[Federal Register Volume 63, Number 70 (Monday, April 13, 1998)]
[Notices]
[Pages 18068-18069]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-9641]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration
[Docket No. 29194]
RIN 2120-AC22


Emissions and Dispersion Modeling System Policy for Airport Air 
Quality Analysis; Interim Guidance to FAA Orders 1050.1D and 5050.4A

AGENCY: Federal Aviation Administration, DOT.

ACTION: Policy Statement.

-----------------------------------------------------------------------

SUMMARY: This document provides a statement of Federal Aviation 
Administration (FAA) policy concerning the required use of the FAA 
Emissions and Dispersion Modeling System (EDMS) to assess the air 
quality impacts of proposed airport development projects. To date, the 
EDMS has been considered an FAA preferred model for airport air quality 
analysis. The policy statement is intended to ensure consistency and 
quality of analysis performed to assess the air quality impacts of 
airport emission sources for purposes of complying with the National 
Environmental Policy Act of 1969, as amended, 42 U.S.C. 4321 et seq. 
(NEPA) and the Clean Air Act as amended, 42 U.S.C. 7401, 7506(c) 
general conformity (general conformity) requirements.

EFFECTIVE DATE: April 13, 1998.

FOR FURTHER INFORMATION CONTACT:
Ms. Julie Ann Draper, Analysis and Engineering Branch (AEE-120), 
Technology Division, Office of Environment and Energy, Federal Aviation 
Administration, 800 Independence Avenue, SW., Washington, DC 20591, 
telephone (202) 267-3494.

SUPPLEMENTARY INFORMATION: The EDMS was developed by the FAA in 
cooperation with the U.S. Air Force (USAF) in the mid-1980's as a 
complex source microcomputer model to assess the air quality impacts of 
proposed airport development projects. It has since been the FAA 
preferred model for airport air quality analysis. On July 20, 1993, the 
Environmental Protection Agency (EPA) accepted the EDMS as a formal EPA 
``Preferred Guideline'' model for use in civil airports and

[[Page 18069]]

military bases. In response to the growing needs of the air quality 
analysis community and changes in regulations, the FAA in cooperation 
with the USAF re-engineered and enhanced EDMS in 1997 to create EDMS 
Version 3.0. EDMS Version 3.0 was built under the guidance of a 
government and industry advisory board composed of experts from the 
scientific, environmental policy, and analysis fields.
    The FAA provides guidance on the use of EDMS in FAA Report No. AEE-
AEE-97-03, ``Air Quality Procedures for Civilian Airports and Air Force 
Bases,'' which updates and replaces the original version of the 
handbook, FAA Report No. FAA-82-21.
    The FAA is taking this opportunity to identify EDMS as the required 
model to perform the air quality analyses for aviation emission sources 
from airport projects instead of the preferred model, as stated in the 
FAA's ``Air Quality Procedures for Civilian Airports and Air Force 
Bases.'' This policy statement will serve as the interim written 
document until the revised FAA Orders 1050, Policies and Procedures for 
Considering Environmental Impacts, and 5050, Airport Environmental 
Handbook, are published.

Policy Statement

    EDMS is designed to assess the air quality impacts of airport 
emission sources, particularly aviation sources, which consist of 
aircraft, auxiliary power units, and ground support equipment. EDMS 
also offers the capability to model other airport emission sources that 
are not aviation-specific, such as power plants, fuel storage tanks, 
and ground access vehicles.
    Except for air toxics or where advance written approval has been 
granted to use an equivalent methodology and computer model by the FAA 
Office of Environment and Energy (AEE-120), the air quality analyses 
for aviation emission sources from airport projects conducted to 
satisfy NEPA and general conformity requirements under the Clean Air 
Act must be prepared using the most recent EDMS model available at the 
start of the environmental analysis process. In the event that EDMS is 
updated after the environmental analysis process is underway, the 
updated version of EDMS may be used to provide additional disclosure 
concerning air quality but use is not required. A complete description 
of all inputs, particularly the specification of non-default data, 
should be included in the documentation of the air quality analysis for 
purposes of complying with NEPA and general conformity requirements. 
Users also must provide one copy of EDMS input files used in the 
analysis and the corresponding output files to the FAA responsible 
official on magnetic media specified by the FAA responsible official.
    As stated above, EDMS currently is not designed to perform air 
toxic analyses for aviation sources, and may be supplemented with other 
air toxic methodology and models in consultation with the appropriate 
FAA regional program office. Use of supplemental methodology and models 
for more refined analysis of non-aviation sources also is permitted in 
consultation with the appropriate FAA regional program office.
    This policy is being issued in order to ensure consistency and 
quality of analysis performed to assess the air quality impacts of 
airport emission sources for purposes of complying with NEPA and 
general conformity requirements.

    Issued in Washington, DC, on April 6, 1998.
Paul R. Dykeman,
Deputy Director of Environment and Energy.
[FR Doc. 98-9641 Filed 4-10-98; 8:45 am]
BILLING CODE 4910-13-M