Public Water Supplies: Guidelines


Conventional water treatment (consisting of coagulation, sedimentation, filtration and chlorination) can generally remove cyanobacterial cells and low levels of toxins. However, water systems may face challenges providing
drinking water during a severe bloom event, when there are high levels of cyanobacteria and cyanotoxins in drinking water sources. If cyanotoxins over the U.S. Environmental Protection Agency’s national 10-day Health Advisory level (see below) occur in tap water, people are at risk of various adverse health effects including upset stomach, vomiting and diarrhea as well as liver and kidney damage (visit Health Risks page). EPA: 810-F-16-006


10 Day Advisory Level Drinking Water

Cyanotoxin Bottle-fed infants and pre-school aged children School-aged children and adults
Microcystins 0.3µg/L 1.6µg/L
Cylindrospermopsin 0.7µg/L 3µg/L