- Air Quality Related Values (AQRV)
- Step 1 - PSD Screening Review
- Step 2 - Review of Atmospheric Modeling Results and Application
- Literature Cited
As set forth in the Clean Air Act, the Federal Land Manager (FLM) for each Class I Area has the responsibility to protect the air quality related values (AQRVs) at such areas, and to consider whether the new emissions from proposed major facilities will have an adverse impact on those values. Class I Areas are defined in the Clean Air Act as National Parks over 6,000 acres and wilderness areas and memorial parks over 5,000 acres that were established as of 1977. Nationally, there are 88 Class I Areas managed by the USDA Forest Service, and 17 of these are found in the eastern United States. Each of the 17 Class I areas are located within a National Forest that is managed by the USDA Forest Service. In the Eastern (R9) and Southern (R8) Regions, the Forest Supervisor, who has the responsibility to manage the wilderness designated as a Class I area, has been delegated the FLM authority. As the FLM, the Forest Supervisor is the responsible official to provide comments to the appropriate air regulatory agency on whether a new source of air pollution may have an adverse impact to one or more AQRVs.
Air Quality Related Values (AQRVs)
An AQRV is defined as "… a resource, identified by the FLM for one or more Federal areas that may be adversely affected by a change in air quality. The resource may include visibility or a specific scenic, cultural, physical, biological, ecological, or recreational resource identified by the FLM for a particular area (FLAG, 2010)." Major new sources of air pollution that are proposed to be located near Class I areas may emit certain air pollutants that negatively impact the AQRVs. The FLM has an affirmative responsibility to consider whether emissions from a new source - permitted under the federal permitting program Prevention of Significant Deterioration, or PSD - may have an adverse impact on AQRVs, and then to provide comments to the permitting authority regarding this issue. The following lists the Class I areas in the Eastern and Southern Regions and each has a link to a webpage describing the AQRVs:
Region 8 (Southern Region) Class I areas
- Bradwell Bay Wilderness (Florida)
- Caney Creek Wilderness (Arkansas)
- Cohutta Wilderness (Georgia/Tennessee)
- James River Face Wilderness (Virginia)
- Joyce Kilmer - Slickrock Wilderness (North Carolina/Tennessee)
- Linville Gorge Wilderness (North Carolina)
- Shining Rock Wilderness (North Carolina)
- Sipsey Wilderness (Alabama)
- Upper Buffalo Wilderness (Arkansas)
Region 9 (Eastern Region) Class I areas
- Boundary Waters Canoe Area Wilderness (Minnesota)
- Dolly Sods Wilderness (West Virginia)
- Great Gulf Wilderness (New Hampshire)
- Hercules-Glades Wilderness (Missouri)
- Lye Brook Wilderness (Vermont)
- Otter Creek Wilderness (West Virginia)
- Presidential Range - Dry Ridge Wilderness (New Hampshire)
- Rainbow Lake Wilderness (Wisconsin)
Step 1 - PSD Screening Review
The USDA Forest Service has a two-step process when conducting PSD reviews. First, the Air regulatory agencies are required to notify FLMs of any PSD permit applications for facilities within 100 kilometers of a Class I area managed by them. Furthermore, a plume blight visibility analysis is required for every source located less than 50 kilometers from the Class I boundary. The permitting authority should also notify FLMs of "very large sources" with the potential to impact a Class I area within their jurisdiction, even if the facility is beyond 100 kilometers from the Class I area. In practice, all sources within 200 (and sometimes 300) kilometers are included in the initial review because the term "very large sources" is not defined in the Clean Air Act. The FLMs have developed a method to screen PSD permit applications to determine whether additional analyses of potential impacts to AQRVs may be warranted. This methodology is based on the potential emissions of certain pollutants as well as the distance to the Class I Area of interest, and is referred to as "Q/d".
- "Q" is the sum of the annualized maximum hourly emissions of sulfur dioxide, nitrogen oxides, particulate matter, and sulfuric acid mist, in tons per year.
- "d" is the distance to the Class I Area, in kilometers.
If Q/d is less than 10, the FLM will not typically require any atmospheric dispersion modeling analyses to assess impacts to AQRVs; it is assumed that that the proposed project will not adversely impact any air quality related values at the Class I Area. If Q/d is greater than 10, the additional analysis listed in Step 2 below is requested from the applicant.
To request a determination as to whether a PSD permit application should include an AQRV atmospheric dispersion modeling analysis, then please consult the Region 9 Contacts page for the Air Resource Management specialist to consult with for the Class I areas in the Eastern Region (R9), while for the Southern Region (R8) please complete this form and submit it to email@example.com.
Step 2 - Review of Atmospheric Modeling Results and PSD Application
If the new source is less than 50 kilometers from the Class I boundary, or the PSD screening review from Step 1 concludes that atmospheric dispersion modeling is necessary to determine whether the AQRVs at Forest Service Class I Area(s) may be adversely impacted by the proposed project, then the applicant should work with the Air Resource Management specialist listed in the Region 8 Contacts or Region 9 Contacts assigned the application to:
- Ensure that the guidance set forth in the latest edition of the Federal Land Managers' Air Quality Related Values Workgroup (FLAG) is followed;
- Discuss atmospheric dispersion modeling protocols with the state air regulatory agency and Air Resource Management specialist;
- Address any comments that the Forest Service has regarding the atmospheric dispersion modeling protocols;
- Provide timely results for any AQRV modeling; and
- Address any comments that the Forest Service has regarding the modeling results.
In the Eastern and Southern Regions of the USDA Forest Service, an Air Resource Management specialist serves as the technical specialists to the FLM for all atmospheric dispersion modeling results, AQRV analysis, and PSD reviews. Please consult the Region 8 Contacts or Region 9 Contacts to determine which Air Resource Management specialist has been assigned lead responsibility for each Class I area managed by the USDA Forest Service.
Federal Land Manager Advisory Group (FLAG). 2010. Federal Land Managers' Air Quality Related Values Work Group (FLAG) Phase I Report - Revised (2010). Found at: //www.nature.nps.gov/air/Pubs/pdf/flag/FLAG_2010.pdf. 118 pp.