CLINTON – The Illinois Department of Natural Resources has placed warning signs around Clinton Lake after an Urbana girl got sick after swallowing water while playing recently at a Clinton Lake beach.

Januari Smith, communications manager for the Illinois Department of Natural Resources, said on Tuesday afternoon that signs have been posted around the lake and at lake concession stands advising boaters, swimmers and other lake users not to ingest lake water and to refrain from swimming in areas of Clinton Lake where algae blooms or stagnant water are present.

"The beach at Clinton Lake is untreated, so all types of things are lurking there," Smith said.

Smith said staff from the Illinois Department of Natural Resources and the Illinois Environmental Protection Agency have been taking samples of water at Clinton Lake for potential blue-green algae blooms.

"Blue-green algae are common in central Illinois waters, but some can produce chemicals that can have a toxic effect on humans, pets and livestock," Smith said. "Until the testing is complete, we would like everybody to be cautious."

Smith confirmed that her department received a report of an Urbana girl who became ill after being at the lake, but she cannot confirm that the illness was due to the water because there is no conclusive test for blue-green algae toxins.

According to the report, a 12-year-old Urbana girl was in an Urbana hospital Friday through Sunday after reporting several symptoms of blue-green algae poisoning.

The girl suffered from nausea, vomiting, headaches, fever and diarrhea after swallowing water while playing at the beach with four other children. None of the other children got sick.

The girl is recovering at home.

According to the Wisconsin Department of Natural Resources website, blue-green algae are a group of bacteria that usually grow in lakes, ponds and streams when warm water is enriched with nutrients such as nitrogen or phosphorus.

The algae can produce toxins that can make people ill through contact with the skin while swimming, through inhalation while motor boating or water skiing or by swallowing contaminated water, according to the site.

Symptoms can include eye, nose and throat irritation; fever; vomiting; diarrhea; rashes; nausea; headaches; and stomach cramps, according to the site.

Smith said this was the first report of possible blue-green algae poisoning at properties managed by the Illinois Department of Natural Resources this year. Smith said her department also received a report of a dog that died after ingesting water at Clinton Lake, but she said an autopsy showed that the dog died from heat stroke, not algae.

Smith said the state had previously been testing the waters of Clinton Lake every two weeks for E. coli bacteria.