Following satellite images dated January 2016 taken by NASA show the landfill site fire at Deonar, Mumbai. The landfill fire caused serious drip in air quality & smog around the city for several days.
Why Landfill Site Catches Fire?
A landfill fire occurs when waste dumped of in a landfill site ignites & fire spreads. In landfills that do not cover their waste with daily cover of soil, biological decomposition creates substantial heat & methane. This flammable combination of heat and methane gas cause materials in the landfills to spontaneously ignite.
What most of us do not know is: Municipal Solid Waste disposed of in landfill generates 2 to 15 kg of “landfill gas” per metric ton of waste per year. Landfill gas generally contains 45-60% methane and 45-60% of Carbon Dioxide.[Source] Methane is 25 to 30 times more potent green house gas and contributes marginally to global worming. Methane generated from landfill sites is highly flammable. Typically the landfill site has about 100 to 300 feet height of garbage stacked over area of several hectors. Such a huge mass of garbage generates hundreds of kilograms of methane every day. Thousands of kilograms of methane remains trapped several feet below surface, waiting to ignite.
Large scale landfill fires indicate lack of following preventive measures:
- Scientific Waste Management: Effective segregation, material recovery and composting of daily municipal solid waste. Government of India has established MSW Rules 2000 for effective management and handling of municipal solid waste. Machinery and Technology is now available to recycle up to 80% of municipal solid waste. This ensures that only 20% quantity of waste reaches landfill site & thereby reduce the fire risk and landfill emission by 80%.
- Cover the landfill with scientific layer of rock bed, geo-textile and soil. Drill methane capture wells in the landfill sites to collect underground methane to fire/explosion.
- Methane Capture (and Flaring/ Waste to energy): The landfill gas must be captured using a scientifically proven methods to prevent landfill fires. Captured methane can be used for energy generation.
- Bio-remediation and scientific landfill site closure: Bio-remediation is the use of biological methods to degrade, disintegrate, transform and/or eliminate contaminants from municipal solid waste. Bio-remediation is a natural process that utilizes the normal life functions of bacteria, fungi & plants. Bio-remediation and scientific closure of landfill site is essential to prevent fire and emission of hazardous landfill gas.
Every day millions of tons of solid waste is sent to landfill sites without scientific measures. In near future, lack of scientific waste management can lead to large scale fires similar to Deonar landfill site across India & globe.
About Author: Suhas Dixit is CEO & Director of Pyrocrat Systems LLP. Pyrocrat has established several waste management projects including 300TPD Municipal Solid Waste Management Facility at Navi Mumbai and Series of Waste Plastic/Tire to Diesel Projects