A WATER firm has given mussels the bullet in a bid to stop them clogging up Banbury’s water pipes.

Every year huge infestations of zebra mussels from the Black and Caspian Seas cost UK water companies millions of pounds by clogging up pipes and treatment works.

Now experts have developed an eco-friendly way to get rid of the pesky molluscs — fat-coated blobs called “BioBullets” and they are being trialled at water treatment works in Grimsbury.

Every year staff at the Banbury plant remove about 16 tonnes of the pest. It is believed zebra mussels hitch rides in the ballast water of ships heading to Britain from Eastern Europe and, once docked, they decamp to water pipes.

With no known predators in Britain to control them, their numbers are ballooning out of control.

Adult zebra mussels, which are no good to eat, can grow up to 4cm long, and females can release more than 30,000 eggs per year. Build-ups of the mussels and the shells of dead ones narrow, and can eventually block, water companies’ pipes.

The BioBullet, which is about 50 micrometres in diameter, has a fatty outer coating irresistible to zebra mussels, covering an inner centre that is toxic to mussels but harmless to humans and other creatures living in the water.

The mussel-killing chemical is fully approved for use in drinking water treatment.

Dr Piers Clark, commercial director for Thames Water, said: “They eat by filtering small particles out of the water, so, in the right place they are potentially beneficial to us as they feed on algae in the reservoirs.

“But in the wrong place, they can block up parts of the water treatment process like fat furring up arteries.

“We believe BioBullets will save hundreds of thousands of pounds in operational costs in a way that has no adverse impact on the environment.”