Power Plants Use Pollution Trading to Avoid Running Filtration Systems | WYPR

Power Plants Use Pollution Trading to Avoid Running Filtration Systems

Dec 6, 2016

Last month, the Maryland Department of the Environment petitioned EPA to try to get the federal agency to force coal-fired power plants in Pennsylvania, Indiana, Ohio, Kentucky and West Virginia to stop releasing so much air pollution, which drifts downwind and contributes to smog in Baltimore and elsewhere in Maryland.

The action was not unprecedented, because about 70 percent of the air pollution in Maryland comes from out of state. 

But here’s what was amazing:   Many of these power plants invested hundreds of millions of dollars to install air pollution control systems to filter out the pollutant of concern, nitrogen oxides.  And these plants, for years, successfully ran these filtration systems (which use a technology called Selective Catalytic Reduction).  But then a few years ago, they stopped. The plants just turned off the filters and let the pollutant, also called NOx, flow out freely.


  “There are 19 plants that Maryland has identified that have controls for NOx, which contributes to ozone, and they are not running them,” said Jamie Smith Hopkins, a reporter for the Center for Public Integrity, which published a story on the subject. “They are saving money as a result of this.  And Maryland wants them to actually run the controls that they have.”  

The upwind power companies – including Duke Energy, which owns the Gilbson Generating Station in southern Indiana (pictured above) – are saving hundreds of thousands or millions of dollars, because the filtration systems require the purchase of ammonia.

But by pinching pennies like this, these power companies are also dumping into the Chesapeake Bay, because nitrogen oxide air pollution is a major source of algae blooms and low oxygen “dead zones” in the bay.  And, more importantly, in addition to worsening smog, these companies could be contributing to the premature deaths of elderly people in Maryland, because nitrogen oxides and other pollutants form microscopic particles that trigger asthma and heart attacks.

“There are health impacts,” Hopkins said.  “People think of smog and they think brown.  But really the issue with ozone is that it’s bad for your lungs, and it’s particularly bad for people with lung diseases, particularly asthma, because it can trigger attacks.”

Bruce Buckheit directed EPA’s air pollution enforcement program from 1996 to 2004. He said it’s becoming increasingly common for coal plants across the country not to run their air pollution control equipment for nitrogen oxides.

 “I looked two years ago at this issue, and looked in Pennsylvania and found lots of plants in Pennsylvania that were not running their NOx controls,” Buckheit said.  “I testified before the EPA’s science advisory board about this.” 

Buckheit explained that this is happening for two reasons.  First, EPA does not flat-out require power plants to run their pollution control systems. Instead, the agency uses a pollution credit trading system in which power companies can buy allowances for their emissions. As long as a power plant is within the pollution allowance that it purchased, it doesn’t have to run the filtration systems.

Second, many coal-fired power plants across the U.S. are closing, because hydraulic fracturing has made natural gas cheaper than coal. This has reduced air pollution somewhat, which is good. But it’s also made it easier for the remaining coal plants to buy the pollution credits they need and still remain under limits that are averaged out over an entire state.

This looseness in the trading system is a problem because it means that we are missing out on a cheap and easy way to reduce pollution in our lungs and in our bay.