Harmful algal blooms can be a big problem for water utilities.
According to a Water World article, the city of Toledo, Ohio, lost access to drinking water for three days due to a sudden deluge of microcystin — a cyanotoxin found in some of the blue-green algae blooms that grow on surface water in warm weather.
The growth and risk of cyanotoxins in surface water is unavoidable, according to the EPA. Cyanotoxins can add a foul odor and taste to water and potentially lead to nausea, rashes, dizziness and even liver and kidney damage.
Drinking water sources in all 50 states are affected by these potentially harmful algae blooms, but there are currently no regulations from the EPA for safe levels of cyanotoxins or microcystin in drinking water.
To mitigate the potential risk posed by these toxins, the EPA suggests that water treatment plants have a cyanotoxin monitoring plan in place. The plan should outline when, where and how often sampling will take place, as well as what screening tools and processes will be used to ensure consistent tracking of these contaminants. The EPA recommends using enzyme-linked immunosorbent assay (ELISA) test kits for initial sampling; however, if cyanotoxins are detected, treatment plant operators may need to invest in more complex mass spectrometer equipment or work with a local lab to identify the level and species of toxins in the water.
Proactive monitoring ensures that drinking water quality and safety is maintained without overwhelming a utility’s treatment budget. The Ohio State University’s Ohio Sea Grant College Program offers summer workshops that cover water treatment plant management strategies for harmful algal blooms.
American Water, in partnership with LG Sonic, performs ultrasonic algae control in its water treatment plants.