# Attachment H

Utility SO 2 

# Correlations1 Attachment H: Correlation of Local, State, and Regional SO 2 Emissions with Monitored PM 2.5 Concentrations in the Knoxville Region

This attachment presents Tennessee’s analysis of emissions and ambient monitoring data to determine if any correlation exists between utility SO 2 emissions and ambient monitored PM 2.5 concentrations. Utility, State, and Regional emissions data for 1999-2006 were obtained from Acid Rain Program monitoring data. Emission trends for TVA’s Bull Run and Kingston plants, and Statewide emissions for Tennessee, are shown in Figure 1.

Figure 1: Utility SO 2 Emission Trends

States were selected for a regional analysis based on EPA’s CAIR modeling results (all State with impact of ≥ 0.2 μg/m 3 on Knoxville PM 2.5 concentrations). Since PM 2.5 design values are based on a three-year average, average SO 2 emissions were calculated for the same time period 1

. Tabulated emissions are shown in Table 1. Ambient PM 2.5 three-year averages were based upon FRM monitor data from Knoxville -area monitors (Table 2).

1 In general, this document uses “three-year averag e” rather than “design value” to describe ambient PM 2.5 concentrations because some of the m onitors shown here did not have enough quarters of data to calculate a true design value.2 Table 1: Acid Rain Program Emissions Data, Three-Year Averages

3-Year Avg. SO 2 Emissions (tons)

3-Year Period Bull Run Kingston Bull Run + Kingston TN Total Region Total 1999-2001 40,461 98,812 139,274 409,516 5,626,491 2000-2002 42,937 88,271 131,208 374,021 5,207,694 2001-2003 45,530 86,616 132,146 345,542 5,079,362 2002-2004 39,554 81,539 121,092 326,615 5,090,458 2003-2005 36,863 74,418 111,281 302,977 5,116,526 2004-2006 31,375 62,247 93,623 276,334 4,964,058 Data Source: US EPA Clean Air Markets Data and Maps ( http://camddataandmaps.epa.gov ) Regional States are: Alabama, Georgia, Illinois, Indiana, Kentucky, North Carolina, Ohio, Tennessee, and West Virginia.

Table 2: PM 2.5 3-Year Averages for Knoxville-Area FRM Monitors

3-Year Period PM 2.5 3-Year Averages (μg/m 3 )
47-093- 0028-1 47-093- 1013-1 47-093- 1017-1* 47-093- 1020-1 47-009- 0011-1 47-145- 0004-1 47-105- 0108-1 All Monitors 1999-2001 17.9 20 17.4 16.1 16.8 17.6 2000-2002 16.4 16.9 17.9 17.1 15.6 15.3 16.5 2001-2003 15.2 16.4 16.4 15.8 14.1 14.1 15.3 2002-2004 14.5 14.9 15.7 15.1 13.9 13.6 15.5 14.7 2003-2005 14.5 13.9 15.6 15.1 14.1 14.2 15.7 14.7 2004-2006 15.2 15.6 15.2 14.1 14.5 15.3 15 * Controlling monitor.

Sulfur dioxide emissions were plotted against PM 2.5 three-year averages for Knoxville-area monitors at the facility, State, and regional level to observe wh ether any linear trends could be observed (Figures 2 – 6). Mon itoring data was plotted as the average of all Knoxville area monitors, plus the thr ee individual monitors that were above 15.0 μg/m 3 in 2006.3 Figure 2: TVA Bull Run SO 2 Chart

Figure 3: TVA Kingston SO 2 Chart4 Figure 4: TVA Bull Run Plus Kingston SO 2 Chart

Figure 5: Tennessee Statewide SO 2 Chart5 Figure 6: Regional SO 2 Chart

For each chart, linear correlation coefficients were calculated to analyze th e linearity of each data set (Table 3). In general, a linear rela tionship appears to exist between ambient PM 2.5 concentrations and SO 2 emissions, based on several metric s. Surprisingly, emissions from TVA’s Bull Run Fossil Plant did not appear to correlate well with ambient PM 2.5 concentrations. The result was unexpected because the facility is located within the nonattainment area.

Review of a line chart for Bull Run (Figure 7) suggests that the relationship at the controlling monitor is more linear if data from two years (1999 and 2000) ar e omitted from the analysis. Table 3 shows that this assumption is generally correct, although performance suffers at monitor 47-093-0028-1. Table 3: Linear Correlation Coefficients

47-093-0028-1 47-093-1017-1* 47-093-1020-1 All Monitors Bull Run 0.266 0.396 0.493 0.360 Bull Run (2001-2006 Only) 0.024 0.863 0.731 0.441 Kingston 0.707 0.828 0.800 0.773 Bull Run + Kingston 0.609 0.738 0.746 0.686 TN Total 0.838 0.922 0.912 0.891 Region Total 0.880 0.942 0.814 0.894
Correlation coefficients are calculat ed for three-year averages of SO 2 emissions and three-year average ambient PM 2.5 concentrations. * Controlling monitor.6 Figure 7: TVA Bull Run Line Chart

Figure 8: TVA Bull Run SO 2 Chart with 1999 and 2000 Omitted