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17th May 2019

A Guide To Landfills

Landfills have formed part of the UK waste management service for a number of years now, and they’re still very much in use. Despite alternative resources becoming available, approximately 25% of UK waste is still deposited into landfills around the country.

Whilst we all rely on landfills to some extent, there have been concerns about the environmental impact they can have. For some people, the use of landfills is a harmful and damaging way of managing waste but, for others, landfills remain the most efficient and effective way of dealing with our rubbish.

What are landfills?

In their most basic form, landfills are simply large holes in the ground which are gradually filled up with waste products. Any refuse which isn’t recycled or disposed of in an alternative way is placed in a landfill site. Unlike landraising sites, the rubbish in a landfill site isn’t visible and doesn’t rise above the ground. Instead, deep pits are used to hold waste materials, such as household rubbish or commercial waste.

Some landfills have been purpose-built but, in many cases, landfill operators have used existing sites and repurposed them. Unused quarries, for example, are often converted into landfill sites. Once the relevant material has been removed from a quarry, all that remains in a deep pit, which is ideal for use as a landfill.

Although landfills are designed to hold waste from a variety of sources, they are not typically open to the public. Due to the potential hazards involved in entering the site, access is usually restricted to trained personnel. However, refuse from households, such as rubbish removal and garden waste, is processed and sent to landfill sites around the UK, so we all rely on landfills in one way or another.

How are landfills constructed?

Although the concept of a landfill might sound simple and straightforward, they are constructed in a specific way in order to protect the local environment as much as possible. Instead of simply dumping waste materials into an open pit, for example, a specially-designed bottom layer is used to separate the contents of the landfill from the earth around it.

Current safety standards require a substantial layer to be in place before the landfill can be used. Typically, a clay liner or plastic liner is used to prevent the contents of the landfill from leaking or leeching into the surrounding soil. However, this is not done just once. Modern landfills may have a number of layers to protect the area around the landfill. By using alternate layers of clay, plastic, soil, gravel and geotextile, landfill constructors can protect the surrounding environment most effectively.

In addition to this, a layer of soil is added to the top of the landfill on a regular basis. Rubbish is placed into the landfill in a strategic way so that certain areas are filled up first. A compactor is then used to reduce the size of the waste and create a relatively even surface. Following this, soil or specialist material is added to the top to ensure that groundwater and rain do not mix with the rubbish. Adding this top layer also helps to prevent smells and gases emanating from the landfill.

What are the disadvantages of landfills?

Many people believe that landfills are harmful to the environment because they produce liquids and gases. Known as leachate, liquid which runs through the landfill comes from the waste itself or the mix of rain and waste. Whilst a top layer being added to the landfill does minimise the amount of leachate produced, some does still occur.

When rubbish decays, it produces acidic chemicals which can then mix with other liquids. Depending on what type of waste is in the landfill, leachate can sometimes become toxic and could present a risk to health.

In addition to this, waste materials produce gas as they break down. Carbon dioxide and methane are the most common gases associated with landfill sites, with one tonne of degradable rubbish producing an estimated 400-500 cubic metres of gases.

Due to these environmental concerns, some people believe landfills are harmful to people, animals and the land. Furthermore, as much of the waste in landfill sites does not biodegrade, there are concerns that landfills do not provide an effective method of waste management and that they simply offer a temporary solution.

What are the advantages of landfills?

Although many people have voiced concerns about the safety of landfills, there are strict regulations in place to ensure they are operated safely. Landfill operators place gas extraction wells in strategic sites within the landfill to remove potentially harmful gases, for example. This prevents the gas from leeching into the nearby area and also makes it safer to operate the landfill itself. In many cases, landfill operators use this gas to produce electricity.

Similarly, landfill operators take steps to reduce the risk of leachate leaking into nearby soil, streams and rivers. As leachate runs to the bottom of the landfill, it is collected in a sump and then stored. Leachate is then treated to ensure it can be disposed of safely, thus removing its potentially harmful properties.

As there are numerous materials which cannot be recycled, landfills provide an alternative way to dispose of materials safely. Fridge recycling, for example, can be extremely dangerous as old fridges can produce gases. By disposing of them safely and in accordance with local guidelines, landfills can be used to ensure these types of products don’t cause undue harm in the future.

Once landfills have reached their maximum capacity, they are usually covered with a permanent liner and the land is redeveloped. Often, landfill operators must agree to fund restoration works following the closure of the landfill so that the area can be put to an alternative use. In addition to this, regular checks and tests must be carried out in order to ensure the safety mechanisms are in place and that the local environment has not been compromised in any way.

Finally.

Currently, companies and households produce waste materials which cannot be recycled or reused. In some instances, waste products can even be dangerous if they’re not disposed of in a specially-designed facility, such as a landfill. As landfills are constructed and managed in accordance with strict guidelines, they do provide a viable form of waste management in Yorkshire and the rest of the UK. When it comes to disposing of waste safely, landfills continue to offer one of the most effective and secure ways of managing waste.