PORTAGE, Ind. (AP) — Documents show that U.S. Steel failed to test a Lake Michigan tributary after an October spill of a potentially carcinogenic chemical from one of the company’s plans in northwest Indiana.

The Chicago Tribune reports the incident was the second time this year that the company’s Portage plant dumped toxic hexavalent chromium into Burns Waterway.

Details about the failed testing were in an inspection report posted online Tuesday by the Indiana Department of Environmental Management.

The records say an inspector visited the plant in November and plant managers said they’d opted not to test for the metal. Steel mills are required to regularly administer two types of tests for chromium.

Portage officials have said they’re deciding whether to join a lawsuit against the steelmaker that’s planned by an environmental law center. Chicago officials also are also drafting a lawsuit.