of the landfill site.

New land

New land

Depending on waste type and volume, landfills take many years to reach maximum capacity. When a landfill reaches maximum capacity it is capped; covered by a final layer of cover material, clay and vegetation. This final layer forms a barrier keeping odours in and rainwater out. It also provides a suitable surface for future use in recreation or light cultivation.

Main links

You are here

Personal tools