by Shane Henson — July 2, 2012—In response to a federal court ruling and data from industry, the U.S. Environmental Protection Agency (EPA) is proposing changes to its 2010 air standards for the Portland cement manufacturing industry.
Portland cement manufacturing is an energy-intensive process that grinds and heats a mixture of raw materials such as limestone, clay, sand and iron ore in a rotary kiln. That product, called clinker, is cooled, ground and then mixed with a small amount of gypsum to produce cement. Research has found that a variety of pollutants are emitted from the burning of fuels and heating of raw materials. Emissions also can occur from grinding, cooling and materials-handling steps in the manufacturing process.
In December 2011, the U.S. Court of Appeals for the D.C. Circuit determined that EPA’s standards were legally sound, but asked the agency to account for rules finalized after the cement standards were issued. According to the EPA, the proposed updates to certain emissions limits, monitoring requirements and compliance timelines—which are expected to result in additional cost savings for industry—are being made in response to this court remand and petitions for reconsideration of EPA’s 2010 final rule, which will dramatically cut emissions of mercury, particle pollution (PM), and other air toxics from cement production.
Based on new technical information, the EPA says it is proposing to adjust the way cement kilns continuously monitor for particle pollution and would set new particle pollution emissions limits and averaging times to account for these changes. The proposed rule would not apply to kilns that burn non-hazardous solid waste; those kilns would be covered by other standards. The proposed extended compliance date would allow industry to reassess their emission control strategies in light of the proposed changes to the PM limits and monitoring methods.
