Hexavalent Chromium Spill

Sydney Merrill

A chemical spill from the U.S. Steel Midwest Plant into the Burns Waterway which contained hexavalent chromium, and was caused by a failed expansion joint in the rinse water pipe.

 “The EPA has determined that the wastewater contains hexavalent chromium, a toxic byproduct of industrial processes. EPA is working with the company to contain the spill. At this time, it’s not known how much has been spilled,” said Rachel Bassler of the EPA in a news release on Tuesday evening.

The removal of the hexavalent chromium is important because hexavalent chromium compounds are genotoxic carcinogens. In genetics, genotoxicity describes the property of chemical agents that damages the genetic information within a cell causing mutations, which may lead to cancer. A carcinogen is any substance that is an agent directly involved in causing cancer.

U.S. Steel issued a statement shortly after noon on Wednesday of the latest findings from the investigation of the spill which caused the closure of area beaches and a warning to the public. The statement worked to reassure citizens that the issue was being handled, and that they should not worry.

“At the U. S. Steel Midwest Plant on Tuesday April 11, there was a release of process waste water from the Tin and Tin Free electroplating lines. The waste water is from the process used to treat the steel strip after electroplating, and the rinse water from this process is conveyed via pipe to a dedicated treatment plant.  The preliminary investigation revealed that an expansion joint in the rinse water pipe failed and resulted in the water being released to a different wastewater treatment plant and ultimately Burns Waterway through an outfall,” according to the statement.

 “Upon detection of the release, notifications were made to the IDEM, the NRC, Coast Guard, and the Porter County Sheriff; all production processes were shut down; and additional steps to mitigate the impact are being taken.  These steps include the isolation and repair of the damaged pipe, recovery of material, and the addition of a water treatment compound, sodium trithiocarbonate (CNa2S3), to the waste water treatment plant to convert and aid in the removal of hexavalent chromium.  U. S. Steel continues to work with the various governmental agencies involved to monitor and resolve the issue,” it continued.

The spill happened sometime Tuesday in the waterway withing 100 yards of Lake Michigan and led to the temporary closing of two beaches at the Indiana Dunes National Lakeshore within Portage and Ogden Dunes.

The EPA’s water testing has shown no harmful results, but the beaches will continue to be monitored.

“The National Park Service is working with the EPA and other agencies to develop a long-term monitoring protocol,” the release said. “Lake currents and waves have the ability to move this hazardous material onto park beaches at a later date. Park staff is concerned with potential impacts to both beach users’ health and long-term harm to wildlife and other park resources.”

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