Severn Trent has launched a major push on Net Zero with a supply chain engagement initiative – the water company is aiming to transform one of its large wastewater treatment works into the first net carbon neutral wastewater treatment works in the UK by the end of March 2024.
Photo: Minworth WwTW - Severn Trent's largest wastewater treatment works serving Birmingham
Severn Trent is aiming to achieve this by installing a combination of innovative technologies that will reduce, remove or offset carbon emissions. Minworth WwTW is Severn Trent's largest wastewater treatment works - however, at this stage no information has been provided on which of the water company's large wastewater treatment works is under consideration.
The water company has issued six separate Prior Information Notices for individual technologies.
The utility would like to obtain support from the market to understand what technologies currently exist under the following targeted Net Zero areas:
- Reduce & Remove Technologies (RRT) - aligned to the Project or Intervention Accounting: Quantified GHG emissions reduction or removal impacts of projects or interventions which are credited for GHG claims to be transferred between entities
- Circular Economy Technologies (CET) - aligned to both the above and Inventory Accounting: Emissions and removals in the GHG inventory. These occur in a company's operations and value chain (Reduce/Remove of Scope 1, 2, 3)
Severn Trent has identified the following six types of technology within these areas which it may consider implementing on the Net Zero site.
The water company is now inviting interested suppliers to get in touch with information about their technologies, including minimum Technology Readiness Levels (TRL) - in the following areas:
1. HEAT RECOVERY - technology must recover heat from the treated effluent using heat pump or heat exchanger technology.
Technology Readiness Level - TRL 7
2. ELOVAC - Vacuum degassing of digested sludge, to increase the amount of biogas captured.
Reduces uncontrolled methane release.
Optional extra of magnesium dosing to precipitate phosphorus.
Technology Readiness Level - TRL 9
3. AMMONIA RECOVERY - Ammonia recovery from sludge liquors by steam stripping and rectification
N2O emissions reduction
Generates 15-20% ammonium hydroxide product
Technology Readiness Level -TRL 6
4. CELLULOSE RECOVERY
Technology Outputs
Technology recovers cellulose from crude sewage for re-use as a product.
Fine screens to be used to capture the cellulose using a two-stage process.
Further washing and screening will separate the cellulose from other fibrous material
Technology Readiness Level - TRL 7
5. NUVODA - An enhanced form of ballasted granular sludge process using a natural plant-based ballast material
The Technology should operate without the limitations of sieves or baffles
The Technology should intensify the activated sludge process sufficiently to allow removal of the NSAF, a significant use of power.
Technology Readiness Level - TRL 8
6. EPHYRA - Reconfiguration of digesters (post-Thermal Hydrolysis Process) to plug flow digestion which will lead to improved volatile solids break down and biogas yield and hence biogas production.
Increased VS and DS destruction which reduces downstream methane emissions and means less sludge requiring dewatering and recycling.
Technology Readiness Level - TRL 8
All of the technologies must be contracted and delivered on site and capable of being installed and operational on site by the end of March 2024.
Severn Trent is asking interested suppliers to provide written confirmation that they can meet the following requirements for the specified technologies:
- Technology outputs
- Meet the TRL level
- Technology could be installed and operational on site by the end of March 2024
The water company will then evaluate the written confirmation, before requesting further information and evidence from the supplier to further validate the supplier confirmation.
Following the conclusion of the PIN process Severn Trent will then decide whether to run a full procurement exercise.
Deadline for suppliers to submit a completed record of interest is midday on 3rd January 2023.
To access the individual tender documentation for each technology:
United Kingdom – Coventry: Net Zero Site - Heat Recovery. Deadline:03.01.2023
United Kingdom – Coventry: Net Zero Site – Elovac. Deadline:03.01.2023
United Kingdom – Coventry: Net Zero Site - Ammonia Recovery. Deadline:03.01.2023
United Kingdom – Coventry: Net Zero Site - Cellulose Recovery. Deadline: 03.01.2023
United Kingdom – Coventry: Net Zero Site – Nuvoda. Deadline:03.01.2023
United Kingdom – Coventry: Net Zero Site – Ephyra. Deadline:03.01.2023
With the UK government demanding a 50% reduction in storm overflow spills by 2029, the era of reactive management is over. Speaking in the House of Commons on 21 July 2025, then environment secretary Steve Reed said, “This Government will cut water companies’ sewage pollution in half by the end of the decade.”
ERG, the leading supplier of odour control systems and industrial gas cleaning & thermal systems, has been awarded the coveted King’s Award for Enterprise.
Welsh Water’s new artificial intelligence-driven tool, ORAI, has been shortlisted for three categories at the prestigious British Data Awards 2026 – underscoring the company’s commitment to using cutting-edge technology to deliver better outcome for customers.
Barhale has completed work on two separate Rapid Action Taskforce Spills projects it is carrying out for Severn Trent.
Hear how Scottish Water has completed its £235 million Ayrshire Glasgow Resilience Project - customers across Greater Glasgow, Ayrshire and East Renfrewshire will now benefit from a more secure and resilient water supply.
Hear how United Utilities is accelerating its investment to reduce spills from storm overflows across the Northwest.
Find out more about the remarkable career opportunities on offer at WSP - scroll down to watch the inspirational video.