What's actually in the water that Southern Water has been releasing into the sea, and could it make you sick if you swim near it?

Southern Water is one of the UK's most notorious water companies when it comes to sewage discharge, having been fined a record 90 million pounds in 2021 after pleading guilty to thousands of illegal sewage dumps. What they release into the sea is not simply treated wastewater but often a mixture of raw or partially treated sewage combined with stormwater overflow. The actual composition of these discharges is genuinely unpleasant and potentially hazardous. The primary concern is human faecal matter, which carries a wide range of pathogens. These include bacteria such as E. coli and Campylobacter, both of which can cause serious gastrointestinal illness. Enterococcus bacteria are also present and are actually used as one of the standard indicator organisms for water quality testing precisely because they survive well in seawater and signal faecal contamination. Beyond bacteria, raw sewage contains viruses including norovirus, which is highly infectious and causes vomiting and diarrhoea, and hepatitis A virus, which can cause liver inflammation. Cryptosporidium and Giardia are parasitic organisms also found in sewage that are resistant to chlorine treatment and can cause prolonged gut illness. There are also pharmaceutical residues, microplastics, heavy metals, and various chemical compounds that pass through the human body or are flushed down drains and are not fully removed by treatment processes. If you swim near a discharge point, yes, you genuinely can become ill. The risk depends on several factors including how recently the discharge occurred, how much dilution has happened, water temperature, and how long you spend in the water. Swallowing even small amounts of contaminated seawater is the main route of infection, though skin contact can cause rashes and eye or ear infections. Surfers and open water swimmers are at higher risk than casual paddlers because they spend more time in the water and are more likely to be submerged. Studies by organisations like Surfers Against Sewage and academic researchers have found that surfers have significantly higher rates of antibiotic-resistant bacteria in their gut compared to non-surfers, which is a particularly alarming finding because it suggests regular exposure is affecting the microbiome in ways that could have long-term health consequences. The symptoms people typically report after swimming in contaminated water include stomach cramps, diarrhoea, vomiting, nausea, and sometimes fever. Ear infections and skin irritation are also common. Most healthy adults recover without needing medical treatment, but children, elderly people, pregnant women, and those with compromised immune systems face more serious risks. Norovirus in particular can be severe and spreads easily within households once someone brings it home. There have been documented cases of people contracting hepatitis A from contaminated bathing water, though this is less common in the UK than bacterial infections. Southern Water operates across Kent, Sussex, Hampshire, and the Isle of Wight, and many of the beaches in these areas are popular swimming destinations. The company has used combined sewer overflows, which are designed as emergency relief valves to prevent sewage backing up into homes during heavy rain, but investigations revealed they were being used routinely and illegally even in dry weather. The water quality monitoring system in England relies partly on self-reporting by water companies and on bathing water designations that only cover specific sites during the official bathing season, meaning many popular spots have no formal monitoring at all. Apps like Surfers Against Sewage's Safer Seas Service now provide real-time alerts based on rainfall and discharge data, which gives swimmers some ability to make informed decisions, but the underlying infrastructure problem of aging combined sewer systems remains largely unresolved despite the fines and public pressure.