Sewage discharges in England: what the latest EDM data really shows
The latest Event Duration Monitoring (EDM) data has been released, and water companies are already pointing to “improvements”. But beneath the headlines a very different picture emerges.
In 2025, water companies discharged raw sewage into England’s rivers and seas nearly 300,000 times. While that figure is lower than the previous year, it’s not evidence of a system improving, it’s a reflection of unusually dry weather. And for water users, the reality hasn’t changed: pollution persists and people are still getting sick.
What is EDM data?
Event Duration Monitoring (EDM) tracks when, where and for how long sewage is discharged from storm overflows into our waterways. These overflows are only meant to operate in exceptional conditions. Not as routine pressure valves for an overstretched system.
Why a drop in sewage spills isn’t good news
The reduction in spills during 2025 needs context, last year saw the driest spring in over a century, alongside record sunshine and temperatures. Less rain means fewer overflow events. But even in those conditions, water companies discharged sewage for 187,000 hours on dry days, including 7,885 hours into bathing waters. These are not storm-related releases, they’re further evidence of a broken system.
The human cost of sewage pollution
Behind the data are real people. In 2025, 1,236 people reported illness after entering the water, with 74% of cases occurring at ‘good’ or ‘excellent’ bathing waters. 233 of those reports were linked to confirmed sewage discharges. And it’s continuing into 2026. In just three months, 164 people have already reported illness, before peak season has even begun.
This isn’t just an environmental issue, it’s a public health crisis.
The worst offending water companies
The 2026 data already highlights repeat offenders. South West Water has recorded the highest total discharge duration so far, with over 39,000 hours of pollution. Southern Water has issued the most sewage alerts, with more than 2,100 notifications.
At site level, some locations are facing relentless discharge. Plymouth Hoe East alone has seen over 5,000 hours of sewage pollution across more than 1,000 spill events. Other hotspots include Chichester Harbour, the Erme Estuary, Mothecombe and the Dart Estuary.
2026 is already on track to be worse
Worryingly, early data suggests the situation is escalating.
In the first 11 weeks of 2026:
- 3,800+ sewage alerts have been issued
- Alerts have been active for over 120,000 hours
- 171 locations have experienced pollution lasting longer than a week
- At Southsea East, a single alert has lasted 76 consecutive days.
- Water companies have already discharged over 69,000 hours of sewage into bathing waters, more than half of 2025’s total.
This is not a system recovering.
What needs to change
This data makes one thing clear: incremental change is not enough. Surfers Against Sewage is calling for:
- Public health to come before profit
- An end to the profit-driven sewage model
- Government to take back control of water companies
- A full restructure of the system to serve people and the environment
- No option, including public ownership, should be off the table.
What you can do
Change requires pressure. Here’s how you can take action: