PORTER, Ind. Indiana officials say a substance found floating on Lake Michigan that led to beach closures is made at a nearby plant shipped out on barges.
Indiana Department of Environmental Management spokesman Dan Goldblatt told The Times of Munster (http://bit.ly/15hJz1p ) on Tuesday that preliminary tests showed the substance is tricalcium orthophosphate, an anti-caking agent used as a food additive and in industrial applications.
Goldblatt didn't identify the Porter plant but says it ships it out of the nearby Port of Indiana. He says the U.S. Coast Guard officials believe the material in the lake originated on a boat or a barge,
Goldblatt says it's not known if the concentrations found in the water caused any health threats.
Beaches were closed Monday after people reported being covered by the substance.