Six months after U.S. Steel dumped a plume of toxic metal into a Lake Michigan tributary, the company quietly reported another spill at the same northwest Indiana plant and asked state environmental regulators to keep it secret, according to newly released documents.
The 56.7 pounds of chromium released in late October by the company’s Midwest Plant was 89 percent higher than its water pollution permit allows over 24 hours, U.S. Steel revealed in a letter sent to the Indiana Department of Environmental Management.
A wastewater treatment system at the plant malfunctioned on the morning of Oct. 25, a problem that wasn’t noticed until the next day. Indiana officials were notified Oct. 27, according to the company’s letter, which is dated Oct. 31 and requested “confidential treatment” of the incident.
Law students at the University of Chicago discovered the letter while tracking pollution violations at U.S. Steel and other factories on the southwest shore of Lake Michigan. The document tops a stack of evidence gathered by attorneys at the university’s Abrams Environmental Law Clinic for a lawsuit they are preparing that will accuse the Pittsburgh-based steel giant of repeatedly violating the federal Clean Water Act since 2011.