Waste

Embracing the circular economy

Demand is putting increasing pressure on natural resources, and a traditional linear model generates excessive waste and pollution.

That’s why we’re committed to pioneering circular economy solutions—creating value through energy production and resource recovery while supporting our journey to net zero.

Our commitment to mitigating climate change remains a critical priority.

We provide clean water and treat wastewater for 4.7 million households and businesses every day in a way that minimises environmental impact.

As part of our net zero transition plan (NZTP), we continue to evolve our ambitions, guided by the Transition Plan Taskforce and backed by £295m in funding to scale up innovative technologies between 2025-2030.

Bioresources

Unlocking infinite possibilities

Bioresources is a hugely exciting area for us with infinite possibilities to further stimulate a circular economy. The bioresources team is responsible for transporting and treating sewage sludge collected from wastewater treatment sites across the region. Our bioresources strategy is centred on anaerobic digestion of the sewage sludge, a byproduct of our waste treatment processes.

We use the sludge to create two useful products

 

Biogas as a source of renewable energy

We use a combination of advanced and conventional Anaerobic Digestion to process and treat the sludge safely at our sites. Firstly, bacteria in our digesters break down the organic matter without oxygen, producing biogas.

Bio-methane, a 100% renewable energy source, is produced by removing CO2 and other contaminants from the biogas. This bio-methane is burned through combined heat and power (CHP) engines and converted into electricity, which we use to power our sites or feed back into the grid. Alternatively, we can further scrub and re-inject the bio-methane into the gas network.

Biogas as a source of renewable energy

At our sewage treatment sites, we clean wastewater and return it to the environment. The organic material we recover (“sludge”) is treated at large, strategically located centres. Excess water is removed to create a dry product—biosolids (a.k.a. “biosolids cake”).

Harnessing value from wastewater

We are innovating to recover valuable resources from wastewater at our treatment works, including:

By repurposing wastewater by-products, we’re reducing our operational emissions and driving progress toward net zero, particularly through process emissions reductions—our most material emissions source.

Green Power

Leading the Way in Food Waste Recycling

As the UK’s largest producer of renewable energy from food waste in England and Wales, we provide cost-effective and sustainable recycling solutions through our award-winning network:

The organisation operates 11 anaerobic digestion facilities and 4 composting sites, complemented by a renewable energy portfolio that includes 30 solar parks, 5 rooftop solar sites, 6 wind turbines, and 8 hydro-electric turbines. Each year, over 500,000 tonnes of food waste and 100,000 tonnes of green waste are recycled, supporting the production of bio-fertiliser and premium-grade compost for farmland.

In 2024/25, these combined efforts are projected to generate 327GWh of green energy, supplying power to homes and businesses across the UK.

In addition to its ongoing projects, the organization is undertaking a major expansion with the construction of 4 large-scale solar sites, expected to add 185GWh of annual energy generation.

In 2023, the company strengthened its position in the sector by acquiring Andigestion Ltd, a leading anaerobic digestion business, with the aim of increasing overall energy generation by 8% per year.

This acquisition enables the organisation to expand its support for companies in Southwest England to help more organisations convert food waste into renewable energy.

Future-focused sustainability

Beyond waste recovery, we’re exploring further circular economy advancements:

Over the past year, Severn Trent has run a trial to capture unwanted, unused and dirty PPE. The items are cleaned and made available to employees to reorder back into the business instead of buying new. This initiative has helped us to save carbon, reduce our waste to landfill and improve our circularity, and even save a bit of cost.

Part of this scheme that has been incredibly successful is our gloves wash-and-return trial. Where gloves were getting thrown away because they were especially unclean, they are now collected at two of our biggest sites, and are washed and returned directly, massively reducing the number of new pairs of gloves we are buying (and throwing away!) This has seen us wash and return over 4,500 pairs of gloves.

Plus! Any PPE that isn’t quite up to standard to be returned is recycled in accordance with the waste hierarchy. Working with our supplier StaySafe, a local midlands-based SME who specialises in PPE recycling, any items that don’t come back to Severn Trent make their way to be used by social schemes and charities or being recycled back into other useable products.

Net Zero Hub

Our Net Zero Hub is installing technology to capture and reduce process emissions, sharing our findings to accelerate progress across the sector.

We're committed to: