WASHINGTON (From news reports) -- A Tacoma tideflats paper mill that specializes in packaging has been fined $52,500 by the state Department of Ecology (DOE) for failing to adequately treat hazardous air pollutants.

WestRock Co., which occupies the end of the peninsula between the Puyallup and Middle waterways, failed a performance test on April 17 when it insufficiently reduced hazardous air pollutants in the mill's wastewater streams, DOE said in a press release. Those levels must meet levels set in WestRock's air quality permit.

The permit requires WestRock to treat hazardous air pollutants dissolved in certain wastewater streams generated during the paper-making process. The main pollutant is methanol, DOE said.

"Treatment of these pollutants in the wastewater system prevents them from being released into the air," DOE said.

WestRock passed a subsequent performance test on May 11.

DOE said it is issuing a compliance order that will temporarily require WestRock to perform tests more frequently to determine the amount of hazardous air pollutants they are treating in their wastewater.

"Hazardous air pollutants can endanger public health," DOE said. "Sensitive groups like children, adults over 65, and people with respiratory issues are particularly vulnerable to these types of pollutants."

WestRock, an international company with over 400 locations, has 30 days to pay the fine or to appeal the penalty to the Pollution Control Hearings Board.

The company's Longview facility was fined $140,000 in November 2021 for COVID-19 safety violations. The company did not immediately return a query for comment.