BAILEYVILLE – The county’s largest employer, Domtar Industries Pulp and Paper Mill, just completed a $300,000 upgrade of its wastewater treatment system, company officials said last week.

“The recently completed work on the system was conducted in several stages and became operational during the mill’s annual maintenance outage in May,” company spokesman Scott Beal said in a prepared release. “The central component of this system is a clarifier, 190-feet in diameter, used for primary treatment of wastewater.”

The mill employs more than 500 people.

The upgrade consisted of a new state-of-the-art hydraulic central drive unit, computerized controls and alarms, and a new corrosion-resistant central walkway. “These upgrades will improve system performance and reliability and further improve wastewater treatment,” he added.

During primary wastewater treatment solid material such as wood fiber, sand, gravel and other similar material are removed from wastewater before it enters the secondary treatment system where the wastewater is further treated.

The mill’s primary clarifier was commissioned in June 1970 with a ceremonial champagne “launch” conducted by then Gov. Kenneth Curtis, Beal said.

During a subsequent upgrade in 1996, specially designed baffles were installed.

Also part of the 1996 upgrade was a modified center well inlet, which improved water quality treatment efficiency by more then 20 percent. Cost of the 1996 upgrades was more than $100,000.

The mill owners initiated these most recent upgrades. “We felt that was a good project for us … and we did that. We didn’t have a gun to our head,” Beal said Monday.

This latest upgrade was under the auspices of the new mill manager, Tim Lowe. He was named general manager in March.

The last wastewater treatment mishap at the mill was in 2003 when workers stopped the flow of treated wastewater into the St. Croix River, although nearly 3,400 gallons did escape. At the time, a frozen pipeline was blamed for the spill.

Domtar is the third largest producer of uncoated free sheet in North America. It is also a leading manufacturer of business papers, commercial printing and publication papers, and technical and specialty papers.

The company manages 22 million acres of forestland in Canada and the United States and produces lumber and other wood products. The company employs more than 10,000 people across North America.