Mega farms in Scotland, including some with more than a million animals, have repeatedly leaked excrement and failed to monitor contamination, putting humans, wildlife and the environment at risk, The Ferret can reveal.

By failing to responsibly contain or dispose of slurry, wastewater and harmful air particles these industrial-sized farms were responsible for 126 breaches of green regulations between May 2022 and November 2024.

The rule breaking is revealed in inspection reports compiled by the Scottish Environment Protection Agency (Sepa), which The Ferret obtained under freedom of information law.

Campaigners and an MSP argued that polluters should face greater penalties for allowing more serious breaches to occur. Scotland’s mega farms “pollute rivers, degrade soils, fail to deliver nutritious food, and drive biodiversity loss,” according to wildlife charity WWF.

In reply, Sepa said mega farms are “regulated closely” and repeat rulebreakers face “enforcement” from the environmental regulator.

Farming sites that have the capacity for more than 40,000 poultry birds, or either 2,000 pigs or 750 sows, must obtain a permit from Sepa and face inspections. Smaller operations, and beef and dairy farms do not require such permissions, despite being major polluters, although they are subject to other rules.

Some 114 pig and poultry mega farms currently have permits, and are collectively allowed to keep nearly 19 million birds and 109,000 pigs, according to Sepa’s data.

The worst offending mega farm company was Hook2Sisters (H2S). The Oxfordshire-based firm, which is permitted to keep nearly 7.5 million birds at its 19 Scottish sites, was responsible for more than a quarter of all intensive farm environmental breaches.

At its poultry complex, near Eccles, Berwickshire, H2S polluted the environment with “chicken litter and dirty water” in 2022, and was not treating surface water to remove pollutants. Around two years later, Sepa found that operators were failing to check whether the site was contaminating soil and groundwater.

Polluted groundwater can threaten drinking water supplies, according to Sepa’s English counterpart. 

No pollution monitoring was taking place at the H2S mega farm near Balado, Kinross in 2022. In each of the two years that followed, the firm contaminated ground via cracked concrete at the site.

Further monitoring failures were discovered at the H2S mega farm, near Meikleour, Perthshire, in 2023. More cracked flooring, and a lack of drainage systems designed to prevent water pollution was found at its poultry complex near Broxburn, West Lothian, in both 2022 and 2024.

The Broxburn site is allowed to hold nearly 1.3 million birds.

At Balado, a “significant build up of dust and mud” had formed under the fans ventilating four chicken sheds in 2023. Poultry farm dust contains faeces and other pollutants, which can harm humans, according to a 2023 study published in the Science of The Total Environment journal.

At its Gogarbank poultry complex in western Edinburgh, dirty water was not being properly contained and “waste material” and rubbish had littered nearby woodland in 2022. H2S had also not adequately concreted the ground to stop pollution.

An H2S spokesperson said: “As of June 2025, we can confirm remedial action has been taken at all farms and all locations as listed are compliant. We remain committed to upholding the highest environmental standards and continuing to invest in our Scottish farming base.”

The Ferret previously revealed that between 2015 and 2017, H2S sites at Alloa, Balado and Broxburn were among the biggest polluters of ammonia.

The harmful gas combines with other pollutants in cities and creates a deadly form of air pollution called PM2.5.

2 Sisters Food Group, a separate entity which runs chicken abattoirs, also has a history of flouting Scotland’s environmental regulations, as we have previously revealed. It has received millions of pounds in taxpayer subsidies from the Scottish Government.

Other factory farms that flouted environmental rules included those run by PD Hook, which acts as a supplier to H2S and other firms. PD Hook’s Helensfield Poultry Farm near Clackmannan, which houses 133,000 birds, failed to monitor soil and groundwater in 2022. 

Cracked concrete flooring was discovered at PD Hook’s Mossbank Farm, near Cowdenbeath, in 2022. PD Hook said that this and all other environmental issues discovered by Sepa had since been resolved. 

At pig producer’s DW Argo Ellismoss Farm near Kinellar, Aberdeenshire, which can hold up to 4,277 pigs, slurry was found to be leaking into surface water in 2023 – an issue that Sepa officers had “raised at several previous inspections”. DW Argo declined to comment.

In 2022, Sepa found that Welsh poultry firm, Annyalla Chicks, allowed dirty wastewater to flow onto land neighbouring its Addinstone complex, near Earlston.

Operators of the site, which can house up to 382,000 chickens, put soil and groundwater at risk due to the “exceptionally poor condition” of concrete surfaces, and allowed dust to accumulate beneath chicken shed ventilation fans.

The farm also lacked a suitable way to store dead chickens and the liquid waste produced by their corpses.

In 2024, Sepa found that York-based Warrendale Eggs Ltd was releasing dust and particulate matter – air pollution which is harmful to humans – via exhaust fans from its chicken sheds at Swinton Poultry Farm near Greenriggs, Duns.

Sepa also found a blocked and broken drain, ground surfaces in poor condition, and large cracks in a drainage channel, both of which risked pollution to soil and groundwater.

Poor drainage, and cracked and worn surfaces were also found in 2022 at Warrendale’s Cottage Wood farm near Earlston. Fragments of polystyrene were discovered in blocked drains on the site, and in nearby water.

Meanwhile, “significant quantities of dust and feathers” had formed on fans, outside surfaces and nearby vegetation.

Campaigners and an opposition MSP argued that polluters should be made to pay for environmental breaches, or have public funds clawed back.

Kirsty Tait, Scotland director of the Food, Farming and Countryside Commission, an independent charity, said: “The challenges of avoidable pollution highlighted in this investigation are ones that citizens involved in The Food Conversation, the UK’s largest public dialogue about food, want addressed.”

“Notably, there was frustration from citizens in the Lothians about the lenient treatment of polluters, and support for making serious ecosystem damage a crime was high.”

Tait added: “Citizens want government and industry to be accountable for their actions and to protect people and planet.”

Jenny Hawley, policy and advocacy manager at Plantlife, also called for Sepa to charge polluters “for the devastation they are inflicting on our natural environment and to extend the permitting system to smaller poultry units and mega beef and dairy farms.”

She claimed that “uncontrolled air and water pollution from this kind of intensive livestock farming is driving Scotland’s wildlife ever-closer to the edge of extinction”.

WWF Scotland branded the rise of mega farming “a warning sign that our food system is heading in the wrong direction”.

“We’ve built a system where the most harmful forms of agriculture are also the most profitable – megafarms that pollute rivers, degrade soils, fail to deliver nutritious food, and drive biodiversity loss,” said Ruth Taylor, WWF’s agriculture and land use policy manager.

She added: “What we urgently need to see is farming with nature, through nature-friendly methods that restore ecosystems, build resilience and ensure farmers stay profitable.”

The Scottish Greens spokesperson for rural affairs, Ariane Burgess MSP said: “These industrial-scale operations, which cram millions of animals into confined spaces, are clearly failing in their responsibilities”.

Burgess added: “The fact that these firms continue to ignore basic environmental protections while raking in taxpayer money is completely unacceptable. There must be consequences for those who break the rules, and that includes the removal of public funding and the suspension of operations until environmental practices are improved.”

Sepa said it expects “all regulated operators to understand their impact on the environment and to comply with their obligations in legislation, and conditions set out in authorisations”.

“Intensive agriculture is regulated closely due to the potential risks it poses to the environment,” said a spokesperson. “Our experience is that most of those we regulate respond to our advice and guidance and come into compliance, preventing repeated patterns of behaviour.

“However, when necessary we will escalate our enforcement response, and have served enforcement notices and final warning letters as required. This has already led to compliance being restored at some sites.

“All sites that are currently non-compliant are scheduled for inspections in 2025.” 

Every mega farming company named in this article was asked to comment.

Header image credit: Carl Banks