Reeds blow algae out of the water

Floating reed-beds could hold the key to stopping dramatic blooms of algae fouling up water treatment works. Algal blooms which are common in summer, are triggered by certain levels of […]

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By Sumit Bose

Floating reed-beds could hold the key to stopping dramatic blooms of algae fouling up water treatment works. Algal blooms which are common in summer, are triggered by certain levels of sunlight and warmth – and they’re a big headache for water companies.

They spring up dramatically and can severely reduce a water works’ output by clogging up key pieces of kit used to clean and treat river water. Removing the algae requires costly chemical treatment, but now a natural answer has been discovered.

Researchers working for Thames Water have created a boom of reeds to float on Farmoor reservoir in Oxfordshire. It is hoped they will stop the algae in its tracks, both at water level and beneath, by introducing microscopic animals that feed on it, like plankton. The platforms will also provide habitats for birds and other wildlife.

Dr Piers Clark, commercial director for Thames Water, said:”The great thing about this idea is that it’s completely natural. We’re not building a big computerised algae-skimmer or dosing reservoirs with a new chemical – we’re just floating some reeds on a reservoir. By getting rid of the algae in the reservoirs before it gets to the treatment works, we can be more efficient in driving down production costs, and also help to protect the environment by using less chemicals.”

Rob Shore, Wildfowl and Wetlands Trust Head of Wetland Conservation said: “It’s great to see Thames Water looking to the natural world to deal with water issues. If this trial goes well, we’d love to see solutions like this adopted by water companies across the country.”

If successful, the booms will be implemented at other Thames Water reservoirs feeding in to water treatment works by 2013.