Where’s the carbon in water – plus, how it can help to go Net Zero and beyond

Barry McGovaney, Sustainability Lead and Innovation & Technology Manager
April 22, 2024

When it comes to Net Zero and reducing impacts on the environment, you may be thinking where’s the carbon in the water (H2O) that’s being used at your organisation?

There are carbon emissions linked to each cubic metre (every 1,000 litres) of water you use at your organisation - and there’s a way to calculate what it is.

In fact, there are more carbon emissions linked to every 1,000 litres of wastewater that leaves your site, than every 1,000 litres of water you’re getting through your pipes*.

As there is carbon associated with both – it shows why being wiser on water helps organisations deliver Net Zero and other targets under the UN Sustainable Development Goals. Plus, using less hot water means lower energy costs too.

How much carbon could I save?

According to the latest greenhouse gas reporting conversion factors for 2021*, there is 0.149 kilograms of CO2e in each 1,000 litres - which is measured as one cubic metre on bills and water meters.

When it comes to the wastewater at your site* – from the water that goes down the drains in kitchens or sinks, to flushes from the toilets and urinals – it’s 0.272 Kg of CO2e in each cubic metre, according to the conversion factor covering emissions from treating it.

This shows that by just boiling the water you need in work kitchen kettles - to reducing water waste from any leaks, including dripping taps, running toilets from cisterns - and elsewhere at your site – it soon adds up to lowering running costs and creating less carbon overall.

Being wiser on water

Water may be in Scope 3 on the emissions’ list – but it shouldn’t be looked at last.

Some simple steps can be taken straightaway to help reduce the impact your organisation is having on the environment – and save on running costs in the future.

Looking closer at what water you use each month is a good first move, if you’re not already doing this. Noting a meter read each month, if it’s safe to access, allows you to track your use and spot water issues early – and data loggers on your meter can also help identify opportunities, with information fed into an online portal for updates throughout 24 hours of operating.  

Hot water can cost between 2 to 4 times more than cold water, once energy costs are considered, and water efficient taps, showerheads and other measures can all help there. So, cutting hot water use has a direct impact on energy costs – and means less carbon being created too.

There are also big tax deductions currently available for organisations that invest in equipment including fittings in their buildings, so there’s never been a better time to consider low-cost water-saving tech – paying you to save more in the future.

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