As swimmers head for Nebraska lakes to cool off this summer, health officials warn: Make sure the spot you choose is safe.

Recent health alerts at Maple Creek Recreation Area Lake in Colfax County, Maskenthine Reservoir in Stanton County and Rockford Lake in Gage County have been lifted but Nebraska health officials said harmful algal blooms can develop quickly during the summer.

David Schumacher, surface water monitoring section supervisor for the Nebraska Department of Water, Energy and Environment, explained what water looks like with an algal bloom.

Image

"What we're looking for is a scum-like, almost (as) if somebody were to spill paint on the surface of the lake. It would have an oily sheen to it. We describe it as 'John Deere green' in color," Schumacher said.

As the bloom dies, Schumacher noted it changes from green to turquoise with white streaks, especially after washing ashore. He urged people to avoid affected water and keep pets away because contaminated water can be fatal to dogs.

Updated health alerts and weekly test results are posted every Friday on the department’s website.

Although Nebraska tests dozens of public lakes each week during the summer, Schumacher acknowledged harmful algal blooms can develop between sampling days. He emphasized which recreational activities are safe and which should be avoided.

"Any activity that takes you out of the water. If you're fishing, using the grounds around the lake are all fine, acceptable. It's just that the full body contact recreation," Schumacher outlined.

Schumacher added Nebraska's monitoring program covers 57 public beaches at 52 lakes but dangerous algal blooms can also develop in lakes not routinely monitored, so he encouraged visitors to inspect the water before swimming, even if no health alert has been issued.