Shenandoah Group 

Contribution Assessmen

Draft May 29, 2007
.

.

.

.

.

Hercules Glade, MO

Mountain Class I Areas
Objectives

 Pollutant Contributions: 2000-2

and Worst Days

 New IMPROVE equation

 Natural Background Calculations

 Glidepath and Progress in 2018 Emissions Sensitivities  Areas of Influence

 Back Trajectory, Residence Time Source Sector Emissions List of Contributing Sources (states 
Average Extinction for 20% Worst Da

New IMPROVE Algorithm (nia)

2000-2004

0

50

100150200250300

SWAN1

ROMA1

OKEF1

EVER1

CHAS1

SAMA1

DOSO1

SHEN1

JARI1

LIGO1

SHRO1

GRSM1

COHU1

SIPS1

MACA1

BRIG1

VISTAS coastal VISTAS inland 

Extinction (Mm -1)
Average Extinction for 20% Best Day

New IMPROVE Algorithm (nia)

2000-2004

0

102030405060

SWAN1

ROMA1

OKEF1

EVER1

CHAS1

SAMA1

DOSO1

SHEN1

JARI1

LIGO1

SHRO1

GRSM1

COHU1

SIPS1

MACA1

BRIG1

BRET1

VISTAS coastal VISTAS inland 

Extinction (Mm -1)
Shenandoah, VA

2000-2004 Reconstructed Extinctio

New IMPROVE Algorithm

20% Worst Days

0

50

100150200250300350400450500

5/10

5/13

6/10

6/14

6/21

6/24

7/1

7/5

7/19

7/22

8/5

8/16

8/23

8/26

9/12

10/18

10/21

10/24

10/27

11/8

5/1

5/4

5/10

6/9

6/12

7/18

8/2

8/5

8/8

8/11

8/14

8/17

8/26

8/29

9/4

9/7

9/13

9/19

9/22

10/22

10/31

11/18

2/28

5/26

5/29

6/4

6/10

6/13

6/19

6/25

7/1

7/4

7/16

7/19

7/22

7/31

8/3

8/12

8/21

8/24

8/27

9/11

9/14

9/17

9/29

10/2

1/30

3/19

5/27

5/30

6/5

6/26

6/29

7/5

7/20

7/26

7/29

8/1

2000 2001 2002 20

Extinction (Mm-1

)
0

1020304050607080

1/8

1/12 1/15

1/29

2/2

3/4

3/18

3/22

4/15

5/24

5/31

7/26

10/30

11/2

11/26

11/29

12/14

12/26

12/29

1/10

1/19

1/22

1/31

2/12

2/15

2/27

3/5

3/14

3/20

5/7

5/19

5/22

7/30

9/25

10/10

10/25

10/28

11/6

11/9

11/24 1/5

1/14

1/23

1/26

2/7

2/19

3/3

3/9

3/18

6/7

7/25

8/9

9/2

9/26

10/11

11/16

12/1

12/4

12/7

12/10

12/13

12/22

12/25

1/3

2/17

2/23

3/16

4/9

4/18

4/24

5/6

5/18

6/17

9/12

10/3

2000 2001 2002 200

Extinction (Mm-1)

Shenandoah, VA

2000-2004 Reconstructed Extinctio

New IMPROVE Algorithm

20% Best Days
0

50

100150200250300350400

2001 2002 2003 

Extinction (Mm -1

)

James River Face, VA

2000-2004 Reconstructed Extinction

New IMPROVE Algorithm

20% Worst Days
0

1020304050607080

2001 2002 2003 

Extinction (Mm -1

)

James River Face, VA

2000-2004 Reconstructed Extinction

New IMPROVE Algorithm

20% Best Days
0

50

100150200250300350400450500

1/26

3/8

5/6

5/13

5/20

6/10

6/14

6/24

7/1

7/5

7/22

8/16

8/23

8/26

9/12

10/15

10/18

10/21

10/24

10/27

3/23

5/4

5/10

6/12

6/15

6/21

6/27

7/9

7/18

7/24

8/2

8/8

8/23

8/26

8/29

9/4

9/7

9/13

9/19

9/22

10/22

11/15

11/18

5/2

5/8

5/17

5/26

5/29

6/1

6/4

6/10

6/13

6/19

6/22

6/25

7/1

7/10

7/25

8/12

8/15

9/11

9/14

9/17

9/20

9/29

10/2

3/19

4/30

5/27

6/5

6/23

6/26

6/29

7/5

7/20

7/26

8/7

8/10

8/13

8/16

2000 2001 2002 2003 

Extinction (Mm -1

)

Dolly Sods, WV

2000-2004 Reconstructed Extinction

New IMPROVE Algorithm

20% Worst Days

Dolly Sods and Otter Creek Wilderness Areas share an 
0

1020304050607080

1/8

1/29

2/2

3/4

3/18

3/22

4/5

4/15

4/22

9/18

10/9

11/2

11/14

11/26

12/14

12/17

12/23

12/26

12/29

1/7

1/19

1/31

2/3

2/15

3/14

3/17

5/25

5/31

7/30

9/16

9/25

10/10

10/16

10/19

10/25

11/9

11/21

11/24

12/3

12/15

12/24

12/27

1/5

1/14

1/23

1/26

2/19

3/9

3/30

4/14

4/29

6/7

10/11

10/20

10/26

10/29

11/16

11/22

12/4

12/7

12/13

12/22

12/25

12/31

1/3

2/14

2/17

3/16

4/9

5/6

5/18

6/17

10/15

10/24

10/27

10/30

11/5

11/14

2000 2001 2002 2003 

Extinction (Mm-1)

Dolly Sods, WV

2000-2004 Reconstructed Extinction

New IMPROVE Algorithm

20% Worst Days
Conclusions: Contrib

 On 20% Worst Days

 SO4 dominates light extinctio Organic carbon generally sec

contribution; fire indicated on 

 NO3 contribution comparativ

 SO4 also dominates 20% B Conclude: Focus on reduci

emissions
New IMPROVE Equatio

 Endorsed by IMPROVE Steering C

accounting for latest science

 Defines two terms each for SO4, NO

higher extinction efficiencies (bext) ahigh mass and lower bext associated 

 Increases mass multiplier for organi

1.4 to 1.8

 Adds term for fine mass sea salt Adds term for absorption due to NO

measurements available)

 Calculates site specific Rayleigh scat
New IMPROVE Equatio

 Light scattering measured by 

nephelometer and calculated IMPEOVE equation show goo

 Original equation under estima

on highest days and over estimscattering on lowest days

 New equation generally indica

extinction on 20% worst days extinction on 20% best days
Aerosol Scattering vs. Nephelomete

Using New or Old IMPROVE Algorithm 

Shenandoah, VA 1996 - 20

All Days

y = 1.04x + 6.27

R2 = 0.79

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol b s p (M m -1 )

y = 0.80x + 13.7

R2 = 0.81

0

50

100150200250300

0 50 100 

24-hr N

24-hr Aerosol b s p (Mm -1 )

New IMPROVE Old 
All Days

y = 1.09x + 10.32

R2 = 0.85

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr A erosol b sp (Mm -1)

y = 0.83x + 16.6

R2 = 0.86

0

50

100150200250300

0 50 10

24-hr N

24-hr Aerosol b sp (Mm -1)

Aerosol Scattering vs. Nephelomete

Using New or Old IMPROVE Algorithm 

James River Face, VA 2000 - 

New IMPROVE Old 
Natural Background Vi

 Tombach reviewed for VISTAS the original ass

et al. 1990 used to define natural background impairing pollutants and recent scientific develmade recommendations for changes in assumpand Brewer, 2005)

 Hand and Malm (2005) reviewed assumptions 

extinction in the original IMPROVE equation anrecommendations for revisions.

 The IMPROVE Steering Committee reviewed an

equation for calculating light extinction (2005).

 Ames (2006) reviewed methods to project natu

levels for 20% worst visibility days using the nequation and IMPROVE approved revised meth

 Revised glide paths calculated for reaching nat

conditions at Class I areas by 2064.
Natural Conditions

0

1020304050

Great Smoky Mtns NP Shenandoah NP Cape Romain W Okefenokee WEverglades 

Left = Default Natural Conditions; Center = New IMPROVE A

Right = W20 with New IMPROVE Algorithm

bext (Mm-1)
Shenandoah Glide Path to Natural Conditions (2

(5-yr Rolling Average for 20% Haziest Days - New IMPROVE equation 

05

101520253035

1986-1990

1988-1992

1990-1994

1992-1996

1994-1998

1996-2000

1998-2002

2000-2004

2006

2008

2010

2012

2014

2016

2018

2020

2022

2024

2026

2028

2030

2032

2034

2036

2038

2040

2042

Deciviews (dv)

Default Glide Path SHEN Default 5-yr Rolling Avg SHEN Annual g90 - Old 

Base old Base 

Shenandoah NP 27.9 29.3 
James River Face Glide Path to Natural Conditions 

(5-yr Rolling Average for 20% Haziest Days - New IMPROVE equation 

05

101520253035

1986-1990

1988-1992

1990-1994

1992-1996

1994-1998

1996-2000

1998-2002

2000-2004

2006

2008

2010

2012

2014

2016

2018

2020

2022

2024

2026

2028

2030

2032

2034

2036

2038

2040

2042

Deciviews (dv)

Default Glide Path JARI Default 5-yr Rolling Avg JARI Annual g90 - Old 

Base old B

James River Face WA 27.7 

dv
Dolly Sods Glide Path to Natural Conditions (20

(5-yr Rolling Average for 20% Haziest Days - New IMPROVE equation 

05

101520253035

1986-1990

1988-1992

1990-1994

1992-1996

1994-1998

1996-2000

1998-2002

2000-2004

2006

2008

2010

2012

2014

2016

2018

2020

2022

2024

2026

2028

2030

2032

2034

2036

2038

2040

2042

Deciviews (dv)

Default Glide Path DOSO Default 5-yr Rolling Avg DOSO Annual g90 - Old 

Base old Base 

Dolly Sods WA 27.6 29.0 
VISTAS 2018 Base G2 Vis

Projections (Delivered Mar 20

 CMAQ Air Quality Model 2018 

 Accounts for Clean Air Interstat

(utility controls)

 Does not include controls for BA

(Best Available Retrofit Tech

 VISTAS states inventories as of  Inventories for neighboring sta

Aug 2006
Model Performance 20% Haziest Days in 

Observations (left) vs Modeled Base G2a (righ

Shenandoah, VA

0

50

100150200250300350400450500

59 146 149 155 161 164 170 176 182 185 197 200 203 212 215 224 233 236 239 254 257 

Julian Day in Worst 20% group

bEXT (1/Mm)
Modeled Responses to 2018 Base G2a Emissions o

Shenandoah, VA

-300-250-200-150-100

-50

0

50

59 146 149 155 161 164 170 176 182 185 197 200 203 212 215 224 233 236 239 254 

Julian Day

Delta Bext (1/Mm)
Shenandoah - 20% Worst Days

29.31

28.12

25.14

22.16

19.18

21.98

05

101520253035

2000 2004 2008 2012 2016 2020 2024 2028 2032 2036 2040 204

Year

Haziness Index (Deciviews)

Glide Path Natural Condition (Worst Days) Observati

New IMPROVE equation

Uniform Rate of Progress Glide Path (Bas

Uniform rate of progre
2000-2004 2

Visibility at Shenandoah on 20% 
Visibility at Shenandoah – Natura
Model Performance 20% Haziest Days in 

Observations (left) vs Modeled Base G2a (righ

James River Face, VA

0

50

100150200250300350

137 146 152 155 161 182 185 191 197 200 203 212 215 218 224 233 236 239 254 257 2

Julian Day in Worst 20% group

bEXT (1/Mm)
Modeled Responses to 2018 Base G2a Emissions o

James River Face, VA

-180-160-140-120-100

-80-60-40-20

0

20

137 146 152 155 161 182 185 191 197 200 203 212 215 218 224 233 236 239 254 257 2

Julian Day

Delta Bext (1/Mm)
New IMPROVE equation

Uniform Rate of Progress Glide Path (Bas

James River Face - 20% Worst Day

29.12

27.92

24.94

21.95

18.96

22.40

05

101520253035

2000 2004 2008 2012 2016 2020 2024 2028 2032 2036 2040 2044 

Year

Haziness Index (Deciviews)

Glide Path Natural Condition (Worst Days) Observation 

Uniform rate of progres
Model Performance 20% Haziest Days in 

Observations (left) vs Modeled Base G2a (righ

Dolly Sods, WV

0

50

100150200250300350400450500

122 128 137 146 149 152 155 161 164 170 173 176 182 191 206 224 227 254 257 260 26

Julian Day in Worst 20% group

bEXT (1/Mm)
Modeled Responses to 2018 Base G2a Emissions o

Dolly Sods, WV

-300-250-200-150-100

-50

0

50

122 128 137 146 149 152 155 161 164 170 173 176 182 191 206 224 227 254 257 260 

Julian Day

Delta Bext (1/Mm)
New IMPROVE equation

Uniform Rate of Progress Glide Path (Bas

Uniform rate of progres

Dolly Sods - 20% Data Days

29.04

27.81

24.71

21.61

18.51

21.71

05

101520253035

2000 2004 2008 2012 2016 2020 2024 2028 2032 2036 2040 2044 

Year

Haziness Index (Deciviews)

Glide Path Natural Condition (Worst Days) Observatio

Rate of progress for Otter Creek is same as rate of progress 
VISTAS Source Sector E

Sensitivities (Delivered Ja

 Evaluated responses to em

reductions for specific pollusource sectors

 Greatest visibility improvem

further reducing SO2 emissutilities and industries
Shenandoah, VA (20% Worst Da

-16.00-14.00-12.00-10.00

-8.00-6.00-4.00-2.00

0.002.00

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

P

ΔBext (Mm-1)
James River Face, VA (20% Worst Day

-18.00-16.00-14.00-12.00-10.00

-8.00-6.00-4.00-2.00

0.002.00

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

PC

ΔBext (Mm -1)
Dolly Sods, WV (20% Worst Day

-16.00-14.00-12.00-10.00

-8.00-6.00-4.00-2.00

0.002.00

SO2_EGU

SO2_nonEGU

NOx_Ground

NOx_Point

NH3

VOCs

PC_Ground

PC_Point

ΔBext (Mm-1)

Emissions sensitivities for Otter Creek are the same as for D
Conclusion: Source Sec

Emissions Sensitivities

 Reductions in SO2 emissions from 

EGU show largest improvements in 

 WV largest contributor  SO2 from KY, VA, MRPO, MANE-VU, a

Conditions (outside VISTAS 12 km doma

contribute

 Small benefits from reducing NOx, 

VOC or primary carbon
VISTAS Geographic Are

Influence

 Hysplit model used to generate 

trajectories for Class I areas (Air 

Specialists)

 Back trajectories for individual 20% 

in 2002

 Helpful for evaluating model perfo

 Residence time plots for 20% wors

2000-2004 indicate probable contr

 Helpful to understand geographic a

to influence Class I areas 

 SO2 Area of Influence defined from 

weighted by SO4 extinction and coemissions

Residence Time for 20% Worst Days in 20

Shenandoah, VA
SO2 Area of Influence for Shenand

Green circles indicate 100-km and 200-km radii from Class Red line perimeter indicate Area of Influence with Residen

Orange line perimeter indicate Area of Influence with Resi
2018 SO2 Emissions weighted by Res

Shenandoah, VA 

Green circles indicate 100-km and 200-km radii from Class Red line perimeter indicate Area of Influence with Residenc

Orange line perimeter indicate Area of Influence with Resid

Residence Time for 20% Worst Days in 20

James River Face, VA
SO2 Area of Influence for James R

Green circles indicate 100-km and 200-km radii from Class Red line perimeter indicate Area of Influence with Residen

Orange line perimeter indicate Area of Influence with Resi
2018 SO2 Emissions weighted by Res

James River Face, VA 

Green circles indicate 100-km and 200-km radii from Class Red line perimeter indicate Area of Influence with Residenc

Orange line perimeter indicate Area of Influence with Resid

Residence Time for 20% Worst Days in 20

Dolly Sods, WV
SO2 Area of Influence for Dolly Sod

Green circles indicate 100-km and 200-km radii from Class Red line perimeter indicate Area of Influence with Residen

Orange line perimeter indicate Area of Influence with Resi
2018 SO2 Emissions weighted by Res

Dolly Sods, WV 

Green circles indicate 100-km and 200-km radii from Class Red line perimeter indicate Area of Influence with Residenc

Orange line perimeter indicate Area of Influence with Resid
Reasonable Progress 

 States consider 4 Statutory F

determine what controls are 

 Costs of Compliance Time to Comply Remaining Useful Life  Energy and Other Environm

Impacts
Annual 2018 BaseG2 Emissions (%) Within Ar

Shenandoah, VA

Tier VOC NOX CO SO2 Fuel Comb. Elec. Util. 1% 26% 1% 53% Fuel Comb. Industrial 1% 17% 2% 28% Fuel Comb. Other 7% 9% 4% 6% Chemical & Allied Product Mfg 2% 1% 1% 2% Metals Processing 1% 2% 4% 4% Petroleum & Related Industries 1% 0% 0% 2% Other Industrial Processes 3% 6% 0% 5% 

Solvent Utilization 39% 1% 0% 0% Storage & Transport 6% 0% 1% 0% Waste Disposal & Recycling 4% 2% 3% 0% Highway Vehicles 19% 20% 45% 0% Off-highway 16% 18% 37% 1% Miscellaneous 0% 0% 1% 0% 

VISTAS Total 100

% 100

% 100

% 100

% 
Annual 2018 BaseG2 Emissions (%) Within Ar

Shenandoah, VA

Tier SO2Fuel Comb. Elec. Util.-Coal 51%

Fuel Comb. Elec. Util.-Oil 1%Fuel Comb. Elec. Util.-Gas 0%Fuel Comb. Elec. Util.-Other 0%Fuel Comb. Elec. Util.-Internal Combustion 1%

Fuel Comb. Industrial-Coal 22%Fuel Comb. Industrial-Oil 3%Fuel Comb. Industrial-Gas 2%

Fuel Comb. Industrial-Other 1%Fuel Comb. Industrial-Internal Combustion 0%

Fuel Comb. OtherCommercial/Institutional Coal 2%

Fuel Comb. Other-Commercial/Institutional Oil 1%Fuel Comb. Other-Commercial/Institutional Gas 0%Fuel Comb. Other-Misc. Fuel Comb. (Except Residential) 0%Fuel Comb. Other-Residential Wood 0%

Fuel Comb. Other-Residential Other 2%
Annual 2018 BaseG2 Emissions (%) Within Ar

James River Face, VA

Tier VOC NOX CO SO2 Fuel Comb. Elec. Util. 1% 26% 1% 53% Fuel Comb. Industrial 1% 17% 2% 28% Fuel Comb. Other 7% 8% 4% 6% Chemical & Allied Product Mfg 2% 1% 1% 2% Metals Processing 1% 2% 4% 4% Petroleum & Related Industries 0% 0% 0% 2% Other Industrial Processes 4% 5% 0% 4% 

Solvent Utilization 39% 1% 0% 0% Storage & Transport 7% 0% 0% 0% Waste Disposal & Recycling 4% 2% 4% 0% Highway Vehicles 19% 21% 47% 0% Off-highway 14% 17% 36% 1% Miscellaneous 1% 0% 2% 0% 

VISTAS Total 100

% 100

% 100

% 100

% 
Annual 2018 BaseG2 Emissions (%) Within Ar

James River Face, VA

Tier SO2Fuel Comb. Elec. Util.-Coal 51%

Fuel Comb. Elec. Util.-Oil 1%Fuel Comb. Elec. Util.-Gas 0%Fuel Comb. Elec. Util.-Other 0%Fuel Comb. Elec. Util.-Internal Combustion 1%

Fuel Comb. Industrial-Coal 23%Fuel Comb. Industrial-Oil 3%Fuel Comb. Industrial-Gas 2%

Fuel Comb. Industrial-Other 1%Fuel Comb. Industrial-Internal Combustion 0%

Fuel Comb. OtherCommercial/Institutional Coal 2%

Fuel Comb. Other-Commercial/Institutional Oil 1%Fuel Comb. Other-Commercial/Institutional Gas 0%Fuel Comb. Other-Misc. Fuel Comb. (Except Residential) 0%Fuel Comb. Other-Residential Wood 0%

Fuel Comb. Other-Residential Other 2%
Annual 2018 BaseG2 Emissions (%) Within Ar

Dolly Sods, WV

Tier VOC NOX CO SO2 Fuel Comb. Elec. Util. 1% 25% 1% 53% Fuel Comb. Industrial 1% 17% 1% 27% Fuel Comb. Other 6% 8% 4% 6% Chemical & Allied Product Mfg 2% 0% 1% 2% Metals Processing 1% 2% 5% 4% Petroleum & Related Industries 0% 0% 0% 2% Other Industrial Processes 4% 6% 0% 5% 

Solvent Utilization 41% 1% 0% 0% Storage & Transport 6% 0% 1% 0% Waste Disposal & Recycling 4% 2% 3% 0% Highway Vehicles 19% 21% 47% 0% Off-highway 14% 17% 36% 0% Miscellaneous 1% 0% 2% 0% 

VISTAS Total 100

% 100

% 100

% 100

% 
Annual 2018 BaseG2 Emissions (%) Within Ar

Dolly Sods, WV

Tier Fuel Comb. Elec. Util.-Coal 

Fuel Comb. Elec. Util.-Oil Fuel Comb. Elec. Util.-Gas Fuel Comb. Elec. Util.-Other Fuel Comb. Elec. Util.-Internal Combustion 

Fuel Comb. Industrial-Coal Fuel Comb. Industrial-Oil 

Fuel Comb. Industrial-Gas Fuel Comb. Industrial-Other Fuel Comb. Industrial-Internal Combustion Fuel Comb. Other-Commercial/Institutional Coal Fuel Comb. Other-Commercial/Institutional Oil Fuel Comb. Other-Commercial/Institutional Gas Fuel Comb. Other-Misc. Fuel Comb. (Except Residential) Fuel Comb. Other-Residential Wood 

Fuel Comb. Other-Residential Other 
4 Statutory Factors

 For Utilities and Industrial Bo

 Switch to fuel with lower s

 Coal or Oil

 Post-combustion controls

 Flue Gas Desulfurization

 Modification trigger PSD re
4 Statutory Factors (c

 Costs of Compliance

 Fuel switch for coal or oil

 May have to blend low S fuel to 

performance

 Price difference for lower S fuel Cost of boiler modifications for l <$1000/ton
4 Statutory Factors (c

 Costs of Compliance

 Flue Gas Desulfurization

 Construction costs: absorber tow

waste handling facility

 Operational and maintenance co Costs per ton vary with boiler si Utility costs range $1,000 - $5,0 Industrial costs range $3,000 - 
4 Statutory Factors (c

 Time for Compliance

 2+ years for fuel switching  3+ years for post-combustio

(dependent on market and alabor and materials)

 Remaining Useful Life

 Facility specific
4 Statutory Factors (c

 Energy and Non-Air Environm

Impacts

 Lower sulfur fuel may affect b

operations

 FGD slightly reduces energy p

 Burn more coal per unit energy  Increase disposal of sludge, wa Increase carbon emissions 

 CO2 is released as byproduct from