TransAlta Fined $331,000 for Mercury, Pollution Violations at Centralia Coal Plant

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TransAlta was slapped with six figures in fines this week after a regional regulator found its coal plant in Centralia violated mercury emissions standards and skirted guidelines designed to prevent nitrogen oxide emissions.

The $331,000 fine imposed by the Southwest Clean Air Agency is the highest the agency has issued since at least 2007.

“I’m not aware of anything higher,” said agency executive director Uri Papish.

TransAlta said in a statement that it disagrees with the penalties and will appeal the decision to the Pollution Control Hearings Board.

Much of the fines — more than $172,000 — comes from an economic benefit estimate, a penalty determined by how much the company saved by not complying. That comes from a finding that TransAlta under-injected 168,000 gallons of urea solution. Urea is used to reduce harmful nitrogen oxide emissions. At just more than $1 a gallon, TransAlta is being asked to pay back the amount they would have spent to meet the set level.

That total represents 25 percent of the 659,000 gallons the company was supposed to have used during that time.

“When you inject that urea, it reduces your NOx emissions,” Papish said.

Although the economic benefit fine is designed to prevent cutting corners — in essence, making sure the cost savings of noncompliance don’t outweigh the penalties — Papish said the fine is not necessarily an indicator of intentional rule-breaking.

“(We) believe we were operating in compliance with the terms of the agency directives,” TransAlta said in its statement.

The under-applied urea resulted in 238 tons of NOx emissions being released, the agency estimates. The total fine for the NOx violation was $210,000.

The mercury-related fine comes from three instances in which the plant exceed the emissions standard, which is set at 1.2 pounds per trillion British thermal units. During an overlapping period last summer, both of the plant’s boilers were found to exceed that limit, with Unit 2 reaching as high as 2.16 pounds per trillion. Unit 2 was out of compliance from July 21 to Sept. 13, while Unit 1 violated the limit from August 5 to Sept. 14.

Unit 2 again failed to meet the standard from Dec. 27 to Jan. 24. The agency imposed more than $121,000 in fines for the mercury violations. According to Papish, such breaches are rare.

“We have not had a lot of this type of violation with the exceedance of emission standards,” he said.

TransAlta self-reported the the mercury thresholds to the agency, as is required by its permit. According to Papish, the company switched from a monitor that provides continuous mercury readings to one that gives weekly results. The plant uses carbon injection to control mercury emissions, and Papish said it’s a complicated process.

“It was not an easy fix, and it’s complicated because there’s a lot of variables involved,” he said.

In its statement, the power company blamed the new system for the violations.

“In 2017, TransAlta Centralia began converting its mercury monitoring system to a new system designed to improve the capture of emissions. Technical difficulties during this transition period led to excess mercury emissions,” the statement reads. “... The Centralia Plant immediately began working with the system manufacturer and other mercury capture system experts to correct the equipment malfunction. We believe we are now in complete compliance.”

The company said it will not comment further while the appeal is ongoing.

The Centralia facility, the only coal-fired plant in Washington, is on the verge of shutting down under a 2011 agreement with the state. The first burner will go offline in 2020, with the second following in 2025. The company will determine by then whether it’s economically viable to switch one boiler to natural gas.