May 2014: Want to Understand Air Quality in Your Area? Check Out IDEM’s Report

Some independent reports we have seen provide misleading information about Indiana’s air quality and omit important facts. Hoosiers need to know that air quality has improved significantly in all regions of Indiana over the past 30 years.

The report breaks Indiana into 12 regions with explanations, charts and data providing historical information about the changes we have seen. This column will discuss Central Southwest Indiana, which includes Greene, Monroe and Owen counties.

The total population for these three counties increased from 145,040 in 1980, to 192,714 in 2010. This is approximately a 33 percent increase. The vehicle miles travelled increased by 140 percent over this same period. In spite of this growth, overall air emissions have decreased from 1980 to 2010:

  • Emissions of carbon monoxide (CO) decreased by 85 percent
  • Emissions of nitrogen oxides (NOx) decreased 82 percent
  • Emissions of fine particles (PM 2.5) decreased by 58 percent
  • Emissions of larger particles (PM-10) decreased by 42 percent
  • Emissions of sulfur dioxide (SO2) decreased by 54 percent
  • Emissions of volatile organic compounds (VOC) remained constant

The following table shows the emission rates for the largest emitters in these counties.

Central Southwest Indiana Sources (tons per year)
Inventory Year County Facility Name CO NOx PM10 PM2.5 SO2 VOC Total
2012 Monroe Indiana University 72.9 87.3 5.8 5.2 184.9 3.7 359.8
2011 Monroe General Electric 3.1 3.7 0.3 0.3 0.0 52.9 60.3
2011 Greene Citizens Gas - Worthington Street 0.0 0.0 0.0 0.0 53.4 0.0 53.4
2011 Monroe Printpack Inc. 3.0 3.6 0.3 0.3 0.0 20.3 27.5
2011 Greene Worthington Generating Station 4.9 7.3 0.7 0.7 0.1 1.9 15.6
2012 Greene Countrymark 1.9 0.8 0.0 0.0 0.0 10.3 13.0
2011 Monroe Printpack Inc. 0.1 0.2 0.0 0.0 0.0 0.0 0.3

Two pollutants have been monitored in Central Southwest Indiana: ozone and PM 2.5. Ozone levels have been measured in Greene County since 2000. The design value from 2000 – 2002 was 89 parts per billion (ppb). The most recent data (2011 – 2013) shows a design value of 76 ppb. The standard for ozone is 75 ppb. Thus the area is slightly above the standard.

Levels of fine particles in the air (PM 2.5) have been measured in Monroe County since 2009. The annual design value for 2009 – 2011 was 10.8 micrograms per cubic meter (ug/m3). The most recent design value (2011 – 2013) shows a value of 9.9 ug/m3. The standard is 12.0 ug/m3, so levels are well below the standard. There is also a daily standard. The daily design value for 2009 – 2011 was 24 ug/m3. The most recent design value (2011 – 2013) is 21 ug/m3. The standard is 35 ug/m3, so levels are well below the standard.

IDEM is planning on installing a new ozone monitor that will measure ozone levels downwind of Bloomington. This monitor, which should be installed later this year, will be located in Brown County.

IDEM expects ozone levels to reduce in this area such that the current standard will be met. However, the U.S. Environmental Protection Agency (U.S. EPA) is planning to lower the ozone standard over the next year. At that point we will need to evaluate ozone levels and determine if they meet the proposed standard. If they do not, IDEM will need to develop a plan that will lower emissions and bring the area back into attainment of the standard.