APPENDIX D
Appendix D 

Campbell County, Kentucky SO2 Monitor 21-037-3002 

2010-2014 Exceedance Analysis 

January 20, 2014 

I. Background 

Between January 1, 2010 and August 31, 2014, 44 exceedances of the 2010 1-hour 

SO2 National Ambient Air Quality Standard (NAAQS) of 75 ppb were recorded at the 

John’s Hill Road Monitoring Site in Campbell County, Kentucky, Monitor ID 21-037-

3002. This monitor, shown in Table 1, is located in the northern part of Campbell 

County, Kentucky, south of Cincinnati, Ohio (Figure 1). 

In this report, data is analyzed to identify potential SO2 sources contributing to the 1-

hour NAAQS exceedances at Monitor 21-037-3002. Two major SO2 emission sources 

were considered for the investigation, given their proximity to the monitors and the 

predominant wind directions potentially impacting the monitor in Campbell County. The 

sources, Duke Energy’s W.C. Beckjord (Beckjord) and W. H. Zimmer (Zimmer) facilities 

in Clermont County, OH, are located east and south-east, respectfully, of Kentucky 

monitor 21-037-3002 (Figure 2). 

II. Methodology 

A back trajectory analysis was performed for the exceedances at monitor 21-037-3002 

using the National Oceanic and Atmospheric Administration’s (NOAA) Hybrid Single 

Particle Lagrangian Integrated Trajectory Model (HYSPLIT)1

. HYSPLIT is a complete 

system for modeling simple air parcel trajectories, both in forward and backward modes. 

The model calculation method is a hybrid between the Lagrangian approach, which 

uses a moving frame of reference as the air parcels move from their initial location, and 

the Eulerian approach, which uses a fixed 3-dimensional grid as a frame of reference. 

For this report HYSPLIT back-trajectories were created using NOAA’s archived North 

American Mesoscale Modeling System, 12 kilometer grid resolution meteorological 

dataset (NAM 12 kilometers). The back trajectories originated at the violating monitor 

location on each hour that corresponds to a measured exceedance of the 1-hr SO2 

NAAQS and were initialized at 500 meters above ground level with the “Model Vertical 

Velocity” model option. The main purpose of these analyses was to determine a 

probable cause of recorded exceedances by simulating the flow of 24-hour air trajectory 

patterns in the backward mode. Meteorological data used to create the HYSPLIT back 

trajectories was taken from the National Weather Service Station located at the 

Cincinnati Northern Kentucky Airport (KCVG). 

Back-trajectories alone were not used for this analysis since they may not always be 

indicative of flow patterns during very short periods of time when exceedances occur 

                                                            

1 Draxler, R.R. and Rolph, G.D., 2012. HYSPLIT (HYbrid Single‐Particle Lagrangian Integrated Trajectory) Model access via NOAA

ARL READY Website (http://ready.arl.noaa.gov/HYSPLIT.php). NOAA Air Resources Laboratory, Silver Spring, MD.
(e.g, single or few hours). In those cases, an analysis of hourly wind patterns aids in 

determining the flow of emissions from these sources for the hours around the 

exceedance. 

Table 1. Summary of the 2010 1-hour SO2 NAAQS exceedances at Monitor ID 21-037-

3002. 

Year Month Day Hour 

(EST) 

Monitored Value 

(ppb) 

2010 April 14 9:00 106

2010 April 14 13:00 142

2010 April 14 14:00 140

2010 April 14 15:00 86

2010 April 14 16:00 86

2010 July 31 14:00 82

2010 August 27 9:00 118

2010 September 14 11:00 99

2010 November 24 11:00 105

2011 February 23 9:00 137

2011 March 3 10:00 86

2011 March 3 13:00 92

2011 March 7 12:00 82

2011 March 7 13:00 76

2011 March 7 15:00 87

2011 March 8 17:00 84

2011 March 20 7:00 89

2011 April 22 3:00 109

2011 June 3 10:00 102

2011 June 3 11:00 142

2011 July 5 10:00 91

2011 July 5 11:00 180

2011 July 15 17:00 76

2011 July 15 18:00 92

2011 August 30 10:00 86

2011 August 30 11:00 76

2011 August 30 12:00 84

2011 August 30 13:00 84

2011 August 30 14:00 80

2012 January 11 12:00 76

2012 January 25 12:00 85

2012 February 3 17:00 82

2012 February 20 12:00 117

2012 February 20 13:00 156

2012 February 28 12:00 77

2012 April 7 11:00 99
Year Month Day Hour 

(EST) 

Monitored Value 

(ppb) 

2012 April 7 15:00 81

2012 May 6 18:00 93

2013 February 9 13:00 96

2013 February 9 14:00 124

2013 February 25 9:00 100

2013 February 25 10:00 125

2013 March 5 6:00 125

2014 March 6 12:00 93
Figure 1. Topographic map of the Monitor ID 21-037-3002 and nearby Airports

Cincinnati Northern Kentucky Airport

Cincinnati 

21‐037‐3002 
Figure 2. Locations of Duke Energy’s W.C. Beckjord and William H. Zimmer facilities

North
The results of the exceedance day HYPSLIT back trajectory modeling were divided into 

the following categories: 

Section III: Beckjord Trajectories - HYSPLIT trajectories passed over or near 

Beckjord (29 exceedances); 

Section IV: Zimmer Trajectories - HYSPLIT trajectories passed over or near 

Zimmer (1 exceedance); 

Section V: Intermediate Trajectories (4 exceedances); 

Section VI: Other Trajectories – HYSPLIT trajectories do not clearly indicate 

either Beckjord or Zimmer (10 exceedances). 

This report is organized in accordance with the above categories. 

For all exceedance days, a further examination of the surface meteorology was 

conducted. There are two surface meteorology stations located near the Kentucky 

Monitor 21-037-3002. To determine the best station to use for this analysis, a windrose 

of all days in which an exceedance was recorded at monitor 21-037-3002 during the 

2010 to 2014 period is shown for both Cincinnati Northern Kentucky Airport (KCVG 

Station #93814) and Cincinnati Municipal Airport (KLUK Station # 93812) in Figure 3 

and Figure 4, respectively. It is readily apparent from the windrose data in Figure 4 that 

the river valley close to Cincinnati Municipal Airport influences the local wind direction. 

Meteorological data from the Cincinnati Northern Kentucky Airport was selected based 

on the similar topography of the airport location and the monitor station location (Figure 

1). Although the weather station located at Cincinnati Municipal Airport is closer in 

proximity to the monitoring station location, the closeness of this airport to the river 

valley channels local winds in a northeast to southwest or southeast to northeast 

direction. This channeling is not expected to be present at the monitoring station 

location. 
Figure 3: Cincinnati Northern Kentucky Airport (KCVG) wind rose for all exceedance 

days, 2010 to 2014
Figure 4: Cincinnati Municipal Airport (KLUK) wind rose for all exceedance days, 2010 

to 2014 
In some instances, the hourly emissions data were also reviewed in addition to the 

meteorological and HYSPLITY back trajectories. Hourly emissions data were 

downloaded from the U.S. EPA’s Clean Air Markets Database (CAMD) and analyzed in 

comparison with the monitor exceedances. 

The annual 2010-2014 emissions, shown in 

Table 2

Table 2. Annual emissions summary for Beckjord and Zimmer, indicate that the 

Beckjord facility emitted significantly more SO2 than the Zimmer facility during the time 

period 2010-2014. It should be noted that the Zimmer facility was fitted with flue gas 

de-sulfurization controls in December of 1990, which operate continuously by permit. 

The Beckjord facility does not have similar, advanced pollution controls for SO2. 

Table 2. Annual emissions summary for Beckjord and Zimmer 

Annual SO2 Emission (tons) 

Facility 2010 2011 2012 2013 2014 

W H Zimmer Generating 

Station 19,388 18,044 11,975 18,457 9,780 

W C Beckjord Generating 

Station 69,156 90,835 67,069 51,900 32,627 

Note: Emissions for Jan. 1, 2010-Aug. 31, 2014 

The following sections of this report describe the results of the findings of the above 

described analyses. 

 
III. Beckjord Trajectories 

This section includes exceedance days in which the HYSPLIT back trajectories pass 

directly over or in close proximity to the Beckjord facility indicating a high probability of 

Beckjord contributing to the exceedances reported at the monitor. In this Section 

surface level wind data is also discussed in relation to the exceedance time and dates. 

April 14, 2010 

On April 14, 2010, five exceedances were reported at Monitor ID 21-037-3002 between 

9:00 and 16:00. The exceedance values ranged from 86 to 142 ppb. Three HYSPLIT 

back trajectories were modeled as shown in Figure 5a to represent the five 

exceedances in the table below. The surface level meteorological windrose data was 

also plotted to determine where the wind was blowing from on the exceedance date. 

Figure 5b shows the windrose data for a 24 hour period on the exceedance day (0:00 to 

23:00), Figure 5c and 5d show the windrose data around the time of the 9:00 hour and 

13:00 to 16:00 hour exceedance periods, respectively. 

All three back trajectories pass directly over or in close proximity to the Beckjord facility. 

This indicates a high probability of Beckjord contributing to the exceedances reported at 

the monitor. In addition, the windrose data at the time of the exceedances shows the 

wind was blowing predominantly from the eastern direction, where the Beckjord facility 

is located. The April 14, 2010 exceedances are attributable to the Beckjord facility. 

Trajectory 

ID 

Year Month Day Hour Monitored Value 

(ppb) 

1a 2010 4 14 9:00 106 

1a 2010 4 14 13:00 142 

1b 2010 4 14 14:00 140 

1c 2010 4 14 15:00 86 

1c 2010 4 14 16:00 86 
a)

b) c) d) 

Figure 5. a) HYSPLIT back trajectory modeling for April 14, 2010; b) 24-hour windrose data at KCVG Station 

hour windrose data from 8:00 to 10:00 at KCVG Station on April 14, 2010; d) 6-hour windrose data from 12:0

North
November 24, 2010 

On November 24, 2010, one exceedance was reported at Monitor ID 21-037-3002 at 11:00. The 

exceedance value reported was 105 ppb as shown in the table below. The exceedance was modeled 

by one HYSPLIT back trajectory in Figure 6a. The meteorological windrose data was also plotted to 

determine where the wind was blowing from on the exceedance date. Figure 6b shows the windrose 

data for a 24 hour period on the exceedance day (0:00 to 23:00), Figure 6c shows the windrose data 

around the time of the exceedance hour. 

The HYSPLIT back trajectory passes in close proximity to the Beckjord facility. This indicates a high 

probability of Beckjord contributing to the exceedances reported at the monitor. In addition, the 

windrose data at the time of the exceedances shows the wind was blowing predominantly from the 

eastern direction, where the Beckjord facility is located. The November 24, 2010 exceedances are 

attributable to the Beckjord facility. 

Trajectory 

ID Year Month Day Hour Reading 

5 2010 November 24 11:00 105 
a) 

b) c) 

Figure 6. a) HYSPLIT back trajectory modeling for April 14, 2010; b) 24-hour windrose data at KCVG Station 

3-hour windrose data from 10:00 to 12:00 at KCVG Station on November 24, 2010.

North
March 3, 2011 

On March 3, 2011, two exceedances were reported at Monitor ID 21-037-3002 at 10:00 

and 13:00. The exceedance values reported were 86 and 92, respectively. The 

exceedances were modeled by one HYSPLIT back trajectory in Figure 7a. The surface 

level meteorological windrose data was also plotted to determine where the wind was 

blowing from on the exceedance date. Figure 7b shows the windrose data for a 24 hour 

period on the exceedance day (0:00 to 23:00), Figure 7c and 7d show the windrose 

data around the time of the exceedance hours. 

The HYSPLIT back trajectory passes in close proximity to the Beckjord facility. This 

indicates a high probability of Beckjord contributing to the exceedances reported at the 

monitor. In addition, the windrose data at the time of the exceedances shows the wind 

was blowing exclusively from the eastern direction, where the Beckjord facility is 

located. The March 3, 2011 exceedances are therefore expected to be attributable to 

the Beckjord facility. 

Trajectory 

ID Year Month Day Hour Reading 

7 2011 March 3 10:00 86 

7 2011 March 3 13:00 92 
a) 

b) c) d) 

Figure 7. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

windrose data at KCVG Station on March 3, 2011; c) 3-hour windrose data from 9:00 to 11:00 at KCVG Statiohour windrose data from 12:00 to 14:00 at KCVG Station on March 3, 2011. 

North
March 7, 2011 

On March 7, 2011, three exceedances were reported at Monitor ID 21-037-3002 

between 12:00 and 15:00. The exceedance values reported ranged from 76 to 87 ppb. 

The exceedances were modeled by one HYSPLIT back trajectory in Figure 8a. The 

surface level meteorological windrose data was also plotted to determine where the 

wind was blowing from on the exceedance date. Figure 8b shows the windrose data for 

a 24 hour period on the exceedance day (0:00 to 23:00), Figure 8c and 8d show the 

windrose data around the time of the exceedance hours. 

The HYSPLIT back trajectory passes in close proximity to the Beckjord facility indicating 

a high probability of Beckjord contributing to the exceedances reported at the monitor. 

In addition, the windrose data at the time of the exceedances shows the wind was 

blowing predominately from the eastern direction, where the Beckjord facility is located. 

The March 7, 2011 exceedances are therefore predicted to be attributable to the 

Beckjord facility. 

 Trajectory ID Year Month Day Hour Reading 

8 2011 March 7 12:00 82 

8 2011 March 7 13:00 76 

8 2011 March 7 15:00 87 
a) 

b) c) d) 

Figure 8. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

windrose data at KCVG Station on March 7, 2011; c) 4-hour windrose data from 11:00 to 14:00 at KCVG Stat

3-hour windrose data from 14:00 to 16:00 at KCVG Station on March 7, 2011.

North
June 3, 2011 

On June 3, 2011, two exceedances were reported at Monitor ID 21-037-3002 between 10:00 and 

11:00. The exceedance values reported ranged from 102 to 142 ppb. The exceedances were 

modeled by one HYSPLIT back trajectory in Figure 9a. The meteorological windrose data was also 

plotted to determine where the wind was blowing from on the exceedance date. Figure 9b shows the 

windrose data for a 24 hour period on the exceedance day (0:00 to 23:00), Figure 9c shows the 

windrose data around the time of the exceedance. 

The HYSPLIT back trajectory passes in close proximity to the Beckjord facility. This indicates a high 

probability of Beckjord contributing to the exceedances reported at the monitor. In addition, the 

windrose data around the time of the exceedances shows the wind was blowing predominately from 

the eastern direction, where the Beckjord facility is located. The June 3, 2011 exceedances are 

therefore predicted to be attributable to the Beckjord facility. 

Trajectory 

ID Year Month Day Hour Reading 

11 2011 June 3 10:00 102 

11 2011 June 3 11:00 142 
a) 

b) c) 

Figure 9. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

windrose data at KCVG Station on June 3, 2011; c) 4-hour windrose data from 9:00 to 12:00 at KCVG Station 

North
July 15, 2011 

On July 15, 2011, two exceedances were reported at Monitor ID 21-037-3002 between 17:00 and 

18:00. The exceedance values reported ranged from 76 to 92 ppb. The exceedances were modeled 

by one HYSPLIT back trajectory in Figure 10a. The meteorological windrose data was also plotted to 

determine where the wind was blowing from on the exceedance date. Figure 10b shows the windrose 

data for a 24 hour period on the exceedance day (0:00 to 23:00), Figure 10c shows the windrose data 

around the time of the exceedance. 

The HYSPLIT back trajectory passes in close proximity to the Beckjord facility. This indicates a high 

probability of Beckjord contributing to the exceedances reported at the monitor. The windrose data at 

the time of the exceedances shows the wind was blowing predominately from the northeast and 

northwest direction. However, given the lack of other significant sources of SO2 located north of the 

monitor and the close proximity of the HYPSLIT back trajectory, it is likely that the emissions from 

Beckjord contributed to the exceedances. 

Trajectory 

ID Year Month Day Hour Reading 

13 2011 July 15 17:00 76 

13 2011 July 15 18:00 92 
a) 

b) c) 

Figure 10. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on windrose data at KCVG Station on June 3, 2011; c) 4-hour windrose data from 16:00 to 19:00 at KCVG Stati

North
August 30, 2011 

On August 30, 2011, five exceedances were reported at Monitor ID 21-037-3002 between 10:00 and 

14:00. The exceedance values reported ranged from 76 to 86 ppb. The exceedances were modeled 

by four HYSPLIT back trajectory in Figure 11a. The meteorological windrose data was also plotted to 

determine where the wind was blowing from on the exceedance date. Figure 11b shows the windrose 

data for a 24 hour period on the exceedance day (0:00 to 23:00), Figure 8c shows the windrose data 

around the time of the exceedance. 

The HYSPLIT back trajectories pass in close proximity to the Beckjord facility. This indicates a high 

probability of Beckjord contributing to the exceedances reported at the monitor. The windrose data 

on the day of the exceedance and at the time of the exceedances shows the wind was blowing 

predominately from the east. The August 30, 2011 exceedances are therefore predicted to be 

attributable to the Beckjord facility. 

Trajectory ID Year Month Day Hour Reading 

14a 2011 August 30 10:00 86 

14b 2011 August 30 11:00 76 

14b 2011 August 30 12:00 84 

14c 2011 August 30 13:00 84 

14d 2011 August 30 14:00 80 
a) 

b) c) 

Figure 11. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

hour windrose data at KCVG Station on August 30, 2011; c) 6-hour windrose data from 9:00 to 15:00 at KCV30,2011. 

North
February 20, 2012 

On February 20, 2012, two exceedances were reported at Monitor ID 21-037-3002 between 12:00 

and 13:00. The exceedance values reported ranged from 117 to 156 ppb. The exceedances were 

modeled by one HYSPLIT back trajectory in Figure 12a. The meteorological windrose data was also 

plotted to determine where the wind was blowing from on the exceedance date. Figure 12b shows the 

windrose data for a 24 hour period on the exceedance day (0:00 to 23:00), Figure 12c shows the 

windrose data around the time of the exceedance. 

The HYSPLIT back trajectory passes in close proximity to the Beckjord facility. This indicates a high 

probability of Beckjord contributing to the exceedances reported at the monitor. The windrose data 

on the day of the exceedance and at the time of the exceedances shows the wind was blowing 

predominately from the east/southeast. The August 30, 2011 exceedances are therefore predicted to 

be attributable to the Beckjord facility. 

Trajectory 

ID Year Month Day Hour Reading 

18 2012 February 20 12:00 117 

18 2012 February 20 13:00 156 
a) 

b) c) 

Figure 12. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

24-hour windrose data at KCVG Station on February 20, 2012; c) 4-hour windrose data from 11:00 to 14:00 

February 20, 2012.

North
April 7, 2012 

On April 7, 2012, one exceedance was reported at Monitor ID 21-037-3002 at 11:00. The exceedance 

value reported was 99 ppb. The exceedance was modeled by one HYSPLIT back trajectory in Figure 

13a. The meteorological windrose data was also plotted to determine where the wind was blowing 

from on the exceedance date. Figure 13b shows the windrose data for a 24 hour period on the 

exceedance day (0:00 to 23:00), Figure 13c shows the windrose data around the time of the 

exceedance. 

The HYSPLIT back trajectory passes in close proximity to the Beckjord facility. This indicates a high 

probability of Beckjord contributing to the exceedances reported at the monitor. The windrose data 

on the day of the exceedance and at the time of the exceedances shows the wind was blowing 

predominately from the east/southeast. Zimmer was not operating on this day; the April 7, 2012 

exceedance is therefore predicted to be attributable to the Beckjord facility. 

Trajectory 

ID Year Month Day Hour Reading 

20a 2012 April 7 11:00 99 
a) 

b) c) 

Figure 13. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

windrose data at KCVG Station on April 7, 2012; c) 3-hour windrose data from 10:00 to 12:00 at KCVG Statio

North
May 6, 2012 

On May 6, 2012, one exceedance was reported at Monitor ID 21-037-3002 at 18:00. The exceedance 

value reported ranged was 93 ppb. The exceedance was modeled by one back trajectory in Figure 

14a. The meteorological windrose data was also plotted to determine where the wind was blowing 

from on the exceedance date. Figure 14b shows the windrose data for a 24 hour period on the 

exceedance day (0:00 to 23:00), Figure 14c shows the windrose data around the time of the 

exceedance. 

The HYSPLIT back trajectories pass in close proximity to the Beckjord facility. This indicates a high 

probability of Beckjord contributing to the exceedances reported at the monitor. The windrose data 

from around time of the exceedance shows the wind was blowing from the east and southeast. Also, 

Zimmer did not operate on this day. The May 6, 2012 exceedances are therefore predicted to be 

attributable to the Beckjord facility. 

Trajectory 

ID Year Month Day Hour Reading 

21 2012 May 6 18:00 93 
a) 

b) c) 

Figure 14. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on windrose data at KCVG Station on May 6, 2012; c) 3-hour windrose data from 17:00 to 19:00 at KCVG Statio

North
February 9, 2013 

On February 9, 2013, two exceedances were reported at Monitor ID 21-037-3002 between 13:00 and 

14:00. The exceedance values reported ranged from 96 to 124 (Table 6). The exceedances were 

each modeled by an individual trajectory in Figure 15a. The meteorological windrose data was also 

plotted to determine where the wind was blowing from on the exceedance date. Figure 15b shows the 

windrose data for a 24 hour period on the exceedance day (0:00 to 23:00), Figure 15c shows the 

windrose data around the time of the exceedance. 

The HYSPLIT back trajectories pass in close proximity to the Beckjord facility. This indicates a high 

probability of Beckjord contributing to the exceedances reported at the monitor. The surface 

windrose data from around time of the exceedance shows the wind was blowing from the east and 

southeast. Zimmer did not operate on this day; the February 9, 2013 exceedances are therefore 

predicted to be attributable to the Beckjord facility. 

Trajectory 

ID Year Month Day Hour Reading 

22a 2013 February 9 13:00 96 

22b 2013 February 9 14:00 124 
a) 

b) c) 

Figure 15. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on hour windrose data at KCVG Station on February 9, 2013; c) 2-hour windrose data from 13:00 to 14:00 at KC

9, 2013.

North
February 25, 2013 

On February 25, 2013, two exceedances were reported at Monitor ID 21-037-3002 at 9:00 and 10:00. 

The exceedance values reported ranged from 100 to 125 ppb. The exceedances were each modeled 

by an individual trajectory in Figure 16a. The meteorological windrose data was also plotted to 

determine where the wind was blowing from on the exceedance date. Figure 16b shows the windrose 

data for a 24 hour period on the exceedance day (0:00 to 23:00), Figure 16c shows the windrose data 

around the time of the exceedance. 

The HYSPLIT back trajectories pass directly over and in close proximity to the Beckjord facility. This 

indicates a high probability of Beckjord contributing to the exceedances reported at the monitor. The 

surface windrose data from around time of the exceedance shows the wind was blowing from the 

east/southeast. Zimmer did not operate on this day, therefore, the February 25, 2013 exceedances 

are predicted to be attributable to the Beckjord facility. 

Trajectory 

ID Year Month Day Hour Reading 

23a 2013 February 25 9:00 100 

23b 2013 February 25 10:00 125 
a) 

b) c) 

Figure 16. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

24-hour windrose data at KCVG Station on February 25, 2013; c) 4-hour windrose data from 8:00 to 11:00 at February 25, 2013.

North
March 5, 2013 

On March 5, 2013, one exceedance was reported at Monitor ID 21-037-3002 at 6:00. The 

exceedance value reported was 125 ppb. The exceedance was modeled by an individual trajectory in 

Figure 17a. The meteorological windrose data was also plotted to determine where the wind was 

blowing from on the exceedance date. Figure 17b shows the windrose data for a 24 hour period on 

the exceedance day (0:00 to 23:00), Figure 17c shows the windrose data around the time of the 

exceedance. 

The HYSPLIT back trajectories pass in close proximity to the Beckjord facility. This indicates a high 

probability of Beckjord contributing to the exceedances reported at the monitor. The surface 

windrose data on the exceedance day and around time of the exceedance show the wind was 

blowing predominately from the east. The March 5, 2013 exceedance is therefore predicted to be 

attributable to the Beckjord facility. 

Trajectory 

ID Year Month Day Hour Reading 

24 2013 March 5 6:00 125 
a) 

b)

Figure 17. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

hour windrose data at KCVG Station on March 5, 2014; c) 2-hour windrose data from 5:00 to 7:00 at KCVG S

North
IV. Zimmer Trajectories 

This Section includes exceedance days in which the HYSPLIT back trajectories pass directly over or 

in close proximity to the Zimmer facility indicating a high probability of Zimmer contributing to the 

exceedances reported at the monitor. Also in this Section, data including surface wind data and 

CEMS data were analyzed to draw conclusions about the likely contribution of Zimmer emissions in 

relation to the exceedance at the monitor. 

February 3, 2012 

On February 3, 2012, one exceedance was reported at Monitor ID 21-037-3002 at 17:00. The 

exceedance value reported was 82 ppb. The exceedance was modeled by one HYSPLIT back 

trajectory in Figure 18a. The meteorological windrose data was also plotted to determine where the 

wind was blowing from on the exceedance date. Figure 18b shows the windrose data for a 24 hour 

period on the exceedance day (0:00 to 23:00), Figure 18c shows the windrose data around the time 

of the exceedance hour. Figure 18d shows the CEMS data for both the Beckjord and Zimmer 

facilities in relation to the recorded monitored values on an hourly basis for the exceedance day. The 

HYSPLIT back trajectory passes in close proximity to the Zimmer facility. This indicates a high 

probability of Zimmer contributing to the exceedances reported at the monitor. The windrose data at 

the time of the exceedances shows the wind was blowing predominantly from the northeastern 

direction with a slight contribution form the southeastern direction between 16:00 and 18:00. 

Examining the windrose data for the entire day shows surface winds blowing predominately from the 

east/ southeast direction. Based on the results of the HYSPLIT data it would appear Zimmer was the 

most likely contributor. However, based on the windrose data it would appear Beckjord was more 

likely the contributor to the exceedance on February 3, 2012. It should be noted emissions from 

Beckjord were over five times the emissions of Zimmer prior to and during the exceedance period. 

Trajectory 

ID Year Month Day Hour Reading 

17 2012 February 3 17:00 82 
a) 

North
b) c) 

d) 

Figure 18. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on hour windrose data at KCVG Station on February 3, 2012; c) 3-hour windrose data from 16:00 to 18:00 at KC

3, 2012.

0

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February 3, 2012 CEMS Data (Beckjord) CEMS Data (Zimmer)

Monitor Value (ppb)
V. Intermediate Trajectories 

This Section includes exceedance days in which the HYSPLIT back trajectories pass between the 

Beckjord and Zimmer facilities and are not directly attributable to either facility. Additional data 

including surface wind data and CEMS were analyzed to draw conclusions about the likely 

contributions of Beckjord and Zimmer emissions in relation to the exceedance at the monitor. 

March 8, 2011 - Beckjord 

On March 8, 2011, one exceedance was reported at Monitor ID 21-037-3002 at 17:00. The 

exceedance value reported was 84 ppb. The exceedance was modeled by one HYSPLIT back 

trajectory in Figure 19a. The meteorological windrose data was also plotted to determine where the 

wind was blowing from on the exceedance date. Figure 19b shows the windrose data for a 24 hour 

period on the exceedance day (0:00 to 23:00), Figure 19c shows the windrose data around the time 

of the exceedance hour. Figure 19d shows the CEMS data for both the Beckjord and Zimmer 

facilities in relation to the recorded monitored values on an hourly basis for the exceedance day. The 

HYSPLIT back trajectory passes in between the Beckjord facility and the Zimmer facility. Examination 

of the wind rose around the time of the exceedance demonstrates that the prevailing surface winds 

were from the East. The surface wind direction data would suggest that emissions from Beckjord 

were most likely impacting the monitor and contributing to the exceedance. In addition, emissions 

data shown in Figure 6e, demonstrate that on this date emissions from the Beckjord facility were 

approximately four times greater than those of Zimmer. Based on the analysis of the data for March 

8, 2011 Beckjord has a high probability of contributing to the exceedance at the monitor. 

Trajectory 

ID Year Month Day Hour Reading 

9 2011 March 8 17:00 84 

a) 

North
b) c)

d) 

Figure 19. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

hour windrose data at KCVG Station on March 8, 2011; c) 3-hour windrose data from 16:00 to 18:00 at KCVG 

2011; d) CEMS data for both the Beckjord and Zimmer facilities in relation to the recorded monitored values o

exceedance day.

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March 8, 2011

CEMS Data (Beckjord)CEMS Data (Zimmer)Monitor Value (ppb)
March 20, 2011 - Beckjord 

On March 20, 2011, one exceedance was reported at Monitor ID 21-037-3002 at 7:00. The 

exceedance value reported was 89 ppb. The exceedance was modeled by one HYSPLIT back 

trajectory in Figure 20. The meteorological windrose data was also plotted to determine where the 

wind was blowing from on the exceedance date. Figure 20b shows the windrose data for a 24 hour 

period on the exceedance day (0:00 to 23:00), Figure 20c shows the windrose data around the time 

of the exceedance hour. Figure 20d shows the CEMS data for both the Beckjord and Zimmer 

facilities in relation to the recorded monitored values on an hourly basis for the exceedance day. The 

HYSPLIT back trajectory passes in between the Beckjord facility and the Zimmer facility. 

Examination of the wind rose around the time of the exceedance demonstrates that the prevailing 

surface winds were from the East. The surface wind direction data would suggest that emissions 

from Beckjord were most likely impacting the monitor and contributing to the exceedance. It should 

be noted that the winds did not begin blowing from the south and southeast until approximately 13:00, 

well after the exceedance was recorded. Additionally, prior to the exceedance emissions from 

Beckjord increased markedly in a relatively short period of time, while emissions from Zimmer 

remained relatively constant. Taking these further data into account, it is highly probable that 

emissions from Beckjord are the likely contributor to the exceedance recorded on March 20, 2011. 

Trajectory 

ID Year Month Day Hour Reading 

10 2011 March 20 7:00 89 

a) 

North
b) c) 

d) 

Figure 20. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on hour windrose data at KCVG Station on March 20, 2011; c) 3-hour windrose data from 6:00 to 8:00 at KCVG 

2011; d) CEMS data for both the Beckjord and Zimmer facilities in relation to the recorded monitored values o

exceedance day.

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March 20, 2011 CEMS Data (Beckjord) CEMS Data (Zimmer)

Monitor Value (ppb)
February 28, 2012 - Beckjord 

On February 28, 2012, one exceedance was reported at Monitor ID 21-037-3002 at 12:00. The 

exceedance value reported was 77 ppb. The exceedance was modeled by one HYSPLIT back 

trajectory in Figure 21a. The trajectory analysis on this date is atypical, as the upper level winds take 

a circuitous route around both Beckjord and Zimmer prior to reaching the monitor location. This 

impedes a straightforward determination of the cause of the exceedance based on the HYSPLIT 

data. The meteorological windrose data was also plotted to determine where the wind was blowing 

from on the exceedance date. Figure 21b shows the windrose data for a 24 hour period on the 

exceedance day (0:00 to 23:00), Figure 21c shows the windrose data around the time of the 

exceedance hour. Figure 21d shows the CEMS data for both the Beckjord and Zimmer facilities in 

relation to the recorded monitored values on an hourly basis for the exceedance day. The surface 

wind data around the time of the violation shows predominant winds from the eastern direction. 

Further examination of the emissions data shows only that emissions data from Beckjord were 

approximately five times greater than that of Zimmer. Taking these further data into account, it is 

highly probable that emissions from Beckjord are the likely contributor to the exceedance on February 

28, 2012. 

Trajectory 

ID Year Month Day Hour Reading 

19 2012 February 28 12:00 77 

a) 

North
b) c) 

d) 

Figure 21. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

24-hour windrose data at KCVG Station on February 28, 2012; c) 3-hour windrose data from 11:00 to 13:00 a

February 28, 2012; d) CEMS data for both the Beckjord and Zimmer facilities in relation to the recorded monibasis for the exceedance day. 

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February 28, 2012 CEMS Data (Beckjord) CEMS Data (Zimmer)

Monitor Value (ppb)
April 7, 2012 – Beckjord 

On April 7, 2012, two exceedances were reported at Monitor ID 21-037-3002. Beckjord was 

determined to be the most probably contributor the exceedance at the 11:00 hour as discussed in 

Section I of this report. The exceedance of 81 ppb at 15:00 is discussed below. The exceedance was 

modeled by one HYSPLIT back trajectory in Figure 22a. The meteorological windrose data was also 

plotted to determine where the wind was blowing from on the exceedance date. Figure 22b shows the 

windrose data for a 24 hour period on the exceedance day (0:00 to 23:00), Figure 22c shows the 

windrose data around the time of the exceedance hour. Figure 22d shows the CEMS data for both 

the Beckjord and Zimmer facilities in relation to the recorded monitored values on an hourly basis for 

the exceedance day. 

The HYSPLIT back trajectory passes in close proximity to the Zimmer facility. This indicates a high 

probability of Zimmer contributing to the exceedance reported at the monitor. The windrose data at 

the time of the exceedances winds were blowing from the east/southeast direction between 14:00 

and 16:00. This would indicate Beckjord and Zimmer may have contributed to the exceedance; 

however, as shown in Figure 22d Zimmer did not have SO2 emissions on this day. Therefore, it is 

most likely that the exceedance was caused by the Beckjord facility. 

Trajectory 

ID Year Month Day Hour Reading 

20c 2012 April 7 15:00 81 

a) 

North
b) c)

d) Figure 22. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on windrose data at KCVG Station on April 7, 2012; c) 3-hour windrose data from 14:00 to 16:00 at KCVG Statio

CEMS data for both the Beckjord and Zimmer facilities in relation to the recorded monitored values on an houexceedance day.

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April 7, 2012

CEMS Data (Beckjord)CEMS Data (Zimmer)Monitor Value (ppb)
VI. Other Trajectories 

This Section includes exceedance days in which the HYSPLIT back trajectories do not pass near 

proximity to Beckjord or Zimmer. For these exceedance days, the analysis relied heavily upon the 

surface wind data and CEMS data to determine the likely contribution of Beckjord and Zimmer 

emissions in relation to the exceedance at the monitor. 

July 31, 2010 - Beckjord 

On July 31, 2010, one exceedance was reported at Monitor ID 21-037-3002 at 14:00. The reported 

exceedance value was 82 ppb. One HYSPLIT back trajectories was modeled as shown in Figure 23a 

to represent the exceedance in the table below. The meteorological windrose data was also plotted to 

determine where the wind was blowing from on the exceedance date. Figure 23b shows the windrose 

data for a 24 hour period on the exceedance day (0:00 to 23:00), Figure 23c shows the windrose data 

around the time of the 14:00 hour exceedance. 

The HYSPLIT back trajectories pass north the Beckjord facility. The windrose data at the time of the 

exceedances shows the wind was blowing exclusively from the direction where the Beckjord facility is 

located. The SO2 emissions at the Beckjord facility markedly increased in the hours priors to the 

exceedance. Based on the combined interpretation of the data presented for this exceedance day, 

Beckjord is the most likely contributor to the exceedances reported at the monitor. 

Trajectory 

ID Year Month Day Hour Reading 

2 2010 7 31 14:00 82 

a) 

North
b) c)

d) 

Figure 23. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on windrose data at KCVG Station on July 31, 2010; c) 3-hour windrose data from 13:00 to 15:00 at KCVG StatiCEMS data for both the Beckjord and Zimmer facilities in relation to the recorded monitored values on an houexceedance day.

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July 31, 2010

CEMS Data (Beckjord)CEMS Data (Zimmer)Monitor Value (ppb)
August 27, 2010 - Beckjord 

On August 27, 2010, one exceedance was reported at Monitor ID 21-037-3002 at 9:00. The 

exceedance value reported was 118 ppb. The exceedance was modeled by one HYSPLIT back 

trajectory in Figure 24a. The meteorological windrose data was also plotted to determine where the 

wind was blowing from on the exceedance date. Figure 24b shows the windrose data for a 24 hour 

period on the exceedance day (0:00 to 23:00), Figure 24c shows the windrose data around the time 

of the exceedance hour. Figure 24d shows the CEMS data for both the Beckjord and Zimmer 

facilities in relation to the recorded monitored values on an hourly basis for the exceedance day. 

The HYSPLIT back trajectory is shown north of the Beckjord facility. The windrose data at the time of 

the exceedances shows the wind was blowing from the east/northeast. The SO2 emissions at the 

Beckjord facility markedly increased in the hours priors to the exceedance. Based on the data 

presented for this exceedance day, Beckjord is the most likely contributor to the exceedances 

reported at the monitor. 

Trajectory 

ID Year Month Day Hour Reading 

3 2010 August 27 9:00 118 

a) 

North
b) c)

Figure 24. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

hour windrose data at KCVG Station on August 27, 2010; c) 3-hour windrose data from 8:00 to 10:00 at KCV

2010; d) CEMS data for both the Beckjord and Zimmer facilities in relation to the recorded monitored values oexceedance day.

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August 27, 2010

CEMS Data (Beckjord)CEMS Data (Zimmer)Monitor Value (ppb)
September 14, 2010 – Beckjord 

On September 14, 2010, one exceedance was reported at Monitor ID 21-037-3002 at 11:00. The 

exceedance value reported was 118 ppb. The exceedance was modeled by one HYSPLIT back 

trajectory in Figure 25a. The meteorological windrose data was also plotted to determine where the 

wind was blowing from on the exceedance date. Figure 25b shows the windrose data for a 24 hour 

period on the exceedance day (0:00 to 23:00), Figure 25c shows the windrose data around the time 

of the exceedance hour. Figure 25d shows the CEMS data for both the Beckjord and Zimmer 

facilities in relation to the recorded monitored values on an hourly basis for the exceedance day. 

The HYSPLIT trajectory does not pass over or in close proximity to Beckjord or Zimmer. Examination 

of the wind direction data reveals that surface level winds on this date were primarily from the east 

which suggests that emissions from Beckjord are the likely cause of the exceedance on this date. 

Furthermore, examination of the emissions data shown in Figure 25d shows that emissions from 

Beckjord markedly increased in the hours leading up to the exceedance. Based on the data, and the 

lack of other significant sources of SO2 along the trajectory shown, Beckjord was determined to be 

the most likely contributor to the exceedance. 

a) 

Trajectory 

ID Year Month Day Hour Reading 

4 2010 September 14 11:00 99 

North
b) c)

d) 

Figure 25. a) HYSPLIT back trajectory from Monitor ID 21-037-3002 on September 14, 2010 at 11:00 ; c) 24-KCVG Station on September 14, 2010; d) 3-hour windrose data from 8:00 to 11:00 at KCVG Station on Septdata for both the Beckjord and Zimmer facilities in relation to the recorded monitored values on an hourly bas

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September 14, 2010 CEMS Data (Beckjord) CEMS Data (Zimmer)

Monitor Value (ppb)
February 23, 2011 - Beckjord 

On February 23, 2011, one exceedance was reported at Monitor ID 21-037-3002 at 9:00. The 

exceedance value reported was 137 ppb. The exceedance was modeled by one HYSPLIT back 

trajectory in Figure 26a. The meteorological windrose data was also plotted to determine where the 

wind was blowing from on the exceedance date. Figure 26b shows the windrose data for a 24 hour 

period on the exceedance day (0:00 to 23:00), Figure 26c shows the windrose data around the time 

of the exceedance hour. Figure 26d shows the CEMS data for both the Beckjord and Zimmer 

facilities in relation to the recorded monitored values on an hourly basis for the exceedance day. 

The HYSPLIT trajectory does not pass over or in close proximity to Beckjord or Zimmer. Emissions 

from both facilities were relatively stable throughout the day and recorded values remained low at the 

monitor with the exception of the sharp spike observed at the exceedance hour. Examination of the 

wind direction data reveals that surface level winds on this date were predominantly from the 

southeast direction where Zimmer is located. Winds data around the time of the exceedance reveals 

that surface level winds during this period were predominantly from the eastern direction where 

Beckjord is located. Based on the data, Beckjord was determined to be the most likely contributor to 

the exceedance. 

Trajectory 

ID Year Month Day Hour Reading 

6 2011 February 23 9:00 137 

a) 

North
b) c)

d)

Figure 26. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

24-hour windrose data at KCVG Station on February 23, 2011; c) 3-hour windrose data from 8:00 to 11:00 at 

February 23, 2011; d) CEMS data for both the Beckjord and Zimmer facilities in relation to the recorded monibasis for the exceedance day. 

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February 23, 2011

CEMS Data (Beckjord)CEMS Data (Zimmer)Monitor Value (ppb)
April 22, 2011 – Beckjord 

On April 22, 2011, one exceedance was reported at Monitor ID 21-037-3002 at 3:00. The exceedance 

value reported was 109 ppb. The exceedance was modeled by one HYSPLIT back trajectory in 

Figure 27a. The meteorological windrose data was also plotted to determine where the wind was 

blowing from on the exceedance date. Figure 27b shows the windrose data for a 24 hour period on 

the exceedance day (0:00 to 23:00), Figure 27c shows the windrose data around the time of the 

exceedance hour. Figure 27d shows the CEMS data for both the Beckjord and Zimmer facilities in 

relation to the recorded monitored values on an hourly basis for the exceedance day. 

The HYSPLIT trajectory does not pass over or in close proximity to Beckjord or Zimmer. Examination 

of the surface wind direction data reveals that surface level winds on this date were predominantly 

from the east. Winds data around the time of the exceedance shows that surface level winds during 

this period were also predominantly from the east where Beckjord is located. Based on the data, 

Beckjord was determined to be the most likely contributor to the exceedance. 

Trajectory ID Year Month Day Hour Reading 

35 2011 April 22 3:00 109 

a) 

35

North
b) c)

d) 

Figure 27. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

hour windrose data at KCVG Station on April 22, 2011; c) 3-hour windrose data from 2:00 to 4:00 at KCVG SCEMS data for both the Beckjord and Zimmer facilities in relation to the recorded monitored values on an houexceedance day. 

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April 22, 2011

CEMS Data (Beckjord)CEMS Data (Zimmer)Monitor Value (ppb)
July 5, 2011 - Beckjord 

On July 5, 2011, two exceedances were reported at Monitor ID 21-037-3002 between 10:00 and 

11:00. The exceedance values reported were 91 and 180, respectively. The exceedances were 

modeled by one HYSPLIT back trajectory in Figure 28a. The meteorological windrose data was also 

plotted to determine where the wind was blowing from on the exceedance date. Figure 28b shows the 

windrose data for a 24 hour period on the exceedance day (0:00 to 23:00), Figure 28c shows the 

windrose data around the time of the exceedance hours. Figure 28d shows the CEMS data for both 

the Beckjord and Zimmer facilities in relation to the recorded monitored values on an hourly basis for 

the exceedance day. 

The HYSPLIT trajectory does not pass over or in close proximity to Beckjord or Zimmer. Examination 

of the surface wind direction data reveals that surface level winds on this date were predominantly 

northwest. Wind data around the time of the exceedance shows that surface level winds during this 

period were from the northeast/east/southeast indicating that Beckjord or Zimmer may have 

contributed to the exceedance. The CEMS data shows the Beckjord emissions markedly increased in 

the hours prior to the exceedance and the emissions at Zimmer were zero at the time of the 

exceedance and for several hours prior. Based on this information, Beckjord was determined to be 

the most likely contributor to the exceedance. 

Trajectory 

ID Year Month Day Hour Reading 

12 2011 July 5 10:00 91 

12 2011 July 5 11:00 180 

a) 

North
b) c) 

d) 

Figure 28. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on windrose data at KCVG Station on July 5, 2011; c) 3-hour windrose data from 9:00 to 12:00 at KCVG Station data for both the Beckjord and Zimmer facilities in relation to the recorded monitored values on an hourly bas

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July 5, 2011

CEMS Data (Beckjord)CEMS Data (Zimmer)Monitor Value (ppb)
January 11, 2012 - Beckjord 

On January 11, 2012, one exceedance was reported at Monitor ID 21-037-3002 between at 12:00. 

The exceedance value reported was 76 ppb. The exceedance was modeled by one HYSPLIT back 

trajectory in Figure 29a. The meteorological windrose data was also plotted to determine where the 

wind was blowing from on the exceedance date. Figure 29b shows the windrose data for a 24 hour 

period on the exceedance day (0:00 to 23:00), Figure 29c shows the windrose data around the time 

of the exceedance hour. Figure 29d shows the CEMS data for both the Beckjord and Zimmer 

facilities in relation to the recorded monitored values on an hourly basis for the exceedance day. 

The HYSPLIT trajectory does not pass over or in close proximity to Beckjord or Zimmer. The CEMS 

data shows a slight increase in SO2 emissions in the hours prior to the exceedance; the Zimmer SO2 

emissions remained steadily elevated throughout the day until dropping off at 15:00. Examination of 

the surface wind direction data reveals that surface level winds on this date were predominantly from 

the east. Surface level wind data around the time of the exceedance shows that surface level winds 

during this period were exclusively from the east indicating a high probability that Beckjord 

contributed to the exceedance. Based on this information, Beckjord was determined to be the most 

likely contributor to the exceedance. 

Trajectory ID Year Month Day Hour Reading 

15 2012 January 11 12:00 76 

a) 

North
b) c) 

d) 

Figure 29. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on hour windrose data at KCVG Station on January 11, 2012; c) 3-hour windrose data from 11:00 to 13:00 at KC11,2012; d) CEMS data for both the Beckjord and Zimmer facilities in relation to the recorded monitored value

the exceedance day. 

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January 11, 2012

CEMS Data (Beckjord)CEMS Data (Zimmer)Monitor Value (ppb)
January 25, 2012 – Beckjord/Combined 

On January 25, 2012, one exceedance was reported at Monitor ID 21-037-3002 at 12:00. The 

exceedance value reported was 85 ppb. The exceedance was modeled by one HYSPLIT back 

trajectory in Figure 30a. The meteorological windrose data was also plotted to determine where the 

wind was blowing from on the exceedance date. Figure 30b shows the windrose data for a 24 hour 

period on the exceedance day (0:00 to 23:00), Figure 30c shows the windrose data around the time 

of the exceedance hour. Figure 30d shows the CEMS data for both the Beckjord and Zimmer 

facilities in relation to the recorded monitored values on an hourly basis for the exceedance day. 

The HYSPLIT trajectory does not pass over or in close proximity to Beckjord or Zimmer. The CEMS 

data shows both facilities emissions remained relatively constant throughout the day. Examination of 

the surface wind direction data around the time of the exceedance shows winds were blowing from 

the northeast/east/southeast direction. It should be noted that Beckjord’s emissions were over four 

times that of Zimmer during the day. This would indicate that Beckjord was the main contributor to 

the exceedance although wind data may indicate Zimmer had a contribution. 

Trajectory 

ID Year Month Day Hour Reading 

16 2012 January 25 12:00 85 

a) 

North
b) c) 

d) 

Figure 30. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on hour windrose data at KCVG Station on January 25, 2012; c) 3-hour windrose data from 11:00 to 13:00 at KC25,2012; d) CEMS data for both the Beckjord and Zimmer facilities in relation to the recorded monitored value

the exceedance day.

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January 25, 2012

CEMS Data (Beckjord)CEMS Data (Zimmer)Monitor Value (ppb)
March 6, 2014 – neither 

On March 6, 2013, one exceedance was reported at Monitor ID 21-037-3002 at 12:00. The 

exceedance value reported was 93 ppb. The exceedance was modeled by an individual trajectory in 

Figure 31a. The meteorological windrose data was also plotted to determine where the wind was 

blowing from on the exceedance date. Figure 31b shows the windrose data for a 24 hour period on 

the exceedance day (0:00 to 23:00), Figure 31c shows the windrose data around the time of the 

exceedance. 

The HYSPLIT back trajectories pass north of the Beckjord facility. The surface windrose data on the 

exceedance day and around time of the exceedance show the wind was blowing predominately from 

the northeast. The March 6, 2014 exceedance is therefore not attributable to Beckjord or Zimmer. 

Ohio EPA is not aware of other major sources of SO2 emissions in the area encompassed by the 

trajectory. 

Trajectory 

ID Year Month Day Hour Reading 

25 2014 March 6 12:00 93 

a)

North
b) c) 

Figure 31. a) Beckjord and Zimmer CEMS data and monitored values at Kentucky Monitor ID 21-037-3002 on 

hour windrose data at KCVG Station on March 6, 2014; c) 2-hour windrose data from 11:00 to 13:00 at KCVG 

2014; d) CEMS data for both the Beckjord and Zimmer facilities in relation to the recorded monitored values oexceedance day.

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March 6, 2014

CEMS Data (Beckjord)CEMS Data (Zimmer)Monitor Value (ppb)
VII. Summary 

Between January 1, 2010 and August 31, 2014, 44 exceedances of the 2010 1-hour SO2 NAAQS 

were reported at Monitor ID 21-037-3002. Review of the data presented in this report indicates 42 of 

the exceedances were most likely attributable to SO2 emissions at the W.C. Beckjord Facility; and 1 

exceedance was likely attributable to the W.C. Beckjord Facility but may have been influenced by 

SO2 emissions from both facilities; and 1 exceedance was not attributable to either facility. 

As presented in Table 2 of this report, the W.C. Beckjord Facility consistently emitted substantially 

higher SO2 emission for the period analyzed. Although emissions themselves are not directly 

indicative of a particular source causing or contributing to an exceedance or exceedances, together 

with the majority of exceedances being attributable to Beckjord demonstrates the Beckjord facility is 

the primary SO2 source causing exceedances of the 1-hour SO2 NAAQS at monitor 21-037-3002.