Book excerpt: Toxic cyanobacteria (blue green algae) have now been reported in 27 countries and are found on all continents including Antarctica. Drinking water authorities world-wide are faced with the challenge of treating contaminated water or the possibility of a toxic bloom occurring sometime in the future. This tailored collaboration project was to provide the international drinking water industry with information to facilitate the confident application of viable treatment techniques for cyanotoxins. Assessment included toxicity of the ozonated solutions, assessment of the protein phosphate inhibition assay technique and the possibility of seeding an activated carbon filter with select bacteria for removal of microcystin-LR. This report offers valuable guidance to the water supplier to aid in deciding upon the most appropriate treatment options for a range of dissolved blue-green algal toxins.