IDEM also released
a timeline of events:
--On Monday, Aug.
12, DNR received a citizen complaint of a distressed fish in the East Arm of
the Little Calumet River. Both IDEM and DNR investigated and observed one
distressed fish, but found no dead fish or any other indicators of a larger
problem. On the evening of Tuesday, Aug. 13, additional complaints were
received identifying the presence of numerous dead fish. IDEM and the
Department of Natural Resources conducted reconnaissance on Wednesday, Aug.
14, and observed that a significant fish die-off had occurred. “The cause,
at that time, was unknown,” IDEM said. “In the course of investigating
potential sources, IDEM learned that ArcelorMittal violated its daily
maximum limit for ammonia-nitrogen.”
--On Thursday, Aug.
15, IDEM was notified by ArcelorMittal that the company had violated the
daily maximum limit for total cyanide. “When IDEM received this information,
agency staff immediately alerted local media, environmental organizations,
and local officials including Indiana American Water and the mayor of
Portage,” the agency said. “In addition, IDEM notified ArcelorMittal that
they were responsible for initiating a spill response to include in-stream
monitoring and increased monitoring of its outfalls to the Little Calumet
--In response to a
directive from IDEM to identify the cause of the chemical spill,
ArcelorMittal stated that its blast furnace closed water loop station
failed. On the Noncompliance Report submitted to IDEM on Thursday, Aug. 15,
ArcelorMittal stated that this failure occurred on Sunday, Aug. 11.
staff will conduct a thorough investigation into the cause of this
incident,” IDEM said. “They will also make a determination as to whether any