CHICAGO, Oct. 12 (UPI) -- The U.S. Environmental Protection Agency is raising objections to a proposal that would allow U.S. Steel to dump more pollutants into Lake Michigan.

In a letter dated Oct. 1, the EPA formally raised objections to the Indiana Department of Environmental Management regarding the draft wastewater discharge permit the state has proposed for U.S. Steel Corp.'s Gary Works facility, the EPA said Friday.

The EPA said it objects to how discharge limits were set for several types of pollutants and the five-year compliance schedules contained in IDEM's draft permit. The objections effectively block Indiana officials from issuing the permit.

The federal agency said it would work with IDEM as it revises its draft permit.

The Chicago Tribune said the draft permit relaxes or omits limits on toxic chemicals and heavy metals the company dumps into Grand Calumet River, which flows into Lake Michigan. The Gary complex is already the largest source of water pollution in the Lake Michigan basin, the newspaper said.