1. 1 Emission and Air Quality Trends Review Iowa May 2013

2. 2 Project Objective  To develop and present publicly available information on trends in emissions and ambient air quality in the U.S. since 1999 in easy to understand visual and tabular formats

3. 3 Emission Trends  Study Team collected and processed U.S. EPA emission inventories for years within the study period of interest (1999-2011)  By pollutant and source category electric generation fuel combustion mobile sources industrial fuel combustion & industrial processes all other

4. 4 Emissions Data Summary  Data Obtained from EPA National Emission Inventory (NEI) and Trends Websites EPA’s Trends reports and emission comparisons include interpolations of all categories between key years (1999, 2002, 2005, 2008, 2011) at county-pollutant level Represented Pollutants: VOC, NOx, SO 2, and PM 2.5  Project Improvement The Study Team augmented above data with year specific CEM emissions (2002 through 2011)

5. 5 Emission Changes  The following slides also include the tonnage-based emissions change from 1999 to 2011 for each pollutant  Negative values indicate decrease in emissions, positive values indicate an increase

6. 6 Iowa Emission Trends (VOC) Annual Emissions (Tons) Source Category1999200120032005200620072008200920102011 Electric Utility Coal Fuel Combustion641667597298 303381335352568 Mobile Sources98,38592,913121,67696,11490,64585,17577,46470,99964,53458,706 Industrial Fuel Combustion & Processes141,896149,941111,693104,931104,014103,098102,181101,263100,34788,325 All Others964110268656758504928 Total241,018243,562234,069201,411195,022188,643180,084172,648165,283147,627 Annual Emissions Change (Percent since 1999) Source Category1999200120032005200620072008200920102011 Electric Utility Coal Fuel Combustion0%4%-7%-54%-53% -41%-48%-45%-11% Mobile Sources0%-6%24%-2%-8%-13%-21%-28%-34%-40% Industrial Fuel Combustion & Processes0%6%-21%-26%-27% -28%-29% -38% All Others0%-57%6%-30%-32%-31%-39%-48%-49%-71% Total0%1%-3%-16%-19%-22%-25%-28%-31%-39%

7. 7 Iowa Emission Trends (VOC)

8. 8 Iowa Emission Trends (NOx) Annual Emissions (Tons) Source Category1999200120032005200620072008200920102011 Electric Utility Coal Fuel Combustion81,73980,25987,51665,50257,51349,98346,29738,49841,88539,786 Mobile Sources190,390182,814202,184201,349192,337183,324172,072161,311150,550141,327 Industrial Fuel Combustion & Processes55,45857,81953,64057,49656,33656,15355,52954,64654,52031,868 All Others1,0249855,0946,7784,4803,7373,6303,1413,837792 Total328,612321,877348,434331,126310,666293,197277,529257,596250,792213,772 Annual Emissions Change (Percent since 1999) Source Category1999200120032005200620072008200920102011 Electric Utility Coal Fuel Combustion0%-2%7%-20%-30%-39%-43%-53%-49%-51% Mobile Sources0%-4%6% 1%-4%-10%-15%-21%-26% Industrial Fuel Combustion & Processes0%4%-3%4%2%1%0%-1%-2%-43% All Others0%-4%397%562%337%265%254%207%275%-23% Total0%-2%6%1%-5%-11%-16%-22%-24%-35%

9. 9 Iowa Emission Trends (NOx)

10. 10 Iowa Emission Trends (SO 2 ) Annual Emissions (Tons) Source Category1999200120032005200620072008200920102011 Electric Utility Coal Fuel Combustion157,255137,268156,074125,964128,454129,048109,51887,990104,61499,844 Mobile Sources12,47612,38811,54310,9039,4578,0105,9694,6533,337767 Industrial Fuel Combustion & Processes109,756114,64775,24484,77082,45181,87380,35278,36877,98129,130 All Others5,5122,7093,3983,9183,0513,6063,244 3,18623 Total284,999267,011246,260225,556223,413222,536199,083174,255189,118129,763 Annual Emissions Change (Percent since 1999) Source Category1999200120032005200620072008200920102011 Electric Utility Coal Fuel Combustion0%-13%-1%-20%-18% -30%-44%-33%-37% Mobile Sources0%-1%-7%-13%-24%-36%-52%-63%-73%-94% Industrial Fuel Combustion & Processes0%4%-31%-23%-25% -27%-29% -73% All Others0%-51%-38%-29%-45%-35%-41% -42%-100% Total0%-6%-14%-21%-22% -30%-39%-34%-54%

11. 11 Iowa Emission Trends (SO 2 )

12. 12 Iowa Emission Trends (PM 2.5 ) Annual Emissions (Tons) Source Category1999200120032005200620072008200920102011 Electric Utility Coal Fuel Combustion5,2575,1969,6107,2897,1186,8489,4248,3938,5594,474 Mobile Sources10,2819,4399,25910,0109,5199,0299,2668,7068,1477,649 Industrial Fuel Combustion & Processes17,92319,12919,81218,61318,46218,32618,18618,03917,90314,608 All Others96,39090,81456,78156,41556,40456,41056,39756,37856,38087,795 Total129,851124,57795,46292,32691,50390,61393,27391,51690,987114,527 Annual Emissions Change (Percent since 1999) Source Category1999200120032005200620072008200920102011 Electric Utility Coal Fuel Combustion0%-1%83%39%35%30%79%60%63%-15% Mobile Sources0%-8%-10%-3%-7%-12%-10%-15%-21%-26% Industrial Fuel Combustion & Processes0%7%11%4%3%2%1% 0%-18% All Others0%-6%-41% -42% -9% Total0%-4%-26%-29%-30% -28%-30% -12%

13. 13 Iowa Emission Trends (PM 2.5 )

14. 14 Emission Trends Summary  All pollutants have decreased since 1999 in aggregate across Iowa  NOx and SO2 from Electric Utility Fuel Combustion sources show decrease over time as a result of Acid Rain and NOx Budget Trading Program implementation  Onroad emission step increase seen between 2004 and 2005 is the result of EPA’s method change and MOVES model integration for estimating onroad mobile source emissions

15. 15 Air Quality Design Values  Ozone Annual 4 th highest daily maximum 8-hour average averaged over three consecutive years Current standard = 0.075 ppm  PM 2.5 Annual Annual arithmetic mean of quarterly means averaged over three consecutive years Current standard = 12 ug/m 3  PM 2.5 24-Hour Annual 98 th percentile of daily averages averaged over three consecutive years Current standard = 35 ug/m 3

16. 16 State-Wide Design Value (DV) Trends  Trends in state-wide maximum DV and average DV Max DV: Maximum DVs over all valid trend monitoring sites in the state in each overlapping three year period Average DV: Average of DVs over all valid trend monitoring sites in the state in each overlapping three year period  Compute linear trend via least-squares regression

17. 17 Data Handling Procedures  O 3 design value (DV) for each overlapping three- year period starting with 1999-2001 and ending with 2009-2011 DV calculated using annual 4 th highest daily max 8-hr averages and percent of valid observations, based on EPA data handling conventions Data associated with exceptional events that have received EPA concurrence are omitted Selection of trend sites require valid DV in 9 out of 11 three-year periods between 1999 and 2011 Identification of nonattainment areas is with respect to the 2008 8-hour standard only

18. 18 Data Handling Procedures  Annual PM 2.5 DV and 24-hr PM 2.5 DV for each overlapping three-year period starting with 1999- 2001 and ending with 2009-2011 DV calculations based on EPA data handling conventions Data extracted from monitors that have a non- regulatory monitoring type are omitted Selection of trend sites require valid DV in 9 out of 11 three-year periods between 1999 and 2011

19. 19 Trend Calculation  Trends based on linear least squares fit to rolling three year design values (DVs)  Negative trend indicates improving air quality  DVs based on each 3-year period: 1999-2001, 2000- 2002, … 2009-2011  Notes On plots, DVs are for three year period ending in year shown (i.e., 2009-2011 DV plotted as 2011 value) Ozone trend values expressed as ppb/year (1,000 ppb = 1 ppm); DVs are plotted as ppm Scale in units of ppm Trend in units of ppb/year

20. 20 Max/Ave O 3 DVs and Trend

21. 21 Ozone Trends by Site in Iowa Note: Only monitoring sites meeting data completeness criteria listed Monitoring SitesCounty 2009-2011 DV [ppm] Trend [ppm/yr] 1901700114420101Bremer, IA0.063-0.90 1904500214420101Clinton, IA0.064-1.65 1908511014420101Harrison, IA0.065-1.38 1911300284420101Linn, IA0.062-0.62 1911300334420101Linn, IA0.063-0.85 1914710024420101Palo Alto, IA0.065-0.60 1916300144420101Scott, IA0.063-1.89 1916900114420101Story, IA0.06-0.25 1918100224420101Warren, IA0.062-0.03

22. 22 Max/Ave PM 2.5 Annual DVs and Trend

23. 23 Max/Ave PM 2.5 24-Hour DVs and Trend

24. 24 PM 2.5 Trends by Site in Iowa Note: Only monitoring sites meeting data completeness criteria listed 2009-2011 DV [ug/m 3 ] Trend [ug/m 3 per year] Monitoring SiteCountyAnnual24-HrAnnual DV24-Hr DV 190130008Black Hawk10.629-0.080.07 190450021Clinton11.129-0.12-0.47 191032001Johnson10.828-0.06-0.25 191130037Linn9.930-0.13-0.38 191390015Muscatine12.8350.020.12 191532510Polk9.627-0.08-0.13 191550009Pottawattamie10.9250.05-0.13 191630015Scott11.429-0.13-0.36 191630018Scott11.529-0.08-0.20

25. 25 Air Quality Trends Summary  Average O 3 design values have decreased since 1999 in Iowa, and average PM 2.5 design values have remained relatively steady since 1999 in Iowa.  There are no currently designated O 3 or PM 2.5 non-attainment areas in Iowa