Nebraska has issued a health alert for toxic blue-green algae at Swan Creek Lake No. 5A in Saline County.

Alerts for Big Indian Creek Lake in Gage County and Kirkman's Cove in Richardson County are continuing.

The alerts stem from water tests earlier this week that show toxin levels beyond the state threshold.

A previous health warning for Swan Creek Lake had ended last week, but new water tests indicated that another alert was merited.

People can still camp, boat and fish, but shouldn't swim in the lakes or drink the water. Ingesting toxin-tainted water can cause health problems, including vomiting, diarrhea and, rarely, death.

Nebraska has been testing 49 public lakes since the beginning of May.