Scottish Water helps clean up the Clyde

A £34m investment in waste water treatment by Scottish Water has finally ended the discharge of untreated sewerage and unscreened water into the Firth of Clyde.

Claimed to be one of the biggest projects of its kind ever carried out in Scotland, the new system took two years to complete. The development includes new waste water treatment works (WWTW) at Bullwood, near Dunoon, has two hours storm water storage capacity and will serve 14,465 people locally.

Formally opened by Scotland’s Cabinet Secretary for Infrastructure and Capital Investment, Alex Neil, the development has been designed to help protect the natural environment of the Clyde.

“It’s of great importance to the people of Dunoon and the local tourism industry,” said the Minister, congratulating Scottish Water on their achievement.

In contrast to the old system’s discharge of untreated, unscreened flows into the Firth of Clyde and Holy Loch, the new scheme initially removes a large amount of untreated sewage before providing a biological secondary process at the Bullwood treatment works, using a 6.2-mile chain of seven pumping stations to pump sewage from the head of the Holy Loch to the new WWTW.

One of the key challenges of the build was lack of space according to project manager, Rick Griffin. The necessary storage structures and treatment plant had to be fitted into a 10km strip of rocky coastline while also meeting residents’ concerns over the visual impact of the installed plant.

Storm tanks at the WWTW were lowered 17 metres to bedrock, providing two hours’ storage under storm conditions. They’re equipped to pump a maximum of 107 litres per second, three times the dry weather flow, to the WWTW for treatment.

The new system complies with the Urban Waste Water Treatment Directive (Scotland) Regulations and meets the Scottish Environment Protection Agency’s guidelines for discharges into recreational waters.

edie staff

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