Dispersion Modeling

The North Dakota Department of Health, Division of Air Quality has developed the following guidance and policy documents to assist permit applicants in the process of drafting complete permit applications.

For more information on Pre-Construction Dispersion Modeling in North Dakota, please direct questions or comments to Rheanna Kautzman at 701.328.5188, or email rkautzman@nd.gov.

For more information on SIP or Planning Dispersion Modeling in North Dakota, please direct questions or comments to Rob White at 701.328.5188, or email RWhite@nd.gov.


Dispersion modeling for criteria pollutants and air toxics may be required prior to issuance of a Permit to Construct in accordance with the Criteria Pollutant Modeling Requirements for a Permit to Construct and Air Toxics Policy.  For facilities with compressor engines and glycol dehydration units, dispersion modeling may be required in accordance with the Dispersion Modeling Requirements for Compressor Engines and Glycol Dehydration Units.


The Department strongly encourages the development of a pre-application dispersion modeling protocol in consultation with the Department in order to expedite the project review process. To aid the applicant in this process, the following Air Quality Analysis Guide has been provided.


More information about air dispersion modeling can be found on EPA's Support Center for Regulatory Atmospheric Modeling (SCRAM) site or through their Technology Transfer Network Clearinghouse for Inventories & Emission Factors site.

Air Quality Monitoring

Construction Permitting

Regional Haze Program


Title

Rev. Date

Topic

AERMET Surface & Upper-Air Meteorology Station 2004 to 2008 Modeling
North Dakota Minor Source Baseline Dates 20 September 2012 Modeling
Air Dispersion Modeling for Emergency Engines / Flares 06 October 2014 Modeling
Compressor Engines & Glycol Dehydration Units 23 January 2015 Modeling
Criteria Pollutant Modeling Requirements for a Permit to Construct 06 October 2014 Modeling
Hourly Ozone Sites 2004 to 2008 Modeling
Model Input Parameters for Flares 10 November 2010 Modeling
Policy for the Control of Hazardous Air Pollutant (HAP) Emissions in ND (Air Toxics Policy) 25 August 2010 Modeling
Recommended AERSURFACE Inputs (North Dakota) 01 March 2017 Modeling
User's Instructions for HRLYNAAQS 24 September 2010 Modeling
Air Quality Dispersion Modeling Analysis Guide 21 June 2013 Modeling

AAQS

Pollutant Averaging Period North Dakota
µg/m3
North Dakota
ppb
Federal
µg/m3
Federal
ppb
PM10 24-HR 150 e 150 e
PM2.5 24-HR 35 b 35 b
PM2.5 Annual 12 g 12 g
SO2 1-HR 196 j 75 j 196 j 75 j
SO2 3-HR 1,309 a 500 a 1,309 a 500 a
SO2 24-HR 365 a 140 a
SO2 Annual 80 30
NO2 1-HR 188 i 100 i 188 i 100 i
NO2 Annual 100 53 100 53
CO 1-HR 40,000 a 35,000 a 40,000 a 35,000 a
CO 8-HR 10,000 a 9,000 a 10,000 a 9,000 a
O3 8-HR 147 c 75 c 137 c 70 c
Lead (Pb) 3-Months 0.15 h 0.15 h
H2S Instantaneous 14,000 10,000
H2S 1-HR 280 d 200 d
H2S 24-HR 140 a 100 a
H2S Quarter 28 20

  • a Not to be exceeded more than once per year.
  • b Three year average of the annual 98th percentile values.
  • c Three year average of the annual fourth-highest daily maximum 8-HR concentration.
  • d Not to be exceeded more than once per month.,
  • e Not to be exceeded more than once on average over a three year period.
  • f Average of annual concentrations for three calendar years.
  • g Three year average of annual concentrations.
  • h Three month arithmetic mean within a three year period.
  • i Three year average of the annual 98th percentile (8th highest) of the daily maximum 1-HR average concentration in a year.
  • j Three year average of the annual 99th percentile (4th highest) of the daily maximum 1-HR averages.
Note that values are corrected to a reference temperature of twenty-five degrees Celsius (25°C/298 K) and a reference pressure of seven hundred sixty millimeters of mercury (760 mmHg/101.3 kilo-pascals).

AAQS Modeling Values (5 Years of NWS MET)

Pollutant Averaging Period SIL
µg/m3
Background
µg/m3
North Dakota
µg/m3
Federal
µg/m3
PM10 24-HR a 5.0 30 150 150
PM2.5 24-HR c 1.2 13.7 35 35
PM2.5 Annual b 0.2 4.75 12 12
SO2 1-HR e 7.8 13 196 196
SO2 3-HR d 25 11 1,309 1,309
SO2 24-HR d 5.0 9 365
SO2 Annual b 1.0 3 80
NO2 1-HR f 7.5 35 188 188
NO2 Annual b 1.0 5 100 100
CO 1-HR d 2,000 1,149 40,000 40,000
CO 8-HR d 500 1,149 10,000 10,000
O3 8-HR 147 137
Lead (Pb) 3-Months 0.15 0.15
H2S Instantaneous 14,000
H2S 1-HR 280
H2S 24-HR 140
H2S Quarter 28

  • a Modeled concentration is the highest-sixth-highest (H6H) 24-HR average across five years of NWS MET data.
  • b Modeled concentration is the highest annual average across five years of NWS MET data.
  • c Modeled concentration is the 98th or highest-eighth-highest (H8H) of the annual distribution of maximum 24-HR concentrations averaged across five years of NWS MET data.
  • d Modeled concentration is the highest-second-highest (H2H) concentration of five years of NWS MET data.
  • e Modeled concentration is the 99th or highest-fourth-highest (H4H) of the annual distribution of maximum 1-HR concentrations averaged across five years of NWS MET data.
  • f Modeled concentration is the 98th or highest-eighth-highest (H8H) of the annual distribution of maximum 24-HR concentrations averaged across five years of NWS MET data.
  • SILs are always highest value.

PSD Increments (5 Years of NWS MET)

Pollutant Averaging Period Class I SIL
µg/m3
Class I
µg/m3
Class II SIL
µg/m3
Class II
µg/m3
Class III
µg/m3
PM10 Annual a 0.1 4 1.0 17 34
PM10 24-HR b 0.2 8 5.0 30 60
PM2.5 Annual a 0.06 1 0.2 4 8
PM2.5 24-HR b 0.07 2 1.2 9 18
SO2 Annual b 0.1 2 1.0 20 40
SO2 24-HR b 0.2 5 5.0 91 182
SO2 3-HR b 1.0 25 25 512 700
NO2 Annual a 0.1 2.5 7.5 25 50

  • a Modeled concentration is the highest annual average across five years of NWS MET data.
  • b Modeled concentration is the highest-second-highest (H2H) 24-HR average across five years of NWS MET data.
  • SILs are always highest value.

List of Ambient Sites and Pollutants Monitored

Site

Site No.

MET

SO2

NO2

O3

CO

PM10

PM2.5

Other(s)

Bismarck Residential 38-15-3 Total Reactive Nitrogen (NOy)
Beulah North 38-57-4 Ammonia (NH3)
Dunn Center 38-25-3
Fargo West 38-25-3
Hannover 38-65-2
Lostwood NWR 38-13-4 Ammonia (NH3)
Ryder 38-101-3
Theodore Roosevelt NP North Unit 38-53-2
Theodore Roosevelt NP South Unit 38-7-2
Williston 38-105-3


Surface Air MET (2009-2014)

Station

Station ID

Lat.

Long.

Elev. (m)

Upper-Air Site

TADJUST

File Type

CYEN–Estevan, Canada 94057 49.217 N 102.967 W 581.0 Glasgow, MT 6 DAT
KABR–Aberdeen, SD 14929 45.45 N 98.421 W 396.2 Aberdeen, SD 6 DAT
KBHK–Baker, MT 94055 46.333 N 104.25 W 902.0 Glasgow, MT 7 DAT
KBIS–Bismarck, ND 24011 46.774 N 100.748 W 506.0 Bismarck, ND 6 DAT
KDIK–Dickinson, ND 24012 46.797 N 102.802 W 787.3 Bismarck, ND 7 DAT
KDVL–Devils Lake, ND 24015 48.117 N 98.917 W 443.0 Bismarck, ND 6 DAT
KETH–Wheaton, MN 24017 45.78 N 96.534 W 313.0 Aberdeen, SD 6 DAT
KFAR–Fargo, ND 14914 46.925 N 96.811 W 274.0 Aberdeen, SD 6 DAT
KGFK–Grand Forks, ND 14916 47.949 N 97.176 W 253.6 International Falls, MN 6 DAT
KHCO–Hallock, MN 24018 48.783 N 96.95 W 250.0 International Falls, MN 6 DAT
KHEI–Hettinger, ND 94038 46.017 N 102.65 W 824.0 Bismarck, ND 7 DAT
KISN–Williston, ND 94014 48.195 N 103.642 W 580.6 Glasgow, MT 6 DAT
KJMS–Jamestown, ND 14919 46.93 N 98.678 W 455.4 Bismarck, ND 6 DAT
KMBG–Mobridge, SD 94052 45.533 N 100.433 W 508.0 Bismarck, ND 6 DAT
KMOT–Minot, ND 24013 48.259 N 101.281 W 522.4 Bismarck, ND 6 DAT
KSDY–Sidney, MT 24021 47.707 N 104.184 W 605.0 Glasgow, MT 7 DAT
Notes:
  • Anemometer height for all stations is 10.0 meters.
  • Surface data is in the CD144 format.
  • Upper-air station data is in FSL format.
  • Station ID has been changed to WBAN code from abbreviated WMO code (ID is also changed in CD144 met files, 1/18/12), for compatibility with AERMET Version 11059 and newer.

Upper-Air MET (2009-2014)

Station

Station ID

Lat.

Long.

KABR0913–Aberdeen, SD 14929 45.45 N 98.421 W
KBIS0913–Bismarck, ND 24011 46.774 N 100.748 W
KGGW0913–Glasgow, MT 94008 48.214 N 106.621 W
KINL0913–International Falls, MN 14918 48.57 N 93.38 W
Notes:
  • Upper-air station data is in FSL format.
  • Station ID has been changed to WBAN code from abbreviated WMO code (ID is also changed in CD144 met files, 1/18/12), for compatibility with AERMET Version 11059 and newer.

NDDoH Additional Modeling Software

Title

File Type

HRLYNAAQS Executable EXE (DOS)
HRLYNAAQS Input Example INP (AERMOD Input File)
HRLYNAAQS Users's Guide PDF
NO2HRSTDBG & SO2HRSTDBG Users's Guide PDF
NO2HRSTDBG Executable EXE (DOS)
NO2HRSTDBG10K Executable EXE (DOS)
SO2HRSTDBG Executable EXE (DOS)
SO2HRSTDBG10K Executable EXE (DOS)
VISCREEN Level 2 ZIP

NO2, SO2 & O3 Background

Title

File Type

NO2_0408S2_DC DAT
NO2_0408S2_LW DAT
SO2_0408S2_DC DAT
SO2_0408S2_LW DAT
Fargo SO2 DAT
Beulah O3 2009–2013 CST DAT
Beulah O3 2009–2013 MST DAT
Fargo O3 2009–2013 CST DAT
Hanover O3 2009–2013 CST DAT
Hanover O3 2009–2013 MST DAT
Lostwood NWR O3 2009–2013 CST DAT
Lostwood NWR O3 2009–2013 MST DAT
Theodor Roosevelt NP (North Unit) O3 2009–2013 MST DAT
Theodor Roosevelt NP (North Unit) O3 2009–2013 CST DAT
Ozone (O3) Sites 2009–2013 PDF
Notes 1/07/2011:

Files of hourly NO2 and SO2 concentrations from NDDoH monitoring sites listed above may be used as hourly background concentrations directly input to AERMOD or may be used to calculate other types of background values, e.g., annual, seasonal, or monthly averages. Monitoring sites with data in these folders represent the NDDoH's preferred sites for providing background concentration data, even though data from other monitoring sites may be used.

Files with designation "0408S2" have substitutions entered for all missing hours. Therefore, use of these hourly background files are preferred for use with NDDoH post-processing software.

Notes 8/14/2015:

Somewhat because of recent EPA guidance on background concentrations used with the new 1-hour NAAQS, the NDDoH does not recommend using hourly concentration data as a first choice for use in regulatory AERMOD modeling in North Dakota. For this reason, the background NO2 and SO2 concentration data listed above have not been updated with 2009-2013 monitoring data.

The NDDoH currently prefers use of a constant background concentration or input of matrices of seasonal, monthly, diurnal, or similar concentrations for use with AERMOD as a 1st and 2nd Tier background. Use of hourly monitoring data as background concentrations input to AERMOD will be considered on a case-by-case basis. Please contact the NDDoH Modeling Program for further information about options for background data.

Terrain

Title

File Type

TIF Terrain TIF.GZ

CALPUFF Inputs

Package

CALMET 2000 (ZIP )
CALMET 2001 (ZIP )
CALMET 2002 (ZIP )
Files included in ZIP package:
  • ABRUAF*.FIL
  • BISUAF*.FIL
  • CMET58*.INP (AERMOD Input File)
  • CMET58*.LST
  • GEO3KM.DAT
  • GGWUAF*.FIL
  • INLUAF*.FIL
  • PRCP0102.DAT
  • RAPUAF*.FIL
  • SURF.DAT
Note: * is for the year, i.e. 20– 00, 01, 02


Last Updated: 01/09/2018