Global warming means algal blooms can only increase. Tom Hall of the WRc Group reports on the latest research into treatment programmes
Excessive algal growth in raw water reservoirs can cause severe problems with water supply, even in a traditional UK climate. Global warming means algal problems could become more frequent and acute in the UK, so effective control measures will become more important. This issue has been the subject of recent research by WRc through Toxic, a European programme supported by UKWIR.
The most common cyanotoxins produced by blue-green algae in European waters are microcystins and anatoxins. The World Health Organisation has set a drinking water provisional Guideline Value of 1μg/l for microcystin-LR, one of the most commonly occurring cyanotoxins. These toxins can occur within algal cells (intracellular or cellbound toxin) or be released from cells (extracellular toxin). An algal bloom with 100,000 Microcystis cells per ml could contain 20μg/l