For more information about National Park Service air resources, please visit https://www.nature.nps.gov/air/.
FLAG: Federal Land Managers'
Air Quality Related Values Work Group
The Federal Land Managers' Air Quality Related Values Work Group (FLAG) is comprised of the National Park Service (NPS), the U.S. Fish and Wildlife Service (FWS) and the U.S. Forest Service (USFS). FLAG was formed to evaluate air pollution effects on air quality related values (AQRVs) and to provide State permitting authorities and potential permit applicants consistent guidance regarding assessment of new and existing source impacts on AQRVs.
Based on knowledge gained and regulatory developments since the original FLAG report was completed in December 2000 the federal land managers have revised FLAG resulting in the FLAG 2010 report.
November 2011—Nitrogen & Sulfur Deposition Analysis Guidance
- Notification of Guidance (pdf, 74 KB) (11/18/2011)
A letter notifying States of new guidance for nitrogen and sulfur deposition analyses, and a new guidance document for deposition analyses.
- Federal Land Mangers’ Interagency Guidance for Nitrogen and Sulfur Deposition Analyses (pdf, 2.3 KB) (11/16/2011)
October 2010—FLAG Phase I Report Revised
- Federal Land Managers' Air Quality Related Values Work Group (FLAG) Phase 1 Report—Revised (2010) (pdf, 4.9 MB) (11/10/2010)
- Response to Public Comments
(pdf, 1.2 MB) (10/28/2010)
- Federal Register Notice of Availability
(pdf, 52 KB) (10/28/2010)
- Public Comments (2008)
Guidance on Nitrogen and Sulfur Deposition Analysis Thresholds
A letter establishing FLM deposition analysis thresholds (DAT) for total nitrogen and sulfur, and an overview of the deposition analysis thresholds are available below.
- DAT Notification Letter (pdf, 62 KB) (1/3/2002)
- Guidance on Nitrogen and Sulfur Deposition Analysis Thresholds (pdf, 34 KB) (3/7/2008)
December 2000 final FLAG Phase I report
- Notice of Availability (pdf, 9 KB) (12/29/2000)
- FLAG 2000 Phase I Report (pdf, 4 MB) (12/29/2000)
- FLAG 2000 Response to Comments (pdf, 363 KB) (12/29/2000)
National Park ServiceSusan Johnson
Air Resources Division
P.O. Box 25287
Denver, CO 80225
US Fish and Wildlife ServiceSandra V. Silva
Chief, Branch of Air Quality
7333 W. Jefferson Ave., Suite 375
Lakewood, CO 80235-2017
US Forest ServiceAnn L. Acheson
Air Quality Program
201 14th St. SW
Washington, D.C. 20024
Last Updated: March 21, 2012