What are PFAS?
PFAS stands for Per- and Polyfluoroalkyl Substances. They’re a large family of over 10,000 man-made chemicals used in everyday products for decades — including non-stick pans, waterproof fabrics, cosmetics, food packaging, and cleaning products.
They’re often called “forever chemicals” because they’re incredibly tough and long-lasting. PFAS resist water, grease, stains, and heat, which is why they’ve been so widely used — but that same durability means they don’t break down easily in the environment.
How PFAS get into water
PFAS can enter water sources in several ways:
Once PFAS are in the environment, they can stick around for years, eventually making their way into rivers which we then take water from to treat, and turn into drinking water.
Should you be worried about drinking your water?
You can be assured that Severn Trent, and other water companies, treat water to the highest standards. We have to meet tight government and regulatory targets to provide some of the best quality drinking water in the world.
According the DWI, the low levels of PFAS detected in some untreated water abstracted for public drinking water supplies has no immediate impact on human health.
While there are currently no statutory standards for PFAS in drinking water England and Wales, the DWI has taken a precautionary approach and produced tiered guideline values for water companies to adhere to, to offer more reassurance that your water is safe.
To understand more about how the DWI sets out guidance on PFAS, visit them below.
Testing your water for PFAS
We regularly test both untreated and treated water for PFAS and assess all our water sources to meet strict Drinking Water Inspectorate (DWI) standards.
The DWI advises that the low PFAS levels sometimes found in UK water aren’t a health risk. If that changes, we’ll act quickly to reduce them further.
We take water quality really seriously, we continuously sample, and monitor our water – not just for PFAS, across a whole range of measures to make sure it’s good to drink.
Why can’t you remove all PFAS at your treatment works?
Ultimately, the best long-term solution is to stop PFAS production at the source — before they enter the environment as they are incredibly tough and hard to break down.
We support a ban on PFAS, but it’s not a simple fix. That’s why water companies globally are updating treatment processes, investing in advanced technologies, and collaborating on research to find effective ways to remove PFAS, some of which we’re proud to be leading on.
What we're doing about PFAS
Although water companies didn’t create this issue, we’re committed to being part of the solution and are leading the way on some innovative trials to remove PFAS.
Some of what we’re doing includes:
We’re in the early stages of these projects, but we will share more updates soon.