Landfills are neither open dumps nor just some hole in the ground. A basic landfill only involves the covering of solid waste with soil. This is important to reduce the amount of landfill gases – methane and carbon dioxide – mixing up with the air, which can be harmful to the earth and living beings.
Large, sophisticated landfills are the specially designed sites, trenched into the Earth. Their unique design prevents leachates from reaching and potentially contaminating the water table. Modern landfills are also equipped with sensors to detect landfill gas emissions and leachate content. In this article, let’s have a look at various advantages and disadvantages of landfills.
What are the Main Causes of Landfills?
1. Population growth and Urbanization
Increasing urbanization and population rate are among the top reasons why the world needs more landfills. The more the population, the more the demand and the more the waste is being generated and dumped. Plastics and all sorts of toxins are a part of urbanization that need to be taken care of in landfills.
2. Agricultural waste
Arises mainly from farm remains animal manure and worn-out agricultural produce. All these are dumped owing to the highly toxic nature and may contaminate land and water.
3. Solid waste
This is the major contributor to landfills. It includes trash from markets, hotels, houses, public spaces, schools, and malls. Damaged wooden materials, plastics, electronic waste, and medical waste also fall under ‘solid waste’. Since most of them are non-degradable and hazardous, their place is inside the landfills,
4. Industrial and construction waste
They include waste from power plants, manufacturing units, oil refineries, and more. Most of them are biodegradable and add up to fill the landfills.
What Happens to the Waste in a Landfill?
Trash put in a landfill stays there for a very long time. Oxygen and moisture content inside a landfill is very little. Under these conditions, trash breaks down slowly. In fact, landfills are not designed to break down the waste materials, merely to bury them. Once space fills up, landfills are usually capped. General trash and hazardous waste materials take different capping systems
For hazardous waste:
- Synthetic material is used to cover the waste. This is then topped with two feet of compacted clay
- A drainage layer is employed to get rid of liquids and chemicals as the waste breaks down
- And finally, a layer of dirt or topsoil completed the capping system
For general waste:
- A solid liner system sits at the bottom of the landfill
- Alternate layers of compacted clay and synthetic material are used to cover the landfill site
- And a final layer of topsoil is added over the clay.
Advantages of Landfills
1. Landfills are an Excellent Energy Source
When trash accumulates and begins to break down, carbon dioxide and methane are produced. These gases can be taken out, filtered out, and used for energy production. In the United States, landfills serve as the third source of methane production. The landfills in the country also produce approximately 95.6 million of these Carbon (IV)oxide per annum.
2. Modern Landfills are Eco-friendly
Older landfills were just open-air dump for nearly everything but it isn’t the case anymore. Thanks to the efforts of environmental experts and conservationists who brought in strict laws, regulations, and standards for landfill sites. Technology is well utilized in the landfills’ design; good soil lining and leachate management system ensures no seepage and damage.
3. Keep Cities, Towns, and Districts Clean
Any city that doesn’t have a landfill or when people know there is no efficient waste management system in place, they would simply dump waste in the vacant spots. This is unhealthy for humans and the environment. With properly maintained landfill facilities, local trash will be dealt with locally instead of shifting them to other countries.
4. Keeps Hazardous Waste Segregated
Landfills provide a place to dump recyclable and non-recyclable waste separately. Also, they provide a place to keep more hazardous materials that need to be segregated from the public.
5. Landfills are Cheap
Garbage transport costs will be reduced, as our waste will only have to travel a short distance to landfill. This will also reduce the amount of pollution caused by transporting rubbish.
6. Landfills Support Jobs and Local Business
An effective waste management system of any country is a million-dollar activity with every stage needing workforce. More local landfills mean more job opportunities and better living for the locals.
Disadvantage of Landfills
Burying waste in the ground is advantageous in many ways but what are the disadvantages associated with landfills. Let’s check.
1. Landfills are Partially Responsible For Climate Change
One tonne of biodegradable waste can produce about 400–500 cubic meters of landfill gas. Landfill gas contains methane and carbon dioxide as the major constituents and traces of other gases. Methane is a greenhouse gas that is 25x more potent than carbon dioxide. Thus, increases the implications of global warming and climate change.
2. Methane Lights up Easily
Methane is a highly inflammable gas. In an enclosed space with poor ventilation, it lights up quite easily and the entire landfill site can be on fire in seconds. The range of air concentrations at which methane becomes explosive is between 5 to 15% of the total air volume.
Dioxin emissions the fires are also hazardous to the environment, not to mention the damaging effects they have on the underground water layer.
3. Contaminate Soil and Water
Although it’s not very common for protective membranes of landfills to rupture, it can be devastating when they do. Hazardous chemicals, gases, and toxins seep from landfills, get mixed with soil and groundwater causing soil and water pollution.
The infiltrated metals, ammonium, carbons, and other toxins make the soil lose its texture and naturality and kills aquatic flora and fauna.
4. Landfills Affect Wildlife
Landfill sites have negative effects on plants and animals. Certain birds and animals feed on landfill sites. By doing so they ingest plastic, aluminum, drywall, and other materials.
A study published in Science Advances shows white storks modified/shortened their regular migration and chosen nests in areas close to landfill areas. This is not only detrimental but can be fatal for the birds in the long run.
5. Accidents Can Happen
Rain, spontaneous combustion of gases or materials, or excessive waste accumulation makes landfill sites vulnerable to collapses; the damages are deep and almost irreversible. The death toll was 113 when a massive landfill outside Ethiopia’s capital, Addis Ababa collapsed in March 2017.
About a month later, the Meethotamulla landfill site in Sri Lanka suffered a massive collapse, destroying 140 houses and taking 30 lives. In February 2020, two workers lost their lives when the Zaldívar landfill site in Spain collapsed.
6. Landfills Affect Human Health
Studies have been shown that people living near or prolonged exposure to landfills have been linked to cancer, respiratory disorders, and developmental defects in children.
Short-term exposures ammonia and hydrogen sulfide in the air can cause eye, nose, and throat irritation as well as asthma. Other reported health complaints include sleeping difficulties, weight loss, and chest pain.
Methane and carbon dioxide can affect the availability of oxygen to tissues causing coordination issues, fatigue, nausea, vomiting, and unconsciousness.
How Old Landfills are Used For Today?
Old landfills aren’t dead spaces anymore. They are getting a serious makeover into public parks, and wildlife habitats.
1. Community Parks
One of the most popular ways to transform old landfills is to convert them into a public park. Landfill parks go back to 1916 when the old Rainier Dump in Seattle was turned into the Rainier Playfield, a public sports facility.
Now, there are more than a thousand parks sitting on old trash sites across the world. From green spaces to golf courses to skate parks – the possibilities are endless. Some of the famous names include Washington Park Arboretum; Pulau Semakau Eco-Park, Singapore; Chambers Gully Reserve, Australia; Red Rock Canyon Open Space, Colorado.
2. Landfill Energy Projects
Capped landfills are also repurposed into energy production sites. Generating energy from landfill gas isn’t new and the electricity produced is used to power everything from homes to vehicles.
Many countries have their solar panel fields installed on old landfills. One such example is the one installed by Public Service Electric and Gas Co, New Jersey.
3. Wildlife Habitats
Environmental conservationists are voicing out for old landfills to be transformed as wildlife habitats. They suggest testing soil profile and water table of the locality to confirm if they can support vegetation and wildlife.
One example is the Alliance Landfill in Taylor, Pennsylvania. Native trees and other plant varieties were introduced and over time, many bird and animal species made it their home.
The Bottomline
Waste around us needs more attention than ever before. Today’s landfills have progressed from a simple pit to meticulously engineered waste management systems. They intend to reduce pollution, control contamination, and protect our health and environment. While we can never rule out contamination risks, landfills are essential to keep the cities clean and healthy as possible.
References:
https://www.health.ny.gov/environmental/outdoors/air/landfill_gas.htm
http://advances.sciencemag.org/content/2/1/e1500931.full
https://www.recyclingtoday.com/article/pseg-solar-farm-50-acres/