The state has discontinued a health alert for toxic blue-green algae at Johnson Lake in Gosper County, after the lake had two consecutive weeks of low readings for toxic blue-green algae.

A health alert continues this week at Red Willow Reservoir in Frontier County. Red Willow had been placed on alert last week when readings exceeded the state’s health alert threshold of 20 parts per billion (ppb) of total Microcystins (a toxin released by certain strains of blue-green algae.) Although levels at the lake were below the threshold this week, lakes that are on health alert must have two consecutive weeks of readings below the threshold before the alert is discontinued.

Signs have been posted at Red Willow Reservoir to advise the public to use caution, and the swimming beach will remain closed during the health alert. Recreational boating and fishing are permitted, but the public is advised to avoid activities that could involve accidental ingestion of water. People can still use the public areas for camping, picnics and other outdoor activities.

The state will continue to conduct weekly sampling at 46 recreational lakes throughout the 2010 recreational season. Sampling results for toxic algae and bacteria will be updated every Friday and posted on NDEQ’s web site, https://dee.nebraska.gov/home

(For more information about potential health effects of toxic blue-green algae, what to look for, and steps to avoid exposure, please refer to the Toxic Algae Fact Sheet.)