A city laid waste
A new rapid bioremediation process that can remove garbage hills and end their ill effects, promises a low-cost solution to waste management and disposal. It is very important that alternative technologies are carefully evaluated on their merit.
Illustration by C R Sasikumar
Most Indian cities are surrounded by hills of garbage, which are a testimony to our neglect over a long period of managing and disposing of the waste we generate in the course of our household activities and commercial activities in the cities. The waste has been dumped for decades, dry and wet, plastic, textiles, and what have you, without sorting, on the outskirts of the cities. Even after the Municipal Solid Waste (Management and Handling) Rules, 2000 specified that landfill sites should be allocated on which sanitary landfills should be developed to receive the final residual waste, the sites have been used only as open dumpsites for all kinds of waste, mixed together.
The proliferation of airless open dumps of garbage leads to emissions of methane, which absorbs the sun’s heat, warms the atmosphere and contributes to global warming. Methane is over 20 times more potent as a heat trapping gas than carbon dioxide. At the same time, leachate, a black liquid oozing out from the waste as it slowly decomposes over a period of 25 to 30 years, contaminates soil and ground water, the latter being used by many in the urban areas as a primary source for drinking. Foul odour from the waste rotting in airless heaps, and smoke from the fires that routinely erupt in them, are other consequences of dumping waste in the open. The garbage hills are now closing in on the cities as the cities expand. The city residents have been going from pillar to post, from courts to the National Green Tribunal, in the hope of some corrective action.
Let us recall that it was civic action — a Public Interest Litigation in the Supreme Court in December 1996 by Almitra Patel, one of the authors of this column — that had put solid waste management on the agenda of the government. The court issued an order to set up an expert committee in January 1998 with Patel as a member, to submit a report on sustainable techniques of managing waste. Based on this committee’s report, the Municipal Solid Waste Rules, 2000 were notified by the Ministry of Environment and Forests.
Even though the progress has been very slow, we now have Solid Waste Management Rules, 2016 which cover much more than only municipal areas, provide for collection charges and for penalties on waste generators for non-compliance, and most importantly, unlike the earlier Rules, make it the duty of every waste generator to segregate the wet waste from the dry, that is, keep the two kinds of waste unmixed. This is actually in line with the duties outlined in Article 51A (g) of the Constitution which lists among every citizen’s fundamental duties, “to protect and improve the natural environment including forests, lakes, rivers and wildlife.”. Current laws in India are also very progressive in that they require “appropriate biological processing for stabilisation of waste”, whether or not the processed waste can be used or sold as compost, while landfilling is restricted to non-biodegradable inert wastes or pre- and post-processing rejects.
The challenge lies in implementation. The earlier so-called landfills, actually old dumps, are without bottom liners and side liners. Capping of these dumps is not a solution because it leaves methane and leachate to form for decades within the cosmetically covered heap. The disastrous effects of building on and around a “closed landfill” were so clearly demonstrated at Malad in Mumbai, where trapped landfill gases seeped sideways through the soil into the basement of the adjoining Mindspace Commercial Complex, wreaking havoc on every possible electronic equipment and causing unwellness for residents nearby.
The good news is that we have a simple, low-cost solution of bioremediation to remove the garbage hills and their lingering ill effects, which permanently achieves near-zero emission of harmful gases (such as methane, hydrogen sulphide, and ammonia) and leachate. A number of attempts at bioremediation and bio-mining were made from as early as 1998 in Nasik, Madurai and Mumbai, and there have been more since then. Most recently, Raaginii Jaain, a national expert on the Government of India’s Swachh Bharat Mission, has developed a rapid bioremediation process for old dumps (wrongly called landfills), and has successfully used it on old waste — six lakh tonnes at the Bhandewadi dump at Nagpur, 20 lakh tonnes at the Bandhwari dump shared by Gurugram (Gurgaon) and Faridabad, 10 lakh tonnes at Durg in Chhattisgarh, and three lakh tonnes in Gandhidham in Gujarat, among others.
Earlier bio-mining efforts by S.R. Maley and Birju Mundhra loosened thin surface layers of the garbage hill and formed this into windrows before screening. In Raaginii’s rapid method, the hill is terraced, grooved and then slashed to form high slices to let air into the waste and drain out leachate. Each heap is turned weekly, four times to ensure aeration of all parts of the waste and sprayed with composting microbes to accelerate biological decomposition. After four turnings, there is about 40 per cent volume reduction in the waste as the organic fraction of the original waste is degraded biologically by the bioculture. Specific microbes are also used for leachate treatment. Once the waste is stabilised, it is ready for bio-mining, and can be separated into different fractions which can then be used for different purposes — for compost, road sub-grade, making RDF (Refuse Derived Fuel) pellets, recycling plastics, or inerts for landfills.
The first step in the bioremediation process at the Nagpur dump in 2016, for example, involved rearranging the old waste in long rows (windrows) on the ground, each heap being four feet wide and five feet high, with a three feet gap between any two adjacent rows to allow the vehicles to move.
In our visit to the Gurugram dumpsite, earlier in June, we saw the waste heaps in neat windrows and trickles of water in the gaps between the heaps where we were told there were rivers of leachate only six months ago when the operation began. There was no smell, nor many flies, and reduced volume of waste — again, a contrast from the scenario in November 2016, we were told. The waste was ready for bio-mining, and this has begun, reviving and using the old compost plant equipment with the arbitrator’s permission while the financial issues between the earlier operator and the Faridabad Municipal Corporation are being resolved.
There are other entrepreneurs and innovators who are also trying bioremediation of old waste. What these examples show is the superiority and simplicity of bioremediation in that it is low-cost and environment-friendly. The most valuable part of this exercise is that the land which was hosting waste dumps is now fully recovered for alternate uses. Since it is very hard to win local acceptance for new waste processing sites, the recovered land can be used for waste management.
There is also a lesson here for decision makers at all levels in government. Equipment suppliers are usually keen to push the technology they are providing and they often have lobbying capacity to predispose the policy in favour of a particular technology. It is very important that alternative technologies, including the simpler and cost-effective ones, are carefully evaluated on their merit.
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