Several hundred Elk Grove Village residents were evacuated from two community pools this afternoon because of a cloud of chlorine gas, fire officials said.
No one was injured.
Firefighters were called to Elk Grove Park District's Pirate's Cove Theme Park and Rainbow Falls Waterpark around 1 p.m.
Employees at Pirate's Cove, which has a water area for bumper boats, and Rainbow Falls started mixing two different types of chlorine to introduce into the water system, Elk Grove Fire Chief David Miller said.
At Pirate's Cove, the mixture of trichloride and dichloride gave off a cloud of chlorine gas. Simultaneously, the same two chemicals were being mixed at Rainbow Falls but no gas was released because the materials didn't mix together completely, Miller said.
"The two types of chlorine interact with each other in a sometimes violent nature," Miller said. "It could heat up enough to ignite a fire."
The chemicals were being mixed in buckets and small containers. The fire department's hazardous materials team used water to dilute them.
Meanwhile, the outdoor pool area at Pirate's Cove, and the Rainbow Falls pool area were evacuated for about two hours, as was the Rotary Fest area, downwind from Rainbow Falls.
Three children in a park district day camp were taken to Alexian Brothers Medical Center for evaluation and were released. Seven adult campers and park employees were evaluated by fire personnel and signed release forms.
"Both facilities are open at this time and everything is going well," Miller said.
Area fire departments assisted with the evacuation, as did the Metropolitan Water Reclamation District.
While there was a danger of fire, or that large groups of people could have inhaled the material, Miller said, "due to employees that had their wits about them and fire personnel that evacuated these people, nobody was hurt seriously."