Research builds knowledge on carbon and water

Sector-wide research is critical for navigating the myriad approaches that the water sector might pursue for reducing its carbon footprint and reaching net zero by 2030, says Dan Green, head of sustainability and innovation at Wessex Water, and programme lead for UKWIR’s carbon research projects.


The UK water sector has ambitious commitments to achieve net zero greenhouse gas emissions, and has produced the world’s first sector-wide net zero routemap. The drive to decarbonise also has big implications for the decisions that will be taken, and will affect everything from investment to day-to-day operations.

Underpinning this agenda are some significant projects being undertaken by UK Water Industry Research (UKWIR) around reducing carbon emissions. UKWIR is responsible for shaping and facilitating the water industry’s collaborative research agenda, drawing on the input of its water company members across the UK and Ireland. This helps the water industry to tackle key challenges, now and in the future.

UKWIR’s work is guided by 11 ‘Big Questions’ facing the water industry, including ‘How do we remove more carbon than we emit by 2050?’ This covers:

  • Energy & transport – decarbonising through avoidance, efficiency and alternatives to fossil fuels
  • Process emissions – minimising emissions through prevention, optimisation or capture
  • Land use & carbon capture – maximising carbon sequestration potential
  • Investment & procurement – minimising emissions in materials, consumables, products and services, and credible offsets
  • Customers – reducing emissions related to customer behaviour
  • Cross-cutting – low carbon, sustainable water cycle management


Dan Green, head of sustainability and innovation at Wessex Water,
and programme lead for UKWIR’s carbon research projects


Measured improvement

Accurate measurement of greenhouse gas emissions is critical. As well as directing attention to activities with the largest emissions, having credible carbon accounting tools helps governments, regulators, stakeholders, and customers have confidence in the water industry’s ability to meet its carbon commitments. 

The sector’s carbon accounting workbook, which is updated each year via UKWIR, provides a consistent method for water companies to report their emissions to regulators and other stakeholders. It is recognised as a leading piece of work, and few sectors have developed anything similar to date.

Among UKWIR’s recently completed projects was the development of a land carbon sequestration tool. This enables quantification of emissions from water sector land holdings, and of how much CO2 is absorbed by different types of land cover. As a result, it also shows how CO2 absorption can be increased through activities such as peatland restoration, tree planting and better land management.


Carbon expenditure

UKWIR has also overseen a review of best practice for calculating whole-life carbon impacts and costs. As well as operational emissions over the entire lifespan of equipment, this includes the embodied carbon of capital investment schemes (also known as capital carbon), and the contribution of other supply chain emissions, such as those related to treatment chemicals.

UKWIR reviewed the tools currently available to water companies for estimating the capital carbon of new assets, and how they are used. These tools are becoming more standardised, but uptake has been variable across the sector.

The research considered ways to ensure that capital carbon is properly assessed alongside operational emissions, that the sector meets the expectations of regulators and other stakeholders, and that carbon reductions are more routinely and consistently built into decision-making and reporting.


Adaption framework

UKWIR has also produced a common framework for climate change adaptation, which looks at how to assess risks from climate change and ensure there is a consistent approach to using climate projections in forecasting.

These recently completed projects are a great example of how water sector collaboration can deliver highly relevant and usable tools and identify best practice, illustrating the potential for joint research on more critical issues.


Current projects

UKWIR’s current carbon projects are increasingly focusing on ways to lower carbon emissions and unlock value. One involves a review of evidence from around the world on the creation of charcoal from sewage sludge. While technologically challenging, such techniques can lock-in carbon as an inert form that will not break down for hundreds of years.

A review is also underway of opportunities to generate renewably-sourced hydrogen – especially from wastewater – along with an assessment of the potential impact of this burgeoning sector due to its significant water demand.

UKWIR is also coordinating research on how to measure and manage emissions of methane and nitrous oxide – both of which are potent greenhouse gases – from water and wastewater treatment processes.



Implications for investment

Virtually everything that happens in the water sector has a carbon footprint. Moreover, work to improve water and wastewater services has tended to push carbon footprint in the wrong direction, because conventional investment typically involves carbon-intensive materials such as concrete, steels and plastics, and often requires large increases in energy or chemical use.

Looking ahead, it is necessary to apply understanding of emissions from both day-to-day operations and infrastructure improvements, to influence the way the condition of watercourses is improved, and to deliver other benefits for society and the environment.

This will mean judging how and when to use ‘green’ or nature-based solutions such as catchment management, constructed wetlands and sustainable drainage; and when more carbon-intensive, conventional ‘grey’ solutions are the only option.

The water sector will also need to make sure that its carbon assessment and reporting are credible, transparent and consistent. We also want to avoid duplicating research and to make sure that emerging knowledge is shared and used fully, leading to meaningful innovation and operational change.

UKWIR’s approach to research – involving active collaboration across water companies and with the supply chain, regulators and academia – gives the water sector a better chance of not only achieving its net zero ambitions, but also working at the leading edge of carbon reduction across all industries.

To find out more about UKWIR’s Big Questions, please visit>



UKWIR has been positively shaping the UK water industry’s future for over 25 years by facilitating, managing and delivering a strategic programme of research projects for its members, the water companies of the UK and Ireland.