Flooding near the Gary Works steel mill in Gary, Indiana, on Nov. 26 has released mercury into the Grand Calumet River, the Chicago Tribune reports.
The flooding was caused by an industrial pipe break.
Mercury levels were highest between Nov. 27 and Dec. 1, reaching 710 nanogram per liter. The mercury output limit for Gary Works is 3.2 nanogram per liter. The maximum contaminant level before water becomes unsafe to drink is 2,000 nanogram per liter.
The river’s water has been tested daily following the flooding. A spokesperson from Indiana American Water said that the Gary and Odgen Dunes water treatment plants are functioning normally and have shown no signs of dangerous contamination.
The Indiana Department of Environmental Management told the Chicago Tribune that mercury levels dropped below Gary Work’s allotment on Dec. 2, but stated that testing will continue in order to ensure that mercury levels remain safe.
The Indiana Department of Environmental Management asks that the public avoid the east side of the Grand Calumet River until further notice.
Read the full story from the Chicago Tribune here.