Argyll and Bute sewage overflow spills figures revealed

In all, the area put more than 1.6 million cubic metres of overflow into Scotland's waterways - one of the highest figures in Scotland.

But the Scottish Liberal Democrats, who obtained the statistics from Scottish Water, warned they could be an underestimate.

Overflows happen when heavy rainfall overwhelms the sewage system and waste water has to be released for drains to cope.

Scottish Water insisted the vast majority of waterways were in "good" or better condition, despite the overflows.

Overflowing drain in Churchill in October 2023 (Image: Kaylea Walsh)

Argyll and Bute saw a total of 3,768 "dumps" of waste water in 2023, compared to 3,082 in 2022. That's a rise of 22.3 per cent.

The total duration of the these spills was 30,073 hours, 35 minutes and 41 seconds.

And the total volume of that overflow was 1,629,807 cubic metres, the fifth highest in the country.

The figures also showed vastly different levels of overflow monitoring across Scotland.

There were 36 overflows minitored in Argyll and Bute, more than any other area, but Edinburgh, Dundee and East Dunbartonshire had no monitoring at all. 

Torrential rain last October in particular flooded much of Helensburgh and Lomond with sewers unable to cope.

Campaigners said residents needed to help where they could by not flushing non-disposable items down toilets and drains. That contirbuxtes to blockages and ultimately spills.

Angela Anderson, of Plastic Free Helensburgh, said: "In Helensburgh the majority of waste water is screened to 6mm as it is pumped along the pipes on the seafront to the treatment works at Ardmore.

"In extreme weather conditions the system can be overwhelmed and there is passive overflow to the Clyde to prevent backflow of sewage to our streets and houses.

"While Scottish Water runs the system, SEPA [the Scottish Environment Protection Agency] is in charge of environmental protection.

"With heavy rainfall there is a high ratio of surface water discharge to sewage and this is deemed acceptable.

"Breakdowns are mercifully infrequent but they are most likely to be caused or exacerbated by blockages.

"A total of 109 blockages were cleared from street stanks last year and the 3-metre split in the main sewer pipe at the start of the John Muir Way was stuffed with wipes.

"At the beach cleans we find lots of sewage related debris, wipes, sanitary, shaving and dental hygiene products, cages for toilet fresheners and all manner of other stuff.

"We also find small items from building and DIY work such as the ops cut off of silicone tubes, tile spacers, rawlplugs and up and down the Clyde thousands of pieces of cellophane from sweets, crips packets and other comestibles."

Ms Anderson said the increasing high winds and heavy rainfall of climate change would only make things worse. She urged the public to stop flushing items down the toilet as well as pouring fats such as milk down drains.

Wipes, sanitary products and other items that shouldn't be flushed down the loo lead to blockages in drains and sewers (Image: Yorkshire Water/PA)

She said blocked road gullies should be reported to the council, and sewage problems to Scottish Water.

Grass verges and other green spaces help absorb water compared to paved surfaces merely pushing water on.

Scottish Liberal Democrat leader Alex Cole-Hamilton MSP said: “Rural areas like Argyll and Bute can be more exposed to the elements and have suffered from a lack of investment by the SNP Government in infrastructure.

"This increases the chance of sewage overflowing into rivers and waterways, especially where the network isn’t up to scratch.

"I want to see the Scottish Government backing my party’s plans for a Clean Water Act because these are proposals that would upgrade our Victorian sewage network and protect local communities.”

The Lib Dems want to see legislation to upgrade the sewage network and ensure all spills are recorded, with binding targets to reduce them.

Professor Simon Parsons, director of environment, planning and assurance at Scottish Water, said 87 per cent of water bodies were rated good or better and said the increase in overflows was because of higher rainfall.

He said: “Around 99 oer cent of these overflows is rainwater, surface water, road run-off, grey water, infiltration of groundwater and trade effluent.

“More than half of the overflows we report are at settled storm sewer overflows [SSSOs] where there has been treatment of the flows, such as primary settlement and screening.

“We recognise releasing waste water, even occasionally, into Scotland’s rivers and seas is a concern to people and we are playing our part in fully informing the public, as well as improving infrastructure, alongside our regulator SEPA.”

A Scottish Government spokesman said: “It is important to note that overflows from sewers are wastewater which has been highly diluted by rainwater, and which normally consists of less than 1 per cent toilet waste.

“Sepa assesses 87 per cent of water bodies in Scotland as having ‘high’ or ‘good’ water quality, up from 82 per cent six years ago.

"This means our rivers and coastal waters are overall in good ecological condition, but we are not complacent, and continue to work closely with Sep and Scottish Water to monitor and improve water quality.

“Scottish Water is taking action and is committing up to £500 million to improve water quality, increase monitoring of the highest priority waters and tackle debris and spills.

"This includes a commitment to install at least 1000 new monitors on the network by the end of 2024.

"Good progress is being made, with around 800 having already been installed by the end of March.

“Scottish Water is also working with SEPA to identify and develop solutions for 108 high priority overflows impacting water quality or causing sewage related debris problems.”

Nathan Critchlow-Watton, head of water and planning at SEPA, said: “More than 87 per cent of watercourses are rated as good or better for water quality and we have a record-breaking number of bathing waters rated as ‘excellent’.

“Combined sewer overflows are an integral part of Scotland’s sewerage system, designed to discharge at times of high rainfall to prevent sewage backing up and flooding houses.

"SEPA regulates discharges to the water environment and assesses sewer network licences, with particular focus on unsatisfactory compliance, as these can discharge sewage litter and impact on people’s enjoyment of the environment.

“Climate change is leading to an increased frequency of high-intensity rainfall events, affecting the number of overflow events.

"We’re clear in our regulatory role in ensuring Scottish Water delivers against the Urban Waters Route Map, prioritising investment where it will have the most benefit for the environment and communities.

“Scottish Water have committed to installing monitors on every CSO discharging to a bathing or shellfish water by the end of 2024, with near real-time monitoring published for all monitored CSOs by the end 2024.

"SEPA will ensure this commitment is delivered.”