Higher temperatures and nutrient loadings in source water supplies have led to increased incidences of algal blooms and occurrences of a number of algal toxins in water supplies.

According to the Water Research Foundation, Denver, there is no U.S. Environmental Protection Agency regulation for algal toxins. However, the agency has included three species in its third Contaminant Candidate List, which it uses to prioritize research and data-collection efforts needed to determine if specific regulations are necessary. The three species are: cylindrospermopsin, anatoxin-a and microcystin-LR. For more information, go to www.waterresearchfoundation.org.