Naperville park officials say algae cause of green water at Centennial Beach

There's a reason the water at Naperville's Centennial Beach has looked similar to the Chicago River on St. Patrick's Day.

According to Naperville Park District officials, the water's recent green coloring was caused by an increase in algae growth in the former quarry. However, officials said, daily testing has shown normal results and that the water is safe for swimming.

“It is not uncommon for Centennial Beach to have algae during the course of the summer swim season,” park district officials said in a statement. “Centennial Beach is classified as a ‘beach' and not as a swimming pool.”

Officials said they received comments and questions from Centennial Beach visitors after the facility opened for the season last weekend. The greenish tint, they said, developed because of the recent high temperatures and lack of rain that allowed the amount of algae to increase in the water.

The 6.2 million gallons of water at the beach are chlorinated, recirculated and hand-skimmed to remove debris, but the water is not filtered like a typical swimming pool. Park district officials said that while the water is safe, they're still working to mitigate the algae to deter further growth.

Visitors also commented on the beach's play features that appear darker in color. Officials said that's a common occurrence as sand from the beach mixes within the system.

Like with the Centennial Beach water, officials said they'll continue to monitor the water around the play features on a daily basis.

On most days through Aug. 16, Centennial Beach, 500 W. Jackson Ave. near downtown Naperville, will be open weekdays from 11:30 a.m. to 8 p.m. Hours are 11 a.m. to 8 p.m. Saturday and 11 a.m. to 6 p.m. Sunday.

Because of times dedicated to adult floats and special needs nights, check napervilleparks.org/beachhours for complete hours through August and early September.

Visit napervilleparks.org/centennialbeach for more information about Centennial Beach.