United States Steel Corp. will make $76 million worth of repairs and pay nearly $400,000 in fines to address air pollution at the largest coke plant in the United States, the Associated Press reports. U.S. Steel must take those actions at its Clairton Coke Works under a consent decree announced Friday by the Allegheny County Health Department. The deal stems from smoke and particulate pollution from the largest of the mill''s 12 coke oven batteries. It contains 75 of the plant''s 816 coke ovens. Coke, which is made by baking coal in large brick ovens for hours to remove impurities, is a fuel used in steelmaking. U.S. Steel must replace the walls in the ovens by June 30, 2010. The company could also be fined by the hour for visible pollution emissions detected by a smoke monitor, and must pay a $50,000 fine if that monitor is not working 90 percent of the time.