Raw sewage is being dumped off the Isles of Scilly – and no one will be prosecuted

Untreated sewage has been dumped into the ocean surrounding the Isles of Scilly in water that is home to some of the rarest and most diverse nature in Britain. Puffins, seals and humpback whales are among the wildlife that can be spotted on the islands, almost 30 miles off the southwestern tip of mainland Cornwall, which attract around 125,000 visitors from mainland Britain each year. The archipelago has historically not been protected by the same environmental rules as the rest of the UK, meaning authorities have been pumping sewage directly into the sea without treatment. Shorts South West Water (SWW), which took over responsibility for the islands in 2020, had plans for “improvement” that would have seen it applying minimal treatment to waste being discharged into a Marine Protection Zone. Islanders were in uproar at the suggestion, forcing SWW to revisit its plans, but locals remain concerned their oceans are being treated as a “big blue bin”. Waste dumped continuously off the Isles of Scilly Despite being under the full jurisdiction of the UK Government, the Isles of Scilly have until recently been exempt from national water and sewerage regulations. Alongside the City of London, the islands are one of only two sui generis authorities in the UK, which hold a special legal status that means they usually have to be specifically mentioned in legislation in order for it to apply. The Duchy of Cornwall owns about 75 per cent of the land and around a third of the homes on the Isles of Scilly. The sewerage infrastructure on the islands is basic and much of it is in disrepair, meaning some of the waste generated on the island is dumped directly into the sea without treatment. The system was operated by the Council of the Isles of Scilly until 2020 when South West Water (SWW) took over responsibility. At this point the UK Government also passed legislation to apply English water regulations to the island and SWW was given five years to bring infrastructure up to standard, however this deadline was recently extended until 2027. A shark swimming in the sea surrounding Scilly – the islands’ treatment is different to mainland Britain, which uses microorganisms in water treatment that remove a range of pollutants (Photo: Brendon White) SWW’s original proposal for the island involved building a longer pipe that would discharge waste that had been ‘screened’ for solids. This is different to the process required on mainland Britain that sees sewage treated with microorganisms that remove a range of pollutants, meaning the remaining wastewater is much less damaging for the environment. SWW has been forced to backtrack on these proposals following an outcry from the islanders and a warning from the Environment Agency that the firm must comply with UK regulations. The company has now said it will treat wastewater on the Isle of Scilly, but said “further work” is needed to understand how the new system will overcome challenges, including how to dispose of the ‘sludge’ created as a byproduct of the treatment process. It could be catastrophic There is still uncertainty around what the final solution will look like for the Isles of Scilly and islanders are concerned about the impacts on tourism and the natural environment. The entire group of islands has been designated a Special Area of Conservation and is surrounded by 11 different Marine Conservation Zones. Many visitors to the archipelago come to participate in activities such as snorkelling, wildlife boat tours and sea cave exploring. The Isles of Scilly are home to a thriving population of Atlantic grey seals (Photo: Brendon White) “Tourism is the main thing that keeps us all going,” said Lewis Johnson, who runs Seal Snorkelling Adventures on the island. “A lot of people come here for the stunning looks of the island and I think the last thing they’ll want to see is toilet paper and things being flushed into the sea around the back of islands.” Matt George, who runs Kernow Coasteering, one of the closest businesses to the proposed discharge site, said the impact on him could be “potentially catastrophic”. George organises coasteering trips from mainland Cornwall so doesn’t have the flexibility to change plans if the conditions are bad. He said it “beggars belief” that SWW were “proposing installing something that is not even up to the standards of the current treatment”. Nikki Banfield, who founded the Scilly Coastal Clean-Up Group, said the surrounding area is home to a range of “nationally and internationally important” wildlife, including atlantic grey seals, dolphins and rare migratory birds. Around 100 puffins nest on the Isles of Scilly each year (Photo: Brendon White) Humpback whales can also be spotted from the islands, particularly during the winter months. “Obviously discharging raw sewage into the sea will have its issues,” Banfield said. “It’s mind-blowing that in 2026 it’s still considered okay by an organisation to put more sewage in the ocean and thinking that it’s going to go away. It’s in the big blue bin.” A spokesperson for South West Water said: “We are listening to our customers on the Isles of Scilly as we develop plans to improve the resilience of the islands’ wastewater network, protect water quality, and support the future needs of the community. “When we took on the wastewater network in 2020, it did not meet current regulatory requirements or modern standards. Since then, we have been developing plans for significant investment across the islands, but there are no straightforward solutions to this essential work.”