Allegheny County Health Department officials expect to issue U.S. Steel Corp. a first-phase installation permit by month's end to begin $1.2 billion in upgrades to the Clairton Coke Works.

Replacement of six older batteries with two new ones, along with extensive rebuilds of six other batteries, is expected to bring air quality in the Mon Valley close to or into compliance with federal air standards soon after the project is completed in 2014.

The Clairton Coke Works is the nation's largest coke producer at 4.7 million tons a year. But the industrial process causes serious air pollution in the county, especially less than two miles north of the plant in the Liberty area.

On May 1, the American Lung Association labeled Pittsburgh the sootiest metropolitan area in the country due in large part to soot spewing from the coke plant.

The industrial process explains why. Coke, a fuel and additive used in steelmaking, is produced by baking coal in large brick-lined ovens without oxygen to remove impurities. The process produces airborne emissions and particles when gases leak from the ovens or when hot, baked coke is pushed from the ovens and cooled with water.

In phase 1, the new Battery C will replace three old batteries and be the first in the nation to use "PROven" technology developed in Europe to draw in gases rather than let them escape. Upgrades also will include a new, low-emissions quench tower to capture pollutants released during the cooling process.

The health department said U.S. Steel's upgrades will help bring levels closer to federal compliance by lowering "PM 2.5 levels," which refer to levels of particulates smaller than 2.5 micrometers. The particulate rate is expected to drop from the current 18.9 micrograms per cubic meter in the Liberty area to the federal standard of 15 soon after the upgrades are completed.

James E. Thompson, the county's acting air program manager, told the board of health yesterday that his office is busy modifying the permit and answering 112 issues raised during public hearings.

"We're on target to approve this in July," he said.

In other action during yesterday's meeting, Cindy Thomas, executive director of Tobacco Free Allegheny, gave an update on implementing the new state smoking law throughout the county. She said the state still must resolve issues, including whether to ban smoking in company cars. The county health department board also must decide what role it hopes to play in implementing the state ban within county borders.

Ms. Thomas said the state plans to unleash a media blitz in mid-August to alert citizens to changes that will occur once the law takes effect in September.

The health department also announced plans to complete the move into the new $5 million bioterror lab in Lawrenceville by Aug. 13. The 10,000-square-foot building was completed in December but further upgrades had pushed back the occupancy date.