Michigan officials said the state's investigation into the old disposal of tannery waste by Wolverine Worldwide has expanded.
The state Department of Environmental Quality, or MDEQ, said it's now investigating 75 sites for toxic industrial chemicals that were used by Rockford-based Wolverine Worldwide, a maker of footwear and apparel, to waterproof shoes.
Department spokesperson Mel Brown said about 26 locations have been referred to the company for further testing.
State officials said the latest testing area includes about 100 homes in Rockford. The department said private well tests indicate that sludge may have been used as fertilizer in the area.
Brown has urged residents to drink bottled water until testing is completed. Wolverine Worldwide has distributed bottled water to residents as it conducts tests.
Governor Rick Snyder has created a task force to oversee the response to contaminants found across the state.