The U.S. Environmental Protection Agency is proposing to give operators of cement kilns more time to comply with a 2010 clean-air regulation and also increase the limits for soot particle emissions. An industry organization welcomed the EPA plan but environmental groups criticized it.

The proposed regulatory change, which EPA Administrator Lisa Jackson signed on June 22 and the agency announced on June 25, would extend the 2010 rule's compliance date for the cement-plant standards by two years, to Sept. 9, 2015. The extension would apply to emissions of particulates—or soot—and mercury, total hydrocarbons and hydrogen chloride.

The proposal also would raise the allowable emissions levels for particulates and change the method kiln owners would have to use to measure those emissions.

The Portland Cement Association (PCA) praised EPA’s action. PCA CEO and President Brian McCarthy said the agency’s proposed revisions “are a win for the nation’s economy, the environment and cement manufacturers.”

McCarthy noted that the cement-producing industry “has been hit hard by the recession” and said the extension of the compliance deadline “is essential to each cement plant’s ability to complete any planning, engineering and construction that may be necessary to comply with the standards.”

But environmental organizations were unhappy about the proposed revisions, including the extension. Jim Pew, an attorney with Earthjustice, said, “Further delay will have horrible consequences for public health and the environment.” Environmentalists also view the new particulate levels as a major weakening of the standard.

One proposed EPA change is to alter the standard for existing cement plants to 0.07 pounds of particulate matter per ton of clinker, based on an average of the readings from three one-hour stack tests; the 2010 regulation’s standard was a 30-day average of 0.04 pounds per ton, using continuous emissions monitoring.

The agency estimates the revised rule would trim particulate emissions nationwide by 9,354 tons per year, which would be about 135 fewer tons annually than the 2010 regulation would cut—a difference of 1.4%.

EPA also estimates the new particulate limits and monitoring changes would save the industry $18.6 million in capital expenses plus $12.2 million in annual costs compared with the costs of the 2010 regulation.