The impact of discharging sewage 06 February 2024

(Image credit: AdobeStock by EpicStockMedia)

2022 figures from UK environmental regulators revealed untreated sewage was discharged into UK rivers and coastlines at the very least 399,864 times; that’s 1,091 times a day. That’s most likely a huge underestimation of the scale of the UK sewage scandal, according to campaign group Surfers Against Sewage

Over 2022, 1,924 sickness reports were reported to Surfers Against Sewage, causing an estimated five years’ worth of (1,987.5) sick days due to sewage pollution - and this is just those reported to SAS. In 2023 alone, the SSRS has reported over 18,000 real-time sewage alerts and pollution risk forecasts for the UK. The Surfers Against Sewage Water Quality Report ’23 summarises the main water quality issues across the UK.


Inland waters throughout the UK are dying. Only 14% of rivers in England meet good ecological status, and none meet good chemical status. This is owing to a variety of factors, including the widespread and persistent discharging of treated and untreated sewage, agricultural runoff, and industrial activity. Of the 86% of inland water bodies which fail to meet targets in England, 36% have been identified as failing directly as a result of sewage and wastewater discharges. This matters not just for the health of our rivers and lakes but also for the ocean and the coastal surf and swim spots we love so much. Ultimately what goes into our rivers goes into our ocean.

Water quality monitoring in the UK is shockingly sparse, but this data is crucial for understanding water quality and ecological health. The most recent round of water quality assessments in England were undertaken four years ago in 2019 by the Environment Agency (EA) as part of the Water Framework Directive.

Prior to that, the last assessment was undertaken in 2016. And now we know the next round of water quality assessments will not be undertaken until 2025. Over the course of a decade, the health of most English rivers will only be checked three times.

What testing we do have only provides a ‘snapshot’ view of how a waterway looked at one point. This doesn’t account for their dynamic nature and decreases the probability of detecting pollution. As a result, our knowledge of the health of UK waters is, on the whole, outdated and inaccurate.

In specific sites with designated bathing water status (shown here with composite maps by nation), water quality is tested on a more frequent basis due to legal recognition that they are popular bathing sites. At these sites, the EA tests weekly for bacterial indicators of sewage. But, there are currently only three sites on UK rivers and these sites are only monitored from May - September (the official bathing season in England). So yet again what monitoring we do, still fails to provide a clear picture of the state of our rivers and the potential impact on human health.


On a weekly basis, citizen scientists test for two main types of bacteria: Escherichia coli (E. coli), and intestinal Enterococci. These are known as faecal indicator organisms (FIOs), so-called due to their common presence in the intestinal tracts of mammals (that is, humans). Because they thrive in the human gut, they are often found in untreated sewage. This, in combination with the ease with which they can be grown in a laboratory environment, means that they are easily detectable and a convenient marker for untreated sewage.

Our community of citizen scientists have collected data over an 18-week period (May - Sept 2023). This data has been collated and used to replicate Bathing Water Classifications. These classifications use the EA statistical technique to categorise each sampling location into either Excellent, Good, Moderate, or Poor, depending on the levels of E. coli and Enterococci in the samples.

The statistical technique looks at the average values over the season, as well as how much the values change over time, to determine the probability of the location being hazardous for water-users’ health.

A total of 40 sites were investigated for our citizen science water quality testing programme. This included 20 locations throughout the UK where communities were applying for Designated Bathing Water status, and a further 20 sites upstream of a nearby sewage overflow (to find out if sewage discharges are causing a decrease in quality).

Of the 40 sites, we found that 24 sites received a ‘poor’ bathing water classification, five sites received a ‘sufficient’ classification, four sites received a ‘good’ classification and just seven sites received an ‘excellent’ classification.

One iconic river that tragically received poor water quality was the River Dart in south Devon. Of the six sampling locations on the River Dart, four locations received a ‘poor’ water quality classification for the 2023 bathing season, and many of the weekly samples taken at these four sites consistently showed dangerously high levels of FIOs such as E. coli and Enterococci.

With more frequent sampling, we would increase the likelihood of testing directly after a sewage discharge, which would likely decrease water quality. What our results indicate is that at least four of our locations are directly impacted by sewage discharges; we cannot say that the other 16 are not. By limiting ourselves to weekly testing, we could be missing bouts of bad water quality. The more frequent testing a location receives, the more accurate picture we have. We know that sewage pollution will move downstream quickly in heavy-flowing water. But ultimately all rivers lead to the ocean - taking the pollution down to the coast as it goes.


Scotland’s public drinking water and sewerage services are provided by publicly owned, Scottish Water. As a public company, the Scottish government and Scottish Parliament ultimately have the power to set out what Scottish Water should be focussed on, and to hold the company to account if they are falling short. The Scottish Environment Protection Agency (SEPA) is responsible for regulating Scottish Water’s environmental performance.

Unlike in England and Wales where nearly 100% of combined sewer overflows (CSOs) are monitored, in Scotland under 4% of overflows are required to be monitored. Scottish Water operates over 3,600 sewage overflows in Scotland, but last year only 103 of these were required to be monitored. What information is available is only published annually, rather than in real-time.

Scottish Water has set out plans to improve the monitoring of sewage pollution and reduce the number of discharges in its ‘Improving Urban Waters’ route map.

Data from the 4% of reported sewage overflows is made available due to their ‘high priority’ status, as defined by SEPA. This includes important sites such as bathing waters and shellfish areas – though importantly, not all bathing waters are reported. Even two popular locations for water users featured in this report, Thurso (a world-famous surfing location) and Portobello in Edinburgh (a popular beach, with thousands of visitors), have noticeably no reporting whatsoever.

The impacts of untreated sewage overflows on blue spaces throughout Scotland therefore remain largely unknown, and Scottish water users rarely have any idea whether it’s safe to use their local water or whether they will unknowingly swim in sewage.

Just like in the rest of the UK, overflows in Scotland are only legally allowed to be used in ‘exceptional circumstances’ such as during periods of unusually heavy rainfall. However, over the last five years, untreated sewage has been released 58,304 times, and this is just from 161 sewage overflows in Scotland that were reported on.


Northern Ireland Water is responsible for operating the sewage network throughout the nation. This includes regulating its sewage overflows, which are designed to discharge sewage in exceptional circumstances of heavy rainfall, but which are now being used far beyond their original purpose.

Northern Ireland has a total of 2,398 operational sewage overflows, however, data for the operation of this infrastructure is sparse. In November 2023 Northern Ireland Water provided a map of the locations of overflows they still provide no data on how often these overflows are discharging sewage, which they say is due to a lack of investment and budget for the provision of infrastructure to monitor sewage discharges. All information regarding sewage assets (including condition and performance) is obtained through manual inspection, rather than automated systems as with other UK-based water companies. This means we have little to no information regarding the state of Northern Ireland’s water and the potential impact that sewage discharges are having on them.

The first phase of the deployment of event duration monitors for obtaining sewage discharge information on Northern Ireland Water’s assets is scheduled for next year (2024). It will be focused on bathing waters and shellfish waters and there are plans to have monitors installed on assets near the highest priority waters by June 2024, with information being sent directly back to the water company.

By the end of 2027, they aim to have over 900 monitors deployed, with the eventual aim of deployment on all sewage overflows. Despite this, Northern Ireland Water has provided little information with regards to how they plan to disseminate this vital information to water users and the public, whether the information will be real-time, accessible or even be made public at all.


We need an enhanced, world-leading testing regime all year round which gives a true picture of the UK’s water quality.

To help us achieve a greater amount of water quality testing across the UK we’re campaigning for the introduction of 200 designated inland bathing waters by 2030, leveraging the legislation that’s already in place to track and improve water quality at local inland sites, so we can start improving the health of our rivers and lakes - which are currently in disastrously poor condition.

As part of our End Sewage Pollution Manifesto, we are calling for the incoming government to prioritise high-risk pollution and take immediate, targeted action to tackle the highest-risk pollution events, which include those impacting on designated bathing sites and other popular water user sites.

There are currently only three inland bathing sites in England (the River Wharfe at Ilkley, Wolvercote Mill Stream at Oxford and River Deben at Waldringfield).

All three of these designations were achieved by incredible community campaigns. This year SAS is engaging with 50 communities, through the Protecting Wild Waters campaign, who want to see improvements to their river and lakes by applying for bathing water designation, 20 of which plan to apply this year.

The 2024 general election provides an opportunity for the next government to end sewage pollution. That’s why we want all parties to adopt our End Sewage Pollution Manifesto - our five point plan to end sewage pollution: enforce the law, stop pollution for profit, prioritise high-risk pollution events, empower a nature-led approach and reveal the truth.

This article is an edited version of the Surfers Against Sewage Water Quality Report ’23 first published in November 2023. The full report is available via


Surfers Against Sewage claims 60% of inland swimming spots that they monitored would be classified as ‘poor’ if officially designated as bathing waters. To note, it is important to be aware that the 40 sites that Surfers Against Sewage mention are not designated bathing sites, and therefore are not include in published bathing water statistics.

Substantial improvements have been made to bathing waters. In 2022, 93% of designated bathing waters met the highest standards of ‘good’ or ‘excellent’, up from just 76% in 2010 and despite stricter standards being introduced in 2015. In the early 1990s, just 28% of bathing waters met the highest standards in force at that time. These improvements have been driven by £2.5 billion of investment and facilitated partnerships.

Surfers Against Sewage’s report also looked at the number of times untreated sewage was discharged into UK waterways. The government and the Environment Agency recognise the volume of pollution in our waters is utterly unacceptable, which is why stringent targets have been set to reduce discharges. Water companies must not profit from environmental damage and Ofwat has been given increased powers under the Environment Act 2021 to hold them account for poor performance.

Water minister Rebecca Pow said: “We agree the volume of pollution in our waters is utterly unacceptable, and this is the first government in history to take such comprehensive action to tackle it.

“Our Plan for Water ( is delivering more investment, stronger regulation and tougher enforcement to ensure every overflow is monitored, reduce all sources of pollution and hand out swifter fines and penalties.

An Environment Agency spokesperson said: “We share Surfers Against Sewage’s absolute commitment to improving water quality in England, and much of the data released today is available because of the significant steps we’ve taken to improve the regulation of our waterways.”

As part of the Plan for Water, over £2.2 billion of new, accelerated investment will be directed into vital infrastructure to improve water quality and secure future supplies, with £1.7bn of this being used to tackle storm overflows to cut over 10,000 discharges by 2025.

We have set stringent targets (Storm Overflow Discharge Reduction Plan) for water companies to reduce storm overflows – driving the largest infrastructure programme in water company history of £60 billion over 25 years. This will result in hundreds of thousands fewer sewage discharges every year by 2050.

The Plan frontloads action in particularly important and sensitive areas including designated bathing waters. Overflows that are causing the most harm will be addressed first to make the biggest difference as quickly as possible.

We are driving up monitoring and transparency so the public can see what is going on – we have increased the number of storm overflows monitored across the network from 7% in 2010, to 91% now, and with 100% expected by the end of 2023.

We are also scrapping the cap on civil penalties and significantly broadening their scope to target a much wider range of offences. These new powers will make it quicker and easier for regulators impose unlimited penalties in instances where the threshold for criminal prosecution has not been met. This will deliver a proportionate punishment for operators that breach their permits and harm our rivers, seas and precious habitats.

The government backed plans for the water regulator Ofwat to take action against water companies that pay out dividends to their shareholders despite failing to meet the required performance standards, and boosted their enforcement capacity with an additional £11 million funding increase.

Operations Engineer

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