Complying with the NAAQS – PM2.5 Air Quality Modeling Considerations by ALL4

www.all4inc.com Philadelphia, PA | 610.933.5246

Atlanta, GA | 678.460.0324 Houston, TX | 281.937.7553

Washington, DC | 703.793.9103

Complying with the NAAQS – PM2.5 Air Quality Modeling

Considerations

Dan Dix | [email protected] | 610.933.5246 x118

May 12, 2015

Presented to NCASI Northern Regional Meeting

by All4 Inc.

2 Your environmental compliance is clearly our business.

Agenda

PM2.5 NAAQS (Where are we now)

Fugitive PM2.5 Impacts vs. Point Source in the forest products industry

Ambient Air Boundary (Important for PM2.5 fenceline impacts)

Source Information (Roadway and Storage Pile Silt Content)

PM2.5 Background Concentrations for NAAQS Analyses

Beta Options (LOWWIND1 and ADJ_U*)

Meteorological Data (Onsite vs. NWS)

Additional Considerations


PM2.5 NAAQS

2006 24-Hour PM2.5 NAAQS (35mg/m3) – Primary and Secondary

1997 Annual PM2.5 NAAQS (15 mg/m3) – Secondary (Primary revoked when 2012 established in 2012)

2012 Annual PM2.5 NAAQS (12 mg/m3) – Primary

Final 2012 Annual PM2.5 NAAQS Designated on January 15, 2015

Updates to some areas initially designated non-attainment to attainment made on April 7, 2015 based on 2012-2014 monitoring data.

U.S. EPA’s “Guidance for PM2.5 Permit Modeling”


PM2.5 NAAQS


Fugitive PM2.5 Modeling

Large concentration gradient associated with forest products industry fugitive sources make compliance with 24-hour and Annual PM2.5 NAAQS difficult.

Modeled (predicted) concentrations exhibit high sensitivity to fugitive source emission rates and outsized impacts when compared to point sources

• 8 lb/hr fugitive emission rate resulted in a predicted 24-hour modeled concentration of 74mg/m3 while a 522 lb/hr point source emission rate resulted in a predicted 24-hour modeled concentration of 63mg/m3 24-hour


Fugitive PM2.5 Modeling

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

Scenario 1 Scenario 2 Scenario 3 Scenario 4

Mo

dele

d E

mis

sio

n R

ate

(lb

/hr)

Mo

dele

d C

on

cen

trati

on

(µ

g/m

3 )

Peak 98th Percentile of 24-Hour Modeled PM2.5 Fugitive Concentrations

Pile Concentration (ug/m3)

Roadway Concentration (ug/m3)

Roadway Emissions (lb/hr)

Pile Emissions (lb/hr)

NAAQS Level (ug/m3)

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

Scenario 1 Scenario 2 Scenario 3 Scenario 4

Mo

dele

d E

mis

sio

n R

ate

(lb

/hr)

Mo

dele

d C

on

cen

trati

on

(µ

g/m

3 )

Peak Annual Modeled PM2.5 Fugitive Concentrations

Pile Concentration (ug/m3)

Roadway Concentration (ug/m3)

Roadway Emissions (lb/hr)

Pile Emissions (lb/hr)

NAAQS Level (ug/m3)


Ambient Air Boundary

Current ambient air boundary established with State Agency

Own property on both sides of the river

Own the up-river dam

Paradigm shift for EPA and State Agencies


Ambient Air Boundary Source Distance to Ambient Air Boundary

Lime Kiln 110 Meters

Power Boiler 15 Meters

Recovery Boiler 150 Meters

Roadway 6 Meters

Chip Piles 20 Meters

Paper Machine Dryers 70 Meters


Mill could easily use security surveillance system to control access to the river

Therefore ambient air boundary could be updated to adjacent property boundary on the other side of the river


Source Distance to Updated Ambient Air

Boundary

Lime Kiln 300 Meters (+190)

Power Boiler 175 Meters (+160)

Recovery Boiler 310 Meters (+160)

Roadway 160 Meters (+154)

Chip Piles 245 Meters (+225)

Paper Machine Dryers 210 Meters (+140)


Understand your ambient air boundary

Work with State Agency to develop appropriate ambient air boundary

Understand where your fugitive (i.e., roadway/pile) and low release point (i.e., process silos/starch silos) sources are relative to your ambient air boundary



Background PM2.5 ambient monitoring data required for NAAQS analyses along with other local sources.

Two methods for combining PM2.5 monitoring data and modeling data summarized in U.S. EPA’s “Guidance for PM2.5 Permit Modeling” finalized in May 2014.

• Tier 1 – Combine design value (i.e., 3-year average annual or 3-year average of 98th percentile of 24-hour)

• Tier 2 – Incorporates seasonal variation for 24-hour NAAQS.

Background PM2.5


Background Concentration Example

• Tier 1: 11.6 mg/m3 – Annual, 28.3 mg/m3 -24-Hour

• Tier 2: 24-Hour –Remove top 8 concentrations from each year, then select max from each meteorological season

Background PM2.5

PM2.5 Concentration (µg/m3)

Year Annual 24-Hour

Winter Spring Summer Autumn

2012 11.6 26.4 25.4 24.1 25.0

2013 11.9 28.4 19.3 23.3 23.2

2014 11.4 26.4 23.5 23.2 21.8

Average 11.6 27.1 22.7 23.5 23.3


Background PM2.5

AERMOD option to vary background concentration by wind sector to avoid double counting of modeled and monitoring concentrations (BGSECTOR).

Monitoring sites inside a 90 sector downwind of the source may be used to determine the area of impact.

With multiple sources the downwind sector can have a greater arc


Background PM2.5


Analysis of Roadway Silt Sampling

Mill specific silt sample conducted for 2 mills following AP-42 Appendix C.1 – “Procedures for Sampling Surface/Bulk Dust Loading” (July 1993) and Appendix C.2 – “Procedures for Laboratory Analysis of Surface/Bulk Dust Loading Samples” (July 1993).

24 samples collected for 18 discrete segments.

Average site specific sL 2.5 g/m2

Average entrance (closest fenceline segment) 0.27 g/m2

AP-42 Appendix C.2 defines sL as PM < 75 micrometers (200 mesh screen)

Mesh sizing available down to 632 (20 micrometers)


Summary of Site Specific Paved Roadways Silt Loadings

Mill Mill Process Area No. of Samples Total Weight (g) % sL Weight (g) Area (m2) sL (g/m2)

Mill A Main Entrance 3 N/A N/A 23.26 62.71 0.37

Mill A Pulping Area 2 N/A N/A 20.27 42.74 0.47

Mill A Paper Machine Area 1 N/A N/A 46.39 20.44 2.27

Mill A Landfill 2 N/A N/A 42.7 30.35 1.4

Mill A Chipping Area 1 N/A N/A 20.61 14.86 1.39

Mill A Lime Kiln 1 N/A N/A 43.21 13.94 3.10

Mill A WWTP 1 N/A N/A 3.87 14.63 0.26

Mill A Lime Kiln 1 N/A N/A 5.46 16.26 0.34

Mill B Main Entrance 1 0.58 1.2 0.01 1.11 0.01



Mill B Chipping Area 3 1689.00 4.3 72.63 3.34 21.72

Mill B Roundwood Area 1 12.69 0.73 0.09 1.11 0.08

Mill B Roundwood Area 1 348.00 4.2 14.62 1.11 13.11





Average

Main Entrance 10 0.27

Pulping Area 2 0.47

Paper Machine Area 1 2.27

Landfill 2 1.41

Chipping Area 4 11.55

Lime Kiln 2 1.72

WWTP 1 0.26

Roundwood Area 2 6.60

Mill A 12 1.20

Mill B 12 3.67

Mill A/B 24 2.57



Summary of AP-42 Table 132.1-3 Paved Roadway Silt Loadings

Industry No. Sites No. Of Samples sL (g/m2)

Copper Smelting 1 3 292

Iron and Steel Production 9 48 9.7

Asphalt Batching 1 3 120

Concrete Batching 1 3 12

Sand and Gravel Processing 1 3 70

Municipal Solid Waste Landfill 2 7 7.4

Quarry 1 6 8.2

Corn Wet Mills 3 15 1.1




0

2

4

6

8

10

12

0

2

4

6

8

10

12

Site Specific Silt AP-42 Silt

Mo

de

led

Em

issi

on

Rat

e (

lb/h

r)

Mo

de

led

Co

nce

ntr

atio

n (

µg/

m3)

Peak Annual Modeled PM2.5 Fugitive Roadway Concentrations

Roadway Concentration (ug/m3) Roadway Emissions (lb/hr) NAAQS Level (ug/m3)



0

5

10

15

20

25

30

35

0

5

10

15

20

25

30

35

Site Specific Silt AP-42 Silt

Mo

de

led

Em

issi

on

Rat

e (

lb/h

r)

Mo

de

led

Co

nce

ntr

atio

n (

µg/

m3)

Peak 98th Percentile of 24-Hour Modeled PM2.5 Fugitive Roadway Concentrations

Roadway Concentration (ug/m3) Roadway Emissions (lb/hr) NAAQS Level (ug/m3)


In the 12345 version release of AERMOD LOWWIND1 and ADJ_U* beta options were incorporated that can be useful in low release point and fugitive source modeling

• Friction velocity (U*) used to calculate mixing height, initial horizontal, and vertical dispersion

• ADJ_U* option for low wind speed stable conditions based on Quian and Venkatram

• LOWWIND1 option increase the minimum value of sigma-v and turns off the meander component

AERMOD Beta Options


Currently are considered non-default options and are therefore subject to the alternative model provisions.

ADJ_U* alternative model justification easier undertaking because of peer-reviewed study (Qian and Venkatram, 2011)

Beta Option Test Case

• Fugitive Roadway Emission from Pulp & Paper Mill with onsite meteorological data and site specific silt loading.

• Base Case: Default AERMET and AERMOD Options

• Beta Case: 0.5 wind speed threshold ADJ_U* Beta Option

AERMOD Beta Options


AERMOD Beta Options

0

5000

10000

15000

20000

25000

0 0.2 0.4 0.6 1 1.2 1.4 1.8

Num

ber

of

Hours

Friction Veleocity, U* (m./s)

Comparison of Base Case and U* Ajusted Data Set Friction Veloticies

U* Adjusted Data Set Base Case Data Set


AERMOD Beta Options

0

20

40

60

80

100

120

140

160

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

Concentr

ations (mg/m

3)

Friction Velocity, U* (m/s)

Hourly Predicted Modeled Concentrations Vs. U* Value

Base Case Data Set U* Adjusted Data Set


Use of offsite meteorological data (usually National Weather Service Data) for PSD air quality modeling analyses requires 5-years of onsite data which usually includes the following measurements used by AERMET:

• Horizontal Wind Speed and Direction

• One Temperature Level

• Pressure

• Cloud Cover

Onsite Met vs. Offsite Met


Use of onsite meteorological data for PSD air quality modeling analyses requires 1-year of onsite data which can include the following additional sensors which are also used by AERMET to better predict atmospheric conditions:

• Vertical Wind Speed (i.e, standard deviation AKA sigma W)

• Multiple Levels of Temperature Data

• Solar Radiation and/or Net Radiation

• Multiple Levels of Horizontal Wind Speed and Directions (collected from a tower or SODAR)



Advantages of Collecting Onsite Meteorological Data

• Site Specific

• Measurements at stack top and plume rise elevations vs. extrapolated measurements

• Especially (and in some cases required) beneficially in complex terrain settings

• Meteorological data can be used for other Mill related activities



Elephant in the Room

• Addressing cumulative PM2.5 impacts of PM2.5 precursors SO2 and NO2.

Additional PM2.5 Modeling Considerations

www.all4inc.com Philadelphia, PA | 610.933.5246

Atlanta, GA | 678.460.0324 Houston, TX | 281.937.7553

Washington, DC | 703.793.9103

Complying with the NAAQS – PM2.5 Air Quality Modeling

Considerations

Dan Dix| [email protected] | 610.933.52.46 x118

Date post:	14-Aug-2015
Category:	Environment
Upload:	all4-inc
View:	71 times
Download:	0 times

Complying with the NAAQS – PM2.5 Air Quality Modeling Considerations by ALL4

Environment