Landfill Pollution: Environmental Impact And Hazards

Landfills are sites designed to store garbage and are used to dispose of waste that cannot be recycled or reused. While landfills are necessary for the proper disposal of solid waste, they have significant negative effects on the environment and human health.

The creation of landfills requires clearing wild areas, leading to habitat loss and degradation. They also produce and release biogas, which contributes to climate change. Landfills are often responsible for the contamination of soil and groundwater, and the gases emitted from landfills can cause respiratory problems in nearby residents. In addition, the liquid produced in landfills, known as leachate, can become toxic and contaminate nearby water sources. Furthermore, landfills are associated with air, water, and land pollution and can cause unpleasant smells and reduce the value of surrounding areas.

Landfills are a cause of climate change

Methane is a dangerous and flammable gas that is 84 times more effective at absorbing heat than carbon dioxide. While modern landfills are completely sealed to reduce contamination of the nearby groundwater, leaks do happen, and the methane released due to decomposing waste is a potent greenhouse gas.

Some landfills have degassing methods, but these are usually performed after the landfill cell has been closed, meaning that methane from biodegradable components will have already been released. Horizontal degassing projects that capture methane while the landfill is in operation achieve better results but can only capture a portion of the methane generated.

The creation of landfills also often involves the destruction of natural habitats for wildlife. With over 3000 active landfills in the United States, as much as 1,800,000 acres of habitat have been lost.

They can cause fires or explosions

Landfills can be the source of fires and explosions, which can have devastating effects on the environment. The methane produced by waste in landfill sites can sometimes cause explosions and fires. This is more common than one might think, as the fires that occur are not regular fires with flames, but fires that occur inside the landfill.

The combustion of the wide range of materials within landfills can emit dangerous fumes. Key parameters of concern are carbon monoxide, hydrogen sulfide, and volatile organics. The production of dioxins and furans is also a documented risk factor.

Subsurface landfill fires are difficult to put out with water unless an overhaul operation is undertaken. They are similar to coal seam and peat fires. The best method to prevent and fight subsurface landfill fires is oxygen intrusion control, as long as firefighting teams can be confident that all air entry pathways are effectively blocked.

Fires in landfills can also cause serious environmental problems if the landfill's membrane (a barrier placed under most modern landfills to prevent the escape of harmful liquids) is destroyed or penetrated by the fire. Normally, this liner prevents harmful liquids from escaping into the groundwater and nearby streams.

There have been several notable landfill fires around the world, including:

• January 1998, Maalaea, Hawaii, USA: a fire 15-20ft underground, which continued to smolder for four months after being extinguished.
• December 1996, Danbury, Connecticut, USA: an underground fire caused a strong odor of rotten eggs due to the high concentration of hydrogen sulfide.
• November 1999, Delta Shake and Shingle Landfill, North Delta, British Columbia: a fire that burned 20-30m deep, causing a state of local emergency.
• September 2007, Fredericton, New Brunswick: a large fire forced residents to stay indoors due to fears that the smoke was toxic.
• December 2010, West Lake Landfill, USA: a smoldering fire that continues to burn today, located roughly 1,000 feet away from radioactive wastes that were illegally dumped in 1973.

They can contaminate soil and water

Landfills are necessary for the proper disposal of solid waste, but they can also contaminate soil and water.

Leachate

Landfills produce leachate, a liquid produced by landfill sites. It is formed from the decomposition of garbage and precipitation that infiltrates and percolates downward through the volume of waste material.

Landfills are required to have plastic or clay lining by federal regulation, but these liners tend to have leaks. This can result in leachate contaminating nearby water sources, further damaging ecosystems. Leachate can contain high levels of ammonia, which can cause eutrophication in nearby water sources. Eutrophication creates "dead zones" where animals cannot survive due to a lack of oxygen. Along with ammonia, leachate contains toxins such as mercury due to the presence of hazardous materials in landfills.

Hazardous Waste

Landfills may contain hazardous waste, which includes harmful and dangerous substances generated primarily as liquids but also as solids, sludges, or gases by various chemical manufacturing companies, petroleum refineries, paper mills, smelters, machine shops, dry cleaners, automobile repair shops, and many other industries or commercial facilities.

Hazardous waste differs from municipal solid waste and construction and demolition debris in both form and behaviour. Its disposal requires special attention because it can cause serious illnesses or injuries and can pose immediate and significant threats to environmental quality. The main characteristics of hazardous waste include toxicity, reactivity, ignitability, and corrosivity.

Soil Contamination

Soil consists of a mixture of unconsolidated mineral and rock fragments (gravel, sand, silt, and clay) formed from natural weathering processes. Gravel and sand formations are porous and permeable, allowing the free flow of water through the pores or spaces between the particles. Silt is much less permeable than sand or gravel, and clay is virtually impermeable to the flow of water.

The greater the permeability of the soil, the greater the risks from land pollution.

Landfills alter the fauna

• Landfills are often responsible for the contamination of soil and groundwater. The contaminating materials (such as heavy materials like lead and mercury) that the stored waste may contain can spread to the soil and water near the plant.
• Landfills can cause fires or explosions. Methane produced by waste in landfill sites can cause explosions and fires. These fires can be spontaneous and uncontrolled, and the resulting emissions are very harmful to the environment. They can also affect aquifers, as their waterproofing membranes are impacted by the fire.
• Landfills have particularly negative effects on bird migration. Some birds feed from landfill sites, inevitably ingesting plastic, aluminium, gypsum, and other materials common in waste, which can prove fatal.
• Landfills are altering the migratory activity of birds. There has been an increase in the number of cases of species that have stopped migrating to the south and are instead choosing to nest in areas near landfill sites, thanks to the endless food supply they provide. This is not only detrimental because it can be a deadly diet, but also because their young already tend to ignore traditional migratory behaviour, so the problem is exacerbated with each generation.

Landfills reduce the value of the surrounding areas

Landfills are known to reduce the value of the areas surrounding them. The foul smells emanating from landfill sites can reach nearby populations, and the gases they emit can enter homes and buildings, causing a range of health issues.

The gases produced in landfills, such as ammonia, sulfides, methane, and carbon dioxide, are of particular concern. Ammonia and hydrogen sulfide are responsible for most of the odors at landfills, and humans can detect these gases at very low levels. Short-term exposure to elevated levels of these gases can cause coughing, irritation of the eyes, nose and throat, headaches, nausea, and breathing difficulties.

The unpleasant smells and health issues caused by landfills can lead to a decrease in property prices in nearby areas. This further perpetuates the devaluation of disadvantaged areas.

In addition to the health and environmental issues caused by landfills, the negative perception of landfills can also contribute to the reduction in property values.

Frequently asked questions