The Zen-Noh Grain Corp. export elevator in St. James Parish is seeking an air permit revision to reflect work the company has made to upgrade its dust collection systems and is asking for additional authority to increase its capacity to handle grain.

The state Department of Environmental Quality plans a public hearing 6 p.m. Thursday at the Parish Courthouse, Council Chambers, 5800 La. 44, Convent.

The elevator has been operating on River Road just upriver of the Romeville community since 1982 and primarily moves corn, milo and soybeans to ocean-going ships on the Mississippi River.

Michael Bowman, an attorney for Zen-Noh, said the company made upgrades in 2012 and 2013. Those improvements include better ship-loading equipment and enclosed conveyors systems to reduce dust emissions. The company also has converted six of its 69 existing storage silos into shipping bins, which handle grain after it has been tested and been weighed.

“It (the permit) will incorporate all of those environmental improvements that the plant has made,” Bowman said.

The company wants to do other improvements that would potentially increase the plant’s hourly capacity to unload grain onto barges.

Nucor Corp., Zen-Noh’s neighbor, has requested the public hearing and previously questioned Zen-Noh’s emissions calculations and whether the elevator should be treated as a major air emissions source.

Being treated as a major source, instead of a minor one as Zen-Noh now is, would require more intensive permitting.

Nucor and Zen-Noh were engaged in extensive litigation over Nucor’s air permit a few years ago. An attorney for Nucor did not return a message for comment Wednesday.

Zen-Noh says planned emissions of sulfur dioxide, nitrogen oxides and volatile organic compounds will decrease with the upgrades while carbon monoxide and particulate matter will increase. Particulate matter of up to 10 microns in diameter will increase by 13.3 tons per year to 76.5 tons annually.

Bryan Johnston, DEQ Air Permits Division senior environmental scientist, said 100 tons of particulate matter per year would trigger treating the elevator as a major source.