ALPENA - The public can have its say on a proposal by Lafarge to tweak a newly added piece of pollution control equipment.
The cement manufacturer is seeking to add a bleed stream to the dewatering portion of its wet flue gas desulfurization system on two kilns, according to an application with the Department of Environmental Quality. The desulfurization system was added as part of a consent decree between Lafarge, the United States, the state of Michigan and others, reached in 2010.
The bleed stream, which will be added to the clinker coolers, is needed in order to remove chlorides and "inert materials" from the exhaust gas before it's recirculated through the kilns, according to the application. Excessive chloride levels could make gypsum unusable for cement.
While the addition of the bleed stream will result in a new emission source of mercury, it won't increase the plant's mercury emissions, according to the permit. Rather, it will redirect mercury already being emitted from the two kilns. The bleed stream won't cause any major changes in pollutant emissions, including particulate mater.
While the written public comment period on the permit has expired, a public hearing on the proposed change is set for Thursday at 6 p.m. at the Alpena County Library. The evening will start with an informational session, with the public hearing portion beginning at 7 p.m. Questions will be answered during the informational portion, but not during the public hearing.
Once completed, the bleed water will vaporize in the clinker coolers and leaves through the clinker cooler stacks, according to the permit. About 35 percent of the bleed water will be solids, and the water will contain mercury.
What: Public informational session, public hearing on Lafarge's proposed modification to its pollution control equipment
Where: Alpena County George Fletcher Public Library
When: May 9, 6 p.m. Public hearing starts at 7 p.m.
Joelle Lipski-Rockwood, communications director, said the change is a "slight modification," and will help the factory reclaim solids to be reused in the cement making process. This means the factory won't need to dispose of them in a landfill, or make surface water discharges.
"Lafarge fully supports issuance of the Wet Scrubber PTI modification as proposed by MDEQ and the opportunities to continually improve our environmental performance at the Alpena Plant, resulting in significant reductions in overall emissions," she stated in an email. "This permit allows the Lafarge Alpena Plant to continue to run and provides for the continued preservation of the 200 jobs at the plant and allows Lafarge to remain a viable and contributing member of this community for many years to come."
The wet flue gas desulfurization system is designed to reduce sulfur dioxide emissions by about 90 percent, according to a fact sheet from Lafarge. The project will allow Lafarge to meet a plant-wide mercury emission limit set at 218 pounds per year.