In the waste sector, greenhouse gas emissions are calculated in accordance with the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, including its 2019 Refinements. The Slovak Republic adapts these principles to national conditions and the availability of statistical data.
The waste sector includes emissions arising from:
- landfilling of waste,
- composting and anaerobic digestion (biogas plants),
- waste incineration,
- treatment and discharge of municipal and industrial wastewater.
The calculation is based on a combination of waste quantity data and emission-influencing factors. Each category has its own specific characteristics:
Landfilling of waste – Methane (CH₄) is generated through the anaerobic decomposition of biodegradable waste. Calculations take into account factors such as the amount and composition of landfilled waste (e.g. share of food waste, paper, garden waste), landfill conditions (temperature, moisture, operational practices), and whether the landfill captures methane for energy use (e.g. electricity generation) or if methane is naturally oxidized in the cover soil layer.
Biological treatment of waste – Composting and anaerobic digestion produce methane (CH₄) and nitrous oxide (N₂O). Emissions depend on the amount of treated waste and the type of technology used. Composting generates mostly N₂O, while biogas plants produce methane.
Waste incineration – The main emission from waste incineration is carbon dioxide (CO₂), with smaller amounts of CH₄ and N₂O. Emissions vary depending on whether the incineration includes energy recovery (e.g. heat production) or not. In the case of energy recovery, the emissions are reported under the energy sector.
Wastewater treatment – Emissions of CH₄ and N₂O are produced during the biological processes involved in wastewater treatment. Calculations in this category consider factors such as the type of wastewater management (e.g. centralized wastewater treatment plant, household treatment system, septic tank), the amount of organic pollution, and the number of people connected to each type of treatment.
Official and verified data from several institutions are used for the calculation of emissions:
- Statistical Office of the Slovak Republic (ŠÚ SR) – data on waste generation, composition, and waste management methods, including municipal and industrial waste.
- Ministry of the Environment of the Slovak Republic (MŽP SR) – data from the Waste Information System (IS OH) and landfill management records.
- Regulatory Office for Network Industries (ÚRSO) – data on electricity production from landfill gas.
- Slovak Hydrometeorological Institute (SHMÚ) and Water Research Institute (VÚVH) – information on wastewater treatment, water quality, and emissions from the water sector.
- National Emission Information System (NEIS) – data on waste incineration and facility operations.
Reliable data are available primarily from the year 2005 onwards; earlier periods are supplemented using statistical methods and estimates (e.g. extrapolation based on household consumption or wage development).
Air pollutant emissions are processed according to the EMEP/EEA air pollutant emission inventory Guidebook 2023, using the same data as for the calculation of greenhouse gas emissions, supplemented by information on the incineration of hazardous and medical waste, as well as fires involving motor vehicles, residential buildings, and industrial facilities.