CHICAGO (CBS) — One day after CBS 2 revealed claims that Indiana steelmaker ArcelorMittal cheated on the results of its toxicity tests, U.S. Sens. Dick Durbin and Tammy Duckworth (D-Illinois) are asking for the federal government to take serious action against the company.

In a letter to the company, the Indiana Department of Environmental Management said ArcelorMittal has made a practice of redoing cyanide and ammonia tests that showed violations, and using the new tests to replace those results, sometimes after they already had been reported to the state.

As CBS 2 Investigator Megan Hickey reported, the tests have been required since the August chemical spill at the Burns Harbor, Indiana plant that killed 3,000 fish in the Little Calumet River, and closed beaches and a nearby drinking water intake facility.

It turns out our story caught Durbin’s attention. He spoke to Hickey late Wednesday afternoon from Washington, D.C.

“I want to make sure that they’re not doing any further damage to Lake Michigan,” Durbin said.

In a letter obtained by the CBS 2 Investigators, Durbin and Duckworth cited our report and asked the Environmental Protection Agency to strengthen the terms of ArcelorMittal’s current permit with the U.S. government. to require “stricter testing, inspection, and emissions limits”

That permit expires in June 2021.

Durbin explained why he feels like we need to bump it up to the federal level?

“Well, we ought to take a look at the order that led to the testing, and whether or not it’s sufficient. Are the enough inspections in place? If they’re going to do it again can we catch them?” Durbin said. “We want the U.S. EPA to get out of the office and into this plant and tell them we’re watching them every day to make sure this is never repeated.”

We reached out to the company for comment on the letter. On Wednesday, a representative told Hickey that ArcelorMittal stands by its statement from Tuesday that it does not manipulate their data.

Megan Hickey