The following chart indicates the threshold levels for each type of advisory.
Threshold Levels
Indicator | Watch | Warning | Hazard |
|---|
Blue-green cell counts (cells/mL) | 80,000 | 250,000 | 10,000,000 |
Microcystin toxin level (μg/L) | 4 | 8 | 2,000 |
Visual identification | Visual confirmation | Significant blue-green algae surface scum | N/A |