A landfill is a place where waste and disposable materials are stored in a controlled and regulated way. What happens at a landfill might not be what you expect.
Modern landfills are designed to prevent waste from biodegrading and to capture and use byproducts of trash decomposition like methane which would otherwise pollute the atmosphere.
Unfortunately, this process is not perfect, and there are still environmental impacts. But what’s more worrisome is the fact that not all landfills are operated in this manner.TER
Below I will take you through what a landfill is, what happens at a landfill, the environmental issues resulting from landfills, and how we can mitigate these.
What is a landfill
What is the difference between a landfill and a dump?
Landfills are managed sites with their own set of regulations and precautions in place during construction and operation to ensure they are safe for the environment.
On the other hand, dumps are unregulated and provide no environmental protection. Because of this, they can pose a significant risk to the environment.
Parts of a Landfill
Discovering the parts helps to understand what happens at a landfill. Before a household’s trash arrives at a landfill, the ground is lined with clay and then a skin of flexible plastic about half an inch thick. Next, the trash is tightly packed and sealed under a rubber and clay barrier. Finally, there is a liner placed over the waste to keep liquids from leaking out. This helps ensure a safe and clean environment.
All these steps are taken to ensure that the waste is properly managed and the environment is protected.
- Cells – Cells are the basic building blocks of a landfill. They are sections of land that are typically lined and filled with layers of waste material, soil, and other materials. Cells are designed to provide containment for waste material, reduce leachate generation and provide a barrier between the waste and the environment.
- Bottom Liner System – The bottom liner system is a protective layer designed to keep waste and byproducts from coming into contact with the environment, particularly groundwater. It may consist of a thick clay layer, followed by a plastic liner, and then a protective layer of sand. The clay is used to form a solid and impermeable barrier while the plastic liner and sand act as a secondary barrier to prevent any leaks.
- Stormwater Drainage – Stormwater drainage in the form of a system of pipes and structures is used to keep rainwater away from a landfill. It works by collecting water from the landfill and routing it into drainage ditches located around the landfill.
- Leachate Collection System – A leachate collection system is a system that filters and collects liquid waste from a landfill. This system is important because it prevents leachate, the liquid produced by trash, from entering and contaminating the surrounding environment. Leachate is typically acidic and contains contaminants that can be hazardous to the environment. The leachate collection system works by having perforated pipes running throughout the landfill, which collect it and carry it to leachate collection ponds. The leachate is then treated, tested, and released back into the environment once it is clean and safe.
- Methane Collection System – Methane collection systems are systems that collect methane gas that is produced by the decomposition of landfill waste. The methane gas is made up of equal parts methane and carbon dioxide, as well as traces of nitrogen and oxygen. If left untreated, this methane gas can be highly flammable and explode, as well as contribute to global warming in the long term. In order to prevent these hazardous conditions, methane collection systems capture the gas and either vent it into the air or convert it into energy, such as electricity, heat, or vehicle fuel.
- Covering or Cap – A landfill covering or cap is a protective barrier between the landfill and the surrounding environment, designed to contain hazardous waste and reduce environmental contamination. Capping is essential to keep humans and the environment safe and to isolate the toxic or hazardous materials in the landfill.
- Groundwater Monitoring – Groundwater monitoring is a process used for landfill management to identify and assess the presence of leachate chemicals in the surrounding groundwater. It involves the installation of pipes that are sunk into the groundwater to capture and sample water. An increase in temperature may indicate that leachate is seeping into the groundwater, while an acidic pH can also be a sign of leachate. Groundwater monitoring is an important part of landfill management as it helps to identify potential issues before they become hazardous.
How does a landfill work?
Now that we know the difference between a dump and a landfill let’s find out what happens at a landfill.
- Step 1: Waste is brought to the landfill facility and sorted. It’s then placed into an open section of the landfill, known as a Cell. The bottom layer of each landfill consists of a liner, such as a dense, compacted clay or a plastic and other synthetic materials, which prevents waste, liquid or gas leaks from seeping into the environment.
- Step 2: Bulldozers and compaction equipment are used to compress the trash, reducing the total air space.
- Step 3: A temporary Daily Cover is placed on top of the exposed trash to protect it from the sun and rain, and also to keep animals or other scavengers away.
- Step 4: Leachate, which is liquid from the waste, seeps out of the trash as it is compacted into the Cell. This liquid is drained down to the base of the Cell where a Sump is located at the lowest point. Utilizing a series of perforated pipes, gravel, and sand at the bottom of the cell the leachate is removed, treated, tested for purity, and reintroduced into the environment after a rigorous clearing process.
- Step 5: Once the Cell is filled to its max capacity, either a new Cell will begin on top or a final cover will be placed over it. The Cell is then capped with several feet of soil and vegetation to prevent erosion or future exposure to the waste.
- Step 6: Methane gas is collected from the old cell and either vented, flared or repurposed for use in generating electricity or other fuels.
- Step 7: The area is monitored and maintained for 30 years to ensure everything remains environmentally sound.
Note that not all landfills work this way. The description above is for a modern landfill that is regulated and managed in a way to minimize impacts. Across countries and regions, there can be very different regulations for landfills, so the way they work can vary.
Effects of landfills on the environment
Landfills can negatively affect the environment, especially if they are not properly maintained. A poorly maintained landfill can have devastating consequences on the environment. Firstly, methane gas, a powerful greenhouse gas, can be emitted from the landfill, contributing significantly to global warming. Secondly, hazardous waste can seep into waterways, damaging ecosystems and possibly contaminating the water supply for the surrounding area. Thirdly, ground and air pollution may occur due to the production and release of hazardous gases, particles, and other toxic pollutants.
Landfills are not designed to break down waste, which means that garbage can remain in landfills for decades, accumulating harmful toxins and pollutants in the soil and air. These pollutants can be transported by wind, water, or air and can accumulate in nearby plants and animals, which can then be passed on to humans through the food chain.
Landfills can leach chemicals and other contaminants into the soil and groundwater
As water seeps through a landfill, it picks up contaminants, creating a toxic mix referred to as leachate. If not managed properly this leachate can seep into surrounding soil and groundwater, polluting ecosystems and impacting drinking water.
Landfills can release methane and other greenhouse gases into the atmosphere
Methane gas is produced by landfills when organic waste decomposes in the absence of oxygen. This process, known as anaerobic decomposition, occurs in landfills because of the airtight environment created by the compaction of waste materials. As bacteria break down the waste, a byproduct of this process is landfill gas, which contains approximately 50 percent methane and 50 percent carbon dioxide, as well as small amounts of nitrogen and oxygen. The methane produced by decomposing waste is a major contributor to climate change, since it is up to 84 times more potent as a greenhouse gas than carbon dioxide.
In order to prevent the release of methane and other harmful gases, landfills are equipped with a variety of components such as primary and secondary liners, gas capture systems, collection pipes, stormwater drains, leak monitors, and caps. The primary liner is made of clay, a synthetic material, or a combination of both to prevent the release of toxins from the waste into the environment. The secondary liner is generally a synthetic material that acts as a backup should the primary liner fail.
The gas capture system uses extraction wells and pipes to carry the landfill gas to treatment areas where it is either vented, burned, or converted into energy.
Landfills are the third-largest source of methane in the U.S. Therefore, reducing the amount of waste sent to landfills is essential in order to reduce the impact of landfill methane on the environment.
Landfills can cause noise and odor pollution
Landfills can cause noise and odor pollution. The process of crushing, compressing, and burying the waste in landfills creates noise, and the anaerobic decomposition of the waste produces methane and other gases, which can cause unpleasant odors. These gases can also be a safety hazard due to their flammability. Additionally, the leachate (toxic liquids) produced by landfills may also contribute to odor pollution.
Landfills can have a negative impact on wildlife and plant life
Landfills can have an adverse effect on both wildlife and plant life. They remove available land and habitat for wildlife but there are also many other issues. The leachate from landfills can contain dangerous toxins, such as lead, cadmium, and beryllium. These can seep into soil and groundwater aquifers and negatively affect local ecosystems. These toxins can be toxic to both wildlife and plant life, causing harm and even death.
Types of waste that land in landfills
Below is a description of the main types of waste whose final destination is a landfill. Some of the most commonly landfilled items are food waste, paper, cardboard, plastic, glass, hard-to-recycle materials, organics, e-waste, metals, textiles, automotive parts, and batteries.
Household garbage
Household garbage is any kind of waste generated from activities in the home. The composition of household garbage varies by region and changes over time, but it typically includes things like food waste, paper, plastic, and glass that are not recyclable, and other miscellaneous items such as clothing, batteries, and other household items. Household garbage includes the following:
Food scraps
Food scraps are the organic materials found in our kitchens, such as vegetable and fruit peels, egg shells, coffee grounds, and leftover food. They are a major contributor to landfills. Unfortunately, food scraps are not always composted and instead are often sent to landfills, where they are buried and left to decompose. This decomposition process produces methane, a powerful greenhouse gas that contributes to global climate change. Composting instead of sending food scraps to landfills can reduce the amount of methane produced and protect our environment from toxins.
Recyclable materials
Unfortunately, a large amount of recyclable material still ends up in landfills. To prevent these materials from being sent to landfills, we need to make more of an effort to increase recycling and find specialist recycling services. Getting to know your local recycling rules can also help reduce the chance of recyclable material being sent to a landfill. When recyclable material is too contaminated with food or liquids or non-recyclable materials, it can be sent to a landfill instead of being recycled.
Household Appliances
Common appliances that can be found in landfills include refrigerators, air conditioners, ovens, stoves, dishwashers, clothes dryers, and microwaves. These appliances typically end up in landfills due to improper disposal. There are many great options for recycling these large appliances. You may even find when you purchase a new item that the company will take away and recycle the old one for you.
Tires
Tires are a common type of waste that finds its way into landfills. Tires are made from a variety of materials, such as rubber, steel, and synthetic fibers, making them sturdy and long-lasting. Since rubber is resistant to degradation, a tire can take several years or even decades to decompose, and the toxins it contains can seep into the environment. Tires are bulky, so they also occupy a lot of space in landfills. Recycling tires can be difficult because they are composed of multiple materials, but it is possible. You can learn more about recycling tires in Recycling Tires: How to dispose of your tires and what happens to them.
Clothing
The majority of clothing waste ends up in landfills, where it can take up to 200 years to decompose. A lot of clothes are made from plastics and contain dyes, so they can contaminate soil, water, and air as they decompose. Find out how to dispose of your clothing in How to Recycle Clothes Sustainably.
Hazardous waste
Hazardous waste is any waste that is potentially dangerous to human health or the environment. There are many types of hazardous waste; unfortunately, many end up in landfills. You can learn more about these in our article on hazardous waste.
Construction and demolition waste
Construction and demolition (C&D) waste is debris generated from the construction, renovation, and demolition of buildings, roads, and other structures. It typically consists of concrete, wood, glass, metal, and other materials that cannot be reused or recycled. C&D waste is usually transported to a C&D landfill, where it’s sorted and recycled or disposed of properly. Not all C&D debris ends up in landfill. Fortunately, much of it can be recycled, helping to conserve resources, reduce the amount of space needed for landfills, and lower the costs of hauling C&D waste. Recycled C&D materials can be used to make new products such as bricks, tiles, and shingles.
Yard trimmings
Yard trimmings are any organic waste from lawns and gardens. This includes grass clippings, leaves, weeds, prunings, and branches. Composting organic material is the best and most sustainable alternative to sending them to landfill, as it allows the waste to decompose and the nutrients to be recovered. Curbside recycling services often pick up yard trimmings, but they can also end up in landfills.
Are there any alternatives to landfills for waste disposal?
Are there any alternatives to landfills for waste disposal? Although landfills are the most common way of disposing of solid waste, as we discovered above, there are many reasons why they are best avoided. Burning waste for energy is one option, but the emissions and air pollution this produces may not be worth the environmental cost.
The more environmentally sound approach would be to decrease our waste production by introducing bans on certain plastics, creating more sustainable packaging, and encouraging individuals to adopt more eco-friendly habits.
What Happens When A Landfill Is Full?
A landfill’s life expectancy can range from 30 to 50 years, depending on the size, disposal rate, and compaction rate of the facility, and all Class 3 landfills must be monitored for at least 30 years after they are closed. In a landfill, the waste is not exposed to oxygen or sunlight to prevent it from decomposing, but as a result plastic and other materials can still take 10-100 years to degrade.
Due to the amount of waste being generated, landfills take up space quickly, and many local landfills are now closing as there is no more room. Once a landfill is full, it is capped with a plastic liner and covered with two feet of soil. Vegetation like grass and plants without penetrating roots are then planted on top to prevent soil erosion from rainfall and wind.
Finally, some landfills may be transformed into community parks, like the famous landfill park Mount Trashmore in Virginia Beach. So, the process for a landfill to die can take several decades, but the end result is a space that is safe and beneficial for the community.
Common Uses for Landfill Sites After They’re Filled
There are many different ways landfills can be used once they are closed. They can be converted into parks, or wildlife habitats, and there are some great examples below. Some closed landfills are also being repurposed as landfill-gas-to-energy sites and solar panel fields, which provide renewable energy for the surrounding community.
Landfill Parks That Benefit the Community
There are a few examples of landfill parks benefiting the community. One of the most popular examples is Mount Trashmore park in Virginia Beach, USA. It is an expansive 165-acre tourist attraction sitting on compacted layers of solid waste and clean soil. Visitors can enjoy man-made mountains, lakes, playgrounds, a skate park, and paths for walking and biking.
Protecting Natural Habitats on Old Landfill Sites
Old landfill sites can be repurposed to protect and restore natural habitats. To do so, the site must first be capped and monitored to ensure it is safe and not leaking any contaminants into the environment.
To convert a landfill to a natural habitat, the soil must be analyzed to ensure it is safe, and then some test planting must be done. A layer of topsoil is added to the landfill to help the vegetation talk hold and create a natural habitat. It’s important that the site is monitored for at least 30 years in order to ensure that no pollutants are leaking into the environment.
The Alliance Landfill in Taylor, PA is an excellent example of an old landfill site being used to protect natural habitats. Vegetation was planted in the best spots to help create a refuge for birds and other animals. Over time, the landfill transformed into a wildlife habitat with trees, plants, and grasses that are all native to the region. The Wildlife Habitat Council has endorsed this effort and encourages the conservation of these sites.
Going Green With Landfill Energy Projects
Landfills offer a variety of opportunities for renewable energy projects, from the conversion of landfill gas into electricity to the installation of solar panels and wind turbines on the site. Here are some examples of how it can be used:
- Electricity: Landfill gas is used as fuel to generate electricity at power plants either at the landfill or nearby. This helps lessen our reliance on fossil fuels and can be fed back into the grid to power our homes and vehicles.
- Alternative fuel: Gas can also be carried to an industrial or commercial facility and used in place of or in combination with fossil fuels.
- Processed gas: The gas can be filtered and transferred for use in places natural gas is normally applied.
- Solar energy: Solar panels can be installed on the landfill site to take advantage of the area’s natural sunlight. New Jersey has taken on multiple solar projects, turning old landfills into sources of renewable energy.
- Wind energy: Wind turbines can be installed on landfill sites, taking advantage of the area’s strong winds. Wind energy can generate up to 40% of a landfill’s electricity.
How to avoid using landfills as a disposal method
Clearly, something needs to change in order to preserve our planet’s limited resources. We must strive to reduce, reuse, and recycle as much as possible in order to help reduce our reliance on landfills. Following the waste hierarchy is a good way to minimize your impact. In the waste hierarchy, landfills are the last option for waste treatment. Exhausting reduce, reuse and recycling options should always be the first option.
Recycle as much as possible
Recycling as much as possible can help avoid using landfills as a disposal method by reducing the amount of solid waste that is sent to these facilities. By diverting recyclable materials from landfills, we can reduce the impact of landfills on the environment and cut down on the amount of raw materials that need to be extracted and processed. Recycling also helps reduce energy consumption, water usage, and air pollution, as one ton of paper saved through recycling can prevent the cutting down of 17 trees.
Learn more about recycling in our 10 Day Curbside Recycling Challenge.
Compost instead of throwing away biodegradable waste
Composting is a great alternative to throwing away biodegradable waste because it offers several environmental benefits. Composting helps to reduce the amount of waste sent to landfills, as well as reducing greenhouse gas emissions. It also returns important nutrients to the soil, helping to improve soil fertility and prevent soil erosion. Composting also helps to reduce the need for artificial fertilizers, reducing pollution and preserving resources.
Utilize Specialist Recycling Services
There are many specialist recycling services that will take hard-to-recycle items and recycle them. Terracycle is a good example, and they have many different programs you can take part in.
Reduce and Reuse Items Instead of Throwing Them Away
Reusing items instead of throwing them away is a great way to reduce waste and make the planet a healthier place.
Here are some simple steps you can take to help get started:
- Reduce the number of single-use plastics that you use by choosing reusable water bottles and cutlery.
- Keep items in use as long as possible by repairing and maintaining the items you own.
- Consider buying second-hand products.
- Choose products that have less packaging. This will help to reduce the amount of trash you generate.
- Compost organic materials like food scraps, yard clippings, and other organic materials into a communal bin, so your waste will decompose and turn into soil.
- Upcycle trash by reusing items in a way that increases its original value. For example, you can transform t-shirts into plant hangers or cleaning rags, or an old suitcase into a table. You can even make DIY home decor out of trash.
By taking these steps, you can make a huge impact in the amount of waste sent to landfill each day.
