Samples taken earlier this week showed Swan Creek Lake was above the state's health alert threshold of 20 parts per billion of total microcystin. This is a toxin released by certain strains of blue-green algae. The health alert will continue at the lake for at least two more weeks, because locations in an alert must have two consecutive weeks of readings below the threshold before it can be discontinued.
The health alert issued last Friday for Willow Creek Lake will continue for at least one more week.
Rockford Lake in Gage County has had two weeks of low readings. Because of this, the alert has ended for that area.
When a toxic blue-green algae alert is issued, signs are posted and designated swimming beaches are closed. Recreational boating and fishing are permitted, but the public is advised to avoid activities that could involve accidental ingestion of water and to avoid full immersion in water. Public areas are still open for camping, picnics and other outdoor activities during the alert.
The lakes will be monitored weekly throughout the recreational season.