JAY – Wausau Paper mill officials shut down one of three boilers at the plant in November after continued soot emissions from its boiler stack. The boiler will remain down until an air heater is repaired.
Twenty-one soot emission incidents were reported in 2004, with nine of those in the third quarter and eight in the fourth quarter, said Shiloh Ring, Jay’s environmental code enforcement officer.
Although the mill reported fewer incidents in 2004 than in the previous four years, members of the Jay Planning Board requested an explanation.
The town’s Environmental Control and Improvement Ordinance sets environmental guidelines on industry in the town.
Ring said the soot emissions do not trigger specific responses under emission standards. The town regulates the incidents under a special condition in the town-issued air-emission permit to the company.
That condition states that Wausau Paper’s Otis Mill may not discharge air contaminants in a volume that soils or damages property, or has an adverse effect on public health, safety or welfare.
The mill has a history of periodically producing soot emissions from its boiler stack, according to background information on the town-issued air emission permit.
These soot emissions occur in the form of dry or wet acid-laden soot particles that rise from the Otis stack and fall out onto the Otis parking lot and residential areas downwind of the mill, according to that information.
Acid soot is formed by combining particulates – soot from combustion of fuel oil, with sulfuric acid derived from burning sulfur fuel when stack conditions allow for the condensation of the sulfuric acid before it is dispersed into the air.
These incidents occur when atmospheric and stack temperatures fall to a range conducive to the condensation of the sulfuric acid gases and their subsequent adhesion to soot particles exiting the stack.
In 2002, the town required the mill to form a Soot Abatement Audit Group that includes the mill’s environmental and safety compliance manager, engineers and production manager. The group monitors mill operations and conditions regularly.
Mill Manager Ron Holmes said Monday the mill shut down a boiler and found some leakage in an air heater after soot incidents increased in August 2004. The heater was repaired and the boiler restarted. When higher-than-normal soot incidents continued to be reported in the fourth quarter, the mill shut down another boiler and found another air heater needed repairs, he said.
That project is ongoing, Holmes said.
Since the second boiler was shut down, Holmes said, there have been no soot incidents.
The boilers produce steam to run the paper-making process, he added.
The mill is also looking at weather conditions to determine if certain conditions aggravate the issue.
There will always be some level of soot events because of the need to conduct soot blows, Holmes said, but the mill is continuing to look at the issues that cause unnecessary soot events.
The Planning Board has recommended that the mill use an oxygen analyzer to identify leaks within the system.
Roy Rike, a compliance inspector for the Maine Department of Environmental Protection, said he hasn’t received any complaints on soot problems. The state also issues an air permit and receives quarterly reports from the mill.
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