Scottish Water is using earthworms and water fleas to treat waste water as part of an international study which aims to protect and improve resources across the world.

The EU funded project is currently being trialled in 11 different countries including Scotland, measuring the effectiveness of earthworms, water fleas and microalgae as a potential method to treat waste water.

The year-long pilot, which is being led by the Research and Innovation team, has just got underway in the small rural community of Littlemill in Nairn, after being chosen based on size, remote location and exposure to the Scottish climate – the perfect place to test the reliability and adaptability of the technology.

Two tanks have been installed at an existing treatment works to pilot the technique which aims to reduce the environmental impact from sewage. During the trial, the water will still be treated using conventional methods once it has passed through the new machinery. The clean water will then be released into local rivers.

Project Manager Anna Baran from Scottish Water’s Research and Innovation Team said: “This is a really exciting project for us to be part of and has the potential to have a real impact on the way waste water is dealt with around the world. The technology we are trialling basically replicates a process which happens naturally within soil but we are using it to clean waste water.

“The first stage of treatment involves a tank filled with earthworms – the worms eat the larger particles of organic matter in the waste water, before it is added to a second tank containing water fleas and microalgae which remove the finer bits of organic matter.

“At this stage, the water should be in a condition that would allow it to be returned back to the natural environment.”

She added: “The objective of the project is to provide a decentralised, ecological waste water treatment for use in rural communities like Littlemill, as well as industries such as agriculture and aquaculture.

“It would also have the potential to be used in developing countries – around 2.5 billion people globally are without sanitation facilities, so the development of an accessible method of treating waste water such as this could be very significant in tackling that issue.”