ENVIRONMENT

WATER QUALITY
AND CONSERVATION

U. S. Steel recognizes the importance of clean water and how scarcity of water can pose a risk to our operations.

U. S. Steel is committed to continually striving to reduce, recycle and reuse process water. Our facilities use an abundance of water for both cooling and process purposes. U. S. Steel is committed to reducing our water consumption and implements conservation practices to meet the goal. Numerous processes use water-recycle systems that return water for reuse in operations, drastically reducing the amount of water brought into plants.

2020 Water Withdrawal

1.2

million Megaliters

U. S. Steel’s water conservation efforts focus on the following areas:

U. S. Steel facilities include more than 20 locations with more than 100 outfalls regulated by the National Pollutant Discharge Elimination System (NPDES) program. We regularly sample for submission to the proper regulatory agencies in accordance with permit requirements. Prior to discharging to public waterways, process water is treated using both chemical and physical processes, such as pH control, precipitation, sedimentation, filtration, and solids removal and dewatering.

Stormwater is also regulated through the NPDES program. Each facility has its own stormwater management practices that it implements along with routine inspections and sampling. Methods to manage stormwater quality are referred to as Best Management Practices (BMPs). Some stormwater specific BMPs include raw material management, street sweeping, catch basin filtration, and stormwater containment areas. In addition to BMPs, several facilities also use full-scale treatment for stormwater prior to discharge.

U. S. Steel is responsible for the operation and maintenance of more than 40 wastewater treatment plants (WWTP). These plants are tasked with treating site-specific process water, ranging from waste oil to hazardous waste, before discharging from U. S. Steel property. Some properties also maintain their own sanitary plants.

The tailings basin utilized at Minntac provides an example of water recycling, ensuring that 90-95% of effluent discharge is reclaimed to satisfy operational water demand. This equates to the reuse of 43,00 gallons per minute, or 62 million gallons per day. U. S. Steel is committed to reusing as much of its effluent as possible to reduce water process demands and potential downstream impacts. Another water conservation measure is to use treated process water as a source of cooling water for the blast furnace slag pits. U. S. Steel also uses leak-detection measures and monitoring of processes, influent water, and effluent water to assist in conservation measures. An example of this is the addition of a seep collection and return system at the western portion of the Minntac plant.

ENVIRONMENTAL AREAS OF FOCUS

U. S. Steel’s current environmental areas of focus align with the results of our ESG Materiality Assessment.