DOZENS of wild swimming spots where water quality is classed as "good" or "excellent" were contaminated with human or animal faeces this summer, analysis by The Ferret has found.
Official testing shows 46 of the country's 89 designated bathing waters - where hundreds of people swim daily - had at least one sample where E. coli or intestinal enterococci (IE) reached unsafe levels.
These bacteria are found in human and animal faeces and can cause stomach bugs, ear and eye infections, and other illnesses.
The worst affected beach was Irvine in Ayrshire, which is rated "excellent" but recorded the highest E. coli reading in Scotland and exceeded safe levels on seven occasions.
Nearly three-quarters of the unsafe samples across the country came from beaches rated "good" or "excellent", the data shows.
Campaigners warned of a "Scottish sewage scandal" and said the findings suggest the public is "being put at risk" even at "supposedly excellent quality beaches". Opposition politicians called for investment in Scotland's "Victorian sewage system" and argued "industrial agriculture" was also worsening water pollution.
The Scottish Government and Scottish Water both argued that water quality is at its "highest ever" level, while the Scottish Environment Protection Agency (Sepa) reiterated its advice to water users not to swim up to three days after heavy rain.
We analysed annual data published by Sepa, which monitors pollution of popular wild swimming spots over the summer.
Water is considered to be low quality and people are advised not to swim if concentrations of E. coli and IE are found to pass certain thresholds.
There were 110 such samples in 2025, a slight uptick from 107 in 2024. Faecal pollution can be linked to discharges from sewer overflows - which are meant to discharge during heavy rain to stop sewage from flooding homes and businesses.
But run-off from farms, as well as dog fouling and bird droppings, are also sources of contamination.
Thirty of the unsafe samples around the country were taken at 15 beaches where water is rated "excellent", while a further 51 were from "good" sites.
At Irvine, E. coli levels were more than 15 times the safe limit on July 7. Sepa's profile for the beach warns that sewer overflows can have a "significant impact on the water quality", although it says these "normally" occur only during rainfall.
Scottish Water pointed out that there is also a major farming catchment close to Irvine, and run-off of farm slurry can also be a source of the bacteria after heavy rain.
Nearby South Beach in Ayr was one of three around the country which had five unsafe samples, along with Kinghorn Harbour Beach in Fife, and East Lossiemouth in Moray.
Other "excellent" beaches on the Ayrshire coast, including Troon South Beach, Prestwick and Saltcoats/Ardrossan also had multiple samples indicating low water quality.
Sepa categorises bathing waters as "excellent", "good", "sufficient" or "poor" based on a four-year average of monitoring results. This means a site can still hold a high rating even if it records multiple unsafe samples in a single summer.
A spokesperson for the regulator argued this approach "ensures results are robust and representative" and gives a clear "indication of overall water quality".
In total, 87% of Scotland's bathing waters are officially rated "good" or "excellent", compared with 85% in England and 94% in Wales.
Scotland's sewage network includes more than 3600 combined sewer overflows (CSOs). These are designed to discharge untreated sewage during heavy rain where there is a risk of homes and properties flooding.
Scottish Water argues even when this does happen, nearly all of what is released is so-called "grey water" from households - including showers, baths and appliances, not toilets. Sewage is further diluted by rainfall, the company said.
But there are concerns that some overflow sites spill far more often than they should. A review by the watchdog that examines the Scottish Government's performance on green issues, Environmental Standards Scotland (ESS), found nearly half of monitored overflows discharged more than 50 times in 2023.
A small number were found to spill even during dry weather, which ESS said is "of greatest concern" because pollution is not diluted by rainfall. Scottish Water claimed any dry spilling CSOs are quickly identified and fixed.
There are also longstanding concerns about lower levels of monitoring of CSOs in Scotland compared with the rest of the UK, which means it is hard to know the extent of the sewage spilling problem.
In 2024, campaign group Surfers Against Sewage found that only 6.7% of Scottish CSOs were monitored.
Scottish Water had installed an additional 1000 electronic monitors at CSOs by the end of 2024, which it says brings coverage to 35% of sites, and a further 700 are expected to be fitted by the end of this year. It has also launched an online map showing near real-time data for over 1000 overflow locations.
Henry Swithinbank, a senior campaigner at Surfers Against Sewage, said Scottish Water and Sepa were only sharing a "tiny amount of data" with water users but that it is enough to show the "public are being put at risk" even in "the middle of summer" at excellent beaches.
Sepa's bathing water testing was "failing to give a true picture of what is happening to our most loved beaches", Swinthinbank (above) claimed, adding that limited information about discharges means "we have no idea about the true scale of the 'Scottish sewage scandal".
He added: "In the build-up to the 2026 election, we need to see all parties commit to full transparency about the scale of pollution in Scotland and set bold targets to end sewage pollution."
In September, the charity added Scottish data to its Safer Seas and Rivers Service app for the first time, allowing swimmers to see live alerts about sewage overflows near bathing waters.
Scottish Greens MSP, Mark Ruskell, said The Ferret's findings underline the need for "continued" investment in what he called Scotland's "Victorian sewage systems" to help Sepa and Scottish Water "clean up the pollution at source".
"But industrial agriculture is also playing a major role in worsening water pollution, there needs to be a concerted approach to clean up catchments with stricter rules to protect rivers and coasts," Ruskell continued.
"These figures aren't good enough. Our waters are for all of us, and people should be able to swim, bathe and relax safely."
Scottish LibDem leader, Alex Cole-Hamilton MSP, was also "extremely concerned" about "shocking levels" of sewage dumping at bathing waters.
"Our bathing waters are visited by thousands of Scots every year, from swimmers to pet owners. They ought to be able to enjoy our coastline without worrying about what is in the water," he told The Ferret.
A Sepa spokesperson pointed out that 2025 saw a record 50 of Scotland's bathing waters classified as "excellent", compared with 17 10 years ago, and noted that it made daily water quality predictions online at the highest risk bathing waters during the summer.
They added: "As there is a risk that water pollution may occur after heavy rainfall, bathing is not advised during, or one to three days after, heavy rainfall due to the potential health risk from water pollution."
Scottish Water said it was "monitoring more overflows than ever before, providing more information on overflows than ever before and investing more than ever before in our waste water network".
"Scotland's water quality is at its highest ever level and we remain committed to targeting resources and investment to preserve and protect Scotland's water environment," a spokesperson claimed.
A spokesperson for the Scottish Government said: "97% of Scotland's bathing waters currently achieve the bathing water quality standards, with 87% being rated 'good' or 'excellent'.
"We encourage everyone to make use of Sepa's resources and information to help make an informed decision about where and when to bathe. We also encourage beach users to continue to take all waste and litter home, and dispose of dog waste responsibly."