Print this page

Understand How Energy-from-Waste Works

Energy-from-Waste (EfW or waste-to-energy) facilities offer a safe, technologically advanced means of waste disposal while also generating clean, renewable energy, reducing greenhouse gas emissions and supporting recycling through the recovery of metals. According to a 2012 whitepaper released by Solid Waste Association of North America (SWANA), energy-from-waste facilities "are economically sound investments that provide multiple financial and environmental benefits to the communities that utilize them."


How EfW Works

1. Municipal waste is delivered to our facilities and stored in a bunker.
2. The waste is transferred to a combustion chamber where self-sustaining combustion is maintained at extremely high temperatures. We maintain the building around the tipping and bunker area under negative pressure and use this air in the combustion process to control odor.
3. The heat from the combustion process boils water.
4. & 5. The steam from the boiling water is used directly, or more frequently, the steam drives a turbine that generates electricity.
6. Electricity is distributed to the local grid.
7. Ash from combustion is processed to extract metal for recycling. It is then combined with residue from the air pollution control process (see items 9 and 10).
8. The combined ash is either disposed of in a monofill (where only ash is stored) that receives only that waste, used as cover material at a conventional landfill, or landfilled with other waste.
9. All gases are collected, filtered and cleaned before being emitted into the atmosphere. We manage gas from the combustion process with state-of-the-art air pollution control technology that operates to state and federal standards.
10. We control emissions of particulate matter primarily through a baghouse (fabric filter).
11. We monitor criteria and other pollutants and operating parameters to ensure compliance with permit conditions.