At a mining facility, sulfuric acid aerosol is sprayed onto a copper ore pile to leach copper sulfate for further processing. How should the facility make threshold determinations for sulfuric acid?
Sulfuric acid is reportable only in aerosol form. Therefore, the facility manufactures sulfuric acid (acid aerosol) each time the acid passes through the spray mechanism. In this particular example, the acid converts to copper sulfate, which is subsequently reacted to generate sulfuric acid and is applied to the ore pile. Because the facility generates another listed toxic chemical (copper sulfate), the facility must count the amount of sulfuric acid (acid aerosol) manufactured each time it passes through the spray mechanism, and apply this amount to the manufacturing threshold of 25,000 pounds for sulfuric acid (acid aerosol), in addition to considering amounts of copper sulfate that are also manufactured. Because all the sulfuric acid (acid aerosol) manufactured is subsequently otherwise used, the facility must apply this same amount towards the otherwise use threshold of 10,000 pounds. Additional information is available in the Guidance for Reporting Sulfuric Acid and the Toxic Release Inventory Reporting Forms and Instructions.