Severn Trent unveils world’s first CO2 neutral waste treatment plant

Circular economy

United Kingdom – Severn Trent, one of the leading water companies in the UK, plans to develop the world’s first carbon neutral waste treatment plant in Staffordshire.

The ambitious project, with a budget of nearly £40 million, aims to transform an existing carbon-intensive Wastewater Treatment Plant into a retro-fit carbon neutral site at Strongford. Backed by UK and Irish water companies, as well as international partners Aarhus Vand in Denmark and Melbourne Water in Australia, this initiative represents a significant step towards achieving net-zero carbon emissions in the water sector.

Net-zero hub

The groundbreaking ‘net-zero hub’ project, which is set to commence in September, will integrate a range of cutting-edge technologies on-site to reduce and eliminate carbon emissions. The implementation of these technologies is expected to eliminate approximately 34,000 tonnes of carbon per year, equivalent to the carbon emissions produced by 34,500 return flights between London and New York.


One of the key technologies to be deployed at the site is Suez’s ‘Actilayer,’ a revolutionary cover for sludge plants that utilizes catalytic materials and sunlight to significantly reduce nitrous oxide emissions. Nitrous oxide is a potent greenhouse gas, and by mitigating its release, Severn Trent’s initiative will contribute to combating climate change. Additionally, the project includes Cellulose Recovery technology from Dutch company Cirtec, which aims to recycle toilet paper from sewage into sustainable materials for insulation or construction purposes.

The site will also feature Digital Twin technology, a virtual representation of the entire treatment plant, including low carbon technologies. Developed in collaboration with Atkins, Explore AI, Siemens, and Xylem, this virtual world will enable Severn Trent to optimize the performance of various technologies, observe their interactions, and automatically apply the learnings to enhance the treatment process, ultimately leading to reduced energy consumption.

Collaborating with technology providers such as Eliquo Hydrok, Royal Haskoning DHV, and CAMBI, Severn Trent aims to optimize sludge management and maximize biogas production. These efforts will result in a combination of methane emissions reduction, decreased natural gas consumption, and the opportunity to generate additional biogas.

Reducing CO2

The establishment of this carbon neutral hub at the Strongford site aligns with Severn Trent’s commitment to reducing its carbon footprint and protecting the environment. As wastewater operations contribute to 80% of the company’s operational emissions, this initiative will play a crucial role in addressing this significant source of greenhouse gas emissions. Moreover, Severn Trent aims to share the blueprint of this carbon neutral hub with other water companies, enabling the retrofitting of wastewater treatment plants globally with similar innovative technologies.

Water Breakthrough Challenge

Severn Trent’s project is part of the Water Breakthrough Challenge, an innovation competition led by Ofwat, the water regulator in the UK. With its focus on achieving net-zero emissions, protecting ecosystems, reducing leakage, and delivering societal value, the Water Breakthrough Challenge provides funding and support for transformative initiatives within the water sector.

Severn Trent’s commitment to sustainability extends beyond the carbon neutral hub project, as the company also secured additional funding from Ofwat for an innovative initiative aimed at detecting and tackling leaks using Dark Fibre sensing technology. By leveraging existing fiber-optic cables near water mains, this approach offers a rapid, reliable, and cost-effective solution for leak detection.