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Energy & emissions

Greenhouse gas emissions from English and Welsh water companies

Water companies need to use a lot of energy to treat water, help it travel to and from your home and then treat it before returning it to our rivers. Water companies strive to minimise the amount of greenhouse gases produced and reduce the impact on climate change. Water companies in England have committed to achieving Net Zero operational emissions by 2030. To find out how companies will be reducing their emissions, see here.

3,301 net operational location based emissions in kilotonnes of carbon dioxide equivalent per year
Equivalent to
2.2 million
average annual car emissions

Source: Water UK; England and Wales, Apr 2022 - Mar 2023

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Why might greenhouse gas emissions vary?

The amount of energy needed to treat water and sewage varies for many reasons. This includes the level of treatment needed for the water, the geography of the area – how flat or hilly an area is will affect how much energy is needed to pump water – and how much water customers are using.

Greenhouse gas emissions also vary depending on how much energy companies generate themselves, as well as variations in the carbon dioxide released in the production of the electricity that they buy from the grid. These emissions are also affected by the way companies process water, sewage and sludge.

There are different ways to calculate greenhouse gas emissions. This section provides ‘location-based’ emissions, which use an average figure for the emissions from electricity in the region where it is used, which gives a consistent view of emissions over time. The data is from the annual performance reports companies provide to the water industry’s economic regulator, Ofwat. As new reporting requirements were introduced in 2022-23, only data after this change is shown to avoid confusion.


Net operational greenhouse gas emissions (KgCO2e) per megalitre of treated water – location based

This graph shows greenhouse gas emissions created by the generation of power used to treat and supply water in the latest year. There are different ways to calculate greenhouse gas emissions. This graph shows ‘location-based’ emissions, using an average figure for the emissions from electricity in the region where it is used, which will give a consistent view of emissions over time.

As companies of different sizes have different levels of emissions, the amount of emissions in kilograms of carbon dioxide equivalent for each company has been divided by the volume of water treated in millions of litres.

There are other things that might make the level of emissions vary between companies, like the level of treatment needed and whether areas are flat or hilly. Including all these factors would make the graph very complicated so, to keep it simple, for this graph emissions have been divided just by the volume of water treated.

To find out more about each company’s carbon emissions, click the button below the graph


      Net operational greenhouse gas emissions (KgCO2e) per megalitre of treated water – location based

      Source: Water UK

      Net operational greenhouse gas emissions (KgCO2e) per megalitre of treated sewage – location based

      This graph shows greenhouse gas emissions created by the generation of power used to treat sewage in the latest year. There are different ways to calculate greenhouse gas emissions. This graph shows ‘location-based’ emissions, using an average figure for the emissions from electricity in the region where it is used, which will give a consistent view of emissions over time.

      As companies of different sizes have different levels of emissions, the amount of emissions in kilograms of carbon dioxide equivalent for each company has been divided by the volume of sewage treated in millions of litres.

      There are other things that might make the level of emissions vary between companies, like the level of treatment needed and whether areas are flat or hilly. Including all these factors would make the graph very complicated so, to keep it simple, for this graph emissions have been divided just by the volume of sewage treated.

      To find out more about each company’s carbon emissions, click the button below the graph.


          Net operational greenhouse gas emissions (KgCO2e) per megalitre of treated sewage – location based

          Source: Water UK

          Conserving water

          You can help water companies use less energy by saving water so they don't have to treat and pump so much around. Take a look at how you can save water.

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