A report shows that in 2012, Indiana was worst in the nation for amount of pollution dumped into waterways.
The ruling would require 28 states including Indiana to reduce their emissions that impact other states.
Indiana and 13 other states are suing the EPA over pollutions standards it set, and the Supreme Court heard oral arguments in the case yesterday.
A settlement has been signed that will cut emissions from the highly-polluting tar sands oil project in Northwest Indiana.
Indiana ranks particularly high in chromium and nickel. Energy companies say they are taking steps to decrease their emissions.
After eleven years, the lawsuit has finally come to a close.
IDEM Commissioner Tom Easterly spoke at length about a report on 25 years of progress in Indiana environmental conditions.
Indiana has been identified as one of the ten worst states for carbon dioxide pollution.
Indiana is in the top five among states for the highest levels of mercury pollution.
A national survey reveals Indiana ranks 38th when it comes to the health of its population.