Landfill operations and issues
There have been landfilling operations at Easter Langlee since the 1970s. The current landfill area started receiving waste in 2007.
Landfill infrastructure
The depositing of the waste takes place in stages, filling the site section by section.
Each section is called a cell. The cells are constructed separately and are subject to strict engineering and environmental controls.
Between 2007 and today we have created four cells. As the waste fills each cell it moves above the cell dividers, to create one filling area.
Waste infilling
We aim to allow vehicles arriving on the site easy access, while filling in a way that maximises the potential for capping.
How it works
- once the waste arrives onto the site it is compacted at the tipping area
- the compaction stabilises the waste, making a firm surface that more waste and cover material can be safely and securely put on top of
- at the end of each working day the tipping area for the day is covered with soil. This minimises litter blowing away or access to the material by animals
Because of all the light plastic that is thrown away, when it is windy there is always some litter that blows from the tipping area. To help to capture the litter, we have put in place:
- permanent litter fences located around the site
- temporary litter fences that we can lift and move to the areas where they are most effective
Landfill capping
Once parts of the landfill have reached capacity, they are capped to prevent rain water getting into the waste. The capping process is subject to strict engineering and environmental controls.
The construction of the cap involves:
- covering the waste with soil
- putting an impermeable layer on top of the soil, either a thick plastic liner or clay liner
- covering the liner with more soil
- the capped area can then be seeded and turned into a grassy hill
Landfill gas
Over time the biodegradable waste deposited in the landfill, such as food and green waste, breaks down. Landfill operators are keen to capture as much of the gas released through this process as possible as it can be used to generate electricity.
How we convert the gas into electricity at Easter Langlee
- as the waste heights reach certain levels, a network of deep wells are installed into the waste which allows extraction of landfill gas using a pump and blower unit
- the gas is directed through a system of connection pipework to a generation compound
- in the compound, special engines utilise the fuel to generate renewable electricity, which can be sold to the local network operator
- the generation compound also contains a gas flaring system which will automatically start and process gas in the event of an engine breakdown
Odour
When the waste breaks down in the landfill, there can be some odours generated. The best way to minimise this is to cap as much of the landfill as possible, and this is one of the reasons why our planning for filling in the landfill tries to maximise capping areas and landfill gas extraction at all times.
What we do to control odour
We operate an odour control system designed to neutralise odours. The odour control system creates a fine mist of water and odour-neutraliser, and is located at the points where there could be a risk of odour.
Conditions when odour is unavoidable
Despite our best efforts, the size of the landfill and the proximity to local housing means there are times when odour from the landfill is detected by local residents. This is a common occurrence for landfills.
At Easter Langlee, odour events seem to be linked to local atmospheric conditions, with cool, still weather increasing the risk of odour being detected.