Around 643,000 tonnes of sewage sludge is being sprayed on fields in Scotland amid mounting evidence that it contains a mixture of toxic chemicals, The Ferret has revealed.
Data obtained from the Scottish Environment Protection Agency (CEPA) through Freedom of Information details the extent to which the substance was applied in rural areas across the country between 2020 and 2024.
Sewage sludge is a by-product of domestic and industrial sewage and wastewater and is treated by Scottish Water and Waste and Water Management companies, during which some pollutants are removed.
The slurry residue is then fed or sold to farmers as a low-cost, nutrient-rich fertilizer that is spread on farmland to help humans and animals grow grass, grains, and crops.
However, recent research from Scotland’s James Hutton Research Institute and Scottish Environment Link has revealed that even supposedly purified sewage sludge contains some contaminants that were not removed by treatment. These include microplastics, eternal chemicals, and pharmaceuticals.
Once spread, these contaminants can enter the soil and leach into the water, impacting the health of wildlife, livestock, crops, and even humans. Spraying raw sludge in Scotland has finally been banned as part of new legislation introduced last year.
An MSP said the scale of the sewage sludge spread exposed by The Ferret was “staggering” and called on the Scottish Government to review it “as a matter of urgency”.
We fund journalism that serves the public.
Ferret investigates what’s going on in Scotland and who’s benefiting. Reader support helps keep our journalism independent.
Please support our reporting
Environmental charities have called on ministers to temporarily ban the spreading of treated sludge until more information is known about the risks.
Sepa said it was working with other companies to monitor emerging contaminants and reduce potential environmental impacts, adding that it was testing areas where sludge was being spread and analyzing soil samples.
We found that between 2020 and 2024, almost a fifth of all sludge spread in Scotland (111,789 tonnes) was in Perth and Kinross. It was followed by Aberdeenshire (97,950t), Scottish Borders (87,000t) and East Lothian (68,500t).
Massive spraying was also carried out in Midlothian, Highland, Fife, Dumfries and Galloway.
More than a third of all nitrogen-rich sewage sludge was spread in areas at risk of agricultural nitrate pollution.
According to the Scottish Government, large amounts of nitrogen can leach into groundwater or into waterways, causing harm to the environment and people.
Sepa’s data also showed that sewage sludge is licensed to be stored at 2,528 sites across Scotland, but the regulator said only a small number of sites may be active at any one time.
Microplastics, eternal chemicals and pharmaceuticals
Sewage sludge has been found to contain man-made organic compounds such as the “forever chemicals” PFAS, as well as PCBs, which can cause cancer in humans. This may also include medications and personal care products that are disposed of down drains or toilets.
The continued release of pharmaceuticals into the environment is associated with certain bacteria and viruses developing immunity to the drugs.
Degraded soils can release vast amounts of carbon stored in them into the atmosphere, cause flooding risks through water leaching, and lose fertility, thereby jeopardizing food production.
Agriculture and forestry pollution degrades hundreds of waterways
Threatened species are at risk from pollution from agriculture and forestry, which has reduced water quality in hundreds of Scotland’s waterways, with dozens rated ‘poor’ or ‘poor’. Fertilizers, pesticides, slurries and other substances can have “severe impacts on river flora and fauna” and reduce drinking
British land has some of the highest concentrations of microplastics in Europe due to the spread of sewage sludge, according to research from Cardiff University.
Scotland’s Hutton Research Institute said repeated spraying of sewage sludge was introducing “significant amounts” of microplastics into agricultural soils, adding that many of the pollutants detected could harm soil health.
The report called for better regulation and monitoring, stricter regulations to limit wastewater contamination, improved wastewater treatment to remove pollutants, and limits on the spread of sludge until further research is completed.
A recent study by the institute and Robert Gordon University in Aberdeen found that microplastic levels rose by 1,450 per cent after four years of sludge application in North Lanarkshire and remained elevated 22 years later.
A 2012 study in which Aberdeen scientists looked at sheep grazing on pastures treated with sludge found that the chemicals were affecting the health and fertility of the animals and their offspring.
Dairy farmers using chemicals similar to those found in sewage sludge have reported similar problems in their cows, including high abortion rates and reduced milk production. A farmer in northern England reportedly lost his entire herd.
Spreading sewage sludge is completely banned in some countries, including the Netherlands, Switzerland, and the US states of Maine and Connecticut.
Officials reportedly found high levels of PFAS in the water, crops, cattle, soil, and farmers at a Maine farm where the sludge was being sprayed. PFAS contamination on some farms in the state has reportedly forced farmers out of business.
In 2023, we reported how environmental charities had accused the Scottish Government of failing to act on the recommendations of a 2016 review. Many of these were eventually adopted in a new law passed last year that tightened rules around proliferation.
But environmentalists warn that the new law does not regulate contaminants found in sewage sludge, such as PFAS, pharmaceuticals and microplastics.
Scottish Government is failing to tackle sewage sludge, says Environmental Rights Center
Environmental charities have accused ministers of failing to regulate the use of potentially dangerous sewage fertilizers, seven years after a Scottish Government report called for action. Foul-smelling sewage sludge is a byproduct of sewage and wastewater treatment and is often used as fertilizer for fields.
“Urgent” review of sludge spread
Environmental charity Fidra and the Scottish Environmental Rights Center (ERCS) have both called for a moratorium on spreading the sludge while the risks and alternatives are investigated.
A Fidra spokesperson said: “More efforts are needed to protect human and environmental health from the potential risks associated with the complex mixture of contaminants found in sewage sludge.”
“Fidra is calling for stronger regulation of Scottish sewage sludge pollutants (currently only certain metals and pathogens) to address microplastics, PFAS, pharmaceuticals/antimicrobials and other substances of concern.”
ERCS claimed that local communities have been raising concerns about the risks associated with the spread of sewage sludge for “over 20 years” and called for a moratorium on the agricultural use of sewage sludge, arguing that new Scottish regulations introduced last year “do not go far enough”.
“We need to adopt the precautionary principle and re-evaluate the risks of sewage sludge, including examining the potential harms of unregulated known and emerging contaminants,” said Dr. Shivali Fifield, Chief Executive of the Law Center.
Scottish Green Party environment spokesman Mark Ruskell MSP said the scale of the infestation revealed by The Ferret was “staggering” and “raises clear questions about what we are allowing into our food system and environment, and the lack of regulation and oversight”.
He added: “There is an urgent need for increased oversight, full transparency on where sewage sludge is being spread, and updated regulations to remove ‘forever chemicals’ from products and supply chains.”
“The Scottish Government must review this practice as a matter of urgency and prioritize public safety and environmental protection over convenience and profit.”
Revealed: Drugs polluting Scotland’s water
Data released by the Scottish Government’s environmental watchdog shows that medicines have breached safety standards and contaminated Scotland’s waterways more than 2,300 times over seven years. Ponds, streams, rivers, and bays across the country are flooded with ibuprofen, estrogen, antibiotics, painkillers,
Sludge contaminants under probe
The Scottish Government said spreading sewage sludge is a “long-established practice and an effective way to recover value and avoid waste”.
“At this time, we have no plans to introduce any bans or suspensions for this activity,” the spokesperson said.
“Scotland’s environmental quality standards are very high and levels of per- or polyfluoroalkyl substances (PFAS), also known as permanent chemicals, found in the environment are generally very low.
“However, this is an area where the Scottish Government is working with other UK governments, both Sepa and Scottish Water, to understand the risks of PFAS and where appropriate mitigation measures are recommended.”
Scottish Water, which processes sewage sludge, said it was working with Sepa to reduce the identified risks of sewage sludge “as far as possible”.
“The water industry is investigating contaminants in sludge and we are actively participating in this research and want to understand the quality of the sludge we produce and the impact it may have on the environment,” the spokesperson said.
“Additionally, as part of our future plans, we are investigating various treatment technologies to understand whether they can remove or reduce contamination levels in biological resources.”
Sepa said it is working with partners to “assess and strengthen the evidence base for emerging contaminants, as well as work to reduce potential environmental impacts.”
The spokesperson added that last year’s changes to environmental laws “strengthened soil conservation values and monitoring requirements, and for the first time prohibited the use of untreated sewage sludge on land.”
“Sepa requires operators to hold the appropriate licenses and meet legally binding conditions, including inspection and record-keeping requirements. Our role is to regulate and enforce this law.”
Farming union NFU Scotland claimed that sludge provides a valuable source of recycled nutrients, “helping to maintain soil health and reduce reliance on manufactured fertilisers”.
David Mitchie, Senior Policy Manager for Crops, said he was aware of concerns about new contaminants in wastewater, stressing that this is a complex issue that extends beyond agriculture.
Regulations on the use of sewage sludge must respond to new evidence, he said. “As responsible stewards of the land, our farmers take soil health and environmental protection very seriously and will continue to comply with all current regulations and guidance,” Mitchie added.
Please help me keep digging.
If this report is important to you, you can fund the next report. The Ferret is independent, member-owned investigative journalism supported by readers who demand accountability in Scotland.
become a member
Source link
