Sewage spilled directly into Scotland’s rivers, lochs and seas at least 12,000 times in one year, new figures obtained by The Ferret have revealed, but the true figure is likely much higher.
Data obtained via a freedom of information request shows that there were 12,238 ‘overflow events’ from Wastewater Treatment Works (WwTWs) and Sewage Pumping Stations (SPS) reported by Scottish Water in 2020. This means sewage is discharged directly into Scotland’s waters, including habitats for rare and important species and others used by swimmers, surfers and anglers.
Scottish Water says it is necessary at times, such as when the system is overwhelmed by heavy rainfall. However, campaigners have described the figures as “shocking,” warning that the discharges are “incredibly damaging to both the environment and human health”.
The figures are likely to be a significant under-estimate of the true number of sewage overflows, as Scottish Water is only required to monitor a relatively small number of these locations – just 101 of Scotland’s total of 3641 ‘combined sewer overflows’ or ’emergency overflows’.
This means that Scottish Water is only required to report data on less than three per cent of its sewage overflow sites to the Scottish Environment Protection Agency (SEPA).
In response to a request from The Ferret’s request, Scottish Water provided only an incomplete list of the waters into which the overflows discharged. However, many locations are identifiable via place names and grid references.
The overflows have been recorded at locations across Scotland, from Hawick in the Borders – which saw 85 overspills – to Kirkwall in the Orkneys, which saw 199.
Six locations showed overflow events happening at least 300 times in a year – making them, on average, a daily occurrence during 2020.
The highest number of overflows recorded was at Helensburgh Wastewater Treatment Works, which discharges into the Firth of Clyde. It recorded 1245 overflows in 2020 alone – an average of more than three per day. Helensburgh developed as a seaside holiday resort and continues to be used by swimmers and windsurfers.
The next highest was Alloa, on the River Forth, where 573 overflows were recorded. Alloa sits near where the river meets the Firth of Forth, much of which is designated a Site of Special Scientific Interest (SSSI) due to its habitats, plants, birds and invertebrates.
Third highest was Meadowhead sewage works, a Private Finance Initiative (PFI) facility on the Ayrshire coast, which recorded 509 sewage overflows.
A facility on Loch Carron in Wester Ross was fourth highest, with 343 overflows in 2020. The Lochcarron Wastewater Treatment Works sits on the shores of Loch Carron, which was recently designated a Marine Protected Area (MPA) because it hosts the world’s largest known flame shell reef.
According to the Scottish Government’s nature agency, NatureScot, large flame shell beds are rare and ‘critically important’ as they provide a habitat for a large number of other species. While dredging is a major threat to them, they are also “sensitive to changes in water quality.”
Mauchline sewage works, which sits on the River Ayr near the East Ayrshire town of the same name, had the fifth highest total with 319 overflow events. The river has two Sites of Special Scientific Interest and is popular with anglers due to its populations of salmon and trout.
Sixth was Hamilton sewage works, on the banks of the River Clyde, which saw 309 overflows.
Campaigners have criticised Scottish Water for these discharges of sewage into the environment.
Amy Slack, head of campaigns and policy at marine conservation charity Surfers Against Sewage, said: “Discharging sewage into waterways is incredibly damaging to both the environment and human health.
“Recent research by the European Centre for Environment and Human Health has shown that as swimmers, paddle boarders, surfers as kayakers, we are three times more likely to have antibiotic resistant bacteria within our guts than non-water users.
“And we are getting just as sick now from entering the sea as we did in the nineties. That’s in addition to the huge environmental damage caused, killing fish and destroying plants. It’s simply unacceptable that Scottish Water continues to pump out sewage into lakes, rivers and seas. We need them to be more transparent about what they are doing so we can stay safe when using Scottish waters and we need to see commitment and action to reduce sewage discharges.”
Charles Watson, chairman of River Action UK, an organisation which works to address river pollution, agreed that the data was shocking. He added: “As long as regulatory agencies are not able to provide comprehensive monitoring, water companies and other polluters will continue to treat our rivers as open sewers with impunity.
“Action from government to address the river pollution crisis by properly funding environmental protection agencies is imperative.”
Many of the spills took place via ‘Combined Sewer Overflows’ (CSOs), which Scottish Water says are necessary relief mechanisms for when pipes containing both sewage and surface water run-off are overwhelmed during heavy rains.
Scottish Water has pointed out that “storm and emergency overflows are licensed by the Scottish Environment Protection Agency (SEPA) to discharge to the water environment.”
However, the River Almond Action Group (RAAG) in West Lothian described the sewage discharges as “totally unacceptable,” and asked whether they “do occur only during heavy rainfalls or if they’re spilling after relatively normal events…due to a lack of sufficient wastewater treatment capacity.”
As the Ferretpreviously reported, the River Almond alone has seen hundreds of sewage spills every year from the wastewater treatment works along its banks, raising concerns particularly due to its popularity with swimmers and kayakers.
Local charity the Forth Rivers Trust has applied to SEPA for a section of the river to be officially designated bathing waters – if successful, it would be the first river in Scotland to receive this status, meaning that water quality would be regularly monitored and classified.
SEPA licenses Scottish Water’s overflows, setting conditions which include recording and reporting events. However, according to Scottish Water, these licenses “do not require permanent spill event monitors to be installed on all overflows.” As a result, Scottish Water was only able to provide data on the number of overflows at just over 100 of these sites – out of 3641 across the country.
A Scottish Water spokesperson said: “We have undertaken a significant amount of investment and improvement in our waste water networks and take our environmental responsibilities very seriously.
“As part of a long-term strategy, we are transforming our waste water services to meet challenges presented by the impacts of climate change and population growth.
“We acknowledge that people and communities feel strongly about the number of spills and we are taking steps to listen, engage and act in order to provide effective waste water networks and treatment and protection for the environment.”
The company said it estimated the overall cost of improving all “unsatisfactory” sewer overflows in Scotland would be “least £650m, and possibly substantially more” and claimed it had agreed priorities with SEPA to start to address issues.
“Scottish Water has installed over 350 event monitors across our networks and are installing a further 77 monitors at key locations over the next three years,” they added.
“Plans are being developed to increase coverage further, as well as rolling out approaches to create ‘intelligent networks’ which will help us provide improved visibility and early warning capability.”
They claimed that the majority of waste water blockages – which can lead to sewage spills – were caused by items such as wipes being wrongly flushed down toilets. “We would urge customers not to do so,” a spokesperson added.
This story was published in tandem with The Herald on 4 July.
Photo thanks to iStock/aquatarkus.