Net Zero Water

Unlocking a net zero carbon future

Introduction to Net Zero Water

As a sector that is rooted in the environment, the water industry is committed to playing its part in tackling the threat of climate change and limiting the rise of global temperatures to 1.5°C.

In 2019, water companies in England joined forces to make a pledge to reach net zero on operational emissions by 2030. Since then, companies in Scotland and Wales have committed to achieving carbon neutrality across all emissions by 2040 with a pledge from Northern Ireland to deliver the same target by 2050.

Find out more about our commitment to reach net zero on operational emissions in the Net Zero 2030 Routemap – the world’s first detailed plan of its kind.

Introduction to Net Zero Water

Water and climate change

The climate emergency presents an extreme challenge to water and sewage treatment in the UK with a significant increase of drought risk predicted between now and 2050. These droughts are increasing in frequency, severity, and duration due to the climate emergency and population growth.

Without action, the risk of not having enough water to satisfy our customers’ demand is very real.

Water companies across the UK are adapting to this challenge in a number of ways, from building the resilience of our supplies by cutting losses through leaks, to the development of bold projects to move water around the country. We’re also preparing for more floods with new investment plans that set climate-ready standards for drainage.

But we know it’s not enough to be ready for climate change. We want to limit it.

Water supply decrease by 7%

Total water supply is forecast to decrease by 7% by 2045 as a result of the climate emergency and limits to sustainable abstraction

Restrictions due to drought x2 as likely

Between 2020 and 2050, we are twice as likely to have a year with water restrictions due to droughts in England when compared to the 1997-2004 time period.

Supply restrictions 1-in-4 – 1-in-7 chance

The chance of a serious drought between now and 2050 that results in water deficits and requires supply restrictions is between 1-in-7 and 1-in-4.

Understanding our emissions

The UK water industry is responsible for the delivery of 15 billion litres of water and the treatment of sewage from over 28 million properties every day. We do this through a significant network of interconnected assets, including over 7,000 treatment sites and enough buried pipework to reach to the moon and back.

Moving and treating water is an energy intensive process, which leads to the emission of millions of tonnes of greenhouse gases every year. Our emissions as a sector can broadly be split into operational and capital, also known as embedded, emissions.

Operational emissions are emitted through our everyday processes and activities.


We use electricity for part of the water treatment process and pumping water, as well as powering offices, buildings and electric vehicles.

Process emissions

Methane and nitrous oxide are released when chemical changes are made to raw materials during the water and sewage treatment process and make up a significant proportion on our overall carbon footprint.


Many of the sector’s vehicles are currently fuelled by diesel or petrol, responding to hundreds of customer callouts every day.

Natural gas and gas oil

We use gas for some wastewater treatment processes and to heat our buildings, while gas oil is used on remote sites for heating and generating electricity.

Capital emissions are associated with building works and construction projects.


A lot of electricity is used in the delivery of new infrastructure, making it the largest source of capital emissions.


Concrete is a very important, but carbon intensive material used in the construction of buildings and sewer systems.


Along with concrete, metal is one of our biggest sources of capital carbon with emissions coming from mining the ore from the ground, shipping it to the factory and turning it into a material we can use.


The equipment and vehicles our partners and ourselves use are mostly run on fossil fuels like diesel.

The journey to Net Zero Water

The sector’s journey to net zero carbon will be a complex one, bringing together a variety of technologies, initiatives and behaviours to drive down emissions. Each water company will have its own detailed plan, reflecting specific operational requirements and localised factors such as electricity grid constraints. Individual company plans will also set out in more detail how net zero will be delivered in harmony with the plans of key regional stakeholders including electricity distribution network operators, local authorities, and environmental NGOs.

Water companies are committed to protecting customer bills by taking a ‘least cost’ approach to decarbonisation that maximises opportunities to generate new income or improve efficiency.


Offsetting carbon

Carbon offsetting is considered as a last resort to address residual emissions after all other opportunities for emissions reduction and deployment of renewables have been taken. We are working to identify the best opportunities for decarbonisation in the UK and have established a dedicated working group to support the development of a robust UK market for businesses to procure offsets to counter hard to abate process emissions.

Offsetting carbon

Tackling emissions

We’re investing heavily in the transition of our operational and maintenance vehicles away from fossil fuels, working with vehicle manufacturers to boost the availability of suitable vans and heavy goods vehicles that run on low carbon fuels such as electricity and biogas. We’re also deploying new measures to directly monitor the emissions associated with the water and sewage treatment process to inform global emissions reporting methodologies, design measures to mitigate the impacts ahead of 2050, as well as searching for new solutions

UV LED Treatment

Case Study

UV LED Treatment

United Utilities has replaced mercury light bulbs with ultraviolet (UV) LEDs at its water treatment site in Cumwhinton near Carlisle in a bid to reduce the amount of energy and chemicals that are needed as part of the process to get water fit for consumption.

The company has installed six UV LED reactors, which are up to 90% more efficient than traditional bulbs, to treat for micro-organisms and help remove taste and odour from drinking water.

Dan Fielden, United Utilities
Dan Fielden, United Utilities
Project Manager

One of the big advantages of UV LED technology is that it significantly reduces power and chemical consumption, provides an environmentally friendly, mercury free solution, and has the potential to increase asset capacity with each new generation of UV LEDs.

Saving water

The treatment of water and wastewater is a carbon-intensive business so we’re working hard to reduce the amount of water that is lost from our network through leaks while helping our customers to play their part in protecting this precious resource. Companies are deploying a variety of techniques to find and fix more leaks from our network of underground water pipes, which extends to almost half a million kilometres. We’re also working to raise awareness of the pressures on the UK’s water resources and help the public to take water-saving measures at home through our Water’s Worth Saving campaign.

Satellite leak detection

Case Study

Satellite leak detection

South Staffs Water and Cambridge Water are using state-of-the-art satellite leak detection technology as part of a range of approaches designed to cut down leakage from its network.

Satellite leak detection technology uses radar sensors to penetrate the first few metres of earth and look for the unique signature of underground drinking water to show where leaks could be. Capable of detecting leaks under tarmac, earth, concrete or brick, the system produces satellite images covering 3,500km which are then sent directly to the company’s field staff to investigate.

James Curtis, South Staffs Water
James Curtis, South Staffs Water
Leakage Strategy Manager

We’ve carried out a very thorough analysis of satellite leak detection and have quantified the improvements in efficiency, effectiveness and cost benefits against other technologies. We are now confident to use it as part of our ‘business as usual’ toolbox for reducing leakage.

Powering a cleaner future

The deployment of on-site renewables such as solar power and advanced anaerobic digestion (AAD) play an essential role in reducing the carbon intensity of our sites, allowing us to produce our own clean power and reduce the amount of power that needs to be imported from the grid. Many water and wastewater treatment sites are already operating on an energy neutral basis and are even exporting green power and gas into the national electricity and gas grids.

Sewage Power

Case Study

Sewage Power

Dŵr Cymru Welsh Water has invested more than £50 million to create a new energy generating facility at its Cog Moors Wastewater Treatment Works in the Vale of Glamorgan.

The 1.5GWh Advanced Anaerobic Digestion (AAD) facility will use state-of-the-art technology to turn sewage sludge into biogas, which will then be burned in gas-powered engines to generate the equivalent amount of electricity needed to power 4,800 homes each year. The plant will be capable of producing enough power to meet the needs of the entire site, making it totally energy neutral.

Shaun O’Leary, Welsh Water
Shaun O’Leary, Welsh Water
Programme Delivery Manager

The advanced anaerobic digester at Cog Moors will improve the way we treat the wastewater at the site, as well as help us to reduce our carbon footprint by producing renewable energy. It will also help keep customer bills down as we will be using our own energy to help power the treatment works.

Harnessing nature

Catchment management approaches including tree-planting and peatland restoration play a critical role in cleaning up water at source, reducing the amount of treatment that is needed before it reaches the customer. Wetland treatment centres also offer an environmentally friendly alternative to concrete and steel infrastructure solutions that are inherently carbon intensive.

Wetland Treatment

Case Study

Wetland Treatment

Anglian Water’s wetland treatment site at Ingoldisthorpe in Norfolk is the first of its kind in England and has been created in partnership with the Norfolk Rivers Trust. The site works as a natural treatment plant with millions of litres of used water passing through the wetland to be further filtered and cleaned by the plants before it’s returned to the River Ingol.

This filtering process further improves the quality of water being returned to the river, benefiting the whole of the river, which is a spring-fed chalk stream. Aside from having a practical purpose the wetland is a huge biodiversity asset attracting breeding birds, amphibians, bats, and water voles to the local environment.

Chris Gerrard, Anglian Water
Chris Gerrard, Anglian Water
Natural Catchment and Biodiversity Manager

The four large, interconnected ponds include typical wetland flora that is native to the UK. Naturally, these plants attract insects like bees and other pollinators, but they also attract mammals, too.

Chemicals like phosphates and ammonia come from urbanisation, domestic products like detergents, as well as from human and animal waste. In the future, we need to find more natural ways to treat them rather than adding more chemicals in our treatment processes or building carbon hungry infrastructure, which is unsustainable, and would have an impact on customer bills too. So, the wetland is a great solution.

Green Finance Taskforce

Delivering the transition to Net Zero 2030 will cost in the region of £2-4bn. Chief Finance Officers and finance and sustainability officers across the industry have committed to working collectively on Green Finance issues which can help unlock the investment required to secure the transition to net zero.

By working together through the Taskforce, the industry will amplify its voice on the regulation and policy required to shape a supportive investment environment, identify strategic opportunities to engage with green finance initiatives and the finance sector, and build on the sector’s excellent reputation for green investment on the world stage at COP26.

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