The proposed permit for U.S. Steel Corp.'s $1 billion upgrade of ovens at its Clairton Coke Works, a project that Allegheny County Health Department officials say will bring the area into compliance with federal air quality standards for soot, is available for public review.

The coke oven installation permit, which has undergone an expedited review by the health department during the past several months, was posted on its Web site yesterday, starting a 30-day public comment period that will culminate in a public hearing in Clairton June 5.

The new coke oven battery and its state-of-the-art pollution controls will replace three older batteries at the world's largest coke-making facility. Coke is a solid carbon fuel and carbon source produced by baking coal and is used to melt and reduce iron ore in the steelmaking process. The new battery is scheduled to be operational by December 2011.

The coke oven permit proposal was released to the public as three environmental groups warned the county Board of Health not to allow changes that could weaken the county's air quality standards, including its unique coke facility emissions rules.

Michael Parker, legal director for the Group Against Smog and Pollution, said the recommendations for changes to the county Air Quality Program announced last month by county Chief Executive Dan Onorato might result in "unlawful backsliding of air quality rules."

Mr. Onorato proposed substituting state air pollution regulations for county air pollution rules, which are more detailed and extensive in areas like diesel and truck idling and coke facility emissions.

Health Department Director Dr. Bruce Dixon, speaking at the health board's regular monthly meeting yesterday, said, "We have no intention of weakening the county air rules."

Persons wishing to review the permit can access it on the health department's Web site, www.achd.net.