British waterways fight invasion by Russian zebra mussels
4 August 2011 Last updated at 06:51 BST
Water companies say they may have found a solution to the spread of an invasive Russian mollusc which is clogging waterways.
The zebra mussel costs Anglian Water alone £500,000 a year to remove from treatment plants.
As Danny Savage reports, it is hoped a new powder will kill them off.