- Most Indian landfills have exhausted their lifespans
- 45 of India’s 62 million tonnes of annual garbage remain untreated
- Scientific landfills reduce environmental and health risks
Urban dwellers in India are accustomed to being woken up by the garbage collector’s whistle and depositing the day’s garbage in a waste collection vehicle. Many remain unaware of what happens to the garbage post its disposal in a municipal vehicle. For years, urban civic bodies in India have adhered to disposing waste in landfills, huge acres of land demarcated specifically for garbage disposal. The concept of landfills in urban India was initially developed as large areas of land situated far away from residential areas and the garbage disposed continuously recycled so that the landfill doesn’t exhaust itself. But urban population expansion over the years has translated to landfills becoming dump yards, with little regard for their capacity or lifespan.
Landfills in India pose numerous threats due to their unscientific design and indiscriminate disposal of waste. One of the major threats landfills pose is the emission of methane gas due to accumulation of waste. Methane is the leading cause of fires at landfills, resulting in garbage burning which causes severe air pollution. Landfills also pose tremendous health hazards due to them being a storehouse of virus and bacteria, causing cardiovascular and lung diseases.
Is it finally time for India to nurture scientific landfills to deal with the growing problem of waste and shrinking landfill spaces?
Unlike just a demarcated space for disposing waste, a scientific landfill is constructed as a sustainable space for waste disposal and treatment of municipal solid waste. The technology deployed in constructing a scientific landfill is simple and a scientific landfill ensures complete control over gas developed in the landfill and leachate (water that has infiltrated through a solid and leached out) as well as limited access of vectors such as rodents and flies to the waste.
Landfills in India were never constructed in a scientific manner. They were simply lands demarcated by state governments and municipal bodies to dump waste. That resulted in most landfills in India exhausting their lifespan and emitting poisonous gases such as methane. Scientific landfills can treat the waste while it is disposed, making them important in urban waste management, said Sohail Ayub, author of ‘Landfill Practice in India: A Review’
Functioning Of a Scientific Landfill
A scientific landfill is termed so because of its scientific design during construction. One of the biggest problems of ordinary landfills is the seeping of solid waste into underlying soil and water, contaminating both. Scientific landfills eliminate the risk of waste seeping underground as the base layer is constructed of 90 metres of clay, thus arresting any seepage or leakage within the landfill. On top of the base layer, a drainage layer made of soil, measuring 15 metres in length and a vegetative layer of 45 centimetres to minimise soil erosion. The presence of these layers ensures that leachate is collected before it seeps underground.
Scientific landfills also act as degassing systems by reducing the production of methane. Since the layers soak most of the impurities in the waste disposed, methane generates slowly compared to the generation speed in ordinary landfills. Vertical wells installed in scientific landfills help extract methane regularly, and the gas can then be used for electricity and heat generation purposes.
A scientific landfill ensures that there is no risk of pollutants seeping underground or enough generation of methane to light up the garbage. This reduces the risk of environmental or health hazards tremendously, said A.K. Agnihotri, Professor, The Energy and Resources Institute (TERI).
Scientific Landfills in India and Challenges
Taking a cue from countries like Sweden, Norway and Estonia, India too has begun work towards developing scientific landfills. The capital city of Delhi, one of India’s biggest municipal solid waste generators in the country has been reeling with the problem of landfills for years. The three landfills near the capital, namely Ghazipur, Okhla and Balswa have all exhausted their respective lifespans and become dumping yards, posing high environmental and health hazards. The newly inaugurated landfill at Narela-Bawana is India’s first scientific landfill. At 150 acres, the Narela-Bawana landfill is situated on an area more than double of Ghazipur at 70 acres. The scientific landfill has the capacity to treat 2,000 tonnes of waste every day, generating 24 megawatts of electricity. Given the Central Pollution Control Board’s estimate of Delhi projected to generate 15,000 tonnes of garbage daily by 2021, the new plant is welcome to change the waste management scenario in capital.
Sadly, Narela-Bawana remains the only scientific landfill in India. The challenges in constructing scientific landfills across India are many, the chief among them being availability of land, technical know-how and availability of funds for construction. The Narela-Bawana landfill was constructed at a cost of Rs. 46 crores, courtesy a public-private partnership model. Unfortunately, not many private companies have been eager to invest in the development of scientific landfills. When the Brihanmumbai Municipal Corporation (BMC) brought out tenders in 2015, inviting private corporations to bid for the development of scientific landfills, there were no takers.
Technical know-how of developing scientific landfills remains another area where India needs to work extensively. Engineers with proper know-how of creating base layers of scientific landfills are limited. Since the area of building scientific landfills was unexplored till recently, the pool of engineers or experts with technical know-how of construction remains relatively void.
Engineers with technical know-how of constructing scientific landfills remain rare, more so because for years this aspect of waste management hasn’t been explored. Asking for advice from European engineers and waste management experts can aid in the building of scientific landfills in India as such landfills are quite common in Europe, said Mr. Agnihotri.
45 million of India’s 62 million tonnes of annual garbage remain untreated, a dangerous statistic that would lead India to severe garbage crisis by 2030. Major landfills in the urban metropolises, from Delhi’s Ghazipur to Mumbai’s Deonar are exhausted and overburdened by the daily disposal of waste. The unscientific design of these landfills has also resulted in severe environmental and health hazards for the urban population of India’s major cities. A CPCB report of 2015 states that since 2011, 7 megacities of India accounted for nearly 48 per cent of total methane emissions in the country, courtesy the large landfills in these cities. Despite the various challenges in their planning and construction, scientific landfills are one of the better waste disposal options for India’s urban spaces.
The only way to reduce pressure on existing landfills is by building new ones which treat waste scientifically. Though there are various challenges in building scientific landfills, they are more effective in dealing with waste and are a good source of energy generation. Similar to building of sewage treatment plants, there should be adequate focus on building of scientific landfills with both the government and private corporations coming onboard, said Dr. Anil Kumar, Director, Department of Environment, Government of Delhi.