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EPA Home > Region 5 > Air > Correspondence



September 29, 1999


James J. Steele, Division Administrator
Federal Highway Administration
Michigan Division
315 West Allegan Street, Room 211
Lansing, Michigan 48933

Dear Mr. Steele:

The United States Environmental Protection Agency (USEPA) has completed its review of the Southeast Michigan Council of Governments (SEMCOG) conformity determination for the Fiscal Year 2000-2002 Transportation Improvement Program (TIP). This letter provides the results of our review of the SEMCOG conformity determination.

The Detroit-Ann Arbor metropolitan area is currently maintenance for ozone and Carbon Monoxide (CO). The maintenance plans the establishes an emissions budget for Volatile Organic Compounds (VOC) and Oxides of Nitrogen (NOx) for ozone maintenance, and an emissions budget for CO for CO maintenance. Under the emissions budget case, conformity is met if the TIP is consistent with the State Implementation Plan (SIP) budget. All TIP conformity determinations must be analyzed for each milestone year, as defined by the conformity rule, for the applicable pollutants.

The SEMCOG applied USEPA's emission factor model MOBILE5a to generate emissions factors for the emissions budget tests for VOC, NOx, and CO for the years 2000, 2010, and 2020. The conformity analysis demonstrated consistency with the maintenance plan for VOC, NOx, and CO.

USEPA wants to emphasize that the State air quality agency plays an important role in the conformity consultation process. Early involvement in this process by the air quality agency assures consistency between the SIP’s air quality goals and transportation planning goals. This approach is outlined in the Inter-Agency Memorandum of Agreement (IAMOU) signed by SEMCOG, The Michigan Department of Environmental Quality, and the Michigan Depart of Transportation. Future conformity determinations should be developed in accordance with the IAMOU.

If you have any questions, feel free to contact me or Michael Leslie of my staff at (312) 353-6680.

Sincerely yours,

Loretta Lehrman for

Stephen Rothblatt, Chief
Air Programs Branch

For further information, contact:
This Information Last Modified On: 09/18/2008 04:03 PM