Pennsylvania's air is getting a lot cleaner, as the amount of nitrogen oxide and sulfur dioxide pollution drops sharply just from 2008 to 2010. Indeed sulfur dioxide pollution from Pennsylvania sources fell by more than 50% from 2008 to 2010, while nitrogen oxide emissions dropped about 27%.
By tons, Pennsylvania sulfur dioxide emissions declined from 813,914 tons in 2008 to 413,438 tons in 2010, according to the EPA Clean Air Market website. Nox emissions dropped from 183,657 tons in 2008 to 133,351 tons in 2010.
What explains the major reductions? Is it the economic struggles of the last 3 years? No. The declines are much bigger than any reduction in electricity demand or GDP. In fact national GDP has grown every quarter since July 1, 2009. What does then?
Many coal-fired electricity generation plant owners have installed scrubbers or other pollution control equipment that is cutting sharply nox and sox emissions from those sources in the last 2 to 3 years. The substantial investments made at plants like Hatfield Ferry and Brunner Island in 2009 to reduce their emissions then puts a harsh glare on other plant owners who have yet to install pollution controls and now sue or lobby for delay in meeting important public health goals.
In addition, some coal or oil plants like Eddystone 1, Cromby 1, Hunlock have closed or switched to gas in Pennsylvania in recent years. Cromby 2 and Eddystone 2 are two more highly polluting plants that will close by May 1, 2012 and will run until then just to meet reliability needs or about 5% of the time that they ran in 2009.
Many other old-coal fired power plants outside of Pennsylvania--for example 18 TVA units; 12 AEP units; 11 Progress Energy units, and more--that emit pollution that blows into Pennsylvania have announced that they will close in the next 5 years.
The movement to gas fired generation too has played a role in cutting nitrogen oxide and sulfur dioxide emissions. As gas has increased from providing just 2% of Pennsylvania's electricity to 13%, coal's Pennsylvania market share has fallen from 57% to 48%, though that is still higher than the national 44% of electricity now coming from coal.
In the first 6 months of 2011 sulfur dioxide emissions were 160,000 tons, indicating that they will decline perhaps another 25% from 2010 levels or to about 325,000 tons annually.
Nitrogen oxide emissions were 73,000 tons in the first 6 months and that may mean no further decrease or even a 10% increase in nox emissions in 2011 compared to 2010. No final judgment is possible until data is available for the last 6 months of 2011.
Nox emissions will be the focus of much attention as a result of gas drilling and the EPA's July 28, 2011 proposed air emission rule for gas drilling. Gas must remain a powerful answer to the problem of dirty air by using the available technologies that sharply reduce emissions from the production of gas.
The data for 2008 to 2010, however, show an unmistakable, dramatic reduction in the pollution loading of our air that causes illness and premature deaths. That is important and good news.
Despite this major progress, more is needed to insure that everyday the air in Pennsylvania is healthy. Communities across Pennsylvania had Code Orange unhealthy air multiple times this summer or air that required the young, elderly, and those with repiratory conditions to stay indoors.