Long before the landfill and environmental regulations, anything and everything was simply dumped directly or buried under the ground at an abandoned site, typically known as dumpsites. A landfill serves the same function as a dumping site, except that the former is well-engineered and regulated by the government.
According to the U.S. EPA, 4.4 pounds of trash are produced per capita per day in the U.S., amounting to over 250 million tonnes of garbage per year. We’re generating trash more than we can deal with sustainably. Only a tiny fraction of this trash is recycled, rest (or a part of it) ends in incinerators, landfills, or oceans-where it’d be sitting centuries from now. Only 9% of the plastic ever produced is recycled!
In the days before today, the concept of the landfill was nothing more than a man-made crater in the earth, a natural disaster! The 1937 Fresno Municipal Sanitary landfill is considered the first modern site of its kind. Landfill sites, today, have been designed in accordance with the 1976 Resource Conservation and Recovery Act to properly dispose of non-recyclable, organic, or inorganic waste.
The garbage from domestic and commercial or industrial sources degrades over the years at the landfill site and releases overwhelming amounts of hazardous gases and chemicals. These toxic substances have harmful effects on the quality of air, water, land, wildlife, and public health. Hazardous and medical waste cannot be disposed off at landfill sites.
Landfill evolution Over the past decades, the number of landfill sites has increased dramatically to manage the swelling heaps of garbage produced per year as the urban areas are choking with people. They’ve developed from a simple, open crater-landfill to meticulously engineered sanitary landfill sites. Here’s how it happened....
California was first to introduce the concept of the modern landfill in 1935--a giant hole to be filled with trash and cover with soil. Over twenty years later, in 1959, the first guidelines for a “sanitary landfill” were introduced. It stressed on compaction of trash and covering it with a layer of soil daily. This laid the foundation for the the1965 Solid Waste Disposal Act (SWDA).
Fast forward, the Resource Conservation and Recovery Act (RCRA) of 1976 is a significant improvement in waste management as it divided waste into two categories: hazardous and solid waste. In 1979, U.S. EPA developed a set of standards for sanitary landfills, providing criteria for new landfills and reducing disease and groundwater contamination in existing landfills. Later in 1991, federal criteria for municipal solid waste (MSW) management were established.
Types of wasteWaste can be categorized as;
Why is it necessary to have landfills?
Although we can never reduce the tonnes of waste generated or avoid the adverse environmental effects of landfill sites, modern landfill sites are necessary to keep our localities clean and healthy. They help with managing non-recyclable waste safely and effectively.
1- Waste is synchronous with population
Increasing population leads to urbanization, and this is a prime reason for massive amounts of waste generation. With over 4 pounds of waste generated per person per day, we need more landfills to manage the triple-digit billion tonnes of waste produced and dumped regularly.
2- Clean localities
Before landfills, there was no waste management system. The waste was simply dumped in the vacant spots nearby, an unhealthy practice for both humans and environments as it produces unpleasant odor and toxic gases. With well-designed and well-maintained landfill facilities, trash can be adequately managed.
3- Well-sorted waste
The landfill sits also establishes the need for waste segregation. Recyclable and hazardous waste is separated before dumping trash at the landfill site.
4- Liner system
Modern landfill sites, aka sanitary landfill sites, comprise the liner system. The bottom is lined with high-density plastic overlaying a dense layer of clay to avoid the percolation of toxic liquids into waterways. Perforated pipes are installed for the collection of this leachate that funnels it to the treatment plant. A gas collection system is also in place to extract and provision of landfill gas for electricity production.Once the site has become saturated with waste, it is capped with another lining of high-density plastic. On top of this, a 2 feet layer of soil is placed, and vegetation is planted to refurbish the land for community use.
5- Waste to energy source
The decomposition of waste produces carbon dioxide and methane gas. These gases can be filtered out and used for the production of electricity.
Modern landfill sites are designed per stringent regulations to be environment-friendly. They have a proper lining and leachate management system to avoid seepage and groundwater contamination.
7- Cheapest waste management strategy
Landfill sites significantly reduce the need for garbage transportation to another country. This also reduces the pollution produced during waste transportation.
Depending on its capacity and type of waste, a landfill site can take years to be completely full. Once a landfill reaches its capacity, it is rehabilitated and repurposed. After its capping with clay and vegetation, it can be turned into community parks that can be maintained for up to 30 years. Capped or abandoned landfill sites can also be repurposed as wildlife habitats.
But, landfill sites are bad for the Environment, & Here’s why!
Although they play a major role in waste management, landfill sites are often touted as bad for the environment. Landfill gases, toxins, and leachate are three major problems from a landfill site, besides habitat degradation and biodiversity loss. Piles of garbage and pungent odor are secondary issues associated with landfill sites. Here’s how landfills are affecting the quality of our environment.
1- Methane: a top contributor to global warming
About 75 percent of the waste that goes to the landfill site is organic or biodegradable in nature. The bacterial decomposition of this waste produces carbon dioxide and methane in a 50-50 ratio, with trace amounts of water vapors, ammonia, sulfides, oxygen, and other non-methane organic compounds.
Wondering about how landfill gas contributes to global warming? About 500 cubic meters of landfill gas is produced per ton of waste. Landfill gas produced from municipal solid waste (MSW) is the third-largest source of human-derived methane emissions in the U.S. According to IPCC fifth assessment report, methane, a climate pollutant gas, is 86 timesstronger than carbon dioxide within the first 20 years of its release. This means it traps more heat in the environment than carbon dioxide and exacerbates global warming even though it doesn’t linger for more extended periods.
Not only this, high levels of methane or other landfill gases migrate to the neighborhood as well as indoors through windows, doors, cracks, or other utility entry points. This might cause indirect public health problems by reducing oxygen levels.
Methane is a highly flammable gas that poses another threat if it builds up in concentration (5 to 15% of total air volume) in poorly ventilated or enclosed spaces. It can quickly start a fire that pollutes the environment and destroy habitats. Fire-retardant foam is used to extinguish this fire--further adding to the chemical footprint of the site.
The enormous amount of methane produced can be collected and used for fueling a power plant or generating electricity. For this reason, landfill gas is often dubbed as renewable energy generation. However, it’s not! Just like coal or oil, methane produces carbon dioxide when burned.
2- Toxin and leachate production
Most of the waste ending at a landfill site contains toxic substances. One such example is electronic waste. Electronic waste such as computers, televisions, and other electronic appliances contain heavy metals like lead, cadmium, mercury, arsenic, PVC, solvents, organic and inorganic acids. Over time, these toxins seep into soil and groundwater and become environmental hazards.
Leachate is a foul-smelling liquor formed when decaying organic waste produces weak acids that react with liquid chemicals in the trash. Usually, rainwater dissolves about 10 percent of the toxin produced in a landfill. This liquid concentrate is highly toxic and pollutes surface and groundwater sources when runoff ends up mixing in groundwater supplies. Also, it gives off unpleasant odors that permeate neighborhoods.
3- Degrades the quality of groundwater
When it rains on the landfill sites, the organic or inorganic substances get dissolved in the rainwater, thus forming highly concentrated leachate. This toxic leachate is rich in ammonia, organochlorides, and pathogens. It is collected at the base of the landfill, where it seeps down into the ground and contaminates the groundwater.
Being chemically saturated, it deoxygenates water, creating a biological oxygen demand (BOD). This is the most outsized effect of uncontrolled waste production and improper landfill management on the quality of marine life and people who depend on it for livelihood.
4- Impacts soil chemistry
Even though modern sanitary landfills have a bottom-liner of high-density plastic, noxious chemicals might leach out from decaying debris. This impacts the quality of soil at or near landfill sites. This can compound the impacts of toxic substances and decaying organic material on soil texture, fertility, local vegetation, and biodiversity.
5- Loss of biodiversity
The creation of engineered landfill facilities consumes a vast area of wildland. This clearing of land leads to loss of vegetation cover and habitat degradation. We might be losing up to 300 species per hectare. The ecological makeup of the region is also disturbed as native fauna is replaced by species that feed on debris. Some migratory birds, white storks, for example, prefer to settle close to landfill sites.
6- Visual pollution
No one appreciates a stinky, trashy view near their locality, a significant cue to the public notion of “Not in My Back Yard.” Landfill sites impact the natural landscape and waft off an unpleasant odor. Ammonia (pungent odor) and hydrogen sulfide (smell of rotten egg) are primary sources of nauseous smell from landfills and are detectable even at low levels. Short-term exposure to elevated levels of these gases can cause coughing, eye, nose, and throat irritation, nausea, headache, asthma, and suffocation.
7- Health impacts
Landfill sites are the potential breeding grounds for bacteria, crows, rats, and other scavengers. These sites are the hotspots for bacteria, vermin, mosquitoes, and disease-causing pests responsible for adverse health effects in humans such as asthma, respiratory disorders, cardiovascular disorders, infectious diseases, birth defects, and even cancer.
8- Risk of onsite accidents
Though very rare with modern sanitary landfills, excessive waste or landfill gas accumulation can lead to serious accidents like the explosion or collapse of landfill sites. One such incident was reported in 2017 in Addis Ababa, Ethiopia that took 113 lives. Another landfill site collapsed in Sri Lanka that took 30 lives and destroyed 140 houses.
How do we reduce the waste going into landfill sites?
It is definitely hard to wrap our minds around the impact of waste in terms of landfill gas and leachate. Reducing landfill waste is an environmental urgency. One can significantly cut down their average 4.4 pounds of waste production by simply changing their throwaway habits and adopting the basic 3R formula.
Look for opportunities to give your unused materials a new life (Reuse); segregate waste using the three-bin concept to ensure maximum waste recycling and composting of organic waste in your backyard (Recycle); adopt waste-to-energy approach (Recover) for most of your garbage. Agricultural and livestock waste, for example, can be treated in a simple digester for biogas production for domestic use.
These practices conserve natural resources and significantly reduce the tonnes of waste ending in the landfill site. It also helps protect the environment, ecosystem, and wildlife.
Nida Riaz is a freelance blogger based in Pakistan. She started writing about her passion for the environment when the world came to a stop in early 2020.