Solid waste management (SWM) is a serious problem in India resulting from rapid urbanisation, population explosion, changing lifestyle and modernisation. This has resulted in generation of large quantity of municipal solid waste (MSW) from urban local bodies (ULBs). About 72 million tonnes (MT) of solid waste (SW) is generated in the country, of which 43 MT are collected and only 12 MT of waste is treated.
About 31 MT of SW is dumped in the landfill without any treatment every day. SW generation is projected to reach 165 MT per day (MTPD) by 2030 and 436 MTPD by 2050. If cities continue to dump the waste at present rate without treatment, it requires about 1,240 hectare of land per year to dump the waste generated in the whole country. Since the land resource in the urban areas is finite and precious, it is necessary to evolve an action plan to minimise the landfill requirements.
Landfilling of MSW generates huge quantity of leachate which can potentially contaminate ground water and surface water causing irreparable damage to precious water resource. Most of the ULBs adopt landfilling as the option for disposal of solid waste. Unscientific landfilling causes groundwater contamination, generates greenhouse gases like methane and hydrogen sulphide and leads to nuisance of foul odour in the area as far as 2-3 km.
This not only overburdens scarce land resource in towns and cities but also exacerbates adverse health impacts on human beings. Widespread agitation by masses against landfill in their neighbourhood is a well-known fact. On the contrary, if MSW is managed properly, it can be valuable manure and a renewable source of energy like biogas.
The Karnataka State Pollution Control (KSPCB), a regulatory authority for waste management, is ensuing substantial advancement in scientific MSW management by enforcing the SWM Rules, 2016. About 13,200 TPD of municipal SW is generated in the state of which 50-55% is wet/organic waste, 30-35% is dry waste and 10-20% is construction and demolition and inert wastes. By 2031, the municipal SW generation in Bengaluru alone will cross 13,000 TPD.
The KSPCB mandates door-to-door collection, proper segregation, transportation and disposal of SW in all the ULBs. Districts like Udupi and Mysuru have successfully achieved a high percentage of door-to-door collection whereas districts such as Kalaburagi, Kolar, Davanagere and Bengaluru have scope for improvement. Some local bodies like Shivamogga and Kundapura have adopted strategies such as pipe composting, community composting etc for efficient management of segregated wet waste.
Wet waste can be best managed by aerobic composting, vermicomposting and anaerobic digestion or bio-methanation. Dry waste is best managed by manufacturing Refuse Derived Fuel (RDF), palletisation, incineration and thermal pyrolysis and the final option for waste disposal must be sanitary landfilling. Composting is the scientific method of producing manure through decomposition of organic waste. Manure contains essential plant nutrients and micronutrients, which can be utilised as fertilizers. If 2,780 TPD of organic waste is composted, it can produce 556 TPD of compost, corresponding to revenue of about Rs 27.8 lakh per day. ULBs should seriously consider the economic viability of waste management and achieve higher rates of converting the organic wastes to compost and implement advanced composting methods such as vermi-composting, co-composting, inoculum-based composting etc.
Organic waste
At present, out of the 6,145 TPD of wet waste generated in Karnataka, only about 3,366 TPD is converted into 672 TPD of compost, which is sold to farmers at a nominal price of Rs 5 per kg, in coordination with the Department of Agriculture. Districts like Dakshina Kannada, Shivamogga, Mysuru, Belagavi and Dharwad are generating more than 20 TPD of compost from organic waste. The compost generated in Ballari, Raichur, Yadgir, Gadag, Kodagu, Chamarajanagara, Mandya, and Chitradurga is only 5 TPD. Only 55% of wet waste is converted into compost in the state and there is lot of scope to improve.
Karnataka generates about 3,476 TPD of dry waste. Out of this, 515 TPD is recycled and 215 tonnes is converted into RDF and 117.88 TPD is sent to cement kilns for co-processing in cement industries as a source of energy. However, the balance quantity of 2,628.12 is being dumped into land fill without converting it into useful energy resource. RDF is produced from the dry waste generated from domestic and commercial activities that include bio-degradable and non-biodegradable combustible materials. RDF with a calorific value higher than 2,000 Kcal/kg would form a good alternative source of energy in cement industries or incinerate in waste-to-energy plants. Furthermore, in the ‘Guidelines on Usage of RDF in Various Industries’ by the Ministry of Housing and Urban Affairs, RDF has been valued at a suggestive price of Rs 600 to Rs 2,400 per tonne, which can be continuous revenue source for the ULBs.
Major districts such as Mysuru, Shivamogga, Dakshina Kannada, Belagavi, Bagalkote, Vijayapura, Uttara Kannada and Kalaburagi ULBs recycle more than 20 TPD of dry waste. Bengaluru rural, Davanagere, Chikkaballapura, Mandya, Chamarajanagar, Hassan, Chikkamagaluru, Udupi, Yadgir, Raichur and Koppal local bodies recycle less than 5 TPD of dry waste. Kolar, Bengaluru Urban, Tumakuru, Uttara Kannada, Bidar, Belagavi and Kalaburagi have taken some steps for converting the dry waste into RDF. BBMP has proposed four major projects in the name of ‘Waste-to-Energy’ initiative, which are still in the early stages.
Poor waste management has led to the creation of nearly 215 landfills across the state. Apart from 10 landfill sites in Bengaluru, many illegal dumpsites are created in and around the city. Considering the fact that the resources for waste management and disposal methods are scarce, strategy for efficient scientific management of MSW must necessarily pivot towards resource recovery thereby making waste a valuable component. The hierarchy of waste management could be optimised by adding the “recovery” option - reduce, reuse, and recycle and recovery.
The economic earnings from segregation of waste and converting it into useable materials are expected to boost the incomes of urban local bodies as well. It is high time we put collective efforts for implementation of waste recycling and composting activities to attain sustainability in economic and eco-friendly waste management.
(The writer is Member-Secretary, KSPCB)