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EPA Home > Region 5 > Air > Correspondence


February 16, 2001

John Baxter, Division Administrator
Federal Highway Administration
575 North Pennsylvania Street, Room 254
Indianapolis, Indiana 46204

Dear Mr. Baxter:

This letter provides the United States Environmental Protection Agency's (USEPA) comments and recommendation regarding the air quality requirements for the Vision 2020 Northwest Indiana Regional Transportation Plan Update, the 2001-2005 Transportation Improvement Program (TIP), and the first amendment to the 2001-2005 TIP. The Federal Highway Administration (FHWA) requested comments concerning these documents on January 31, 2001.

There are five primary criteria of the conformity rule (62 FR 43779) that must be met. These criteria include the following: use of the latest planning assumptions, use of the latest emissions model, use of appropriate consultation procedures, consistency with the mobile source emission budget in the State Implementation Plan (SIP), and provisions for timely implementation of transportation control measures in the SIP. The conformity analysis for the Vision 2020 Regional Transportation Plan Update meets these criteria. Furthermore, the 2001-2005 TIP, as adopted on January 25, 2001, is a direct subset of the conformity analysis for the Vision 2020 Regional Transportation Plan Update and, therefore, also meets these criteria.

It should also be noted that the Indiana Department of Environmental Management (IDEM) has submitted new mobile source vehicle emission budgets for volatile organic compounds (VOC) and oxides of nitrogen (NOx) as part of the final attainment demonstration and rate of progress requirements through the attainment year. We are aware that the modeling used to formulate those budget is the same as the modeling that was used both for the current 2007 budgets as well as this conformity analysis, with the exception of the benefits calculated from Tier II vehicle engine standards and low sulfur fuel (Tier II). The conformity analysis also uses updated population forecasts. The only difference between the budgets that the state submitted in December 2000 and the budgets that are currently adequate is the use of Tier II benefits. The State calculated that these benefits provide for enough emission reductions for this Plan and TIP to meet both the updated VOC and NOx budgets for 2007. The Plan and TIP already would meet the 2005 VOC budget. The Northwest Indiana Regional Planning Commission (NIRPC) was not required to analyze 2002, so it is not immediately clear if this Plan and TIP would meet that VOC budget.
From a legal standpoint, it is most important that these planning materials are consistent with the current attainment demonstration. NIRPC has demonstrated that their TIP and Plan meet the currently adequate budgets. In addition, considering the fact that the conformity modeling has not yet taken into account the effects of Tier II, it is also understandable why the estimated emissions are higher than the newly proposed budgets. Furthermore, IDEM’s estimated benefit of taking the reductions from Tier II into account show that it is likely that the area will be able to meet the new budgets. It is important that NIRPC become familiar with the calculation of benefits from Tier II, so that if the new budgets are found adequate, NIRPC can use a consistent methodology and can demonstrate conformity for their Plan and TIP. A summary of the currently approved and recently submitted budgets is enclosed.

In summary, USEPA recommends that the Department of Transportation find that the Vision 2020 Regional Transportation Plan Update, the 2001-2005 TIP, and the first amendment to the TIP, adopted January 21, 2001, by the NIRPC Transportation Policy Committee, conform to the State Implementation Plan for air quality. Furthermore, we feel that if the recently submitted budgets are found adequate, it is important that NIRPC demonstrate that their planning is consistent with the updated attainment demonstration.

If you have any questions regarding these comments, please contact
Ryan Bahr, Environmental Engineer of my staff, at (312) 353-4366.

Sincerely yours,


J. Elmer Bortzer, Chief
Regulation Development Section


cc: Scott Deloney, Senior Environmental Manager
Air Programs Branch
Indiana Department of Environmental Management

Janice Osadczuk, Division Chief
Division of Preliminary Engineering and Environment
Indiana Department of Transportation

James E. Ranfranz, Executive Director
Northwestern Indiana Regional Planning Commission

cc by E-mail:

Phyllis Hockett, Manager
Environmental Services Section
Indiana Department of Transportation

Dan Buck, Transportation Planner
Environmental Services Section
Indiana Department of Transportation

Larry Heil, Planning and Program Development Manager
Federal Highway Administration - Indiana Division

Joyce Newland, Transportation Planner
Federal Highway Administration - Indiana Division

Vanessa Adams Donald, Community Planner
Federal Transit Administration

Steve Call, Metropolitan Planning Engineer
Federal Highway Administration - Indiana Division


YearNorthwest Indiana NOx and VOC Emissions (grams/day)
Conformity Analysis -Estimated Transportation System Emissions (NIRPC)Current SIP approved motor vehicle emission budgets -
9% ROP Plan and Attainment Demonstration
Submitted/ proposed ROP and attainment demonstration motor vehicle emission budgetsDifference from Tier II reductions
1999 VOC18,550,565
2002 VOCnot required at this time11,911,458
2005 VOC9,411,7809,970,605
2007 VOC8,815,85528,981,3048,524,572453,604
2007 NOx22,631,97125,059,56322,032,3443,020,925

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This Information Last Modified On: 09/18/2008 04:09 PM