The Columbia Energy Center power plant outside Portage is in the final stages of work before flipping the switch on a revamped process which will cut nitrogen emissions in half.
The coal-fired plant is installing a selective catalytic reduction system, in one of the plant’s two immense boilers. When it is turned on — which is scheduled for late March, according to Alliant Energy spokesman Scott Reigstad — the system will strip nitrogen from the plant’s exhaust, reducing risks to residents’ respiratory health and environmental hazards that can contribute to acid rain.
“It’s a technology that has been in development for years and started in Japan, then in Germany, and 10 to 15 years in the U.S. — technology that can clean up to 90 or 95 percent of the NOx from going into the atmosphere,” said Gregory Nemet, professor of public affairs and environmental studies at the University of Wisconsin’s LaFollette School of Public Affairs. “Basically we’re talking about preventing, especially kids, but other people with respiratory illnesses from getting sick and having to go to the hospital.”
The particular ingredients being cut from the plant’s emissions, nitrogen oxide and nitrogen dioxide, are referred to together as NOx.
“The real reason they are being controlled is that they are ingredients to other pollutants that are of concern to Wisconsin,” said Tracey Holloway, a professor of civil and environmental engineering at the University of Wisconsin’s Nelson Institute for Environmental Studies. “One is ozone— colloquially known as smog, which is a summertime air pollutant, and then another is nitrate particulate matter, and in the Midwest nitrate particulate matter is a particularly big problem in the winter.”
At the Portage Emergency Planning Committee meeting on Jan. 24, Columbia County Emergency Management Director Kathy Johnson explained that the system would be coming online and with it a new routine involving semi trucks delivering ammonia, which is part of the system.
“(Alliant Energy Senior Environmental Specialist) Nate Sievers and I are in contact all the time — it was a while ago he told me that it was coming up,” Johnson said in an interview later that week. “This is not an extremely hazardous chemical, but it is ammonia with the fumes that go with it, and the quantity that it is two 40,000 tanks.”
In the event of an emergency such as a fire or a chemical spill, Johnson said that Alliant also has its own in-house fire department among its city-scale facilities, making it especially unlikely that the Portage Fire Department would be called to the scene. Nonetheless, Johnson said that she made the rounds of local first responder agencies to show local emergency response agencies an updated map of the facility and let them know that there is something different in the area.
“I would be less concerned about the ammonia than I would about the nitrogen getting in the air, and the reason is that it is well documented that NOx leads to ozone and then hospitalizations,” Nemet said. “So that is pretty direct — there are on the order of 100 of these that have been installed around the country in the past year.”
The process of installing such a system costs about a $100 million, which, when added to other environmental protection measures as the plant, come to a cost roughly equivalent to the price of the plant in the first place. The drivers behind that kind of investment are hardly a spur-of-the-moment changes.
“This is really coming from federal policy, not of late, but in 1970, when Richard Nixon passed the Clean Air Act and it has been ramped up over time with various levels of enforcement,” Nemet said.
Following a missed deadline for Wisconsin state officials to report air quality pertaining to air pollutants of 2.5 micrometers or smaller in June 2012, the Environmental Protection Agency threatened new rules if the state did not submit a plan to ensure air quality safety.
“There has been a lot of changes in the direction of energy policy in the past year since the Trump administration took over, but rolling back things like ozone standards — which is how Wisconsin got into trouble in the beginning,” Nemet said. “If Trump wanted to loosen regulations to stimulate the economy, that would be one of the hardest ones to change, because it is tied to the Clean Air Act and has been implemented over the last 40 years.”
One of the successes over that time has been the virtual elimination of acid rain, which was a notable environmental problem in the early 1990s, killing forests and waterways.
“If you look at sulphur dioxide, emissions in the U.S. have come down 30 to 50 percent, and that has been while the economy has been growing by a factor of about two over the last 20 or 30 years,” Nemet said, referring to acid rain’s key pollutant ingredient. “You don’t hear about acid rain today and that is a result of two things — one is equipment like the scrubbers that have been installed in Portage.”
That scrubbed sulphur dioxide can then be turned into gypsum and then into building materials. Conversely, acid remains a problem for some European countries, China and Japan, who inherits the eastward-blown pollution problems of China’s northeast provinces, where coal-based air pollution is at its worst.
In 2014, the Chinese government blocked the U.S. Embassy website after after an influx of Chinese citizens began using the site for accurate updates on air conditions.
“So in a sense, it is a good news story that we have cleaner air despite a demand for more energy and it is because of technology like the ones that they are putting on the Portage power plant,” Holloway said. “But the bad news is that there is no technology like that for carbon dioxide, and that’s a pollutant that people have heard about because it contributes to the warming of the planet.”