Air Quality Modeling Guidance for Permits

Colorado Modeling Guideline Supplemental Guidance, Forms, and Information Meteorological Data Maps, Figures, Tables Federal Modeling Support On-Line Training Other Links

Stationary Sources Map

This webpage presents current air quality permit modeling guidance for estimating impacts from stationary sources of air pollution.

For general permitting questions, contact the Stationary Sources Program. For modeling or monitoring questions, contact the Technical Services Program modeling and monitoring staff.

Colorado Modeling Guideline for Air Quality Permits

Many of the Division's modeling guidance documents on this site were revised in late December 2005 to update regulatory citations because of changes to Colorado AQCC Regulation No. 3 and Appendix W to 40 CFR Part 51.

• guide.pdf (1,442 k) (December 27, 2005) - This is Colorado's primary permit modeling guideline. It is intended to be used along with applicable federal guidance. The guideline was revised in December 2005 to reflect revisions to Colorado AQCC Regulation No. 3 (pdf) and Appendix W to 40 CFR Part 51 - Guideline on Air Quality Models (pdf). Here is a side-by-side comparison with the previous version: Guide-12_comparison_to_Guide-11_oldversion.pdf (6,440 K)
• The federal rule adopting AERMOD became effective December 9, 2005. As of December 9, 2006, the new model--AERMOD--should be used for appropriate application as a replacement for ISC3. (see Federal Register Volume 70, Number 216 FR70-No216-Wed-09Nov2005.pdf).

Email attachments: Please verify that emails with attachments are received by the Division. Emails with ZIP, executable, and some other types of attachments are automatically rejected by the state's email system.

Supplemental Modeling Guidance, Forms, and Information

• Air Quality Modeling Form - AQImpactForm1.pdf (118 k) (March 8, 2002) This optional form is a supplement to the Pollution Emission Notice (APEN) and application forms. If the optional modeling form is filed with the Division, it will help permit reviewers determine if modeling is warranted. If modeling is warranted, the data on the form may be used in the modeling process.
• Checklist for Non-PSD Sources/Modifications (e.g., minor sources) - MinorSource ImpactChecklist.pdf (333 k) (March 8, 2002; updated 9/19/08) Permit applicants for sources not subject to the major PSD rules (e.g., new minor sources, minor modifications) may use this optional checklist to help determine if the permit application has all of the information necessary for the Division to complete the air quality impact analysis required by the regulations. Many of the items in this checklist are discussed in section 7 (page 45) of the Colorado Modeling Guideline. It applies to sources emitting particulates, carbon monoxide, lead, sulfur dioxide, and nitrogen oxides. Sources emitting only volatile organic compounds (VOCs) may disregard this checklist.
• SCREEN3 Stationary Source Modeling Guidance - screen.pdf (92k) (January 1, 2002 with hyperlinks updated 12/28/05)
• Checklist for Modeling Protocol - protocol.pdf (42k) (June 17, 1997)
• Database of "scenic and/or important views" - scenicvw2005.pdf (88k) (March 11, 2005) Database of the Class II sensitive views for major source PSD permits. This database is used by the Division to determine if there are any sensitive Class II views that might trigger the visibility "additional impact analysis" requirements under the PSD rules.
• Prevention of Significant Deterioration (PSD) Increment Tracking - psdtrac.pdf (154 k) (February 26, 2001; updated 12/28/05) Explains how PSD increments and increment consuming/expanding emissions are currently tracked in Colorado; provides guidance for selecting increment consuming/expanding sources for major source PSD increment modeling.
• Maps, Figures, Tables
• Meteorological Data

Meteorological & Geophysical Data for Air Quality Permit Modeling

This page provides information about meteorological data for regulatory air quality modeling. The Technical Services Program of the Air Pollution Control Division has data from current and historic meteorological towers in Colorado that are suitable for use in regulatory models. Contact the Division for data. Division approval should be obtained on a case-by-case basis before meteorological datasets are used for regulatory (e.g., air permit) modeling.

• USEPA - SCRAM Meteorological Data and Processors
• National Climatic Data Center
  • Integrated Surface Database - global hourly and synoptic observations compiled from numerous sources, into a single common ASCII format.
  • TD 3505 - Integrated Surface Data - subscription.
  • SAMSON CD-ROM - hourly NWS surface data from across the U.S. (1961-1990) [Note: The station listed as "Boulder" on the SAMSON CD is actually Denver Stapleton Airport.]
  • HUSWO CD-ROM - hourly NWS surface data from across the U.S. (1990-1995)
  • Hourly Precipitation CD-ROM - hourly TD3240 precipitation data from across the U.S. (1900- June 1998)
  • Radiosonde Data of North America CD-ROM - RAOB upper air data
• NOAA
  • FSL/NCDC Radiosonde Data Archive
    • Radiosonde Database Access - download preliminary RAOB data.
  • Environmental Services Data Directory
• NCAR
  • Scientific Computing Division's Data Support Section (DSS)
  • Dataset Catalogs
• Colorado Climate Center
  • CoAgMet data
• High Plains Climate Center
  • Data holdings
    • Automated Weather Data Network
      • Colorado
• Western Regional Climate Center
• RAWS Stations
• WebMET - (Lakes Environmental) - meteorological data.
• WebGIS - (Lakes Environmental) - geophysical data.
• WorldGeoData (an extension of Trinity Consultants, Inc.) - meteorological and geophysical data for modeling.
• BREEZE software
• Meteorological data services from Bee-line Software
• CALPUFF/CALMET data sets (TRC)

Maps, Class I Receptors, Figures, Tables for Air Quality Permit Modeling

The following list provides various maps, figures, and tables that might be useful during the permitting process. Some of these items are copied from Colorado permit modeling guidance documents. Others are unique to this page.

• Colorado PSD baseline areas and minor source baseline dates [colorado PSD baseline map.pdf] (36 k)
• 8-hour Ozone Control Area Map (Ozone Boundary Map)
• Federal Class I Areas (Figure 4 from Colorado Modeling Guideline) (41 k)
• Class I Area Maps as provided by National Park Service
• Class I Area Maps for the Rocky Mountain Region as provided by the US Forest Service
• Standard Class I receptors
• Class II areas with the protection of Class I increments for sulfur dioxide (Figure 3 from Colorado Modeling Guideline) (17 k)
• Flowchart of permit review process from a modeling perspective (Figure 5 from Colorado Modeling Guideline) (24 k)
• Diagram of roles and responsibilities in the modeling review process for construction permits (Figure 6 from Colorado Modeling Guideline) (24 k)

Federal Modeling Support

• U.S. EPA
• Support Center for Regulatory Atmospheric Modeling (SCRAM) - EPA guidance, models, user's guides, and related information. The primary EPA modeling guideline is Appendix W to 40 CFR Part 51 [appw_05.pdf]. Refer to the Model Support and Guidance area for additional guidance and modeling-related memos.
• Technology Transfer Network (TTNWeb)- a collection of related Web sites containing information about many areas of air pollution science, technology, regulation, measurement, and prevention.
• New Source Review (NSR)
  • 1990 "New Source Review Workshop Manual" [wkshpman.pdf]
• OAQPS Air Quality Modeling - topics and areas associated with air quality modeling.
• Atmospheric Sciences Modeling Division (ASMD) - the Division is part of NOAA's Air Resources Laboratory and is responsible for performing much of the air pollution meteorology research for the USEPA.
• Chemical Emergency Preparedness and Prevention Office (CEPPO) - this site includes links to databases and software for emergency preparedness and prevention.
• Air Toxics Website
• EPA Region VI - Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities - this site includes a chapter [chpt3-hh.pdf] (260kb) on air dispersion and deposition modeling; including "recommended models, site-specific characterization, use of unit emission rate, partitioning of emissions, meteorological data requirements, meteorological preprocessors, ISCST3 model input files, ISCST3 model execution, use of modeled output, modeling fugitive emissions and modeling acute risk."
• Federal Land Managers
  • National Park Service Air
    • Permit Applications
  • USDA ForestService - National Air Resource Management Program
    • Rocky Mountain Region - Colorado, Kansas, Nebraska, South Dakota, and eastern Wyoming
    • Air Program Resources
    • Southwestern Region - Arizona and New Mexico
    • Intermountain Region - southern Idaho, Nevada, Utah, and western Wyoming

On-Line Training

• Air Pollution Training Institute
• OS411 - Computational Atmospheric Sciences

Other Links

• EPA
  • Support Center for Regulatory Air Models (SCRAM)
  • AirData
  • Envirofacts
• National Geospatial Data Clearinghouse
• USGS
  • GeoData - Digital Elevation Models (DEM) and other data;
  • EROS Data Center
• Bureau of Land Management
  • BLM - Colorado
    • Geospatial Data and Metadata On Line for BLM Colorado
• U.S. Census Bureau
  • Maps and cartographic resources - generate maps showing population density and other data
  • TIGER files - a digital database of geographic features, such as roads, railroads, rivers, lakes, political boundaries, census statistical boundaries, etc.
• National Atmospheric Deposition Program - NADP/NTN Sites in Colorado
• Vegetation and Soils
  • USDA Agricultural Research Service
    • Air Quality Program
  • PLANTS database