Elevated levels of a potentially carcinogenic chemical were found in a water sample from Lake Michigan after a nearby wastewater spill this week at a U.S. Steel plant in Indiana, the Chicago Department of Water Management said.
However, the results showed the chemical was well below federal safety standards, according to the Associated Press.
The sample showed 2 parts per billion of hexavalent chromium - a toxic heavy metal used in a variety of industrial processes, including steelmaking and corrosion prevention.
It's a higher level than what normally would be found in lake water, but just a fraction of the Environmental Protection Agency's drinking water standard of 100 parts per billion for chromium, the agency said.
"Preliminary data suggests that hexavalent chromium from the spill is not present near drinking water intakes," spokeswoman Rachel Bassler said, according to the AP.