Algal blooms have long been of concern to the drinking water
industry due to the tastes and odours that are often associated
with their presence. Of particular importance are the cyanobacteria
or blue-green algae which may produce earthy–
musty odours caused by the compounds 2-methylisoborneol
(MIB) and geosmin. Both compounds are volatile saturated
tertiary alcohols that can be detected at extremely low
concentrations of between 10 and 20 ng/L.