With growing population and rapid urbanization, waste generation in India has increased significantly in India. 62 million tons of waste are generated each year in India out of which 43 million tons are solid waste.Amongst the solid waste collected, 11.9 million (22-28%) are treated and 31 million (72-78%) are dumped at landfill sites. A landfill site is a site for the disposal of waste materials by burial and is the oldest form of waste treatment.
Land filling are done for the following types of waste:
(i) Comingled waste (mixed waste) not found suitable for waste processing;
(ii) Pre-processing and post-processing rejects from waste processing sites;
(iii) Non-hazardous waste not being processed or recycled.
Land filling will usually not be done for the following waste streams in the municipal solid waste:
(i) Bio-waste/garden waste;
(ii) Dry recyclables.
Advantages of Land Fill (Over other forms of waste disposal)
· Landfills are often the most cost-efficient way to dispose of waste, especially in countries with large open spaces.
· Landfills have fewer fixed or ongoing costs.
· Gases are produced in landfills due to the anaerobic digestion of waste by microbes.
· Landfill gas can be upgraded to natural gas and hence in a properly managed landfill this gas is collected and used.
· Thus, Landfill gas haspotential for revenue stream.
· Having a specific location for disposal that can be monitored also enables waste to be processed to remove all recyclable materials.
Disadvantages of Land Fill
· Many materials that end up as waste contain toxic substances. Over time, these toxins leach into the soil and groundwater, and become environmental hazards for years.
· Electronic waste is a good example. Waste such as televisions, computers and other electronic appliances contain a long list of hazardous substances, including mercury, arsenic, cadmium, PVC, solvents, acids and lead.
Bhalswa Landfill [Delhi] case
This landfill is located in north-west Delhi. The 40-acre site is overflowing with waste and about 2,700 tons of garbage collected from four zones of the city is dumped there every day. The dump expired its shelf life in 2006, but is still in use. A putrid stench and thick black smoke envelopes the whole neighboring area in summers due to high temperatures setting the garbage ablaze. At least 4 lakh people who reside near the Bhalswa landfill are suffering from various heat-related illnesses and respiratory issues. Dispensaries and hospitals nearby are full of long queues of patients.
· Leachate is the liquid formed when waste breaks down in the landfill and water filters through that waste. This liquid is highly toxic and can pollute the land, ground water and water ways.
Ø Greenhouse gas
· When organic material such as food scraps and green waste is put in landfill, it is generally compacted down and covered. This removes the oxygen and causes it to break down in an anaerobic process.
· Eventually this releases methane, a greenhouse gas that is 21 times more potent than carbon dioxide.
· The implications for global warming and climate change are enormous.
· Methane is also a flammable gas that can become dangerous if allowed to build up in concentration.
· Apart from the financial costs, garbage buried in landfill breaks down at a very slow rate and remains a problem for future generations.
· Landfill gases have an influence on climate change.
Restrictions on Land Fill
To tackle the issue of pollution through landfills, "Solid Waste Management Rules, Construction Waste Management Rules, Plastic Waste Management Rules, Bio-medical Waste Management Rules and Hazardous Waste Management Rules were revamped."
The SWM Rules 2016 provide for detailed criteria for setting‐up solid waste processing and treatment facility, solid waste management in hilly areas, for waste to energy process, for Sanitary Landfills,for site selection, development of facilities at the sanitary landfills, specifications for land filling operations and closure on completion of landfilling, pollution prevention, Closure and Rehabilitation of Old Dumps etc.