Expera looks for technical solution to complicated air quality issues
A Rhinelander business has found itself in the statewide news spotlight this month, when two environmental groups filed suit against the Wisconsin Department of Natural Resources. According to The Midwest Environmental Defense Center Inc. and Clean Wisconsin, the DNR is in violation of EPA laws, by failing to update the state’s air quality standards to reflect tighter federal regulations enacted in 2010 for sulfur dioxide and nitrogen oxide emissions.
In response, DNR Air division administrator Pat Stevens said the process involves a lot of work, and that most of the state falls within federal standards. Except, that is, for Rhinelander, home to Expera Specialty Solutions mill. Both the DNR and Expera say they have been working on the air quality issue for years, and will continue to do so until a solution is found. While the Rhinelander mill is not the focus of the lawsuit, Expera officials say they will find a solution to control the sulfur dioxide concentrations to comply with the National Ambient Air Quality Standards (NAAQS). Sulfur oxides come from fossil fuel combustion by power plants, large industries, mobile sources, and from some industrial processes.
“The issue here is pretty complicated as we have one of only a handful of SO2 (sulfur dioxide) monitors that the WDNR operates in Wisconsin, only 700 meters downwind and on a hill from our stack,” said Expera Rhinelander Mill Manager Jeff Verdoorn. “We pass all air current modeling requirements other mills are subject to, but because there is a physical monitor, and because (we believe) of local topographical issues, there are times where we get inversions that take the plume of our stack into the sampling area of the monitor.”
That monitor is located on the water tower on High Street. Verdoorn says they are working with the WDNR and the EPA on a technical solution that would involve raising the height of the stack. There are many federal, state and local criteria that need to be met in order to increase the height of the stack. So far, Expera has approval from the Federal Aviation Administration, and until April 1, 2015 to come to an agreement with the DNR and EPA on that solution.
“Air modeling to date has indicated our existing stack does not meet current EPA criteria and is substandard with respect to height,” Verdoorn emphasized. “Most likely that’s due to localized ground effects (hills and river valley based on the mill’s location). Raising the stack to EPA standards eliminates those effects and makes the model more reliable and predictable. With the model reliable, we can then chart the best method of compliance.”
Natural gas versus coal
The Rhinelander mill has retired over 100,000 tons of annual coal capacity and converted to natural gas. However, Verdoorn said natural gas pipeline constraints mean total conversion is not a viable option.
“In the near term, there is simply not enough pipeline capacity to meet the growing natural gas demand. Rhinelander is essentially at the end of the natural gas pipeline from the Rhinelander area’s source of supply. Industrial users are the first to be curtailed when demand exceeds the pipeline capacity to supply. There are a number of large coal boilers to the south of Rhinelander that are being converted to natural gas, creating the pipeline transportation shortfall,” he said. “The economic reality is we have gone as far as we can go with coal to natural gas conversion – we must maintain one coal boiler to mitigate interruptions in natural gas. In doing so, our commitment is to meet all regulatory requirements for continuing to use coal.”
According to an EPA report, the agency first set NAAQS for SO2 in 1971, establishing a primary 24-hour standard, an annual average standard and a 3-hour secondary acceptable level.
In 2010, EPA revised the primary SO2 standard by establishing a new 1-hour standard.
The report states that since 1980, levels of nitrogen and sulfur oxides in the air have fallen by more than 50 percent and more than 80 percent, respectively.
The lawsuit seeks to force the DNR to order the updates and put a hold on all pending air permits until that happens. Clean Wisconsin says the state’s lax standards have led to more health problems, including more asthma among children.