The modern sanitary landfill is considerably more than just a landfill or an open dump. This is because waste materials in the sanitary landfill are treated in a more controlled manner in order to protect the quality of groundwater in the vicinity. Lighter materials are deposited near the bottom of the sanitary landfill, where the majority of dangerous substances are buried, safeguarding the surrounding ecosystem. Approximately 37% of waste is disposed of globally in a landfill, with 8% of that going to sanitary landfills with landfill gas collection systems. According to the University of Michigan's website, each day's new waste is covered with a new layer of soil in the hopes that it will decompose before the landfill's barrier between the waste and groundwater fails. This article will explain to you about which Sanitary Landfills for the disposal of solid waste will be helpful in preparing the Environment syllabus for the UPSC Civil Service Exam.

Percentage (7.7%) of Sanitary Landfills in Waste Disposal

Sanitary Landfill- Concept

• A sanitary landfill is generally a pit with a covered bottom where waste is buried in layers and crushed into a solid mass.
• This method of waste disposal was first introduced in Fresno, California, in 1935.
• A sanitary landfill can be described as a more secure and well-organized waste management system.
• The major goal of sanitary landfills is to keep wastes safe by limiting the amount of harm caused by accumulated waste and allowing for safe decomposition.
• Garbage and soil are alternately layered to speed up decomposition.
• Since decomposition produces methane, a harmful gas, it is collected at the landfill and used to generate electricity rather than being discharged into the atmosphere.
• A clay lining separates the waste from the environment at the sanitary landfill.
• Furthermore, it involves well-designed engineering approaches for protecting the environment from solid or liquid waste contamination.
• When the sanitary landfill is full, impermeable clay is used to seal it up, and the area can then be used for other purposes if it is sealed safe.

Sanitary Landfill - Working

• Layering waste in a huge hole is how sanitary landfills work. There are many tiers of waste layering to help in the decomposition of materials.
• This can also aid in trapping hazardous gasses released during the process.
• To prevent the land from collapsing, the layers are constructed so that the bottom half has the least volume and the top part has the largest.

A Typical Sanitary Landfill

First Layer (Liner System)

• The liner system is the first layer. This is the lowest layer and the first to be utilized in constructing the sanitary landfill's foundation.
• The procedure comprises the use of compact and solid clay to prevent liquids from seeping in or out.
• This is why this clay is absolutely impenetrable to water.
• This contemporary style of sanitary landfill also includes high-density plastic reinforcing put on top of the clay.
• This engineering design ensures there is no space for liquids to penetrate, preventing pollution of the underground water.

Second Layer(Drainage System)

• The drainage system is the second layer. The drainage system takes care of the liquid that is generated when some waste materials decompose.
• This liquid should not pass through the liner layer due to its toxicity.
• The drainage layer aids in the drainage of this liquid so that it does not come into contact with the liner system.
• Rainfall and snow may also seep through the top surface and into the landfill, which must be drained.
• These liquids could contain toxins from the garbage, which could erode the linear system and contaminate the soil and water beneath the landfill.
• To mitigate this risk, the sanitary landfill is equipped with perforated pipes on top of the liner layer to collect all liquids that drain to the bottom of the landfill, resulting in leachate.
• The leachate is then sent through the plumbing system to treatment plants where it is treated before being reused.

Third Layer (Gas Collection System)

• The gas collection system is the third layer. Gasses are formed in the same way as liquids are produced by natural processes.
• The most common of these gasses is methane. Methane is a gaseous hydrocarbon that is both volatile and poisonous, contributing to global warming and endangering general environmental health when released into the atmosphere.
• In this layer, there are extraction pipelines that collect methane gas and transfer it to treatment plants.
• There it is treated before being used to generate electricity and power various processes.

Fourth Layer (Trash)

• This is the largest and most important layer.Waste collected from diverse sources on a regular basis will be dumped in this layer.
• The waste disposed of is compressed on a daily basis to avoid taking up so much space.
• Following that, a layer of compacted soil is put to the sanitary landfill's surface.
• Soil is effective in controlling odors and preventing the growth of unwanted microbes like bugs and flies. In addition, the compact soil keeps windblown debris at bay.
• This layer is then reinforced with a 2-3 foot layer of topsoil, and vegetation is planted.
• When all of this is finished, the land will be reclaimed and can be put to various uses.

Sanitary Landfill- Advantages

• Excellent Energy Source: Sanitary landfills act as excellent energy sources due to the fact that they generate carbon dioxide and methane when the waste starts decomposing.
• These gasses can be extracted, purified, and used to generate energy.
• Every year, roughly 95.6 million tonnes of Carbon (IV) oxide are produced in the country's landfills.
• Eco-friendly: Due to the efforts of environmentalists and conservationists who pushed for tight landfill legislation, regulations, and standards, sanitary landfills are eco-friendly.
• Landfills in general were just used as an open-air disposal for practically everything, but that is no longer the case in the sanitary landfill.
• The sanitary landfills are designed with engineering technology in mind; good soil lining and a leachate control system ensure minimal seepage or damage.
• Cleanliness And Waste Management: When a community lacks a sanitary landfill or residents are aware that there is no effective waste management system in place, they will just dump waste in vacant lots or in open dumps.
• Thus, sanitary landfills help in maintaining cleanliness in cities, towns, and districts.
• These are places where recyclable and non-recyclable waste can be dumped separately.
• Good Storage Facility: They also serve as a storage facility for more hazardous goods that must be kept away from the general population.
• Low Cost Option: The waste in the sanitary landfill will just have to travel a short distance to the dump, lowering transportation expenditures.
• Pollution Reduction: This will also help to reduce pollution caused by garbage transportation.
• Employment Generation: Any country's successful waste management system is a multimillion-dollar undertaking that necessitates personnel at every stage. More sanitary landfills in the area offer more job opportunities and a higher quality of life for residents.

Sanitary Landfill- Drawbacks

• Demands Continuous Maintenance: A landfill takes a lot of time and effort to construct and maintain. Furthermore, it only protects public health when properly administered and continuously maintained.
• Failure to take preventative steps could result in difficulties with the lining systems. As a result, the threat of groundwater contamination is constantly present.
• Consumption of Huge Land: The fundamental fault in the sanitary landfill concept is that it consumes a lot of land and resources to keep the garbage contained, as well as being potentially harmful to the environment.
• Leachate: Rainwater soaks into the landfill, resulting in foul-smelling liquid waste (leachate) that can transfer poisons from the waste into the groundwater. This is why it's critical to properly line the landfill and avoid placing it near a river, stream, or lake.
• The easiest approach to prevent leachate is to keep the dump covered until it is capped with a roof, canvas, or plastic cover.
• Hindering of the City’s Growth: Landfills may also hinder a city's growth because they are typically built inside current municipal limits without taking into account future expansion and land-use needs.
• No one wants to acquire property on or near a dump, hence the landfill and its surrounding region are effectively a no-land.

Difference Between Sanitary Landfills And Open Dumps

Conclusion

Despite the sanitary landfill being sealed and the area being utilized by covering it with plants, methane may still be produced. The existence of circular areas of dead grass is one sign of such an occurrence. This can be extremely dangerous because an explosion could occur. Although sanitary landfills have limitations of their own, and alternatives are being considered, they are unquestionably better than enormous piles of accumulated openly dumped waste.