A record £1.85m fine has been imposed on South West Water after a parasite outbreak left hundreds of people ill and forced thousands of households in Devon to boil their water. The penalty, issued at Exeter Magistrates’ Court on 2 June 2026, is the largest ever levied for a drinking water offence, according to the Department for Environment, Food and Rural Affairs.
South West Water pleaded guilty to a criminal offence under the Water Industry Act 1991 relating to a cryptosporidiosis outbreak in Brixham during the spring and summer of 2024. District Judge Stuart Smith described the failure as “serious,” “wide-ranging, multilayered and profound,” noting that water companies are “regional monopolies” with “captive customers” and that the incident had created an enduring mistrust of local tap water. He ruled that the offence should be sentenced under food safety legislation because it concerned drinking water.
The outbreak, linked to the parasite Cryptosporidium, made 537 people ill. Of those, 159 had contact with the healthcare system and ten were admitted to hospital. Symptoms included diarrhoea, stomach cramps, dizziness, sickness, fever and headaches. Some individuals reported long-lasting health issues, including irritable bowel syndrome and psychological impacts. Around 16,000 to 17,000 homes and businesses – serving a population of almost 39,000 – were issued with a boil water notice that remained in place for up to 54 days for some properties, not being fully lifted until 8 July 2024.
The impact on the community was severe. Joe Millington, for the Drinking Water Inspectorate (DWI), which brought the prosecution, told the court that schools and other services were affected and the local economy was hit. Brixham College reported that school attendance and GCSE results had suffered, especially for disadvantaged children. One primary school closed because of a lack of assurances and bottled water from the company. Business owners reported that tourists cancelled bookings and there were long queues at bottled water collection points. Millington said the outbreak “significantly undermined” people’s confidence in the water supply.
The court heard personal testimonies from those affected. One resident who needed hospital treatment said: “My illness made me feel as if I was beaten up and it has been a long process getting over it.” Another said the water tasted as if it had come from a pond and they lost almost a stone. A mother described how her son had to be put on a drip in hospital, calling the experience “nothing short of horrendous”; afterwards he would only bathe in bottled water because he was so frightened. A woman said that during the weeks the boil notice was in place she had to watch her four-year-old while he showered to make sure he did not drink water. Another parent said her child had night terrors about a “bug in the water”. School pupils described missing classes, exams, trips and sports; one said she felt too ill to revise for exams. A child developed a serious eating disorder, and one child was so frightened of bathing in tap water that he only bathed in bottled water.
Failures in inspection and maintenance
The outbreak was likely caused by a compromised air valve on farmland where cattle and sheep were kept, the court heard. The valve was covered in mud, its seal was broken, and water was pooling across the field. A soil sample taken next to the valve tested positive for cryptosporidium. Millington said the risks around air valves had been known for more than ten years and the DWI had recommended that water companies have formal inspection policies four years before the outbreak. Despite this, he said, “Not a single air valve was inspected.”
Millington told the court that the air valves South West Water had in place “were not being inspected in accordance with the policy [SWW] drafted in 2020”. The farm itself had never been inspected, despite being a “high-risk site”. The air valve had not been visually inspected since 2011. South West Water admitted it had created a policy on air valve inspection following the DWI recommendation but accepted it had not been implemented. The DWI has since issued improvement notices to the company requiring the finalisation of a Group Air Valve Management Policy by March 2026 and the implementation of associated procedures and training.
Millington also highlighted that at one point during the crisis, South West Water wrongly lifted its instruction for 28 houses to boil water because of “issues with its digital mapping system”.
Company’s defence and explanation
Dominic Kay KC, for South West Water, said the company unreservedly apologised and felt genuine remorse. He said the company believed there was a second ingress of cryptosporidiosis into the water system from the farm. When officials inspected after the outbreak, they found illegal “cross connections” – links between safe drinking water and water not fit for human consumption. The company believes cryptosporidiosis first got into the mains water from these cross connections, and later via the air valve. Cross-connections can lead to contamination events and temporary shutdowns of water supply.
Kay also said the valve’s cover had been deliberately removed, allowing silt, soil and water to collect around it. The damage was not reported to South West Water. He told the court the company had warned people to boil water as soon as it became clear there was a problem. The company said it received the first report of illness on 13 May 2024, reviewed sampling data finding no initial detections of cryptosporidium, but further monitoring on 14 May identified the parasite in the Hillhead supply area in the early hours of 15 May, at which point boil water notices were issued. However, the UK Health Security Agency was first made aware of five cases by Torbay Hospital on 10 May 2024.
The court heard that South West Water has 22 convictions since June 2014 – including supplying water unfit for human consumption in north Devon in 2018. In April 2023, the company was fined £2.15m for environmental offences across Devon and Cornwall. In September 2025, it was fined £24m by Ofwat for breaching legal obligations in operating its wastewater network. The outbreak cost South West Water £16.3m in compensation to affected customers, and the company pledged a £1.2m fund to help tourism recover. The total cost to Pennon, South West Water’s owner, was £16m.
Caroline Voaden, the Liberal Democrat MP for South Devon, said: “Words like incompetent and reckless are so often used to describe our broken water industry that they have almost lost their meaning. But the truth is South West Water failed at their most basic duty, and no amount of money will ever fully regain the customer trust they squandered.”
David Harris, managing director of water services at South West Water, said: “We have cooperated fully with the Drinking Water Inspectorate throughout its investigations and through the end of the legal process. We apologise again to our customers who were impacted and have always taken full responsibility for the water that was supplied.”