Category 5: Waste generated in operations
This category includes emissions from third-party disposal and treatment of waste that is generated in a reporting company’s operations. This category includes emissions from the disposal of both solid waste and waste water. It may also include emissions from transportation of waste.
Waste treatment activities may include disposal in a land fill, disposal in a land fill-gas-to-energy facility i.e. combustion of landfill gas to generate electricity, recovery for recycling, incineration, composting, combustion of municipal waste to generate electricity and waste water treatment.
Only waste treatment in facilities owned or controlled by third parties is included in scope 3. This is because the reporting company purchases waste management services. Waste treatment at facilities owned or controlled by the reporting company is accounted for in scope 1 and scope 2.
A reporting company’s scope 3 emissions from waste generated in operations include the scope 1 and scope 2 emissions of solid waste and waste water management companies.
The type and quantity of greenhouse gases emitted from waste depend on the type of waste. Generally, there are three greenhouse gases emitted:
CO2 from the degradation of both fossil1 and biogenic2 carbon contained in waste.
CH4 from the decomposition of biogenic materials in landfill or waste-to-energy (WTE) technologies.
HFCs from the disposal of refrigeration and air conditioning units .
There are three methods that can be used to calculate emissions from waste:
Supplier-specific method which involve collecting waste-specific scope 1 and scope 2 emissions data directly from waste treatment companies.
Waste-type-specific method which involve using emission factors for specific waste types and waste treatment methods.
Average-data method which involves estimating emissions based on the total waste going to each disposal method and average emission factors for each disposal method.
The decision tree below can be used to determine the type of method to use.
Method 1: Supplier-specific
This method involves obtaining scope 1 and scope 2 emissions from waste treatment companies. Since these companies serve multiple clients, their emissions should be allocated to the reporting company. Emission factors are not needed, as the waste treatment companies already estimate emissions.
Emissions are calculated by summing across waste treatment providers as shown below:
Method 2: Waste-type-specific
This method involves collecting data on the type of waste and the type of waste treatment method. Disposal methods can be identified from utility bills or obtained from internal systems. The emission factors needed to calculate emissions using this method are waste type-specific and waste treatment-specific emissions factors. The emission factors should include end-of-life processes only. They can be obtained from IPCC guidelines, lifecycle databases and industry associations.
Emissions can be calculated as follows:
Method 3: Average-data
The final method involves collecting data based on the total waste diversion rates from the reporting organisation. This method is preferable when the type of waste produced is unknown.
The data needed here is the total mass of waste generated in operations and the proportion of this waste being treated by different methods e.g., percent landfilled, incinerated, recycled, etc. This data can be obtained from internal systems or utility bills. Additionally, companies should collect emission factors based on all waste disposal types. Emission factors can be obtained from life-cycle databases or national inventories. Emission factors should include end-of-life processes only.
This method can be used to calculate emissions as follows:
Recycling
One of the ways to reduce emissions from waste is through recycling. This can happen in two main ways:
Failing to dispose products and hence reducing emissions from waste disposal.
A difference in emissions generated when material are produced from scratch (cradle-to-gate emissions) and emissions generated when preparing recycled material for reuse.
Companies may encounter recycled materials in three ways:
They may purchase material with recycled content.
Emissions from these products are reported in category 1 (Purchased goods) or services or category 2 (Capital goods). This is because the upstream emissions of these products are factored in the cradle-to-gate emission factors and hence reflected in these two categories.
They may generate waste from their operations, some of which may be sent for recycling.
They may sell products with recyclable content. Emissions from these products are reported in category 12 (End-of-life treatment of sold products).
Where a company both purchases material and sells products with recyclable content, there is a risk of double counting or miscounting emissions. In this case, emissions should be allocated using the recycled content method. This method allocates emissions to the company that uses the recycled material, reported as category 1. It is recommended for scope 3 inventories since it is easy to use and generally consistent with secondary emission factors available for recycled material inputs.
Another method that can be used to allocate emissions is the closed loop approximation method. This method may be applicable when a recycled material output has the same inherent properties as virgin (new) material input. It accounts for the impact that end-of-life recycling has on the net virgin acquisition3 of a material.
When companies are not certain about which method to use, they should use the recycled content method.
Footnotes
This is carbon that comes from oil, coal, or gas↩︎
This is carbon that comes from natural sources like plants, trees, and animals. It is part of the natural carbon cycle, meaning it is absorbed and released by living things.↩︎
This is the amount of new (virgin) material needed after accounting for recycled material use.↩︎