Sewage in the sea

'Emergency' overflows adding to sewage polluting our seas

2 minute read

Picking up plastic bottle on a beach Triocean

Clean Seas Team

6 Jun 2023

We put in a Freedom of Information request to the Environment Agency to find out if Emergency Overflows are being used by water treatment works. The data (and lack of!) is shocking.

We've found out that less than 10% (686) of Emergency Overflows in the sewerage network are monitored for sewage discharges, of 7,016 across England.

What little data the Environment Agency do have, shows a really bad picture. We were expecting the data to show that these types of emergency overflows aren't used at all. The data not only shows that they are being used (with over one in three monitored Emergency Overflows discharging in 2022), but that 60% of those that discharged last year did so more than once.



Emergency Overflows monitored for sewage discharges


Credit: Neil Mitchell/

Emergency Overflows should only be used when there is a mechanical, technical or physical failure in the sewage network.

Storm Overflows were designed to be used when excess rainfall floods the system resulting in diluted sewage leaving the system. Their overuse, particularly during dry weather, has been heavily criticised. We’re even taking legal action against the government on their overuse.

Emergency Overflows are different to Storm Overflows. They are designed to be used as a very last resort. The Environment Agency requires them to have several key protection measures in place to prevent them from ever being used. The fact that they are being used so frequently, and often repeatedly, demonstrates that current preventative measures are inadequate.

Laura Foster, Head of Clean Seas said, "Emergency overflows are designed to be used as a last resort. Yet, from the tiny amount of data we do have, we can see that these discharges aren’t an uncommon occurrence, and there are repeat offences.

“It's not clear why, after the first incident, measures aren't being taken to prevent another emergency overflow discharge.

Water companies are paid to treat our sewage and they need to be fulfilling this duty. The failure to put procedures in place, which they’re required to do, is putting marine life, and people, at risk.

Will you sign our #StopOceanPoison petition?

Take action today

Untreated sewage poses a risk to marine life and those who swim in affected waters. It contains harmful chemicals, bacteria and viruses. In addition, it’s not just invisible toxins that are causing problems. Last year, sewage-related pollution, such as wet wipes and sanitary products, were found on 75% of the beaches our volunteers surveyed across England.

At present, Defra are ‘considering the inclusion of Event Duration Monitoring on all emergency overflows, with regulatory reporting requirements’, but with no timeline or targets in place, this could take years to come to fruition.

Chris Tuckett, Director of Policy and Conservation, said, "We need more data from emergency overflows in England. Without the data, we can't see the full picture of the damage being done. Monitoring must be urgently put in place on all emergency overflows as the first step to address yet another route of pollution of our marine environment."

Make a donation to support our work

Healthier oceans, protected oceans