A family looking for marine life on the Isle of Wight. The study found one source of Pfas was from treated effluent from Southern Water plants on the mainland. Photograph: Nikreates/Alamy
Study of Channel finds levels of toxic Pfas in Solent at 13 times safe limits in some places, with much coming from treated sewage
Scientists have found high levels of toxic Pfas, or “forever chemicals”, in soil, water and throughout the marine food chain in the UK’s Solent strait, including at protected environmental sites, according to a new study.
In some samples, pollution was 13 times the safe threshold for coastal waters. Others, which were below legal limits for individual chemicals, failed tests for combined toxicity.
The samples were taken from the Solent strait, which runs between the Isle of Wight and the mainland, forming part of the Channel. The chemicals are thought to have entered the environment from wastewater treatment plants, sewage outflows, historic landfills and nearby military sites.
Researchers said their findings highlighted the need to monitor chemicals in combination and to make a blanket ban on Pfas part of the government’s water reform agenda.
Prof Alex Ford, a biologist at the University of Portsmouth and one of the study’s authors, said: “If there was an oil spill in the Solent that industry would have to pay for the restoration of those habitats, but that doesn’t happen with sewage.
But he added: “This is one thing I don’t necessarily pin on the water companies because they don’t have the capacity to treat these compounds. That’s why they should be banned at source.”
“It’s not good enough to plan to have a plan,” said Calum Duncan, head of policy at the environmental charity. “We urgently need action and we have this once-in-a-generation opportunity with the water reform process to get on and do that.”
England’s privatised water industry may one day be considered a textbook case study of failed corporate responsibility, regulation and governance. The Cunliffe review, the recent report into England’s privatised water industry, concluded that the financial regulator, OfWat, needs to be disbanded and a new water regulator will be introduced.
For that to work effectively, better pollution monitoring and more clearly defined pollution incident criteria are essential. While politicians and water companies have claimed to be reducing pollution incidences, they might not strictly be tackling sources of pollution, so communications must be carefully scrutinised for disinformation.
The UK’s environment minister Steve Reed MP has described the water industry as “broken”. The public have rising water bills. Water companies owe over £60 billion in debts and have left the country with uncertain water security in the face of climate change.
The Environment Agency (EA) in England recently announced that serious pollution incidents in 2024 rose by 60% to 75 from 47 in the previous year. The EA classifies pollution incidents using a four-point scale called the common incident classification scheme. Trained EA officers consider the evidence reported via their incident hotline to assess its credibility and severity.
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Category 1 is for major incidents, 2 for significant, 3 for minor incidents and 4 for no impact. Category 1 and 2 typically involve visible signs of dead fish floating. For salmon, if more than 10 adult or 100 young fish are dead, this is category 1. With fewer than ten adult and 100 young fish dead, it’s category 2.
No dead fish, no serious problem? The EA can also record damage on protected habitats as “pollution incidents” but these are harder to substantiate without investigative research that takes time and money.
Last year, more than 450,000 sewage discharges were recorded by event duration monitors. These are devices fitted to the end of overflow pipes that indicate when and for how long they have been discharging.
These discharges represent 3.6 million hours of untreated sewage going into our rivers and coasts. These contain chemical contaminants including pharmaceuticals, detergents and human pathogens. Only 75 incidents were recorded as serious or significant in 2024. Another 2,726 were classed as minor.
So lots of sewage discharges are not being classified as pollution incidents, despite containing pollutants. The EA advises its investigating officers to “record substantiated incidents that result in no environmental impact, or where the impact cannot be confirmed, as a category 4”.
The EA has been criticised for turning up late to 74% of category 1 and 2 pollution incidents and for being pressured to ignore low-level pollution – all claims that they have denied. However, they admit they are constrained by finances. Any new regulator must be adequately resourced and independent.
Pollution isn’t always classified as an official pollution incident. YueStock/Shutterstock
In their recent report into pollution incidences, the EA states that they respond to all category 1 and 2 (serious and significant) water industry incidents and will be increasing their attendance at category 3 (minor) incidents. They highlight that more inspections will identify more issues. This shows some acceptance that the more incidents they attend, the more would be substantiated or recorded appropriately.
Most sewage discharges would not have been reported to, or recorded by, the EA as pollution incidents because they were permitted discharges from combined stormwater overflows. Water companies are allowed to discharge untreated wastewater under exceptional rainfall or snowfall conditions to prevent sewage backing up through the pipes.
Extra water flow in rivers from rainfall is meant to dilute chemical contaminants in wastewater. However, some discharges can last days or weeks. The EA is currently investigating whether water companies have been breaching their permits and discharging untreated wastewater when there is low or even no rainfall.
What counts as pollution?
The UN classifies pollution as “presence of substances and energy (for example, light and heat) in environmental media (air, water, land) whose nature, location, or quantity produces undesirable environmental effects”. This definition differs markedly from the EA’s working definition of pollution incidents.
Many sewage discharges containing low concentrations of pollutants won’t kill fish but might still be harmful to fish larvae or small insects, for example.
However, the broad picture from EA data is that invertebrate communities at least are in a better state than they were three decades ago before wastewater treatment plants were upgraded following the EU’s Urban Wastewater Directive.
Some pollutants bioaccumulate through the food chain, so they become concentrated in top predators such as orcas. Some chemicals mimic reproductive hormones even in low concentrations and can feminise fish, for example. High levels of nutrients from agriculture and sewage in rivers can cause fungal diseases in seagrass meadows.
Other families of chemicals build up in wildlife and people, such as persistent “forever chemicals”, much of which comes from wastewater discharges. Continued discharges of antibiotics into waterways might not be classified as pollution incidents but still pose a substantial risk to human and ecosystem health through bacteria developing antibiotic resistance.
The government has just committed to cut sewage pollution by 50% by December 2029 based on 2024 data. But it’s not yet clear whether these involve cutting the frequency of discharges, the duration or both.
This data could also be manipulated so that a large number of small discharges can be consolidated into one official discharge event. Currently, the volume of discharges from stormwater overflows isn’t known. Without this vital data we can’t ascertain the risk posed by their contaminants.
Pollution causes more illness and early death than any other environmental threat, accounting for one in six deaths worldwide. For decades, the US Environmental Protection Agency’s (EPA) Office of Research and Development (ORD) has driven many of the biggest advances for safeguarding human health and ecosystems from chemicals. Now, this scientific research office is being closed down by the US government
But that changed when a recent Supreme Court ruling gave the Trump administration the green light to proceed with widespread redundancies and the total elimination of ORD.
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Now, in so doing, the US is not just gutting its own scientific foundation. It’s also putting decades of global progress in chemical safety, pollution control and public health at risk.
ORD is the EPA’s independent science arm, conducting research that supports clean air, water and land. From detecting pollutants and assessing health risks to guiding environmental cleanup, it ensures EPA decisions are grounded in credible, evidence-based research. ORD develops this science under intense scientific, policy, political and legal scrutiny, which means it produces the best available science that is credible and robust.
While most scientists focused on known pollutants, ORD used advanced screening tools to detect GenX, a little-known synthetic “forever chemical”. Despite evidence that GenX was contaminating the river basin since the 1980s, not much was known about its potential to harm living systems.
Forever chemicals were found to be polluting North Carolina’s Cape Fear River in the US. Kosoff/Shutterstock, CC BY-NC-ND
ORD rapidly filled this void, linking GenX to decreased birth weight and increased mortality in newborn rats, prompting swift regulatory action against the manufacturer to ensure cleaner, safer water for local communities. No other government agency in the world delivers this kind of rapid, science-led response.
It’s not just the strength of ORD’s science that sets it apart, but also its visionary thinking. Among ORD’s most influential ideas is a model that maps out how a chemical is causing harm.
This works like a chain of building blocks, linking tiny effects (like a chemical disrupting a hormone) to much bigger problems, such as cancer or even extinction. Each step shows how one change leads to another until it reaches something we truly care about. This approach helps scientists detect danger early, before it leads to irreversible damage.
Then there’s the EPA’s groundbreaking work in computational toxicology. Nearly two decades ago, leading scientists warned that chemical safety testing relied too heavily on outdated methods and animal experiments.
In response, ORD built ToxCast, a system that uses tiny cells and computer models to screen thousands of chemicals for effects like endocrine disruption or cell damage. It’s faster, cheaper and more humane, and helps scientists predict which substances may pose serious risks.
These scientific breakthroughs don’t come from policy offices. They require researchers with the independence to explore and innovate.
Beyond the US
Europe has bold goals to phase out animal testing. Much of the science driving this shift comes from ORD.
Tools like Ecotox (the world’s largest chemical toxicity database) and the CompTox dashboard (a platform that links predictive models and non-animal test data for over a million substances) are widely used across the EU and UK. Without ORD, these vital resources, hosted by EPA, could disappear, stalling global progress toward safer, more ethical chemical testing.
ORD has been a leading scientific institution with global reach. Its tools and ideas have shaped how governments detect hazardous chemicals, understand their effects, and protect people and the planet. From toxicity databases to modern, non-animal testing methods, ORD has underpinned how we respond to pollution. Eliminating it could create a dangerous void, just as chemical and climate threats are accelerating.
Donald Trump urges you to be a Climate Science denier like him. He says that he makes millions and millions for destroying the planet, Burn, Baby, Burn and Flood, Baby, Flood.Nigel Farage urges you to ignore facts and reality and be a climate science denier like him. He says that Reform UK has received millions and millions from the fossil fuel industry to promote climate denial and destroy the planet.Neo-Fascist Climate Science Denier Donald Trump says Burn, Baby, Burn.
Water companies are panicking they will be left unable to dispose of millions of tonnes of sewage sludge due to tougher pollution rules, and rising concern over the contaminants sludge contains.
Read the full investigation with supporting documents from Unearthed, here.
Sewage sludge is the human faeces and other solids left behind when wastewater is cleaned. Around 90% of the UK’s sludge is treated and spread on farmland as a source of nutrients to fertilise crops. However, concern is rising in the UK that this could be introducing damaging levels of contamination to agricultural land.
An analysis for trade association Water UK last year found that in a “worst-case” scenario the industry could be left with “3.4 million wet tonnes” of sludge with nowhere to go, documents obtained by Unearthed under freedom of information laws show.
The key documents not already in the public domain (available via the Unearthedwebsite) include:
National Plan B: water industry analysis of sludge disposal crisis
The National Landbank Assessment Report 2024: water industry capacity modelling
EA CEO internal briefing: prepared by the Environment Agency
Earlier this year, environmental regulators in the United States warned that toxic PFAS ‘forever chemicals’ in sewage sludge spread on American pastures were posing a cancer risk to people who regularly ate meat or dairy from those farms. This came after investigations by Unearthed and others found that sludge destined for British farmland also contained a range of harmful contaminants, including microplastics and forever chemicals.
The water companies fear increased scrutiny of sludge-spreading in the UK could trigger a ‘backlash’ akin to the public outrage they have faced over sewage released into rivers and seas, Unearthed has learned.
Reshima Sharma, political campaigner for Greenpeace UK, said:
“This investigation is yet more proof that we can’t trust the privatised water companies to deal with waste responsibly. So long as they can get away with it, they will just pass any problems on to our countryside and pocket the money they should be investing in solutions.
“In addition to the national scandal of river pollution, their negligence has led to a cocktail of toxic contaminants being spread on the soil that grows our food. The government must stop toxic sludge from being spread on farmland immediately and water companies must be made to pay for disposing of it safely, without passing the buck to bill payers.”
