The issue of waste in Indonesia is becoming increasingly complex, as shown by data from the Ministry of Environment and Forestry (KLHK) in 2024, which indicates that Indonesia produces around 64 million tons of waste each year. Waste management is necessary to prevent environmental pollution.

  The Supit Urang Landfill is a final processing site located in Malang City that has a modern waste management system. It manages around 505 tons of waste per day, including organic waste processing, inorganic waste management, leachate management, and sanitary landfill. Supit Urang Landfill also processes inorganic waste with the aim of sorting recyclable materials, such as sacks, plastic bags, PET (Polyethylene Terephthalate) bottles, nylon plastic, paper, UBC (Use Beverage Carton) tetra packs, PP (Polypropylene) plastic, and metal. Waste that is not sorted in this process is then disposed of in a sanitary landfill. When the waste pile in a sanitary landfill is exposed to rainwater or surface water, it produces leachate, which is formed from the decomposition of the waste pile. Leachate contains heavy metals, ammonia (NH₃), dissolved organic compounds, and pathogens that can cause environmental pollution. Leachate management is carried out at the Supit Urang landfill with the aim of treating leachate produced by waste piles in sanitary landfills below the leachate quality standards set by the government, so that it is safe when the water is discharged back into the environment.

  Organic waste amounting to 15 tons per day originating from Green Open Spaces (RTH) and Gadang Central Market will be processed into compost. The organic waste composting process consists of four parts, namely the loading area for collecting waste, the fermentation area for the decomposition process, the maturation area for cooling the compost after the fermentation process, and finally the storage area for storing the compost. Composting is carried out using the aerobic composting method, which requires oxygen for the growth of decomposing bacteria in the organic waste mounds in the fermentation area. Aerobic composting releases heat energy into the environment, which is useful for aerobic microbes to accelerate the decomposition of organic matter. The aerobic process involved is exothermic with the following reaction:

  The composting phase generally includes the decomposition phase and the cooling phase. The decomposition phase involves the breakdown of organic compounds by microbes, causing the temperature to rise (mesophilic 20-40℃) to thermophilic (>40℃). The increase in temperature occurs due to the activity of microorganisms releasing heat, which causes the composting temperature to rise. The aerobic composting method used at the Supit Urang landfill uses the Windrow model, where composting is carried out using an open system. The waste pile is aerated and occasionally stirred to increase aeration within the compost. (malangkota.go.id, 2024; wastecinternational, 2025; waste4change.com, 2022; destiasari, ajeng, dkk, 2024)