S. John Collins / Baker City Herald file photo Ash Grove is continuing efforts to control mercury emissions from its Durkee plant.
By Joshua Dillen
An official from Ash Grove Cement Co. said he is “cautiously optimistic” that the company’s Durkee plant can meet federal limits on airborne mercury emissions slated to take effect in two years.
“I’m glad we have till 2015. It appears we will (meet the EPA’s regulations),” said Curtis Lesslie, corporate vice president of environmental affairs for Ash Grove, which is based in Overland Park, Kan.
The company’s plant near Durkee, along Interstate 84 about 27 miles southeast of Baker City, had been Oregon’s largest producer of airborne mercury before Ash Grove spent $20 million to install emissions controls in 2010.
There are no current federal standards for mercury releases from cement plants.
The equipment Ash Grove installed at the Durkee plant in 2010 has reduced mercury missions by about 95 percent.
The Environmental Protection Agency (EPA) has set a deadline of Sept. 9, 2015, for all Portland cement manufacturers to meet a standard limiting emissions to 55 pounds of mercury for each million tons of clinker.
(Clinker is the material that is crushed and ground to produce cement powder. Limestone, shale and clay from a quarry near the plant are mixed with iron ore and iron containing materials and heated in a massive kiln to produce clinker.)
In 2012 the Durkee plant produced 618,000 tons of clinker and released 41 pounds of mercury compounds via its air stack, according to an EPA report and Doug Welch, a permit engineer with the Oregon Department of Environmental Quality (DEQ).
Based on the EPA regulations that take effect in 2015, if Ash Grove produced the same amount of clinker — 618,000 tons — the Durkee plant would have to reduce its mercury emissions that year to about 34 pounds — 7 pounds less than the 2012 total.
Jim Pew, staff attorney for the nonprofit environmental public interest law organization Earthjustice (formerly the Sierra Club Legal Defense Fund), said he understands the challenges Ash Grove faces with its Durkee plant.
The limestone the company quarries at the site contains higher-than-usual concentrations of mercury.
“It’s an unusual plant. It has naturally high mercury emissions,” Pew said. “It is the highest releaser of mercury compounds in the country.”
Terry Kerby, who manages the Durkee plant, said Ash Grove has invested considerable time, as well as the $20 million, to deal with keeping the highly toxic metal out of the environment.
He explained that limestone at Durkee contains up to 1,100 ppb (parts per billion) of mercury compared to other cement plants whose materials may contain only 5 ppb.
“That’s one of the things that makes it difficult -— not everyone is on equal ground,” Kerby said.
He said the EPA’s “one- size-fits-all rule” has put his plant in a unique situation.
“We have been given an impossible goal. We accepted the challenge,” Kerby said. “We have developed and created a solution and are proud we were able to do that.”
In 2011, the Durkee plant released 85.51 pounds of mercury. The highest release year in the EPA report was 2006, when 2,581.07 pounds of mercury was released. This information is available at http://iaspub.epa.gov/enviro/tris_control.tris_print?tris_id=97905SHGRV330CE.
The cement production process creates dust that is treated by the control system, which captures the mercury using activated carbon that is then shipped to a waste facility.
Ash Grove officials intend to further refine and improve the highly technical process over the next two years to meet EPA regulations.
Although Pew acknowledges Ash Grove’s progress in reducing mercury emissions, he contends the company can do better.
Pew said many other Portland cement plants are using well-established mercury reduction technology.
“The process involves removing the mercury compounds from the cement kiln dust,” Pew said.
Dust can be treated and then disposed of rather than putting it back into the system, he said.
Combining this process with the current technology Ash Grove has installed at Durkee should bring the plant into compliance with the 2015 rules, Pew said.
“They claim it is cost-prohibitive,” Pew said. “They have lower costs to control hydrogen chloride emissions, so this should offset the cost of mercury removal.”
Kerby disputed Pew’s claims.
“I don’t think Pew has been to a plant in his life,” Kerby said, “so I don’t value his opinion about how to operate a kiln.”
Lesslie responded to Pew’s reasoning that the costs involving hydrogen chloride emissions offset mercury removal costs.
“It’s a strange line of logic to me,” he said.
“I think what they have done (at the Durkee plant) is the best in the country -— as far as what I have seen before,” Welch said.
The Durkee plant is among Baker County’s larger private employers, with 110 employees and an annual payroll of $6.2 million, Kerby said.
Ash Grove also is among the county’s larger property taxpayers, with an annual bill of about $760,000.
“A lot of that money goes to local entities,” Kerby said.