Skip to Content


Federal Land Managers' Air Quality Related Values Work Group (FLAG)

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble


National Park Service, Interior.


Notice of availability.


The National Park Service, in cooperation with the U.S. Fish and Wildlife Service and the U.S. Department of Agriculture Forest Service, is announcing the availability of, and accepting comments on, the draft FLAG Phase I Report—REVISED.

The F ederal L and Managers' A ir Quality Related Values Work G roup (FLAG) was formed (1) to develop a more consistent and objective approach for the Federal Land Managers (FLMs), i.e., National Park Service, U.S. Fish and Wildlife Service, and U.S. Department of Agriculture Forest Service, to evaluate air pollution effects on their air quality related values (AQRVs); and (2) to provide State permitting authorities and potential permit applicants consistency on how to assess the impacts of new and existing sources on AQRVs. The FLAG effort focuses on the effects of the air pollutants that could affect the health and status of resources in areas managed by the three agencies, primarily such pollutants as ozone, particulate matter, nitrogen dioxide, sulfur dioxide, nitrates, and sulfates. FLAG formed subgroups that concentrated on four issues: (1) Terrestrial effects of ozone; (2) aquatic and terrestrial effects of wet and dry pollutant deposition; (3) visibility; and (4) process and policy issues. In December 2000, after undergoing a public review and comment process that included a 90-day public comment period announced in the Federal Register and a public meeting, the FLMs published a final Phase I report (FLAG 2000), along with an accompanying “Response to Public Comments” document.

FLAG 2000 has been a useful tool to the FLMs, State permitting authorities, and permit applicants. It was intended to be a working document that would be revised as necessary as the FLMs learn more about how to better assess the health and status of AQRVs. Based on knowledge gained and regulatory developments since FLAG 2000, the FLMs believe certain revisions to FLAG 2000 are now appropriate. The draft revised report now available for public review and comment (FLAG 2008) reflects those changes. The most significant changes proposed in the draft FLAG 2008 revision are summarized as follows:

  • Adopts similar criteria derived from EPA's 2005 Best Available Retrofit Technology (BART) guidelines for the Regional Haze Rule to screen out from AQRV review those sources with relatively small amounts of emissions located a large distance from a Class I area (i.e., Q/D ≤ 10).
  • Utilizes the most recent EPA estimates to determine average annual and 20% best natural visibility conditions for Class I areas, using the new EPA-approved algorithm.
  • Adopts criteria derived from the 2005 BART guidelines that utilizes monthly average relative humidity adjustment factors to minimize the affects of weather events (i.e., short-term meteorological phenomena) on modeled visibility impacts.
  • Adopts criteria derived from the 2005 BART guidelines that sets a 98th percentile value to screen out roughly seven days of haze-type visibility impairment per year.
  • Includes deposition analysis thresholds and concern thresholds for nitrogen and sulfur deposition impacts on vegetation, soils, and water.
  • Increases transparency and consistency of factors considered for adverse impact determinations.

The agencies are soliciting comments on the merits of adopting the EPA BART approach in assessing new source impacts to the federal lands that they administer. For example, the agencies are soliciting comments on exclusively using monthly relative humidity adjustment factors (parallel to Method 6 in the CALPUFF post processor) or also allowing an option for the use of short-term average relative humidity adjustment factors (parallel to Method 2 in the CALPUFF post processor used in FLAG 2000).


Written comments on the FLAG 2008 draft report must be received by September 8, 2008.

If there is sufficient interest, the FLMs will conduct a public meeting to discuss the proposed changes to the FLAG report. Please contact John Bunyak at the address below if you would like the FLMs to conduct such a public meeting.


A copy of the draft FLAG Phase I Report—Revised can be obtained from John Bunyak or downloaded from the Internet at:​air/​permits/​flag/​index.cfm.

Mail comments to: John Bunyak, Air Resources Division, National Park Service, P.O. Box 25287, Denver, Colorado 80225. E-mail comments can be sent to

Start Further Info


John Bunyak at the above address or by calling (303) 969-2818.

Start Signature

Dated: June 26, 2008.

John Bunyak,

Acting Chief, Air Resources Division.

End Signature End Further Info End Preamble

[FR Doc. E8-15397 Filed 7-7-08; 8:45 am]