1 Emission and Air Quality Trends Review Utah May 2013

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

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 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 Utah Emission Trends (VOC) Annual Emissions (Tons) Source Category Electric Utility Coal Fuel Combustion Mobile Sources72,65370,85978,59463,32560,77858,23257,24255,62554,00752,543 Industrial Fuel Combustion & Processes73,49665,09268,12895,33195,04794,76394,47894,19493,910159,276 All Others ,231 Total146,683136,500147,099159,165156,353153,532152,276150,322148,402222,281 Annual Emissions Change (Percent since 1999) Source Category Electric Utility Coal Fuel Combustion0%-1%-24%6%7%4%8%-2%-5%-49% Mobile Sources0%-2%8%-13%-16%-20%-21%-23%-26%-28% Industrial Fuel Combustion & Processes0%-11%-7%30%29% 28% 117% All Others0%29%-62% -44%-21%-17%-27%-33%12797% Total0%-7%0%9%7%5%4%2%1%52%

7 Utah Emission Trends (VOC)

8 Utah Emission Trends (NOx) Annual Emissions (Tons) Source Category Electric Utility Coal Fuel Combustion72,81571,51469,12164,66870,25369,19368,44661,80361,24249,207 Mobile Sources108,286104,748102,229112,047106,479100,91299,88997,79295,69594,975 Industrial Fuel Combustion & Processes44,36044,83024,91530,98030,89830,81630,73430,65230,57036,141 All Others1,1391,5931,0211,2901,5871,4991,4391,3531,1401,226 Total226,600222,685197,285208,985209,218202,420200,509191,601188,648181,549 Annual Emissions Change (Percent since 1999) Source Category Electric Utility Coal Fuel Combustion0%-2%-5%-11%-4%-5%-6%-15%-16%-32% Mobile Sources0%-3%-6%3%-2%-7%-8%-10%-12% Industrial Fuel Combustion & Processes0%1%-44%-30% -31% -19% All Others0%40%-10%13%39%32%26%19%0%8% Total0%-2%-13%-8% -11%-12%-15%-17%-20%

9 Utah Emission Trends (NOx)

10 Utah Emission Trends (SO 2 ) Annual Emissions (Tons) Source Category Electric Utility Coal Fuel Combustion31,27729,52434,68034,80437,41324,21321,70520,86221,85120,407 Mobile Sources6,8116,8104,3784,5193,9483,3771,9421,5991,2571,042 Industrial Fuel Combustion & Processes20,42021,74913,36612,62012,33612,05211,76811,48411,2006,144 All Others Total58,54458,12152,44851,96153,71939,67035,44433,97134,33327,628 Annual Emissions Change (Percent since 1999) Source Category Electric Utility Coal Fuel Combustion0%-6%11% 20%-23%-31%-33%-30%-35% Mobile Sources0% -36%-34%-42%-50%-71%-77%-82%-85% Industrial Fuel Combustion & Processes0%7%-35%-38%-40%-41%-42%-44%-45%-70% All Others0%5%-36%-49%-38%-24%-20%-29%-33%-3% Total0%-1%-10%-11%-8%-32%-39%-42%-41%-53%

11 Utah Emission Trends (SO 2 )

12 Utah Emission Trends (PM 2.5 ) Annual Emissions (Tons) Source Category Electric Utility Coal Fuel Combustion4,6714,3425,1294,5774,6544,7694,7334,4394,1771,610 Mobile Sources4,4944,3222,8954,0073,8213,6344,1234,1344,1444,387 Industrial Fuel Combustion & Processes20,15714,6496,0236,2256,2006,1746,1496,1246,09911,253 All Others34,96030,5817,9247,896 7,8957,8947,89323,190 Total64,28353,89521,97022,70422,57022,47322,90122,59022,31340,441 Annual Emissions Change (Percent since 1999) Source Category Electric Utility Coal Fuel Combustion0%-7%10%-2%0%2%1%-5%-11%-66% Mobile Sources0%-4%-36%-11%-15%-19%-8% -2% Industrial Fuel Combustion & Processes0%-27%-70%-69% -70% -44% All Others0%-13%-77% -34% Total0%-16%-66%-65% -64%-65% -37%

13 Utah Emission Trends (PM 2.5 )

14 Emission Trends Summary  All pollutants with the exception of VOC have decreased since 1999 in aggregate across Utah VOC increases largely due to Industrial Processes  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 Air Quality Design Values  Ozone Annual 4 th highest daily maximum 8-hour average averaged over three consecutive years Current standard = ppm  PM 2.5 Annual Annual arithmetic mean of quarterly means averaged over three consecutive years Current standard = 12 ug/m 3  PM Hour Annual 98 th percentile of daily averages averaged over three consecutive years Current standard = 35 ug/m 3

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 Data Handling Procedures  O 3 design value (DV) for each overlapping three- year period starting with and ending with 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 hour standard only

18 Data Handling Procedures  Annual PM 2.5 DV and 24-hr PM 2.5 DV for each overlapping three-year period starting with and ending with 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 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: , , …  Notes On plots, DVs are for three year period ending in year shown (i.e., 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 Max/Ave O 3 DVs and Trend

21 Ozone Trends by Site in Utah Note: Only monitoring sites meeting data completeness criteria listed Monitoring SitesCounty DV [ppm] Trend [ppm/yr] Cache, UT Salt Lake, UT Salt Lake, UT Salt Lake, UTN/A San Juan, UT Utah, UT Utah, UTN/A Utah, UT Weber, UT

22 Max/Ave PM 2.5 Annual DVs and Trend

23 Max/Ave PM Hour DVs and Trend

24 PM 2.5 Trends by Site in Utah Note: Only monitoring sites meeting data completeness criteria listed DV [ug/m 3 ] Trend [ug/m 3 per year] Monitoring SiteCountyAnnual24-HrAnnual DV24-Hr DV Box Elder Cache Salt LakeN/A Salt Lake Utah Utah UtahN/A38N/A Utah WeberN/A41N/A Weber

25 Air Quality Trends Summary  Average O 3 and PM 2.5 design values have decreased since 1999 in Utah.  There are no currently designated O 3 non- attainment areas in Utah; 24-hr PM 2.5 design values have decreased since 1999 at Logan, UT and Salt Lake City, UT non- attainment areas but have remained steady at Provo, UT non-attainment area