FreeWord – Landfills, a solution or a threat to our environment?
Hello fellas! Today I’m going to enlighten you about landfills.
I was driving on the highway and lost attention to my surroundings. I was steering to these vast hills of green that rose alongside the road. This has been a familiar sight to me for decades, and for so many others, but only a few people pay attention to what they hold inside.
A landfill is an area of land that has been specifically engineered to allow for the deposition of waste into it. The process starts when most of us toss something into the trash, and we give it no further thought. We’ve done our part – consume, dispose, and then move on. As of today, most of it eventually ends up in landfills.
According to the waste management hierarchy, landfilling is the least preferred legal option and their usage should be limited. If the waste is to be landfilled, it must be sent to landfills that comply with the Landfill Directive 1999/31/EC.
Technical requirements need to be strict to safeguard surface water, groundwater, soil, and human health. The purpose of the directive is to prevent or reduce the negative effects on the environment.
The difference between a dump and a landfill
A dump is an open hole in the ground where trash is buried and where animals often swarm. As of today, dumps are illegal, since dumps do not offer any environmental protection while lacking regulation.
A landfill is a carefully designed and monitored structure that isolates the trash from the surrounding environment, which works in theory. Unfortunately, this is far away in reality. There are a variety of reasons why landfills are harmful to the environment. When a landfill decomposes, it takes numerous years to disintegrate and will remain a problem for future generations.
Problems with landfills
The purpose of a landfill is to bury the trash in a way that it will be isolated from groundwater, kept dry, and avoid contact with air. In these conditions, waste will decompose very slowly. A landfill is different from a compost pile, where the purpose is to bury trash in a way that it will decompose quickly.
A landfill has a liner system at the bottom to catch toxic waste that can contaminate the water. However, they have been found to emit hazardous gases. When all of our spam ends up in one giant heap, this heap will eventually become toxic soil. The biggest offender is carbon dioxide and methane, which is emitted into the ecosystem as the decomposition process begins. Since processing trash releases carbon, landfills are significantly contributing to climate change. There have been health reports that people living near solid waste landfills have had an increased chance of bladder cancer or leukemia.
When it rains, some water runs down the side of the landfill into ditches that guide this stormwater to a particular pond. On the other hand, some rainwater water still soaks into the landfill, goes through the trash, and becomes a liquid called “leachate.” Leachate is the result when water is mixed with chemicals and bacteria as it has soaked down through the trash. The older landfills didn’t try to secure or treat the leachate. However, with modern systems, there are many components to collect and dispose of it properly.
Global treatment and disposal waste percentage 2016 (source)
Landfill Regulations have been set to differentiate waste, which may be accepted in different classes of landfill. The Landfill Directive defines the various categories of waste as municipal, hazardous, non-hazardous, and inert.
Municipal solid waste (MSW) landfill – A highly designed, state-approved disposal facility where municipal waste (hazardous waste from private housing, commercial and industrial waste) can be disposed of for long-term management and monitoring. All modern MSW landfills must meet or exceed federal Subpart D regulations to ensure environmentally friendly and safe disposal facilities.
Landfills for hazardous waste – A waste with an attribute that make them dangerous or potentially harmful to human health or the environment. Most hazardous waste materials contain toxic substances. Over time, these toxins leach into our soil and groundwater and become environmental hazards for years. For example, electronic appliances contain a long list of hazardous substances such as mercury, arsenic, cadmium, PVC, solvents, acids, and lead.
Construction & Demolition landfill – Construction and demolition (C&D) debris refer to materials produced in the process of construction, renovation and/or demolition of structures such as concrete, asphalt, wood, paper, glass, rubble, and roofing materials. Some state definitions also include soil cleaning waste, such as strains, rocks, and dirt. C&D garbage is classified as non-hazardous and regulated by the state and local governments.
Inert landfill – Forms from the earth and earth-like products such as concrete, cured asphalt, rock, bricks, yard trimmings, and land clearing debris such as stumps, limbs, and leaves. These materials, depending on the state’s definition, are permitted by law to be disposed of in inert landfills.
Structure of landfill
The main components of any secured, permitted landfill are:
Bottom liner system – Separate trash and subsequent leachate from underlying natural soils and groundwater. In Municipal Solid Waste landfills, the bottom liners are generally constructed using some type of durable, puncture-resistant synthetic plastic. A combination of clay soils, along with synthetic plastic, can also be used. The used materials/systems vary according to the type of waste. E.g., a sanitary landfill uses a clay liner. A municipal solid waste (MSW) landfill uses a synthetic (plastic) liner.
Cells (old and new) – Where the trash is stored within the landfill for disposal. These cells vary in size from a few acres to 20+ acres.
Stormwater drainage system – It is designed to control water runoff during rain and storms, which is done by directing the runoff through a series of berms and ditches to holding areas, known as sed pond.
Leachate collection system – Collects and removes the water that has percolated through the landfill itself and contains contaminating substances (leachate). The leachate collection system typically consists of a series of perforated pipes, gravel packs, and a layer of sand or gravel placed in the bottom of the landfill.
Cover or cap – Seals off the top of the landfill. Covering isolates the waste from exposure to the air, pests, and controls odors. When a section of the landfill is filled to capacity, it is permanently covered with a combination of a layer of polyethylene plastic, compacted soil, and a layer of topsoil which will support the growth of vegetation to prevent erosion.
Groundwater monitoring stations – Set up to directly access and test the groundwater around the landfill for the presence of leachate chemicals. It includes a series of wells, which monitor the water quality before and after it’s gone through the process, to make sure there hasn’t been any impact or contamination of the groundwater.
Methane collection system – Collects methane gas that is formed during the breakdown of trash. Since methane is highly flammable, it is collected with a series of pipes that are embedded within the landfill, and once it’s collected, it can be either naturally vented or control-burned to energy.
Converting landfill gas into energy
Converting landfill gas to energy is how mature landfills deal with the issue of gases created within their facilities. It is an effective means of recycling and reusing a valuable resource. In fact, the U.S. Environmental Protection Agency (EPA) has endorsed landfill gas as an environmentally friendly energy resource that reduces our reliance on fossil fuels, such as coal and oil. Landfill gas-to-energy projects are the most successful when partnered with mature MSW landfills, as opposed to newer or C&D landfills.
We’re running out of space. We’re generating more trash than ever before. Landfills are a collection of waste that could have been handled or disposed of differently. Most of the burden placed on landfills is entirely unnecessary, but consumers are often unfamiliar with their recycling options.
Landfills can only temporarily mitigate the immediate consequences of enormous waste production and have already cost our environment a good amount of land. Landfills are an unfortunate and necessary part of modern society.
If we really want to tackle the problem of municipal solid waste, we should first look at its core. With less waste generated in the first place, the challenge of finding environmentally friendly ways to dispose of is much easier. Reduce, reuse, and recycle is an excellent way for people to help reduce waste and through it – landfills.
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