New tech offers solution to waste sheep dip disposal
© Tim Scrivener An on-farm treatment system that removes almost all traces of insecticide from used sheep dip could solve one of the sheep industry’s biggest environmental challenges.
If approved for use by regulators, it could offer a solution to the growing shortage of legal disposal routes.
See also: FW Inventions Comp 2023: Powell James’ sheep dipping crate
Sheep scab, a highly contagious parasitic disease caused by mites, remains endemic across much of the UK.
Many farmers are returning to plunge dipping as the primary method of control, because of increasing resistance to injectables.
Diazinon is the only product licensed for sheep scab control in the UK. However, there remain huge environmental and regulatory challenges regarding its disposal.
The current disposal method is land spreading, which requires permits from environmental agencies because of the risk of environmental and watercourse contamination.
Alternatively, the waste dip can be transported to licensed disposal facilities. However, these are becoming scarce. Natural Resource Wales (NRW) is no longer issuing new permits for disposal.
About 28.9m litres of used dip was generated in the UK in 2025, yet permits cover only about half of this volume, and it is uncertain how the remaining 14.5m litres are being disposed of.
Trial success
Sheep farmers Ruth Clements and Roland Bonney have developed Clear Dip, a mobile filtration unit that has been proven to remove close to 100% of the insecticide in Defra-funded trials via the Innovate Adopt scheme.
The work is being supported by the wider industry, including the National Association of Agricultural Contractors, National Sheep Association, Sustainable Control of Parasites in Sheep, and Bimeda Animal Health, which manufactures the dip.
The system has been trialled at Stobo Farm near Peebles in the Scottish Borders.
Since November, the team has run 18 trials, progressively improving the innovation. In the last seven of these, the technology removed the insecticide to well below concentrations that would have any environmental effect.
“The trials have been highly effective and very reproducible. It means we have water coming out of the system with diazinon levels 40 times lower than in drinking water,” Ruth revealed.
How the technology works
The used dip passes through a series of filters that remove debris, separate oil and finally capture the diazinon.
“This will allow us to safely remove the diazinon on farm for controlled, onward disposal, massively reducing the environmental risk and enabling the continued use of sheep dipping, which is vital for sheep health and welfare,” said Ruth.
“Diazinon has been detected in river water associated with sheep producing areas, which is a concern to the industry, not least to farmers themselves who are increasingly being asked to deliver public goods, including clean water.”
Commercial use
Initially, the technology is likely to be operated by professional dipping contractors. Farmers who carry out their own dipping could either hire a contractor to treat the spent dip or potentially invest in a shared unit with neighbouring farmers.
Researchers are now working with the Environment Agency, NRW and the Scottish Environment Protection Agency to establish a framework that would allow the technology to be used commercially.
As part of the framework, they will need to determine how treated water should be classified. One option under consideration is reusing the treated water for future dipping.
A UV disinfection filter can be fitted to the unit to improve biosecurity. First, however, regulators must decide whether the treated water is safe to reuse or, if not, the most appropriate way of handling it.
The diazinon recovered by the machine is collected as solid waste, and researchers are currently proposing it would be collected and processed by an existing network of licensed operators.
Ultimately, the aim is to make it cost-effective for farmers to encourage wide adoption, Ruth explained.
“We want to make this available as widely as possible and are mindful that we can’t expect farmers to pay twice for the permit to spread to land as well as for external disposal.
“We need this to ensure that public money is spent on a solution that has a high chance of delivering for the benefit of the sheep sector, for animal welfare and importantly for the environment.
“We want this to be a win-win for all involved.”
Ruth was speaking at the NSA Sheep Event at Malvern on 28 July 2026.