adem.alabama.gov

AERMOD Experiences during the Birmingham

Area Particle Study (BAPS)

EPA 9th Modeling ConferenceOctober 9, 2008

adem.alabama.gov

Background

• EPA designated Jefferson, Shelby, and a small portion of Walker counties as nonattainment for the annual standard effective April 5, 2005.

• Current PM2.5 Design Values – 2005-2007:– North Bham – 18.9 ug/m3 (18.7)– Wylam - 17.7 ug/m3 (17.5)

• NAAQS = 15 ug/m3

adem.alabama.gov

State Implementation Plan

• Contracted with ENVAIR to help identify causes of high PM2.5.

• Based on the conclusions of the ENVAIR study, the SIP focuses on reduction of emissions of fine particles in the area surrounding the North Birmingham and Wylam monitors.

• The plan also relies on reductions from national programs such as CAIR, and cleaner cars, diesels and fuels.

• Base Case 2002/2009/2012 modeling to help develop attainment plan is being completed using a CMAQ/AERMOD integrated approach in accordance with EPA implementation guidance.

adem.alabama.gov

Measurement Sites

840 860 880 900 920 940 960 980 1000 1020 1040-760

-740

-720

-700

-680

-660

-640

-620

-600

-580

Ashland

Gadsden

Birmingham North

route 8 Mcadory

1801 Bruce Shaw RdWylam

Hoover

PinsonWarrior

Tuscaloosa

Jasper

Childersburg

Birmingham North

1801 Bruce Shaw Rd

CTR

Birmingham PM2.5 Observation SitesFRMSTNSEARCH

adem.alabama.gov

Birmingham Area Design Values

15.9215.60Leeds

13.7513.4613.0712.3012.6314.08Providence

14.5914.5214.2213.5313.8714.95Corner

14.6014.4514.1813.5713.7214.72Pinson

15.6015.4915.0114.5914.7315.65McAdory

15.1215.1414.7614.3314.7316.18Hoover

17.4517.2816.4916.0516.7418.43Wylam

18.6718.5618.2417.531819.63North Bham

2005-2007

2004-2006

2003-2005

2002-2004

2001-2003

2000-2002Site

3 Year Avg.

adem.alabama.gov

Annual PM2.5 Design Values 2005-2007

14.6 15.1 15.9 15.614.6 13.7

18.717.5

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

Corner Hoover Leeds McAdory Pinson Providence NBHM Wylam

Site

Con

cent

ratio

n (u

g/m

3)

adem.alabama.gov

Modeling predicts that EPA’s adopted regulations for mobile sources and electric utilities will reduce regional and general urban PM by about 1 μg m–3.

Additional modeling suggests this may be higher, i.e. 1 – 1.5 μg m–3

This reduction will help, but is not likely to bring Wylam and North Birmingham into attainment by 2010

Are reductions of local PM possible? Need to understand what local PM is and where it comes from.

VISTAS/CAIR Modeling

adem.alabama.gov

Major Findings of ENVAIR Study

• Nonattainment due to N. Birmingham & Wylam• Local and urban PM contributions are

superimposed on regional component– Regional - ~12-14 μg/m3

– General urban - ~2 μg/m3

– Local - ~3-4 μg/m3

• Multiple lines of evidence link local excess PM at Wylam and North Birmingham to several geographical source complexes

• Evidence includes wind directions, carbon compounds, elements (metals), day-of-week variations, fence-line samples, & PM spikes

adem.alabama.gov

• With moderate decreases projected in regional PM, local emission reductions will likely be needed to attain the standard

• Since Wylam and N. BHM drive nonattainment, first attention to source complexes surrounding those sites

• Many sources are intermittent or semi-continuous processes in open buildings

• Very high infrequent PM concentrations• Transportation – rail and trucking – contribute • What to do now? Model and see….

Major Findings of ENVAIR Study

adem.alabama.govPM2.5 (μg m-3)

0102030

adem.alabama.gov

PM2.5 (μg m-3)0

102030

adem.alabama.gov

ENVAIR to ENVIRON/AG

• Taking the findings from the monitoring study, JCDH and ADEM contracted with ENVIRON/Alpine Geophysics to conduct a model attainment demonstration– Contract awarded in Fall 2006– Using the CMAQ platform with MM5/SMOKE

to model the regional and urban signals– Using the AERMOD model to evaluate local

source impacts– Integration of modeling platform results

adem.alabama.gov

What doesn’t kill you….

• This has been a learning process• Many different stakeholders• New territory for modeling• Uncertainty in emissions inventories• Uncertainty in modeling integration• Highly variable emissions from many types

of sources, many of whom have never been involved in a modeling study of this magnitude

• Sheer number of sources

adem.alabama.gov

Emissions Inventory Development

• Multiple 2002, 2009, and 2012 CMAQ and AERMOD inventories have been developed to identify direct, inert PMfine emissions– Much bigger challenge than expected– Many sources never modeled with this much detail

and scrutiny– Emissions factors for PM2.5 poorly defined, if even

available– Needed to weigh a perfect inventory against time and

resource constraints– Known errors in emissions are being corrected in the

final runs– Small sources may have significant impacts

adem.alabama.gov

Emissions Inventory Issues

• Mistakes were made by both the regulatory agencies as well as the facilities. This is due in large part, to the lack of understanding of what is needed to model at this level– For transparency, we insisted on active involvement of facilities. – If we had known how difficult it would be, we might have contracted for

the inventory development.

• This led to multiple revisions of the 2002, 2009 and 2012 SMOKE runs

• SMOKE outputs were run through CAMx to produce consistent hourly emissions profiles to be input into AERMOD

adem.alabama.gov

AERMOD Modeling

• Our studies showed a clear “local sources”signature, especially for primary PM2.5.

• CMAQ, even with 4 km grid spacing, was not considered adequate to resolve impacts due to local emission controls.

• AERMOD selected as the best way to model the significant industrial contributors.

• Which local sources should be modeled?

adem.alabama.gov

AERMOD Modeling Local Source Criteria

• No established criteria- all new territory.• Based on the results of the ENVAIR study, it was assumed

that every source identified by the study would be included.• Any source within 5 km of either monitor with PM2.5

emissions greater than 1 tpy (~1/4 lb/hr) was included.• Between 5 – 10 km of either monitor, any source with PM2.5

emissions greater than 4 tpy (~1 lb/hr) was included.• A Q/d and Q/d2 analyses supported the above criteria fairly

well.• Total of 46 facilities identified; roughly 1200 individual

emitting sources. Included point, area, volume and buoyant lines.

adem.alabama.gov

AERMOD Modeling Grid

• Initial discussions with EPA and among the study participants led to a 1 km X 1 km AERMOD receptor grid with 100 meter spacing

• Plant property issues

• Additional discussion led to agreement on a 300 m X 300 m Cartesian grid with 100 meter spacing.

• For the attainment demonstration, concentrations will be averaged across all receptors

• For culpability and RACT, concentrations at the monitor were used

adem.alabama.gov

AERMOD Met Data

• Used 2002 met data – same as base case emission data year.

• Options– Conventional NWS ASOS data at Birmingham airport

(BHM) – 7 – 18 km from key monitors.– SEARCH site wind data at North Bham monitor.– Hourly-averaged ASOS data at BHM.

• Choice – hybrid of hourly ASOS data augmented by conventional ASOS data as necessary. SEARCH data had too many holes and quality questions. OAQPS invaluable in developing the hybrid data set.

adem.alabama.gov

AERMOD Met DataNBHM PM2.5 - AERMOD PREDICTIONS VS. OBSERVED - LIGHT

WINDS IMPACT STUDY (Q1 2002)

0

20

40

60

80

100

BHM_1-min BHM_ISHD NBHM PM2.5 SEARCH(1.0) SEARCH(.28)

adem.alabama.gov

AERMOD Overview

AERMOD run for local significant facilities– ADEM assessed “significance” and

determined facility list for AERMOD– Only primary PM2.5 was simulated– Wind inputs generated using draft EPA

1-minute ASOS data methodology– For 2002 MPE, 24-hr concentrations

saved at WYLM and NBHM monitor coordinates

adem.alabama.gov

AERMOD Overview

Thus, we expect AERMOD to predict lower concentrations than daily FRM observations

– Observation-based analyses (ENVAIR Study) suggest annual local industrial contribution is

• ~3 ug/m3 at NBHM• ~2 ug/m3 at WYLM

But we recognize AERMOD is considered a“conservative” (high) model

adem.alabama.gov

AERMOD Results

5.316.47Annual

4.936.094th

5.176.483rd

5.737.022nd

5.46.271st

WYLM

19.6733.49Annual

21.3335.874th

22.1837.663rd

20.1634.692nd

15.0225.741st

NBHM

2009 Quarterly PM2.5Concentration

2002 Quarterly PM2.5ConcentrationQuarterMonitor

adem.alabama.gov

2002 by Quarter at WylamSequenced 24 hour PM2.51st Quarter, WYLM Monitor

0

10

20

30

40

50

2010

124

2010

424

2010

724

2011

024

2011

324

2011

624

2011

924

2012

224

2012

524

2012

824

2013

124

2020

324

2020

624

2020

924

2021

224

2021

524

2021

824

2022

124

2022

424

2022

724

2030

224

2030

524

2030

824

2031

124

2031

424

2031

724

2032

024

2032

324

2032

624

2032

924

Date

ug/m

3

Sequenced Observations

adem.alabama.gov

Sequenced 24 hour PM2.52nd Quarter, WYLM Monitor

0

10

20

30

40

50

2010

124

2010

424

2010

724

2011

024

2011

324

2011

624

2011

924

2012

224

2012

524

2012

824

2013

124

2020

324

2020

624

2020

924

2021

224

2021

524

2021

824

2022

124

2022

424

2022

724

2030

224

2030

524

2030

824

2031

124

2031

424

2031

724

2032

024

2032

324

2032

624

2032

924

Date

ug/m

3

Sequenced Observations

2002 by Quarter at Wylam

adem.alabama.gov

2002 by Quarter at WylamRanked 24 hour PM2.5

1st Quarter, WYLM Monitor

0

10

20

30

40

50

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79 82 85 88

Rank

ug/m

3

Ranked Observations

adem.alabama.gov

Ranked 24 hour PM2.53rd Quarter, WYLM Monitor

0

10

20

30

40

50

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79 82 85 88 91

Rank

ug/m

3

Ranked Observations

2002 by Quarter at Wylam

adem.alabama.gov

2002 Wylam Frequency Distribution

Annual Frequency DistributionW YLM

0

20

40

60

80

100

120

140

160

0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50 >50

ug/m3

Freq

uenc

y

Obs AERMOD

adem.alabama.gov

WYLM Results

Agrees with expected patterns (good)– Always lower than daily FRM total obs

• Expected local industry contributions are ~2 ug/m3

• AERMOD annual mean is ~ 6.5 ug/m3– AERMOD is rarely >10x the assumed

local component (4 days)• >5x local component 20% of the year

– Annual frequency distribution is heavy in the 0-10 ug/m3 range

adem.alabama.gov

2002 by Quarter at NBHM

Sequenced 24 hour PM2.52nd Quarter, NBHM Monitor

0

20

40

60

80

100

120

140

160

2040

124

2040

424

2040

724

2041

024

2041

324

20416

2420

41924

20422

2420

42524

20428

2420

50124

20504

2420

50724

20510

2420

51324

20516

2420

51924

20522

2420

52524

20528

2420

53124

20603

2420

60624

20609

2420

6122

420

6152

420

6182

420

6212

420

6242

420

6272

4

Date

ug/m

3

Sequenced Observations

adem.alabama.gov

Sequenced 24 hour PM2.53rd Quarter, NBHM Monitor

0

20

40

60

80

100

120

140

160

2070

124

2070

424

2070

724

2071

024

2071

324

2071

624

2071

924

2072

224

2072

524

2072

824

2073

124

2080

324

2080

624

2080

924

2081

224

2081

524

2081

824

2082

124

2082

424

2082

724

2083

024

2090

224

2090

524

2090

824

2091

124

2091

424

2091

724

2092

024

2092

324

2092

624

Date

ug/m

3

Sequenced Observations

2002 by Quarter at NBHM

adem.alabama.gov

2002 by Quarter at NBHMRanked 24 hour PM2.5

3rd Quarter, NBHM Monitor

0

20

40

60

80

100

120

140

160

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79 82 85 88 91

Rank

ug/m

3

Ranked Observations

adem.alabama.gov

2002 by Quarter at NBHMRanked 24 hour PM2.5

4th Quarter, NBHM Monitor

0

20

40

60

80

100

120

140

160

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79 82 85 88 91

Rank

ug/m

3

Ranked Observations

adem.alabama.gov

2002 NBHM Frequency Distribution

Annual Frequency DistributionNBHM

0

10

20

30

40

50

60

70

80

90

100

0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50 >50

ug/m3

Freq

uenc

y

Obs AERMOD

adem.alabama.gov

NBHM Results

Dramatic over predictions (bad)– Usually higher than daily FRM total obs

• Expected local industry contributions are ~3 ug/m3

• AERMOD annual mean is ~ 5x higher– AERMOD is >10x the assumed local

component ~1/2 of year• >5x local component 2/3 of the year

– Annual frequency distribution is heavy in the >30 ug/m3 range

adem.alabama.gov

Quantile-QuantileComparison

Q-Q PlotRanked Modeled vs. Observed

y = 0.58x - 2.93R2 = 0.97

y = 3.08x - 21.41R2 = 0.99

0

20

40

60

80

100

120

140

160

0 20 40 60

Observations (ug/m3)

AER

MO

D (u

g/m

3)

WYLMNBHMLinear (WYLM)Linear (NBHM)

adem.alabama.gov

Conclusions• Q-Q plot shows a marked difference in

the character of AERMOD prediction between NBHM and WYLM– NBHM shown to be dominated by facilities

in very close proximity– Are sources characterized adequately?– Should we expect AERMOD to perform

poorly for certain source configurations?– What are our expectations from AERMOD?

adem.alabama.gov

Conclusions, cont.• Additional revisions to source characterizations

have been made, and emission rates have been revised

• Will these changes affect AERMOD performance?• Unknown

• Hope to show compliance with CMAQ alone• Think that future modeling exercises like this should

focus on refining photochemical models to handle at very small grid scales– Don’t feel this is the best use of these models

adem.alabama.gov

• AERMOD was run for selected local sources for the 2002 and 2009 bases to simulate the dispersion of primary inert PM2.5.

• CMAQ was run to simulate the dispersion of urban and regional scale primary as well as secondary emissions of PM.– Secondary and gaseous PM from all facilities

• CMAQ was run twice for the 2002 and 2009 bases– Each base year was run once with all sources and once without the

AERMOD sources– Additional runs, including alternate future years, are being

considered• The results of the combination of CMAQ and AERMOD

were used to obtain the future year projections of PM2.5.

CMAQ - AERMOD Integration

adem.alabama.gov

• Followed EPA’s modeling guidance

• EPA’s involvement has been invaluable– Met data– Modeling assistance– Discussion on issues such as source

characterization, policy implications and model performance

• Even with this involvement, it is still difficult to determine whether this is an appropriate application of the model for this situation.

CMAQ - AERMOD Integration

adem.alabama.gov

2009 DV ProjectionsCirca Spring 2008

• CMAQ “all-source” runs– 1x1 and 3x3 grid cell averaging around

NBHM and WYLM• CMAQ + AERMOD runs

adem.alabama.gov

CMAQ "All Source" 2009 DV Projection (3x3 cell average)

0.00

5.00

10.00

15.00

20.00

2002 NBHM 2009 NBHM 2002 WYLM 2009 WYLM

Ann

ual C

once

ntra

tion

(ug/

m3)

PBWNH4NO3SO4OCECCrustal

18.4

15.5

17.116.7

adem.alabama.gov

CMAQ + AERMOD 2009 DV Projection (3x3 cell average)

0.00

5.00

10.00

15.00

20.00

2002 NBHM 2009 NBHM 2002 WYLM 2009 WYLM

Ann

ual C

once

ntra

tion

(ug/

m3)

PBWNH4NO3SO4OCECCrustalLocal

18.4

15.0

17.1

15.7

adem.alabama.gov

2009 CMAQ“All-Source” Projection

3x3 averaging

2002 2009 ReductionN. Bham. 18.4 16.7 -1.7McAdory 15.0 13.8 -1.2

Providence 13.0 11.7 -1.3Wylam 17.1 15.5 -1.6Hoover 15.1 13.7 -1.4Pinson 14.0 12.6 -1.4Corner 14.1 12.6 -1.5

adem.alabama.gov

ASIP Modeling Results

• Updated modeling for 2012 (12km) accomplished by ASIP in July/August for GA and AL SIPs

• All states provided updated emissions inventories• Alabama rolled in the “to-date” 2002 BAPSinventory

• CAIR controls assumed

adem.alabama.gov

ASIP Modeling Results• The 2012 results are promising

– It’s important not to look to closely at the number per se, but rather the reduction

–2002/2009 results used different emissions inventories than the 2012 (VISTAS vs. BAPS)

–Still, we think the results show that controls in GA and AL will help bring the area into attainment

• The following chart illustrates the 2002 Base, 2009 Best and Final, 2012 Initial, 2018 Best and Final results for Alabama assuming CAIR implementation.

adem.alabama.gov

ASIP RESULTS- ALAlabama, 2002 Design Value, 2009 base G4a 12km and 36km,

2012 base G4a 12km and 36km, and 2018 base G4a 12km and 36km Projected DVF

0

2

4

6

8

10

12

14

16

18

20

DV

CD

VF

09g4

12k

mD

VF

12g4

12k

mD

VF

18g4

12k

m

DV

CD

VF

09g4

12k

mD

VF

12g4

12k

mD

VF

18g4

12k

m

DV

CD

VF

09g4

12k

mD

VF

12g4

12k

mD

VF

18g4

12k

m

DV

CD

VF

09g4

12k

mD

VF

12g4

12k

mD

VF

18g4

12k

m

DV

CD

VF

09g4

12k

mD

VF

12g4

12k

mD

VF

18g4

12k

m

DV

CD

VF

09g4

12k

mD

VF

12g4

12k

mD

VF

18g4

12k

m

DV

CD

VF

09g4

12k

mD

VF

12g4

12k

mD

VF

18g4

12k

m

DV

CD

VF

09g4

12k

mD

VF

12g4

12k

mD

VF

18g4

12k

m

DV

CD

VF

09g4

12k

mD

VF

12g4

12k

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VF

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DV

CD

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VF

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m

Baldwin 0010 Clay 0001 Colbert 1002 DeKalb 1003 Escambia 0002 Etowah 0010 Jefferson 0023 Jefferson 1005 Jefferson 1009 Jefferson 2003

μg/m

3

SaltPWBNO3SO4NH4OCECCrustaBLANK

State Alabama set 1

Name dataset

Data

adem.alabama.gov

Determination of Attainment Year

• ADEM will propose an attainment date that represents attainment as expeditiously as practicable based on implementation of existing Federal and State measures and all new reasonable local measures.

•We believe that 2012 will represent the best future year for theBirmingham NAA•However, we will model both future years and develop RRF’s(2009 and 2012)

• In our 2009 basecase, we will account for controls already on the books such as CAIR and mobile source controls, as well as local industry controls implemented between 2002 and 2009.

• Same for 2012

adem.alabama.gov

Final Attainment Plan

• The process of identifying significant contributors and candidate control strategies will continue until an emissions reduction plan is developed that demonstrates attainment.

• JCDH will modify permits to reflect final emission controls.